In this two-part video we're going to be
taking a detailed look at the steam
turbine powered propellant pumps used in
the world's first ballistic missile - the
turbopump of the infamous V2 rocket
The turbopump was one of the most
critically demanding developments in the
evolution of the A4 later known as the
V2 missile. In fact, someone once said
with only a little exaggeration that a
liquid-fueled rocket engine was a turbopump
with just a few other bits and
pieces bolted on. The turbopump is seen
here extracted from the plumbers
nightmare of pipes and valve. But we're
going to confine it still further as we
will not discussing the liquid oxygen
valve and LOX distributor so let's
remove those items and we won't be
saying much about the tanking
connections so let's remove the metal
bellows at the propellant intake flanges
as well that leaves us with the turbine
powered pumps plural it certainly is one
big singular lump but in fact it's two
separate pumps powered by the same
central steam turbine but first let's
get an overview of the components of the
turbo pump system
ok let's quickly take you to bits before
we actually put it back together again
what I want to show you here is the
fundamental components of the turbo pump
what we're looking at here is the
turbine the steam turbine system all I
probably want you to pick up from this
is that the turbine rotor in the center
there very easily visible the green part
here is actually the rotor I've got you
another little cardboard cutout so that
you can see there in a bit more detail
but the turbine rotor actually sits
inside that case just there and we can
see at the tip here the rim of the
turbine rotor has two sets of steam
buckets a little one and a big one we'll
look into all of that a little bit more
data so put your notebooks away from now
we're going to look at this in a bit
more detail in just a moment let's just
put the steam manifold on there so the
steam comes in from the 360 degree
manifold on the left and is passed by
pipes into the inner steam manifold that
distributes the steam on to the nozzles
we can actually see one of the nozzles
one of the steam
just here passing into this row of steam
buckets over here on the right onto that
waiting shaft heavily splined to receive
it will fit the fuel pump this is a
centrifugal style pump we can see the
impeller here in blue other little
details to pick up here is the shaping
of the volute case that is transferring
the fuel that is coming in at the top
here passing into the eye spinning
around the rotor into the volute case
that we see here and passing it down
having provided it with a great deal of
increased pressure down into the outlet
flow just here the only other thing I
probably want you to see on the fuel
pump is this structure just here this is
sometimes incorrectly identified as a
governor it is not this is a simple
safety switch this is in fact the only
direct electrical connection to the
turbo pump and it is designed entirely
to detect the revolutions per minute of
the pump and when they exceed 5,000 it
closes a relay that actually cuts off
the steam supply permanently to the
turbo pump we're going to look at this
in a bit more detail but probably not to
the second half of this video part two
so look out for that a bit later on
let's just put the liquid oxygen pump in
place here as well not connected to the
same shaft but connected to a flexible
joint here nevertheless that the shaft
runs through both pumps and it is in
principle it's the same shaft that's
running through the sonic through the
turbine there once again we can see the
pump impeller marked out in red this
time the variation in shape of the
section through
whoops section through the volute case
here fuel liquid options starts at the
top is pulled through into the pumps
into the eye of both pumps and then pass
through to the outlet flanges at the
bottom here and then directly on into
the pipe work that will carry it into
the thrush chamber without further ado
let's get a look before we move on and
look at the pump proper in detail let's
just get a view of where the pump turbo
pump is actually located on the missile
if the v2 ballistic missile could be
said to have a beating heart it would
certainly be the turbo pump the steam
turbine powered pumps used to drive the
propellants into the thrust chamber are
certainly one of a handful of enabling
technologies that made the ballistic
missile a functional possibility even
today with large liquid fuel rocket
engines the turbo pump is the critical
technology that enables them to function
the location of the pump is relatively
easy to find we can see it situated
immediately above the thrust chamber and
below the first of the propellant tanks
the tanks here this is the fuel tank
this is the liquid oxidizer tank the
liquid oxygen and the turbine powered
pump system is immediately below the
liquid oxygen tank and you can see it
here very easy to find as a landmark
where the fins meet the body of the
missile draw a line across where that is
and that's pretty much where you can
find the turbo pump on v2 so even if
you're looking just on the outside of
the missile that's a fairly easy
location to find where the turbo pump is
actually doing its business let's look
at a another model here this is my soda
model it's getting a little bit bashed
about now but I'm just going to take it
to bits for you for a moment again to
show the idea of where the turbo pump is
located let's just take off all the bits
and pieces like the exhaust pipe system
and the heat recovery system and the
return pipe here and if I take off this
entire assembly so we've got the thrush
chamber this is a very stylized model by
the way this is not a scale perfect
replica but it's a didactic model just
to be able to show you where the parts
are and if I take off this rather
peculiar looking assembly at the top
here this is actually the system
responsible for generating the steam to
drive the turbo pump so let's take that
off and have a look at that separately
and then we've got the turbo pump so
here we've got the system broken down
really into its critical components
we've got the tanking we've got the
thrust chamber and then we've got the
turbine driven pump system and then the
steam drive system for the turbine these
are the two items we're going to talk
about today the steam the turbo pump and
the steam drive system these other items
will wait for another video perhaps
later on looking at the missile itself
now that we've got a an idea of where
though the turbo pump is actually
situated what about if we're not looking
at a missile that's got a nice clear
clear side to it is there anything we
can see on the outside of the missile
that tells us something about the turbo
pump we can definitely see something on
the outside of the missile that gives us
a clue to the action of the turbo pump
and that's in the form of the exhaust
vents and if we look if I spin it around
to one and two fins one and two here we
can see the vent built into the body of
the missile and this actually receives
two pipes on the inside of the missile
there's one coming from the turbo pump
and the
exhaust steam exhaust actually comes out
of hearing his is quite distinctive on
footage taken at the time of test
launches so it's quite a good way of
being able to orientate the missile and
give you an idea of where it's going and
we there is also the liquid oxygen tank
also vents to this to this exhaust port
as well if we go around and look at the
fins between two and three we can see
the five way connection point used for
connecting the missile to the ground the
station we go round a bit further
between 3 & 4 we find another steam
exhaust port very similar to what we
were looking at earlier only this time
only steam comes from this exhaust vent
in fact that's not entirely true there
is oxygen issuing from this vent but
it's coming from the steam drive system
and not the liquid oxygen tank you'll
see why later
now the useful thing about these vents
and the one between fins 3 & 4 in
particular is that they are handy in
analyzing the function of the turbo pump
in test launches and understanding where
the missile should be heading no matter
how bad the film footage of a launch is
we can usually see the steam vent shown
here and the stream of exhaust steam
blowing down from the vent like a
miniature version of the thrust jet only
more susceptible to the effects of winds
at least in the first few seconds of fly
anyway now from the simple fact that we
know the missile was designed to lean
over in the direction of fin number one
and that no photographer who wasn't
completely crazy would allow the v2 to
fly over their head
we know that the pitch program will only
take the missile either away from the
camera or to the left or right of the
frame it follows from the position of
the vent that this must be fin number 3
and that means this must be fin number 2
with the fin on the right being fin
number 4 fin number 1 is
furthest away from us and despite how it
looks from the angle of the missile is
in the direction that the missile will
be traveling in after a couple more
seconds when the pitch program guides
the missile into a ballistic trajectory
finally if we go round to one and four
we'll find the liquid oxygen top-up
valve anyway so there are things on the
outside of the missile that can give you
a clue to the functioning of the
turbopump and in fact in part two we're
going to look at that in a bit more
detail okay so we've looked at the
turbopump
in terms of its gross details of its
structure we've looked at the location
of the turbopump
in the context of the whole missile and
we've got a clue as to some of the other
parts we're going to be looking at in
the video let's put our models to one
side for the time being and actually go
to a place responsible for the
development of the v2s
steam turbine powered propellant feed
system and look had a genuine original
v2 turbo pump in rather more detail
we've come to the Peenemunde a
historical technical museum where
they've kindly let me monopolize their
v2 turbo pump so that I can show it to
you it's an excellent presentation
showing the complete assembly cut open
so we can see what's going on inside so
let's get an overview of the layout of
the turbo pump one of the first things
that's clear is the physical size of the
pump it really does impress as a chunky
piece of engineering when you see it
like this this is a turbine and dual
pump system so we've got two centrifugal
pumps here on this side of the steam
turbine we have the alcohol pump
impeller and on this side of the turbine
wheel we've got the liquid oxygen pump
to the usual position the assembly is
upside down so these supports here are
usually the other way up at least for
launch these are the outflow ports the
high-pressure outlet side of the pump
and the low pressure or inlet side of
the pump
is actually down here other features you
can see here is the steam exhaust outlet
the Spence theme is sent through here
where it passes to the heat exchange
