The Salt Revolution Program will contain a
section that explores the development of steam
power during the 18th & 19th centuries.
Two early pioneering engineers of steam were
Thomas Newcomen and James Watt.
It was steam technology which literally acted
as the driving force behind the industrial
revolution -- and with that in mind, during
the course of this year, I'm going to be visiting
a couple of Living Museums...
Beamish near Newcastle and the Black Country
near Wolverhampton.
At Beamish I want to obtain some video and
photographic reference material of the early
steam engines and the working locomotives
which they have there.
And at the Black Country museum, I have my
eyes set on the working exhibit of the Newcomen
1712 Atmospheric Steam Engine....
Now I've already created some working CGI
models of Newcomen's engine and also of the
Separate Condensing engine built by James
Watt in 1776 which I'll be using in the final
production.
So why don't we take a brief look.
Before the dawn of steam, man harnessed power
from his own labours, livestock and from the
elements -- but the energy output would always
be limited and restrictive.
This was the Age of Reason....
Of Enlightenment....
A time when Britain began its unfettered journey
towards leading the world in science, technology,
trade, commerce and even Empire building.
Thomas Newcomen was an English inventor, born
in Dartmouth, Devon in 1664, he became an
Iron Monger by trade and in 1712, Newcomen
built his first Atmospheric Steam Engine which
was used to pump water from the bottom of
mines.
The machine was a beam engine that condensed
steam to create a vacuum that in turn allowed
the atmospheric air pressure to push down
on a piston which was contained within the
condensing cylinder.
Which is about as clear as mud for most people....
So let's look at this machine in cross-section
..
Here we have the furnace using coal as fuel
to heat up the water in the boiler.
This generates steam which then enters the
Condensing Cylinder when the valve is opened.
The Inlet Valve is then closed, and a jet
of cold water is sprayed into the Condensing
cylinder.
This causes the steam to rapidly cool and
creates a vacuum.
As the external pressure is now greater than
that within the cylinder it pushes the piston
down...
And the cycle is then repeated.
In Newcomen's design, it isn't the steam which
forces the piston back up to the top of the
condensing cylinder.
The Beam is actually weighted more on the
side of the pump connecting rod, and it's
this weighting which pulls the piston back
up as the cylinder's pressure is gradually
equalised with the external atmospheric pressure.
In earlier designs, the valves or plugs as
they were then called were manually operated
by a 'Plugman'...
But this cyclical action had to be accurate
and it was therefore more preferable to have
this operation automated.
Now it may look a little Heath Robinson, but
with the introduction of a plug-tree connected
to the beam action, Newcomen was able to accomplish
this.
James Watt was a Scottish inventor....
Born in Greenock in 1736.
It was whilst Watt was working as a Mechanical
Engineer and Instrument Maker at the University
of Glasgow, that he was asked to repair a
working model of Newcomen's steam engine.
He came to realise that Newcomen's engine
design was less than efficient.
With every stroke, energy was being wasted
as the condensing cylinder was being repeatedly
heated and then cooled.
Watt's solution to this problem was to build
a steam engine that incorporated a separate
condenser.
Watt sporadically developed his engine between
1763 and 1775, and as we can already see...
there's a little bit more to it than that
of Newcomen's engine.
So let's take a moment to examine its main
features
It's the combined furnace and boiler that
produces the steam which is then transferred
through the steam pipe to a series of Inlet
and Exhaust valves.
Which in turn are connected to the piston
cylinder.
The piston is connected to the Beam which
operates the Rotary Arm -- one end of which
has a static cog known as the 'Planet' and
that appears to rotate about another cog known
as the 'Sun'.
And it's the Sun & Planet gears which operate
the Fly-wheel.
We also have a Cold Water Tank and a Hot Water
Tank.
In this cross section we can see that Watt's
engine is 'Double Acting'.
That's to say, that steam enters the cylinder
at each end alternately, forcing the piston
up or down.
This process is controlled by the engine's
valve gear -- shown here in this cutaway.
Active steam alternately enters the valve
system at these points here, whilst the exhaust
steam exits the system through these pipes.
All of which is controlled by a plug tree
or rod which is again linked to the beam.
Here we can see the exhaust steam pipe leading
into the Cold Water Tank, in which are housed
two cylinders.
This is the Separate Condenser and the other
is a pump which extracts the condensate into
the separate hot water tank -- which then
recirculates back to the boiler.
There are still a number of innovative features
about these steam engines which I've still
not mentioned, but I think we'll come back
to those after my visits to the living museums
and within the main Salt Revolution production.
