Hello everyone!
Welcome to Train Talk!
In episode 10 of Train Talk, I discussed steam
locomotive wheel arrangements with the promise
that I would cover other types of steam locomotives
that cannot be classified by wheel arrangement.
In this episode, we will take a look at a
large group of locomotives that are not driven
by side rods connected to large drive wheels
but rather rely on a complex system of gears
to transfer power from the cylinders to the
wheels.
So today, we are going to talk all about geared
locomotives!
We’ll compare the major types of geared
locomotives and then look briefly at the history
of each.
But before we get any further, what is a geared
locomotive?
As I just alluded to, geared locomotives are
a group of steam locomotives that use a system
of various gears, transmissions, and drive
shafts to transfer power from the steam cylinders
to the wheels.
The basic idea behind a geared locomotive
is to use a set of gears to achieve a gear
reduction.
A gear reduction means that the gears rotate
quicker than the wheels on the locomotive.
This allows the locomotive’s wheels to turn
more easily but costs them in terms of having
a lower top speed.
In addition, the geared drive system allows
power to be more evenly applied to the wheels.
These things combined result in a geared locomotive
having more traction and thus a better ability
to pull heavy trains up steeper grades.
There are three basic designs of geared locomotives:
Shay, Heisler, and Climax.
I’ll talk a little more about all three
in just a bit.
Geared locomotives have wheels that are grouped
into sets called trucks for purpose of attaching
the wheels to the locomotive.
Each truck holds two axles for a total of
four wheels.
Trucks allow the locomotive to ride more easily
over rough track and travel through tighter
curves than a conventional steam locomotive.
To fully understand geared locomotives, you
need to know about where they were designed
to run.
Geared locomotives were built specifically
to operate on mountainous logging railroads
in North America.
These were railroads that were typically built
quickly and on the cheap.
New tracks were constantly being laid to various
log camps.
Sometimes, grades on these railroads were
over 10%.
The locomotives would pull trains of fresh
cut timber out of the mountains, usually to
large saw mills where the logs would be cut
up for shipment.
Some of these locomotives were used in other
industries such as mining.
Let’s talk briefly about how geared locomotives
are classified.
Geared locomotives are typically grouped based
on their basic type of Shay, Heisler, or Climax,
as well as the number of trucks they have.
Most geared locomotives had two to three trucks,
but some had as many as four.
Manufacturers had their own class designations
for various locomotives they produced as well.
For instance, Shay locomotives were broken
down into one of four classes based on the
number of trucks they had as well as the number
of cylinders.
Class A locomotives had 2 trucks and 2 cylinders,
class B had 2 trucks and 3 cylinders, class
C had 3 trucks and 3 cylinders, and class
D had 4 trucks and three cylinders, the only
geared locomotives to be offered in a 4 truck
design.
A similar convention was used for classifying
Climax locomotives.
Now, let’s briefly compare the three major
types of geared locomotives and then talk
about the history of each.
Shays are the oldest design of the three major
logging locomotives.
They are unique from the Heisler and the climax
in that they have vertically mounted cylinders
on the right side of the locomotive boiler.
To counteract the weight of the cylinders,
the boiler is offset to the left side of the
frame, giving the Shay a very unique look.
From the cylinders, power is transferred along
the entire length of the engine by means of
a drive shaft that runs along the outside
of the axles on the same side of the locomotive
as the cylinders.
In contrast, both the Heisler and the Climax
have a drive shaft that runs directly underneath
the boiler.
In the case of the Climax, cylinders are located
along both sides of the boiler on a slight
incline and power is transferred from the
cylinders to the drive shaft through a transmission
box.
Heisler locomotives have their cylinders mounted
in a “V” shape, pointed toward the center
of the frame beneath the boiler and power
is directly transmitted to the drive shaft
from the cylinders.
On Shay and the Climax locomotives, the drive
shaft transfers power to all axles on each
truck.
On the Heisler, only one axle is directly
powered by the drive shaft.
Power is shared with the other wheel set on
each truck through the use of a connecting
rod.
The gears on the trucks of the Heisler are
housed in a box filled with lubricating oil,
increasing their service life.
Shays were the slowest of the geared locomotives
while Heislers were the fastest.
In terms of pulling power, the Climax was
the most powerful of the geared locomotives
compared to other locomotives of a comparable
weight.
However, the most powerful geared locomotives
built overall were the shays.
In terms of cost, Climax locomotives were
the least expensive and had the shortest service
life of the three types of geared locomotives.
Shay locomotives were built from 1880 to 1945
and were designed by Ephraim Shay.
They were the first largely successful geared
locomotive to be built.
Shays were manufactured by the Lima Locomotive
works of Lima, Ohio.
For a brief period in the 1920s, the shay
patent expired and the Willamette Locomotive
Works of Portland, Oregon built copycat locomotives
using a near identical design.
Over the course of 65 years, more than 2,700
Shays were built for various railroads all
over the world.
Today, there are just shy of 120 shays that
are preserved, many in operating condition.
The Climax was first manufactured in 1888
by the Climax Locomotive Works of Cory, Pennsylvania
and designed by Rush Battles.
A few years later, the basic design was improved
by Charles Scott.
It is estimated that anywhere from 1000 to
1100 climax locomotives were produced but
unfortunately, no records survive to confirm
this.
Due to the Great Depression and the overall
decline in the lumber industry, the Climax
Locomotive works was closed in 1928.
Some railroads eventually opted to convert
their Climax locomotives from steam to diesel
or gas power.
Today, less than 25 Climax locomotives around
the world survive and of these only about
5 are ever operational.
This may be in part due to the fact that Climaxes
were relatively cheaply built and were among
the first of the logging locomotives to be
scrapped.
At last, we come to the Heisler.
Designed by Charles Heisler, these were the
last geared locomotives to be
designed and built.
Originally, they were built in 1891 by the
Dunkirk Engineering Company of
Dunkirk, New York.
Later, the locomotives were built by the Heisler
Locomotive Works in Erie, Pennsylvania.
Like the Climax, some Heisler locomotives
were later converted to diesel or gas power,
retaining their gearing and drive shafts,
but losing their steam boiler in exchange
for an internal combustion engine.
Only about 625 Heislers were built by the
time the Heisler Locomotive Works
closed in 1941.
Just under 40 Heislers survive today.
Of these, about 10 are currently operational
on various tourist railroads in North America
and New Zealand.
While the era of the geared steam locomotive
has drawn to a close, they were essential
to the lumber industry for over half a century
and today, they continue to work hard on various
tourist railroads throughout the world.
Well, that does it for this episode of train
talk, thanks for joining me!
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That’s it for now.
Until next time, I’m Mike Armstrong.
I’ll see you down the line!
Thanks for watching!