system and then is dumped overboard via
two exhaust pipes we can see the
location and part of the casing of where
the overspeed switch device would be
located it's actually missing on this
example this is a mechanism whose sole
purpose is to shut the turbo pump down
permanently if it reaches 5,000 rpm and
so prevent premature loss of the missile
due to the turbo pump over speeding and
destroying itself and the missile other
things to note the large steam turbine
rotor here is a Curtiss two-stage
impulse type the gas buckets or blades
that capture the steam are two different
sizes the row of buckets nearest the
steam nozzles are slightly shorter than
the buckets furthest from the nozzles
reflecting the way the gas expands as it
passes from the nozzles and does its
work through the two rows of buckets the
steam arrives via the inlet distributor
here which is constructed of cast and
welded paths attached to the oxygen side
of the pump the steam passes into the
steam nozzle distribution manifold
through these two pipes the gas is then
free to pass around the turbine rotor
and through these nozzles that we see
here we've got one set of cast iron
nozzles here another one running down
here and two sets at the back there for
in total the steam is distributed all
around the rotor and it gives you a clue
as to the volume and energy in that
steam that it can be distributed over
this area and turn this peaceful looking
machine into a screamin 600 horsepower
monster so there's a lot of energy in
this steam pressure that's hitting the
turbine rotor the rotor turns in this
direction we can see the direct effect
that has on the pump impellers the shaft
is not actually continuous the turbine
rotor and the alcohol pump impeller is
on one shaft and then there's a flexible
joint on the other side of the turbine
rotor connecting another short shaft
going through to the liquid oxygen
impeller so two shafts even though they
function
as a single shaft this was done to
simplify construction and improve
stability we can see the faceplate here
of the liquid oxygen side of the pump
and another important feature is the
volute case which can be seen from the
outside here we can see the change in
the cross-sectional area of the interior
of the pump casting actually I think
it'll be easier to show you this
important structural form of the pump
casings from a drawing so here's a
drawing of the a stuff or liquid oxygen
pump from 1942 and you can easily see
here the spiral shape of the volute case
as it heads down towards the discharge
flange here it'll be easier to see if I
colorize the space and you can see now
how the cross-sectional area increases
remember the liquid oxygen or fuel is
the same for both pumps is coming in at
the inlet port at the top here the
propellant is then pulled into the eye
of the impeller this round area that you
can see here and centrifugal forces are
turned into kinetic energy
throwing the propellant outwards
radially from the center of the impeller
where it moves through the smoothly
expanding volute case reducing in
velocity but greatly increasing in
pressure as it flows down towards the
discharge pipe now you can see the lack
of symmetry in the cross sectional area
of the volute space in the drawing on
the left side of your screen in fact
it'll be easier to see if I switch to
another drawing this is a cutaway
through the beast off or alcohol side of
the pump and you can see here we've got
the centrifugal impeller and the spaces
in fact I've colored the impeller so
that you can see that so the part
outlined in red is the part that's
spinning the impeller and if I colorize
the volute spaces here as well top and
bottom here you can see the difference
in the cross-sectional shape easily the
cross-sectional area increases in the
direction of the outflow pipe reducing
the velocity of the propellant but
greatly increasing its pressure
providing in its transit through the
pump the high level of force needed to
drive the propellants into the
combustion space through the thousands
of injector orifices in the v2 thrust
chamber
I'm just going to show you the pump kind
of running as one of the great things
about this exhibit that I can get my
hands on to show you as though it's
running albeit rather slowly the steam
entering through the nozzles here would
be driving the turbine rotor in this
direction we can see the steam buckets
here very clearly the alcohol had a
little above a tank pressure of one
atmosphere would be picked up at the eye
of the impeller here we're spinning at
around 4,000 rpm powerful centrifugal
forces would throw the fuel outwards
through the shrouded braids of the pump
impeller here driving it into the spiral
shape of the volute case centrifugal
forces here being turned into kinetic
energy and converted into increased
pressure by a factor of more than 10 and
driving the fuel from the outlet port
here into the thousands of orifices and
apertures in the combustion chamber
I think after nearly 80 years it
probably deserves a spot of oil another
couple of things to note here you can
see these bronze colored bearing surface
savers here mounted in the face plate
and in the main body these are large
bearing cum seals and are lubricated by
the alcohol being pumped we can see the
conventional sealed ball bearing here
and another larger ball bearing here
it's worth noting that the bearings in
the liquid oxygen pump are of a simpler
journal type and are lubricated by the
liquid oxygen that's being pumped though
not complete we can see some sales and
packing pieces here
it was vitally important to keep these
systems fully isolated from one another
and not allow the fuel or liquid oxygen
to come into contact with the
superheated steam from the turbine were
still allow the liquid oxygen to party
with the fuel as a rapid unscheduled
disassembly of the turbo pump tends to
follow so a lot of care taken here to
keep both propellants away from the
steam turbine casing let's have a quick
close up look at that important
overboard dump pathway fuel or on the
other side liquid oxygen used for
buffering and lubrication and building
up in the low pressure cavity here is
allowed to pass out of a pump case and
be dumped over
bored there's no flow restriction here
so if needed flow can increase up to the
limit set by the passage diameter so to
round off let's take a look at some of
the marks and stamps we found on the
turbopump a lot of the stampings and
numbers some are part codes others are
batch run numbers and some typically
just a pair of numbers or a letter are
used as quality control references to
identify assembly personnel and
techniques more interestingly some parts
display three-letter codes the system of
secret three-letter armament codes
allows us to identify the primary
companies involved in manufacturing the
turbopump
as well as firms contract it to them to
make specific parts this is the liquid
oxygen pump impeller showing EB b4 Klein
Shenzhen and Beca AG of Frankenthal a
manufacturer of pumps on the prime
contractor for the v2 turbo pump and
still trading worldwide turbine casing
also showing EB be for KS B the steam
distributor casing again showing EB be
the liquid oxygen Inlet throat blanking
plate also showing EB be for KS B this
is the steam manifold connection flange
marked Ovie M for a Reba en Baja Toobin
welding works of royal Egan a maker of
commercial kitchen appliances and still
trading today this is the alcohol fuel
pump faceplate showing the letters jus
unusually in capitals this time for
Velma light metal foundry GAE in Bihar
actually a contractor to KSP supplying
aluminium castings and conveniently
dated 18th of October 1943 the last
number just telling us how many castings
have been run from the pan this is the
alcohol fuel pump impeller and at first
we see a serial number scratched out for
some reason if we rotate the impeller
counterclockwise a bit we see a new
serial number
and rotating the impeller again reveals
a three-letter code and some web name
number quality control stamps the
letters here are etf for machine and
bower AG Balki Frankenthal a
manufacturer of pumps and pump parts as
here working as a contractor to KSP of
course other examples of the turbo pump
like this relic of an oxygen pump from
early 1945 might display quite different
three-letter codes from alternative
contractors even if the primary
contractors ksb or later Maybach are
unchanged for example this inlet throat
blanking cap is marked GMS and i've
examined well over 20 steam manifold
inlet flanges and so far this is still
the only one marked ovm for the rebar
tube and welding works that I've seen
let's just take a breath for a moment
and just think this through and make
sure we're all on the same page and see
this a bit more as a problem and how the
turbo pump solves our problem if you've
got this far you've been looking at the
turbo pump a couple of things might
begin to creep into your mind that maybe
this is a technology of yesteryear the
the time before smartphones and that
really we don't need to do it this way
anymore if you know a bit more about it
you're probably aware that things like
the redstone missile here that vv2 mark
2 still had turbo pumps and of course
we're still getting into orbit today
with liquid fuel rocket engines that
have got turbo pumps sometimes even with
this type of steam generator and
sometimes with the steam or the the gas
used to power the turbo pump coming from
the main combustion chamber so why what
is it about this puzzle that seems that
can only be solved by using this
incredibly fragile and complex system of
the turbo pump and it's steam generation
system after all the problem looks quite
simple we've got our propellant
in the tanks here this is my soda can
model that we're looking at here we've
got our fuel at the top we've got our
liquid oxidizer
and we've got on the v2 we've got about
8 tons of this propellant we've got to
drop that propellant into the thrust
chamber here in about a minute if we're
gonna burn enough of it to hurl the
whole missile 200 miles we've got to get
all of that 8 tonnes in here in a round
about a minute well surely if we just
take this to bits
let's get rid of this incredibly
complicated gas generator yeah let's put
that to one side let's take off this 600
horsepower whirling devil of a turbo
pump with all the risks that we run of
it ruining our missile if it goes wrong
if you look at the early tests of the v2
very often a turbo pump under run or a
problem with the gas generator very
common in the in the figures for failure
so let's get rid of that how much better
our missiles gonna be now here we are
with the thrust chamber we've got our
fuel inlets down here with the large
fuel inlet hole just here for the liquid
oxygen we've got another big one over
here and then these white pipes going to
their burners this is a very simplified
stylized version of the v2 combustion
chamber thrust chamber now we've got our
liquid oxygen tank we can see we've got
nice big outlets on that we just simply
match them up with the outlets on the
thrust chamber missing slightly yeah
