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The Shay

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Trying to abide along the line and scope of "railroading", I ran across some interesting mention of the "shay" in the occupation or industry of "logging".


Although not of the Railroad theme, it initiates the forerunner of the "logging" industry, which actually was the reason for the Shay.  I believe it more interesting to have some background, for which circumstances lead to the creation of the Shay.


With the increased necessity for lumber in the expansion of territories by the explosion in population, the logging business  became an industry of problems, as well as profit.   Back breaking manual hauling, flumes with water, logs dragged by animals, initiated a better means for "hauling".  Hence the start in the creation of the "donkey engine", which had the power to drag logs.  But then there was the problem to haul the logs to a mill.   SO, this bagan the "cart hauling" on wooden rails, pulled by oxen, donkeys, or horses.  A solution, but the animals were not always able to climb some of the steeper inclines, and on down grades the loads could catch up to the animals, and possibly kill them.


That brought us to the creation of the Shay.  And that was the idea of Ephraim Shay of Haring, MI.  Engines were being used, but they were of the "piston" type, and at times, weighed too much for the wooden bridges, as well as poorly ballasted roadbeds.  The "powerful thrusting rods that ran from the pistons to the driving wheels, provided uneven traction, and the wheels would spin under heavy loads and on grades greater than 1 percent ( 1 foot of rise in 100 feet of track), and the engines would loose traction altogether.  To attempt to overcome the problem, some lumbermen commissioned lightweight engines with double-flanged wheels that ran on "pole roads" of wooden rails.  It was of some advancement, and this experiment gave Shay a "germ" of an idea.


Althourough the 1880s, Shay had experimented with a "radical engine", that was light and did not work as the conventional "piston-and-rod" arrangement.  So in 1880, Shay introduced a "mad inventor's nightmare", as it was called.   The pilot model of the loco-motive consisted of a "short railroad flatcar", with a "wooden water tank" at the one end, and a "wood bin" at the other end.  There was also the "unsightly assortment of machinery surrounding an "upright boiler" in between.  It was "lopsided with the boiler on one side, and the "geared transmission machinery" on the other side.

(I am sorry that I do not have the capacity to download the picture depicting such a creation.)


Unsightly?  But effectively incorporated Shay's central idea.  Power from the lone cylinder was transmitted by gears, not rods, to the four driving wheels in each of two trucks mounted on a single chassis - 8 wheels total.  The gears were the key to greater & steadier traction.  A gear shaft ran from the engine to each wheel, meshing with a ring of gears on the wheel.   Locked in its gears, the wheel could not spin.  This system entitled the Shay to taverse a 3 percent grade, (3 foot rise in 100 ft of track").  In June 1881, Shay was awarded a patient with a No. 242,992, and thereby started to improve his invention with more powerful versions in the 2 and 3 cylinders.

(I fail to remember the radius of which the Shay can negotiate.)


It is just a bit of history of which we take for granted.  However, there is a web site which will give those interested with more of the Shay upgrading of equipment.   Hope you enjoy.  :)

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Thanks envelope


Gear locomotives have long been of interest to me. 


Generally there were three types of gear locomotives built in America.

The Shay was the most popular.  The Climax and the Heistler (sp) Less popular.


As you stated the Shay mounted the cylinders on one side which off-set the boiler.  The drive line connected to the outside of each axle with beveled gears. 

Because the gears were on the out side and were easy to access, repairs were easy, which made the Shay the most popular. 


Because of shay's patents, newer loco designs for the gear loco had to be developed differently.


The Climax used the center line of the loco for the cylinder placement.  The center drive line was placed below the axles and centered under the boiler.

the bevel gears were hard to machine as they had to be machined off center.   The Climax also had a two speed gearbox for a faster light load speed.

Climax also made locos for a loco designer  a Mr Gilbert . Called the Gilbert loco, eventually it merged with the Climax company.  


The Hiestler had a cylinder on each side of the boiler.  They formed a V  where the drive shift drove the inside axle of each truck.  This eliminated the need for special beveled gears.  The outside two axles were driven by side rods from the inside axles.  These Hiestler locomotive were very dependable.  They just came too late.



An interesting note about the Shay:


After Mr Shay retired, he bought some timber land and designed 3 locos for his special Narrow gauge RR.   These locos were designed to be very low riding. 

Mr. Shay basicly used the boiler as a frame and mounted the trucks and cylinders to it.  There were other features that I have now forgotten about.


There were other gear locomotives built in other countries, some very different than the America Gear Locomotives.


The gear Locomotive could climb a 5 % grade pulling one or two cars and transverse a very sharp curve.  But there were a number of potential problems.

If the train was pulling more than a few cars around a sharp curve, the loco could pull over and dump the cars.   Trackage was not the best and loggers never stopped a train on a bridge.   The stopping train could push the bridge off it's piers.  Etc.  

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That is some very interestng comments Gwizz.   My post was basically in mostly "quotes" from an article I had read, which was to give a back ground as to the reason for which the Shay was invented.   However your post gives more of a back ground as to other comparitive inventions, which also adds to the history of locomotives.    Very interesting history, of which we should appreciate the endeavors of the inventorys

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