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American Geared Locomotives

by Doug Teggin

Part 1 - Historical Background ~ Part 2 - Bachmann & Rivarossi models ~ Part 3 - DCC installation


Like so many technological advancements, invention is often derived from need. These interesting geared locomotives were conceived and designed by men working on site and looking for better ways to transport logs as quickly as possible on temporary rails over rough terrain. Ephraim Shay was one of these men and the story starts with him.


Ephraim Shay (1839 1916) designed the first Shay locomotive and patented the type.

Ephram Shay (right) studied to become a school teacher and taught in New Jersey and Ohio during the late 1850's. From 1861 to 1864 Shay Ephraim served in the Western Theatre of the Civil war, under General William Tecumseh Sherman. Upon his discharge in 1864, Shay married and moved to Michigan he established a general store and sawmill and was running a logging business to supply the mill.

In the early days of logging, the loggers would transport the logs down the rivers to the sawmills. When no river was available or when the trees near to the river had all been harvested, they used ox and horse drawn sleds in the Winter to haul the logs out of the forests. When demand increased, crude railcars pulled over wooden rails set to a 26-inch gauge were used to haul out more and even bigger logs.

In 1876 Shay realised that a steam powered locomotive would greatly help his business and allow him to haul more logs and become more competitive.

He started off with a very crude and simple twin cylinder locomotive (perhaps similar to loco pictured left), but soon. Shay realised that the dynamic force of conventional locomotive pistons on either side of the loco proved to be too much and damaged the track curves.


He thus set about designing a solution that applied an equal amount to torque to each side of the locomotive. In 1877 he hired William Crippen of Cadillac, Michigan to build a boiler and cylinders that were connected to the axel of the little loco by a belt-drive (right).

Shays design was not patented and Crippen went on to produce the locomotive for the local industry. The Lima Machine Works in Ohio was requested to build the locomotive by James Alley as Crippen was over booked. Again as there was no patent, the Lima company produced the locomotive and a few variants for the logging business.

Shay modified his designs according to his needs, but in 1880 he need an upgrade. As Crippen was too busy, Shay contacted the Lima Machine works company and they worked with him on his redesign.

A Lima Works engineer, John Carnes, came up with the idea of powering each axel of both trucks using bevelled gears situated outside the trucks on one side of the locomotive. The gears were connected by horizontal shafts that were subsequently connected to a crankshaft driven by the steam powered cylinders, vertically oriented above.

SN-6, pictured above, was a duplicate built for Milton J. Bond who had seen and was impressed by Shay's locomotive. The SN-6 was the first of 2770 Shay locomotives built by Lima (left).

Shay finally realised that he had something interesting here and he filed for patent on March 30th 1881 (drawing below). This was his 'Golden egg' as it was the Lima works that would be building the locomotive and he would be paid royalties for every one made. Is patent covered the concept of using gears to drive the axels. A patent that covered many forthcoming locomotive designs.

He spent his later life promoting his locomotives and in 1901, at the age of 62, Ephraim Shay sold all of his stock in Lima, thereby completely ending links with the company. Shay kept on inventing and lived out the rest of his live in Harbor Spring, Michigan.


Here we look at the 3 most popular geared locomotives of the late 1800's and early 1900's.


The Shay Locomotive

The classic Shay loco as we have come to know it is consisted of 2 or 3 vertical steam cylinders positioned on the right side of the engine  just forward of the crew cab. The piston rods were attached to a "crank shaft" similar to that used in today's automobile engines. Attached to either end of the "crank shaft" were drive shafts that extended to a gear box on the outside of each wheel. The left side had no gearing or cylinders. The boiler is located off centre and to the left of centre of the entire frame. This was necessary for the location of the cylinders

Initially the locos were manufactured with either two or three cylinders. The three cylinder models were used on the larger and more powerful engines.

Models with  two,  three, or four truck sets were manufactured. More trucks meant more distributed weight and thus more powerful locos could be built. The two truck models carried their fuel and water bunker at the back of a single frame for the entire locomotive. On the three truck models, an additional tender with its own single driving truck was added to the basic two truck locomotive frame. With the four truck model, the tender was longer and was supported by two driving trucks.

The first Lima factory built Shay was a two truck Class "A" sold to J. Alley Co. for $1,700 in 1880, with two others being sold that year. The last Shay built was the three truck Class "C" locomotive (sn-3354) sold to the Western Maryland Railroad in 1945.


The Climax Locomotive

San Joaquin & Eastern RR #109 - c/n 1627 - Auberry, California
Built 10/1922 - Std gauge - 70 tons - Class C - 3 Trucks

Photo courtesy of the Marc Reusser collection. Source: http://www.gearedsteam.com/

Designed by Charles Darwin Scott - Spartansburg, Pennsylvania. Patented by George D. Gilbert.   Gilbert, who was a relative by marriage of Charles D. Scott, was an design engineer for the Climax Manufacturing Company. The locomotive was first manufactured by Climax Manufacturing Company and subsequently by Climax Locomotive Works both of which were located in Corry, Pennsylvania. It was built between 1888 and 1928.

The basic Climax consisted of 2 steam cylinders whose piston rods came out of the cylinders and attached to a transmission located under the centre part of the engine frame. Connected to front and rear of the transmission were drive shafts which ran along the centre line of the engine below the boiler, cab, and fuel bunker.  The drive shafts were connected to gear boxes in each truck. These gear boxes supplied power directly to both wheel sets in each truck.

Models with either two or three truck sets were manufactured. The three truck models were used on those engines that required more power and more fuel. The third truck was powered and carried a tender (similar to those on "rod" engines) to carry additional fuel and water.


The Heisler Locomotive

 McKean Chemical Co. #58 (Dahonga & Highland RR) - s/n 1021 @ Dahonga, Pennsylvania circa 1916
Built 1898 - Std. gauge - 37 tons
Photo: Marie McMahon collection. Source: http://www.gearedsteam.com/

The first locomotive of the Charles Heisler design was built in 1891 by the Dunkirk Engineering Company. The design was patented by Charles Heisler in 1892.

The Heisler consisted of 2 steam cylinders positioned in a "V" under the boiler about 3/4th the way back from the front. The piston rods came out of the cylinders and attached to a "crank shaft" located under the centre of the boiler. Attached to either end of the crank shaft were drive shafts. The drive shafts were located below the centre line of the engine. On the two truck models, the drive shaft attached to a gear box located on each truck's wheel set that was located furthest from the centre of the engine frame. Power was then supplied to the other wheel set on the truck with an outboard tie rod connecting two wheel sets together. This tie rod is readily visible in the picture above.

In terms of speed, it was the fastest of the 3 most prevalent geared steam locomotives shown here. It also had the fewest numbers manufactured of these type of locomotives.

Models with either two or three truck sets were manufactured. The three truck models were used on those engines that required more power and more fuel. The third truck was powered and carried a tender (similar to those on "rod" engines) to carry additional fuel and water.


Part 1 - Historical Background ~ Part 2 - Bachmann & Rivarossi models ~ Part 3 - DCC installation


 - December 2006


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