there that goes and then we've got our
fuel tank here there's a pipe running
all the way down into the fuel inlet of
the thrust chamber and put my tank on
the top here and there we go we're ready
to roll we've got our propellant all
lined up with the thrust chamber all
I've got to do now is put a couple of
valves here open them up drop the
propellant into the combustion chamber
well I guess if those holes were bigger
and it just fell through we probably
could empty these providing it was well
enough vented at the rear end here we
probably could drop that stuff in there
and around about a minute but there's a
problem and the problem is these
thousands of apertures that this
propellant has got to go into to make
our jets and to form the nebula that is
going to be burnt actually inside the
combustion chamber and you can kind of
picture that in your mind how difficult
that would be imagine you've got a
length of garden hose and you put your
lawn sprinkler on one end but instead of
connecting it to the tap
you just put a funnel in it and you
start pouring water in out of a bottle
or out of it out of a bucket I think you
can picture fairly easily that once the
pipe filled up and the water starts to
dribble out the other end you're going
to be the rate limiting step is the rate
at which it's dribbling out the other
end you're actually going to be metering
in the water relatively slowly here as
it drains through that system because it
hasn't got the pressure of the tap and
it's not going to force the water out
the other end into a nice jet not unless
you put that funnel and the pipe way up
in the air anyway so we've got our
propellant at roughly one atmosphere and
with a little bit of a drop I think it
would take about twenty minutes to go
through all those nozzles possibly even
longer rather than the one minute that
we need for our four hour burn well okay
that's pretty easy to fix why don't we
just take compressed nitrogen or
compressed air these things are pretty
common and why don't we just pump the
air directly into the tanks we can
easily meter the amount of nitrogen that
we're going to pump out of a compress
tank like this and we should be able to
get that pressure consistent all the way
through the trajectory at least for the
length of the burn and get the right
kind of 10 atmospheres that we need
don't forget the we need quite a bit of
pressure because not only we've got all
those nozzles we've got the the fiery
furnace there the combustion chamber
burning and creating a lot of pressure
inside the combustion chamber pushing
back at it so really there's a lot going
on in there to stop the propellant
getting into the combustion chamber but
we should be at we should be able to fix
that
so really what's the problem how come a
there's a fat Englishman on YouTube that
can solve something that the Germans all
these smart engineers couldn't solve all
those years ago first of all I'm gonna
need my Meccano on a roll
Ellen Musk eat your heart out Dunaway
you didn't think of using this stuff to
cut your costs bits of this
so here it is looks a bit odd with the
tanks in tandem like this rather than in
single-file one behind the other
but in principle you've got everything
you need here we've got our thrust
chamber down the bottom we've got our
piping pipe going to the fuel tank and a
pipe going to the liquid oxygen and
we've got two valves here which I can
operate by just squeezing them together
a couple of electric valves here a bit
another few other bits and pieces and
we've done away with the turbo pump
completely we've got a nice simple
system that just needs a bit of piping
and a couple of valves how much better
that would have been than this very
complicated system here so let's hear it
for the fat Englishman who had a much
better idea than all those clever
Germans all those years ago well come on
think about it for a moment there's a
problem here and you can kind of see it
if you look at these tanks look at the
soda-can tanks on the model here and
they're actually a pretty good scale
modelling of the tanks from the original
v2 they really if you if you scaled the
tanks of the v2 down to this side
immediately would be as incredibly thin
as a soda can soft like this now look at
the tanks on the gas propellant system
they're made of steel all these seams
here are still this is all soldered
together these are very tough thick
tanks these are made of very heavy metal
now there's a crossover point if we
think about the missiles that were being
made 80 years ago the predated the v2
and even made at the same time like the
a5 all of those missiles up to the a5
used this gas pressurization system
rather than a turbo pump but there's a
crossover that comes apart on the graph
if you plot the thrust and range of the
missile and whether you can get away
with
this system and there's a cut-off point
where if the missile goes over a certain
size you just can't use this system
anymore you've got to go with something
that is a lot lighter otherwise you're
going to completely hobble your missile
in terms of its range and its carrying
capacity because quite simply the tanks
end up heavier than the turbo pump and
this happens simply because as the size
goes up the amount of bracing and
support an extra metal there's got to be
piled in to make those tanks be strong
enough to be able to take the pressure
dramatically increases to the point as I
say where and a missile the size of the
v2 the tanks are going to be a lot
heavier than the turbo pump system so
the logic behind using the turbo pump is
still overwhelming so when you look at
liquid fuel a motors today you're still
going to be seeing this turbo pump
technology reigning supreme for anything
other than a very small missile now
before we go back to the engineering
I just want to expand on one of the
points that came up at the end of that
presentation of the Peenemunde a
technical museum about the role of
commercial contractors not just in the
supply chain supplying parts and
assemblies but actually in the
development history of the turbopump in
the mid 1930s when the army missile team
were first getting to grips with the
idea of using high-performance pumps
rather than a gas feed system that we
were looking at a moment ago someone in
the group drew their attention to the
flow and pressure performance already
available in firefighting water pumps
and this set them on a mission to talk
to people with commercial expertise in
this area although the final mass
production of the turbo pump involved
other companies boom AG of görlitz
Heinkel of en Beck and later my bag of
Nohr thousand the crucial work of the
development was entrusted to industrial
pump experts at the southwest German
company of Klein Shenzhen and Becker or
ksb for short we know from historical
documents of the project to develop the
v2 turbo pump began as early as 1930
five this document written by the
technical leader of the missile program
Wernher von Braun is a progress report
to his master's in Berlin and it details
new projects underway or expected to be
in the current year the report is dated
1935 and point number seven refers
specifically to a project already begun
to develop a centrifugal propellant pump
with commercial partners client
Chancellor an evangelistic sort of in
some about the kleine schranz lien of
Becker founded by johannes klein in 1871
by 1916 ksps factory site in Frankenthal
was one of the biggest in germany
covering over 60,000 square meters and
employing over 4,000 people
KSP had a good record of pump innovation
and owned a number of valuable domestic
and foreign patents pertinent to the
pumping industry by 1930 they one of the
most prominent pump designers and
manufacturers in the world this drawing
for the turbo pump design
he stated 1937 shows that initially at
least the pump development group of
Peenemunde a-- seem to have been
communicating with the people of machine
and fabric or desig and bahar the odessa
company who are still trading by the way
was acquired by Klein schenzel and
abettor in 1929 and from 1939 the
company was known officially as Klein
schenzel in odessa Guillen Behar a
wholly owned subsidiary of ksb we can
see in this drawing from the 1st of
October 1940 that a lot of work has been
done since 1937 and the design of the
pump is starting to look a bit more
familiar with details like the general
location of the inlet and outlet flanges
and the design and position of the steam
Inlet shown here in red
and the steam exhaust port here but the
outlet flanges are still not in line
with the inlet flanges are not
positioned in line with each other but
off to one side and the mounting
brackets are shown at the cardinal
points one on each end of the pump and
to either side of the turbine casing
this rare but poor quality movie clip
shot in Peenemunde er sometime in
nineteen forty two forty one shows a
turbo pump variation indicative of the
late nineteen
development period seen in the drawings
in fact most of the features we've just
been looking at her here
the off-center outflow on the right
mounting brackets our cardinal points
and the non 360 degrees steam manifold
by the end of October the exhaust port
throat area has been enlarged and they
are trialing the steam input manifold in
a new location adjacent to the fuel pump
and dangerously close but the outlet
flanges are still level and off to one
side and the mounting brackets on the
turbine case are more robust but all
four are still at the cardinal point
position oh and right down the bottom
there they finally spotted the spelling
error good lads
this drawing from June 1941 looks almost
like a production series turbo pump and
very similar to the pump we showed you
earlier the steam Inlet has arrived in
his final position and stood off 250
millimeters from the steam nozzle array
and positioned outboard of the liquid
oxygen pump case critically the outlet
flanges are now in line with the inlets
and no longer level the mounting
brackets are settled larger and located
only at the horizontal positions
integrated into the castings either side
of the pump volute cases and the bottom
right there Edessa is still formally
identified as the supplier this
long-running misidentification was
finally corrected three months later in
November 1941 with this almost identical
drawing showing more refinements to the
internal diameters of the inlet and
outlet atures and changes to the over
speed switch area and down at the bottom
there ksb klein shenzhen Abeka
is now identified as the primary
contractor now just to put the last
drawings and the next into a wider
context the first but unsuccessful pay
for flight test model was completed 25th
of February 1942 this undated clip shows
an a4 missile being assembled in
Peenemunde sometime towards the end of
1941 or the first weeks of 1942 in this
drawing originating from the first
quarter of 1942 we see an almost
production series system and the
patent for the turbopump that probably
flew on the first successful launch of
the v2 on the 3rd of October 1942 it's
still not quite the 1943 machine I
presented from Peenemunde or earlier but
it's getting close the inlet throat
shape and the fuel loop back areas have
yet to be finalized but the first ring
of the steam Inlet manifold is a full
360 degrees now rather than the 200
degrees of the earlier versions and the
overspeed switch assembly and its
location has now settled into something
resembling the production series pan
interestingly if we look at the data
panel here showing the dates and drawing
numbers it's worth noting that the first
two names responsible for this drawing
are the same names that appear on all
but the first oldest drawing we've shown
you will close this section with a
memorable endorsement of the turbopump
development contractor by Peenemunde as
technical production manager Arturo
Rudolph in 1989 responding to questions
from space historian dr. Michael no
felled Rudolph stated we hired Cline
Shenzhen and Becker to do this
development and they did marvelously
really marvelously later on when
discussing the v2 missile project as a
whole Rudolph drew attention jointly to
KSP and guidance specialists kriezel
karate gear in Bihar stating that these
were the outstanding contributors now
obviously that's just a sample of some
of the communications between the pump
experts at the client Shenzhen Becker
KSP and the turbopump technicians at
peenemünde ER and there's obviously a
fantastic amount of detail that could be
piled in there in the design and the
development work from its inception in
1935 through to the first drawings that
we saw there in 1937 all the way through
to the first successful flight of the v2
in late 1942 a huge amount of effort was
made to develop this absolutely crucial
part of the v2 s liquid propellant
rocket engine system in fact you would
probably say that the turbo pump is the
critical technology in making that motor
systems
I want to go back to the engineering of
the turbopump now and cover one of the
points I think there was in the air in
that presentation that I showed you from
Peenemunde that when we were looking at
the relic turbopump
from I think 1943 I spoke a lot about
the hardware of the turbine and the the
use of superheated steam that came up a
lot but I didn't talk at all about how
the superheated steam is made and where
it actually comes from in doing his job
of driving the turbine so we rather left
that out let's deal with that issue
right now and look at how the
superheated steam was actually
manufactured that drives the v2s turbo
pump
we're at the Deutsche technique Museum
in Berlin where they have a very
accessible v2 engine turbo pump
propellant tanks and more importantly a
well displayed steam generation plant
it's incomplete but that's not a problem
for our current purposes we'll be
returning to this excellent exhibit in
this and other videos so let's look at
where this powerful jet of superheated
steam that powers the turbine part of
the turbo pump actually comes from and
how it's made
this is a full-size model of the valta
steam generation plant used on the v2
missile the superheated steam that
powered the gas turbine was generated in
this combustion chamber the steam passed
through this steel pipe lagged with
asbestos here and on to the turbine of
the turbo pump to make this
demonstration model showing just the
essential elements of the steam plan
we've actually used a small number of
original relics from the v2 steam plant
like the main valve here the 25-ton
valve the sodium permanganate tank and
the contact switch as well as
recreations like the gas generator pot
and turbine connection pipe we've also
used new parts to complete the model
like the piping here the air and flow
control valves up here are modern these
valves when we discuss much in this
video but they do feature in another
video we have planned about the yacht
katate or J device the integrating
accelerometer used to determine the
range of the missile we're going to look
at the daemon in the machine the
monopropellant chemistry that lies at
the heart of the Valtor steam generation
plant in a moment but first let's get a
helicopter view of the main hardware
components of the system so the basic
fuel used in the steam generator is
high-strength hydrogen peroxide or h2o -
yep the same stuff used to white until
you complete chair only in a vastly more
concentrated form it's carried in a
pressure tank above the steam generator
we can see the ellipsoidal shape
hydrogen peroxide tank in this museum
exhibit the yellow h2o - container looks
like a giant American football or a
rugby ball and we can see the large
diameter pipe carrying the h2 o2 down to
the 25-ton valve seen here in cutaway
revealing his internal parts and here's
that same pipe carrying the hydrogen
peroxide down to the 25-ton valve here
okay let's just hold it there for a bit
we're going to come back in a moment and
we'll take
look inside some of these key components
and see what's actually going on inside
there but first let's look at the stuff
that is actually flowing through this
plumbing and get ourselves a little bit
more familiar with the surprisingly
simple monopropellant chemistry that
generates this steam that passes through
this pipe and onto the turbine and turns
that nearly 20 inch turbine wheel at
speeds of up to 5,000 revolutions per
minute before we look at the steam plant
for the v2 turbo pump in any more detail
let's just try to get a basic
understanding of the essential
principles and chemistry used in the
helmet Valkyr steam generation plant to
do that we're going to do a little
demonstration outside rather than in
here using some bits and pieces that we
put together the original steam plant
system for the v2 used high-strength
hydrogen peroxide h2o2 to an 80%
strength a very dangerous product we're
not going to have any truck without at
all we're going to be using 35 percent
strength hydrogen peroxide and we're
going to be using potassium permanganate
crystals so we're going to use the
potential the energy potential of these
two products to basically we're going to
use the energy potential of this product
hydrogen peroxide and we're going to
liberate that energy using a catalyst
the potassium permanganate the Germans
would have used sodium permanganate to
do this but the technical literature
does often mention that they used
potassium permanganate I'm really not
qualified to say whether that's true or
not because I can't quite understand why
they would because potassium
permanganate
I don't think takes up water as well as
the sodium and though the products are
virtually identical in the way that they
would work as a catalyst for the
hydrogen peroxide the slurry the
suspension that would be made up
with the sodium permanganate I think
would be a lot more efficient than
potassium permanganate anyway that's
what we're going to use that same
permanganate you've almost certainly
encountered it before in fact you've
probably even tasted the stuff when
you've been at the dentist you've had a
filling done and you've heard those
words rinse out please it's exactly the
same stuff lower dilutions then we're
using it here of course but potassium
permanganate it's exactly the same stuff
Cheers
we're going to need a little bit more
apparatus so let's just look at that
well the first and most important part
of our demonstration apparatus is this
dual pump and turbine this is a single
shaft with two centrifugal pumps on
board this is the genuine article this
is from an s75 Dvina Soviet
surface-to-air missile the sigh of
design bureau that came up with this
little item had the v2 missile and the
German Vasa farmers are very much in
mind and from our point of view it's
quite a good mini analog for the turbine
rotor and pump rotors for the v2 it's
quite a bit smaller obviously than the
the v2 system the turbine wheel here's
around 8 inches in diameter the v2 was
twice the size of that over twice the
size in fact and there's nothing to be
learnt by looking at the design of this
rotor because the German system was
completely different I'm going to show
you that in just a bit what I want you
to get from this is just the general
design of it the the German system was
regarded as a single shaft turbo pump
but in fact it had a broken shaft so the
fuel and the rotor only to turn it
around this is the fuel side so the fuel
and steam turbine was on one shaft there
was then a soft joint that enabled the
oxidize a shaft to be putted on but in
principle what it meant there was no
gearing or anything else in the way it
meant that a single rotation of the
turbine equalled exactly a single
rotation of the pump rotors on either
side of it rather different to the v2
are the varying size of the oxidizer
here and the fuel pump on this side
you'll notice that the fuel pump is a
bit smaller on this system we see the
eye in the center here where the fuel
goes in and we've got a nice shrouded
pump rotors and fuel pump rotor here but
if we look on the other side for the
oxidizer we can see that it's a larger
diameter so this would have a different
dynamic when supplying the oxidizer
which incidentally wouldn't have been
liquid oxygen on this type of missile
because the missile needs to be ready
for instant firing this would have used
a non cryogenic oxidizer like fuming red
nitric acid same design though we've got
the fuel the oxidizer is taking in in
the eye and then sent down into the
combustion chamber one of the little
things to note here is that the side
where I'm gonna be shooting the the gas
you can see it's slightly smaller so the
gateway and in the rotor blades here is
a little bit less than the gateway on
the other side and you can see that the
rotor the turbine rotor has got this
rather nice kind of Kent on it
to reflect the fact that the Gateway is
slightly smaller on this side and as the
gas expands through on the outside
hopefully you might be able to see that
when we do the demonstration anyway
we've made up a little rig here to hold
this you just got to put the bearings in
the right position and that brings us on
to the next most important part and
that's the gas generator itself the gas
pot sometimes referred to as the
disintegrator by the Germans and in the
on drawings and in literally
what I'm using is a plastic bottle this
is actually a prosthetic pressure bottle
from a popular home a carbonated drinks
system so basically you would plug this
into one of these gadgets where you pull
a lever down and it would pump cum
dioxide into the beverage of your choice
to make a fizzy drink I've chosen this
because it's quite a tough bottle it's
very made a very thick material and it's
got these kind of this nice kind of
pressure body shape and everything is
very tough and I'm going to be able to
do stuff up very tightly with it I've
turned the lid into a steam nozzle and
I'm going to bolt the base screw that
down onto the wooden platform here so
that I can put the bottle into position
and put it at a good angle to put steam
onto the rotor buckets here then I'm
going to supply the hydrogen peroxide
from this little simple dispenser what
I've got here is a little tip which I'm
going to drill into I'm going to drill a
hole in here and I'm going to glue this
into position into a hole in the side of
the my gas bottle here and you can see
that the hole in the tip there is only
about one and a half millimeters in
diameter so that I get a very modest
flow here by just squeezing the bottle
the feed pipe goes all the way to the
bottom and I can control the amount of
hydrogen peroxide by just varying the
amount of pressure I put on the bottle
I'm doing that because I really don't
want to get myself showered in in hot
fluid from this system and I want to be
able to control the amount of pressure
so I've got a fairly generous sized
nozzle this is about seven eight mil in
diameter this piece of copper pipe
because I don't want too much pressure
actually building up inside here it may
only be 35% hydrogen peroxide
but it still got more than enough energy
to blow this bottle apart I think and I
really don't want any accidents we've
done some tests with this combination of
materials just to make sure this will
work but we haven't actually tried this
out yet so that'll be you'll be with us
when we do that outside but I am
reasonably sure from the tests we've
done that what we're doing here is quite
safe or straightforward now hold that
for just for a second let's just pause
and take a breath partly for light
relief but also to remind ourselves of
an important watchword in the history
and development of the liquid-fueled a 4
v2 missile and that word is testing test
and test again so by way of light relief
just have a look at one of the tests
that we did to test the strength of the
35% hydrogen peroxide and the potassium
permanganate that we were going to use
to power this test over here take a look
at this
whoosh
there you go pretty energetic meiyan
another and introduce the squirt of
potassium permanganate now
happen is going to mix the potassium
permanganate with water I'm not going to
use too much water I'm going to put a
charge of about 50 milliliters of water
and I'm going to add as much of these
crystals as I can so that the water will
take up most of it let's just show you
this and form a suspension and a slurry
with the material I'm probably going to
put more in it than I think the water
can take up because I want to make sure
that the water is a saturated by the
came in at for as I possibly can and I'm
then once I've got it sitting in the
bottle here and that pretty well mimics
what the Germans were doing the Germans
made sure that the potassium sorry the
sodium permanganate that they were using
arrived in this tank first they then
continued to meter so a slurry of sodium
permanganate in to the gas the gas flask
throughout the burn process so for
upwards up to about 70 seconds they
carried on feeding sodium permanganate
into the steam generator bottle until
the end of the burn and obviously they
continued supplying a liberal quantity
of high strength hydrogen peroxide into
the bottle as well anyway without
further ado let's take it all outside
and make it go
we need so the equipment's pretty much
ready we just take off the lid and gas
jet from the combustion chamber and load
in the potassium permanganate catalyst
I've got about 100 milliliters of this
stuff and I've put quite a bit of
permanganate in there if I've got as
much in as I think the water can take up
and there's quite a bit of sediment in
there so it's pretty much a thick slurry
get the jet nozzle lined up again a
little bit concerned that it's a bit too
far away from the turbine wheel but
we'll go ahead anyway fill the
applicator up with hydrogen peroxide
being a bit sparing with this making
sure I've got enough to go for a few
tests just in case this first one
doesn't come off I've put enough in
there to give us a few puffs to get this
going a small quantity of hydrogen
peroxide now these videos are meant to
be a laugh but I'm not Harold Lloyd so
safety first so we're ready to go first
try
so you'll notice that the bottle is
starting to distort and the model is
starting to creep away from the wheel
because of the heat being built up in
there so I think we need to get the
nozzle in closer and maybe make the
nozzle in the hydrogen peroxide
applicator a bit bigger to get a bit
more h2o to in there so let's try again
really going very fast but good enough
to make the point I think and those are
still creeping away in the heat try it
again a bit closer another run that
makes the point I think once more very
close just to see what's happening Rob
against the rotor the rotor buckets you
can see there's quite a bit of this
dirty fluid we spent catalyst in it well
we didn't destroy the apparatus by
getting it too hot I think if we'd have
been able to get more hydrogen peroxide
in there other through my little jet we
could have probably got the RPM up the
snag is it would have destroyed my
plastic bottle and it wouldn't have been
quite so visible what we were doing so
all in all I think that was quite good
one thing that did surprise me was how
the extent to which the catalytic
potential of the sodium sorry the the
potassium permanganate didn't actually
degrade with all the water that was
being put in it seemed to carry on I
seem to be getting roughly the same
amount of energy every time I gave it a
year it still works even now every time
I give it a puff of hydrogen peroxide it
sort of carries on working I get roughly
the same amount of steam perhaps not
quite as good
every time I give it a puff anyway
that's that
well we've washed up the equipment so
let's have a wash up and see what we can
actually carry away from this little
demonstration some of the equipment
didn't fare too well our gas bottle here
the gas generator took quite a bit of
punishment and ended up being quite
badly distorted but I guess it held
together well enough if I could ended up
being quite a bit smaller after the test
and it started which surprised me rather
I knew it was gonna buckle a little bit
but I didn't expect it to get uniformly
smaller as a result of the heat but then
I suppose it's not that surprising I
guess the main thing we need to carry
away from this is the fact of using a
monopropellant the h2o - the hydrogen
peroxide combined with a catalyst to
create an energetic stream of steam
under pressure with oxygen in the case
of the 80% very energetic remember the
test that we've shown you is a thousand
times less energetic than the real
turbine jet steam pressure would have
been the 80 percent hydrogen peroxide is
a very energetic propellant compared
with what we were using here the 35%
we've shown how that steam pressure can
be used to generate the rotary motion of
a turbine which in turn can be used to
as the propulsion system of two
centrifugal pumps to push the propellant
down into the combustion chamber I think
we've established that quite nicely the
along the way I think we we noted almost
in passing
that the catalyst in the way that it
gets drawn and combined with the
hydrogen peroxide only needs to be
supplied in a in a sufficient quantity
could easily be to excess because the
h2o to basically utilizes the catalyst
as required so providing there's enough
or more than enough we don't need to be
too particular about the amount of
material this you know then it's
probably a good thing on the a4 v2 steam
plant because quite a bit of this
catalyst would have been carried away
with the steam you may have noticed in
the test that the steam that we were
producing was quite wet this is because
it wasn't superheated steam remember the
steam coming from the steam generation
plant they using the high strength 80
percent hydrogen peroxide this would
have been super heated dry steam so we
wouldn't have seen all of this wet over
the turbine but it is worth bearing in
mind that some of the catalytic slurry
would have been carried onto the turbine
and that's probably not a particularly
clever idea when you consider the speeds
and pressures that we're talking about
here one of the other things that we saw
was the angle of the gas jet as
presented to the turbine wheel and that
the exhaust jet the expanding exhaust
jet was moving away at a sharp angle and
returned basically to a sharp angle in
the opposite direction also we noticed
that the exhaust jet was expanding as it
moved away from the exhaust side of the
turbine rotor we saw it rather nicely
just here we saw the steam going in at
this angle and we saw the exhaust path
of steam coming away at a sharp angle in
the opposite direction we also saw the
gradual expansion of the steam as it
passed through the rotor bucket game
okay so let's carry all of those ideas
with us as we take a more detailed look
at the turbine steam generation plant
the gas jets and the steam turbine rotor
wheel of the actual a for v2 missile
rocket motor
okay back with the steam plant hardware
again let's try to tie all these ideas
together into a functional whole earlier
I said we would look at some of the
components of the steam plant in a
little bit more detail let's kick that
off by looking at these crucial valves
responsible for releasing the hydrogen
peroxide in to the gas generator pot as
I showed you earlier the primary valve
in the steam plant that controls the
flow of hydrogen peroxide is called the
25-ton valve the second valve just above
it here is known as the eight-ton valve
and it also controls the supply of
hydrogen peroxide the eighth and 25-ton
valve names are derived from the amount
of steam delivered to the turbine and
therefore the amount of rocket engine
thrust that is achieved by the effect of
these valves when the eighth and 25-ton
valves are open together the generator
produces enough steam to drive the
turbine at its rated speed of three
thousand eight hundred to four thousand
nine hundred rpm and push enough fuel
and liquid oxygen into the engine to
produce around 25 tonnes of rocket
thrust at ground level when only the
eight ton valve is open on its own the
thrust drops by two-thirds not too
surprisingly to a little over eight tons
hence the name the most important point
to notice at this stage is that both
valves are being supplied by the same
hydrogen peroxide pipe that connects to
the main hydrogen peroxide tank there
are no special extra pipes or anything
like that both valves are being supplied
by the same pipe it looks a little bit
confusing because the outflow on the
electric flow valve here the eight-ton
valve is connecting directly to the air
controlled 25-ton both
valve here and both valves are passing
hydrogen peroxide in to the gas
generator tank this is an important
feature of the steam plant both for this
and future episode so we'll need to look
at this in a little bit more detail here
we see the whole steam plant
sub-assembly with this battery of seven
air or nitrogen bottles attached the
assembly was a surprisingly simple
structure and was secured to the chassis
of the b2 with just a handful of bolts
let's isolate the 25-ton valve from the
plumbing so that we can get a better
look at it and then section it so we can
see inside this valve is pneumatic and
we can see the air piston on the left
side a heavy spring keeps the valve
normally closed and the piston is driven
down the cylinder to the right by the
air or nitrogen as it's typically
specified of 500 pounds per square inch
the air pressure moving the plunger off
its rubber seating to open the valve
allowing h2o2 to flood into the gas
generator pop below at exactly the same
time the eight-ton electric flow valve
also opens and allows just over 30% of
the total h2o to to reach the gas
generator pop by a bypass route through
the same 25-ton valve the significance
of this bypass route becomes apparent
when the 25-ton valve is closed halting
the main supply of h2o2
to the guest generator as now a greatly
reduced volume of h2o2 continues to
reach the gas pot via the eight-ton
valve and bypass route so even though
the primary valve is closed the turbine
keeps running only at around 1/3 its
original speed from this reduced supply
of h2o to less hydrogen peroxide in the
gas pot means less steam on the turbine
so fewer revolutions from the pumps and
thus less propellant pumped into the
rocket engine let's take a quick look at
what we can learn from a 25-ton now of
Relic recovered from a launch failure
from the 1943-44 era made of light alloy
and still showing its original anodized
color it was incomplete when we received
it missing the air piston end cap I'll
just remove the airline connection the
cap here is made of ABS and I 3d printed
from an original part drawing
transcribed by my friend Alexandra
savochkin you saw his drawings earlier
we can see here on the rector h2o2 feet
pipe the connection point for the
eight-ton bypass valve and here again on
the main valve let's just unscrew and
remove the hydrogen peroxide feed pipe
and union so that we can see the valve
plunger you can see it's slotted to aid
assembly the spring was missing so I
fitted a much weaker one so that I can
easily press the piston in and show the
valve working let's just undo the nut
holding the makeshift piston and seal to
the end of the valve stem I can remove
the valve core or plunger now all light
alloy construction we can see the stem
gas seal down the bottom there held in
by a c-clip and the valve seat here
which is normally loose like this and
held in place by the h2o to feed Union
it has an integral valve seat made of
some form of hard rubber substitute the
valve stem just fits back in and we can
see a little air relief hole here to
relieve pressure on the valve side of
the piston otherwise it would resist
movement if we didn't let the air out
the h2o to outlet pipe running to the
gas port here is not original but we can
see the high pressure seal here if we
just pull the plunger and seal out again
we can just see the pathway from the
bypass connection through to the main
h2o2 outlet probably easier to see if I
poke my pointer in the bypass valve
opening and then just flip the valve
over and poke it in the main a low
opening so you can see both holes open
into the same cavity okay let's get back
to where we were again when the start or
preliminary stage button is pressed a
system of sub valves allows propellant
to flow under the action of gravity into
the combustion space of the engine or a
simple pyro or firework like a Catherine
Wheel lights the fuel and oxidizer mix
into a steady flame even though the v2s
rocket engine now begins
run at around 2.5 to 3 tons of thrust
not the 8 tonnes that you've read about
in some books the steam plant and turbo
pump remained completely idle they make
no contribution to the running of the v2
rocket engine at this stage at this
point fuel and liquid oxygen is simply
falling out of the tanks and through the
static pumps into the thrust chambers
combustion space over when the main
stage or helps to fur button is pressed
a valve opens that allows air to pass
into the sodium permanganate tank
through this pipe and allows the
catalyst to begin flowing into the steam
pot but still nothing changes the rocket
sits on the launch stage the engine is
running at about 10 percent of maximum
thrust but an automatic process has
begun that requires no further human
intervention
the sodium permanganate continues on
down this pipe to this contact switch
though it has a pipe running to it this
is not a valve it's just a switch the
fluid pressure pops a diaphragm inside
and closes a set of contacts the switch
closes a relay that instantly energizes
and opens these two valves the twenty
five and eight ton valves together so
we're now in a position to appreciate
what's going on in the secret darkness
of the steam generation flask the sodium
permanganate liquid catalyst arrives
first allowing the arrival of the
high-strength h2o to where a violent
chemical reaction occurs instantly
reducing the hydrogen peroxide
catalytically to superheated steam and
oxygen the steam blasts out of the
bottom of the gas Parton is carried by a
steel pipe missing on this exhibit to
the steam Inlet flange on the steam
distributor of the turbo pump and
onwards directly to the steam nozzles to
provide power for the turbine rotor the
steam encounters no more valves or any
form of hindrance and hits the turbine
rotor which spins the pump in peles
sending fuel and liquid oxygen under
greatly increased pressure onto the main
thrust chamber valves opening them by
sheer force the fuel and liquid oxygen
gains access to the combustion space by
forcing the valves open by pressure
lent to both propellants by the
turbopump and we haven't liftoff the 25
tonnes of rocket thrust overcomes the 12
ton missile frame and tank weight and
the missile Rises at roughly the same
speed as a falling object and continues
to do so and thus attaining great
velocity and altitude before the burn
ends a little over a minute later hold
on a second we need to go back as we
haven't explained why we need these two
valves we've covered that they are both
fully open to start the turbine but why
do we need to throttle back from 25 tons
of thrust to just eight tons via that
second valve now the v2 is requirement
to throttle back immediately before
engine shutdown was done to refine the
final velocity measurement to improve
the range calculation of the missile now
it's far too interesting an idea for me
to skim over lightly here while we're
talking about the steam plant and we're
going to deal with it in a lot more
detail in the subsequent video that
looks at the gyroscopic accelerometer
and how it was used to control those two
valves and more precisely control the
range of the missile anyway that's in
the subsequent video don't forget to
subscribe if you want to see it let's
get back to Alexander sbatch kins
drawing again for a moment and look at
the steam plants gas generator part in
detail let's pull it out of the plumbing
again the h2 o2 comes in as we've seen
from the left here and a steady flow of
catalyst is fed into this smaller union
lower down the body of the pot if we
section the pot so that we can see
inside at the bottom of the h2 o2 inlet
tube we can see a spring-loaded pass
valve that ensured that only propellant
at the correct pressure could enter the
steam pot and further in a non-return
bore valve in the tip ensured that no
matter how violent the reaction in the
chamber
nothing could be pushed back into the
hydrogen peroxide feed system and cause
a malfunction or even an explosion the
catalyst pathway shows a rather more
direct and open route the pot has a
number of features designed to
allow maximum exposure of the catalyst
to the incoming h2o to the jet of sodium
permanganate is designed to spatter on
contact with the small round target
visible at the base of the funnel we can
see surrounding the h2o 2 nozzle a
number of baffles separate the area
below the funnel from the lower section
of the gas pod and most intriguing of
all is the helical helter-skelter slide
that passes around the central core the
shape is well shown in this drawing they
were designed to slow down the exit of
the sodium permanganate to make sure
that it had the best chance of
thoroughly catalyzing the h2o 2 into the
maximum volume of superheated steam ok
let's take a look at the steam rotor of
the v2 turbo pump the agent that
actually turns this powerful jet of
steam into the rotational motion of the
pump impellers earlier I showed you the
steam rotor and pair of combined pump
impellers and I made the point that it
was a fairly good analog if a somewhat
miniature one for the v2 turbo pump
hardware but not a good analog for the
actual design of the rotor itself and
that's because the rotor here on the
sigh of steam turbine is stainless steel
a made of pressed and welded parts in
contrast the steam turbine rotor of the
a 4 v2 turbo pump is actually a 45
centimeter machined light alloy wheel
with two slots machined into the
perimeter of the wheel a few years ago
we shot some footage of a very badly
corroded turbo pump on display at the
technical Museum in Peenemunde ER and
although the the the turbine is in
pretty poor condition quite badly
corroded
it does allow us to show you the salient
points of it I think really rather well
we can see its construction here is
his physical size really quite nicely
yeah the thing I want you to notice is
the type of construction we've got
here's that slotted rail you can see and
the teeth inserted into it as separate
components it's very although it's badly
corroded looks like in spinning water
you can actually see it very clearly
down here the separate rotor blades
actually looking like teeth in a jawbone
got a couple of examples here of the
turbine buckets the turbine blades that
have been converted from original
drawings by lars osborne and i was able
to print these out in a 3d printer quite
easily and they show a lot of the detail
you can actually look at these yourself
on Thingiverse where this drawing has
actually been uploaded the really good
thing about bits like this is that i can
actually print them out and in enlarged
form this land of the giant version here
which is going to be a lot easier to
show you the details it shows how the
rotor blades actually fit together and
it's easy to show how once we start
putting a stack of them together like
this you can actually see a curve
starting to form here quite easily and
we get this a very distinctive fish
scale look to the top of the rotor here
which you'll see in pictures easily
enough you see if I put them in a line
here
the other ones up against them you can
see there's quite a gap if I squeeze the
bottoms together there's quite a gap at
the top and if I squeeze those together
you could see that they start to form a
curve so they really are very craftily
made in they take up the shape just by
squeezing them together without putting
them into any kind of a slot they really
are designed to create this curve of the
rotor now it's a good illustration of
the difficulty that the Germans had
rolling the v2 out into a mass
production product when we gives
consideration to this little gadget the
turbine blade or bucket we've got a
really very complicated structure here
with something like seven or eight
machine tall operations being required
to make this to a very very high
standard when you consider that a
similar item can be made with just two
operations stainless steel cutting and
bending making a very simple but very
effective blade each turbine required
over 460 of these rather complicated
little items and that's pressing towards
three million for the German rocket
program as a whole and it's pretty easy
to see why the mass production project
was so difficult to initiate when you've
got prototypical products like this that
really could and should have been
replaced by something much simpler we
can actually use a couple of relics here
to investigate the structure of the
steam rotor we can see it these look
like they're fantastically miss shapen
after the severity of the impact that
these steam rotors actually went through
at some point in their lifetime but we
can actually see here the the inner
section of the rotor and the rotor wheel
we can see its general sight shape and
size and in particular we can see the
two rows of rotor buckets here
they're getting ready to actually come
out they've been quite badly damaged but
we can see the difference in height and
we can see how they've been fitted in to
the rotor I think I can show it to you
better with this one it's got a much
cleaner break and I can fit my 3d
printed turbine blades or rotor buckets
into there will fit the second one in
quite nicely there's enough room for it
now if I push it home and you can see
how they fit in there but it's all very
damaged and buckled it would be nicer if
I could do this on on the land of the
Giants version of the rotor wheel and
just by chance and as I say on Blue
Peter here's one we made earlier you can
see I've put a run of rotor blades in
here already
and we'll just put a few more of these
in and you'll see how they fit together
neatly and take up a nice snug position
against one another fitting together
perfectly and you can see picking up
that fish style fish scale look to the
top of the rotor buckets here looking
very distinctive in the way that that
method of construction leaves the steam
rotor looking now of course there was
two rows of these buckets on the steam
rotor we saw that the v2 turbo pump had
a two-stage rotor that used to separate
rows of steam buckets or blades in
contrast to the relative simplicity of a
single stage steam rotor like the Soviet
era rotor were used in the demonstration
the v2 rotor system needed an essential
bit of extra hardware between the two
rows of rotor blades just like a single
stage rotor the steam jet is directed
into the first row of steam blades at
the best angle for maximum rotational
efficiency of the turbine rotor but the
steam still has a lot of energy that has
not been harvested by the first row of
blades so the way to exploit their
energy is a second row of blades the
snake here is that the steam jet has
been bent well away from the ideal angle
by its passage through the first
of Blades the solution is a fixed Rove
blades in the middle with an identical
curve but in the opposite direction
called a stator the stator blades
restore the steam jet to the ideal angle
for the second roller blades we can see
one of the turbine status sets here in
the left hand picture and we can just
see the base of one of the stator blades
shown in red this Peenemunde a drawing
from 1944 identifies the moving rotor
blades as a and C and the fixed stator
blade as B the lower picture shows the
angle of the steam nozzles and the
Switchback nature of the steam path
through the blades perfectly okay so
let's round off by seeing what we can
learn from some turbo pump relics these
are historical parts from impacts and
from experiments that are basically
wreckage and debris we've got a good
collection here of parts there's not
enough for a complete turbo pump so this
is not a do-it-yourself turbo pump kit
but there's quite a few bits and pieces
here that we can look at and and learn a
few things let's start with the bit that
I've got in my hand here which is
actually a section of the fuel pump we
can identify its fuel pump very easily
from these frogeye spacings the frog eye
holes here are the holes we see on the
on the face plate and we can see from
how close these holes are together this
is definitely a part of the fuel pump
and if we compare it with the face plate
of a liquid oxygen pump we can see here
the spacing between the holes are much
larger except where we see something
like this for the for the pusher but
otherwise this is definitely a part of
the fuel pump a couple of things we can
see here one is the shape of the volute
space we've got a little
paper piece here that goes in there we
could see that that would be the shape
of the volute space at this point and as
it moves as it moves through you can see
how the volute space shape would
actually change here so this is this is
giving us a snapshot really of the
volute space there's other things we can
see on here that are quite interesting
one is this remains of the tracing of a
m16 thread here m16 course and I've
actually got one of the studs that would
be used on the turbopump here and you
can see it rather fits nicely into that
and then the bolt would do up on to the
faceplate there if I take the bolt
that's the nut that's here off this
washer is still intact and one of the
things you can see about it is the
washer is bent the bike that it's
actually a spring washer and it's
designed to stop that the nuts coming
undone sometimes you don't notice that
when you look at these things but the
this is a spring washer whoops and if I
just take this off gently if I could
possibly show it to you on the edge here
then if you can see in that little gap
there and there's a little bit of it
just there we can actually see a bit of
an o-ring seal and if I take it apart
carefully there it is we can see the
remains of a little section of a ring
that fits into that recess just there
it's a bit grubby but you know it's been
it was in the ground for about 80 years
so anyway that's that section of the
fuel pump another interesting item that
we've got here is the steam jet this is
a complete cast iron steam jet from the
turbo pump it's a little bit broken off
at one end but it's pretty much intact
otherwise this is pretty much the size
of it we can see the angle here of the
Jets if I use my
point absence we can see that the
jungles are something like that as they
go through the jet the steam enters on
this side of the plate and moves through
to be then applied to the turbine we can
see that this would be pretty much at
this angle this is an outlet flange
again I think from the from the swerve
here again from the a pump the liquid
oxygen side of the turbine turbo pump
we've actually got the component that
would have been mounted on here and
that's this chunk so this is something
that would actually fit onto the outlet
flange before going down into for
example the liquid oxygen distributor
now the Germans found there was just too
much variation from pump to pump despite
their best efforts to keep the
engineering to the narrowest possible
tolerances of the time based on the
findings of individual test run
procedures the pumps needed calibrating
with chokes like this so that the
combined output from the turbo pump
could be balanced to ensure that the
correct mix of fuel to liquid oxygen
arrived in the thrust chamber the reason
why of the relatively crude agency of a
choking ring was required to appreciate
these rings would be different sizes is
that they had no way of controlling the
speed of the pump independently of the
turbine there wasn't there was no
gearing or anything they could adjust
you saw from the demonstration that the
pumps actually run at exactly the same
speed as the steam turbine rotor so a
method of choking was employed you can
actually see the chokes colored red and
blue in this picture from the horseback
collection you can see that the fuel
choke is colored red here and the liquid
choke is colored blue very clear on this
picture this is a blanking cap from the
inlet throat of the turbopump
looking at it like this I can't tell you
if this is from the liquid oxygen or the
fuel side of the pump but I can tell you
it was made prior to April 1944 because
this actually changed in April 1944 or
at least one of them did and that's the
blanking cap for the fuel side of the
turbo pump the the blanking cap that we
see here is nicely shown in this horse
back image again same image we were
looking at a moment ago and you can see
the blanking capped looking very similar
on both of the inlet throats on the
liquid oxygen and on the fuel pump we
can see on the cap that I'm looking at
here we've got the remains of two of the
fast fastenings are still in place
judging by the damage to the hole over
here this was wrenched off violently in
a an explosion we can also see some
traces of a gasket that was used to
actually seal this up this is this is
the interior the blanking plates on the
horse Peck exhibit there I think it only
been put on temporarily but they are
actually the wrong way around
now this blanking plate is quite
different instead of other it's the same
size and fitting as the previous
blanking plate we were looking at this
one has got a pipe Union fitted to it
and this is part of the rotating line
for the fuel pump now the thing to get
here is that before late April 1944 when
this design first starts appearing on
the drawing boards at peenemünde ER the
fuel blanking plate looked like this
after late April 1944 this component has
been changed to this and presumably they
start turning up on actual missiles
probably in early May 1944 the rotating
line itself not a new idea but to
actually pass the rotating line back to
the fuel pump throat was a new idea that
didn't really come in until late 1944
previously the rotating line was
supplied about ten or twelve inches
higher up to a point immediately below
the fuel tank not connected to the turbo
pump at all you can see it quite nicely
on this drawing we can see what I'm
calling the rotating line that's that
was a common name for this it was
actually a pipe that connected the fuel
valve at the center of the thrust
chamber allowing a pipe to pass back so
after the fuel had been pumped into the
inlet manifold of the thrust chamber
this valve actually allowed fuel back to
the or this pipe rather allowed fuel
back to the low pressure side of the
turbo pump now previously it had done
this by connecting to a point just below
the fuel tank and you can see it here in
this drawing we've marked it in red you
can see that this rotating line pipe or
return pipe doesn't connect to the turbo
pump after late April 1944 we can see in
this drawing the rotating line or return
pipe connects directly to the
low-pressure side of the fuel pump and
it did it through the Union that we see
here now the reason why this was changed
why did they move it these these twelve
inches from the point just below the
fuel tank onto the turbo pump it's quite
straightforward they found that the
vibration profile of the turbo pump and
motor were very similar whereas the
motor fuel tank vibration profile was
quite different
because they were connected to different
parts of the missile the turbopump was
connected to the thrust frame which was
also connected directly to the engine so
the resonance of the vibration was very
similar for those two components the
fuel tank had a completely different
vibration resonance because of the way
it was connected to the rest of the body
of the missile through a number of
different soft connections so it was far
more likely to fracture or become
damaged and so they made this fairly
simple modification of moving the return
pipe away from the fuel tank and
connecting it directly to the turbo pump
look at a couple of slightly larger
items here here we've got the faceplate
for a fuel pump seemingly uninjured and
undistorted we've got the face saver
still attached to it here this would
have been providing a seal as the rim of
the impeller would have sat in here and
this would have provided a sealing and
self lubricating point for the impeller
we can see the seals here we can see a
rubber or rubber substitute seal still
intact here with a spring seal on the
inside seemingly intact we could see
another one on the inside here with a
bit more damage we can see the seating
point for the over spin the safety
cutouts which just here as well and some
of the fastings still intact and we can
see the output point for the overboard
dump for the lubricating and flow fuel
used the found its way into this cavity
this was being used as a chicken feeder
I think when I got a hold of it
somewhere in Western Europe and she
rather a good as a chicken feeder I
think - one way or another I'm no farmer
but I can see it from the point of view
of the chicken I think
same thing again this time the faceplate
of the liquid oxygen pump we can see a
couple of interesting details on here
the flanges
arrangements are quite different a
little bit simpler this relied only on a
very simple mastic seal and it was
actually quite difficult to get this
this this face to seal properly with the
liquid oxygen pump body face and they
tolerated a few drips with the pump
without that being too much of a
calamity we can see here FTP the
manufacturers mark
on it and we can also see I think we've
got a couple of marks here for my bag as
well on this face as well as some
numbers on the outside here thing to
draw your attention to on the inside is
we've got a set of bronze journal
bearings set into this face instead of
having an elaborate bull race here we
couldn't have any oil or grease coming
into contact with the liquid oxygen so a
very simple journal bearing was used and
the liquid oxygen itself was used as the
lubricant finally we've got a complete
or semi complete oxygen pump here a face
plate I was showing you a moment ago has
been taken off here we can see the
fastenings this was so badly distorted
it really was quite a job and he
actually getting that face plate off
here a couple of things to look at
there's the the bearing component that
would have been in the Proms journal
bearings I was showing you earlier
here's the rim where the face the
surface saver bearing and sealer would
have been running we could see a set of
holes on the inside some of them are
threaded for some action that was made
during the assembly process we can also
see on this face the remains of some
sort of sealant
possibly a complete gasket it was quite
badly destroyed when we when we pulled
the pump apart I didn't think it looked
like a complete gasket I think it
actually looked like some sort of
sealant of some kind you know a hermit I
type product that was smeared onto this
face before it was put together done
very carefully I'm sure but nevertheless
I don't think it was a gasket at least
not on this particular pump I don't
think it was a gasket
the other thing we can see here quite
nicely is the eye of the liquid oxygen
pump does normally get a good chance to
see that and part of the splined this
very heavy spline shaft that's going
into the liquid oxygen pump here now
this end here would have had that
flexible joint onto it this wouldn't
have been a continuous shaft as we're
sailing we've got one of the sealing
rings here as well various parts are
actually missing from here but what we
can see is the nature of the eye of the
impeller they're showing up quite well
another little point to notice on this
one which is quite interesting and it's
a good way actually updating it now this
self purged block is one of many
features we can use on the turbo pump to
give us some approximation of dating
often not exact because we can find
these things on drawings and then
sometimes we have to make a bit of an
estimate of when they might have
actually been found on the pump proper
but this particular one we know doesn't
really appear on manufactured pumps
until after November December 1944 and
is a good way of looking at a cut-off
point between the very end of 1944 in
the beginning of 1945 and it's the case
that most of the pumps you're ever going
to see in museums
the great majority of them because by
their very nature they were pumps
associated with the late war period
that's how come they survived most of
them will have this modified self purge
system rather than the very simple
drilled drilled hole simply going from
the inside of the throat straight
through into the volute chamber they've
usually got this little block on them
now the pump I showed you earlier on in
this video actually didn't have this so
that's another good confirmation that it
was a pump
well previous to late 1944 so you can
usually bracket things and put them in
certain areas and this is a good example
of something that we can use to do that
we can see some of the background
history to this improvement of the self
purge system in this drawing of the
turbo pump from August 1944 the original
self purge pathway shown on the left in
red itself still a fairly new idea in
1944 and driven by pump failure
experience had to be drilled at a very
steep angle through the narrow web in
the aluminium casting connecting the
throw of the liquid oxygen pump to the
top of the volute case this was never
gonna be an easy shot any machinist
would tell you drilling small deep
precise holes in aluminium is no fun at
the best of times but you can see in
this turbo pump from the late 1943-44
era the low shallow web made the job
much harder and especially harder to do
quickly and with the minimum skill at
some point in mid-1944 the pump
production specialists proposed the
original web shown here in red be placed
higher up in the throat to reduce the
steepness of the drill angle and
simplify this operation the new higher
web is shown here in green having to
approach the metal at an angle like this
and with the cutter a long way from the
head just makes the whole job much
harder and riskier - with the
ever-present risk of spoiling the
workpiece forcing a part to be pulled
from the production line and either
written off or passed for repair either
way reducing vital production volume
even with the improved web position it
was still a slow
each process requiring a small flat
landing zone to be milled at the point
where the drill cutter would be
operating the whole thing required
highly skilled and slow setup to get
every casting in precisely the right
position for drilling even with these
changes the production team still needed
a much easier way of machining the self
purge pathway no such modification was
required on the fuel pump you can see in
the inlet throat of the fuel pump on the
right side of your screen that the self
purge pathway was much safer to
manufacture simply because the design of
the throw allowed the drill to be
presented to the metal at a steeper more
normal angle and for a much shorter
Borland this was a stumbling block in
the production of the turbo pump and
needed to be simplified and we see the
effects of that simplification process
here we can see that they've added a
lump on to the casting so they took the
old pattern and added this section on so
now the holes can be drilled very simply
they simply drill down once into the
volute case and then one simple hole
actually still not easy to do a long
small hole through aluminium they make a
single boring right the way through this
part and into the flow casing so don't
forget this so we're seeing the volute
case here the pump case but just this
area here this open space with this vein
splitting it is the low pressure area of
the pump so if I put the pump up this
way the idea would be here any gas
oxygen or anything else for that matter
air that is in the top part of the pump
here would faint back into the low
pressure side of the pump but if you
look carefully at what's gone on here
you can see this actually hasn't worked
very well for them so they've driven a
drill through they've made a boring that
goes right through the top of the pump
and it comes out here but if you look
very closely you can see here that the
little piece of metal that should
I've come off has acted like a little
trapdoor and it's actually gone back
into the hole again now they couldn't
get access to this point very easily so
they haven't noticed that this has
happened and someone actually hasn't
cleaned this hole up properly you can
see that if I put my my probe in there
this hole is probably what oh I don't
know a third of the size it actually
should be simply because the drill has
gone all the way through and then when
they retracted the drill it's actually
pulled this little flap of metal back
inside the hole again so there we go
was that anything to do with the failure
of this missile well we'll never know
this was actually a launch failure this
component was found in central Germany
as part of I think a collection of
components that had been studied
forensic ly to see what the cause of the
failure had actually been whether that
was attributed with any failure I
couldn't say so there is just some of
the things that we can learn by looking
at missile relics
well that's about it for this video
we've completed our overview of the gas
turbine driven fuel and oxidizer pump
system of the v2 missile in part two
we're going to be looking at the over
speed switch and in particularly the
peculiar logic behind the over speed
switch in a bit more detail we'll also
be looking at how you can assess the
health of the turbo pump by analyzing
launch footage original launch footage
of v2 s in flight in the next episode as
well as well as looking at details like
the gyroscopic phenomena associated with
it where all any T's turbo pump
and the turbopump as a source of some
significant but unpredicted missile
thrust I know what you're thinking but
that's thrust over and above well above
the trivial boost provided by the outlet
of the steam exhaust system so I'll
leave you with that small mystery that
will resolve next time if you want to
see more stuff like this don't forget to
subscribe and do take a look at our
web-site v2 rocket history.com and until
next time bye for now
you
