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The Shay Geared Locomotive

The development of the engine known as “the hill climber”

LOCOMOTIVES - 44

THE “M. J. BOND”, one of the earliest geared locomotives built by Mr. Ephraim Shay for logging in Michigan.

IN 1873 an enterprising American lumber magnate, Mr. Ephraim Shay, owned and operated an extensive saw-mill at Haring, in the centre of the Michigan lumber country. In common with his contemporaries Mr. Shay was puzzled how to keep his mill adequately supplied with logs. Hungry saws are like horses in a stable - financial loss results when they are idle or are not working steadily at their full capacity.

The greatest difficulty was the transportation of the logs from the forests to the mill. Lumbering being essentially a winter calling, it is obvious that advantage must be taken of every minute of time. But the impassibility of the roads owing to snow and ice constituted a serious obstacle. Mr. Shay followed the conventional methods of logging by means of wheels and horses and encountered the general run of aggravating delays and difficulties, while the lumber was proving somewhat costly to bring down.

Under these circumstances he was forced to reflect whether a simpler, more expeditious, and cheaper system of haulage could not be introduced. The railway and the steam locomotive offered an obvious alternative, but he recognised that the conditions were adverse to its utilisation. Circumstances demanded a permanent way of the cheapest possible construction, comprising virtually the laying of the pair of rails upon the ground surface, ignoring banks and curves. There was another factor which had to be borne in mind. The rails would have to be moved time after time to tap the points where the lumber-jacks were at work.

Thereupon the ingenious saw-mill proprietor resolved to work out his own solution of the issue. He thought of a geared locomotive, where the power developed by the engines might be transmitted through shafting and gear wheels to the roads. The more he reflected the more convinced he became of its practicability.

“THE HILL CLIMBER” ascending a rise of 1 in 20 on the Mount Arisan logging railway in Formosa.

He set to work to build a locomotive according to the ideas he had evolved. The materials and facilities at his command in the backwoods were severely limited, but this fact did not deter him. He contrived some rails from maple wood, and laid them on rough sleepers fashioned from waste parts of the logs. He used the standard gauge because he bought some flat deck cars for his experiments, and they were built to this gauge. His locomotive was extremely crude. It comprised a vertical boiler which he placed upon a double truck flat deck car. At one end of the vehicle he placed his water-tank, while at the opposite extremity he rigged up a bunker for carrying wood fuel. The engine, with its cylinders set vertically, was placed upon one side of the boiler, while the piston rods, extending downwards, were connected to a flexible shaft extending longitudinally alongside the truck wheels, and gearing with the latter through bevel and pinion wheels.

Such was the first Shay geared locomotive. Its creator became the butt of ridicule among the camps for his pains. The locomotive certainly was a quaint-looking and primitive machine, giving every impression of having been made from odds and ends rescued from the scrap-heap. But it had cost its builder several hundred pounds, considerable thought, and many hours of tedious labour and disappointment. That it should be received with mirth galled him to the quick, and he accordingly resolved that, come what might, he would make it work successfully.

So it did, and to such advantage that those who had hailed its appearance with laughter began to regard the experiment with serious interest. Directly the locomotive got out upon the road all sorts of troubles asserted themselves, but as they developed its designer attacked and remedied them. The result was that at last he got it to work pretty smoothly, and evinced the greatest pride in the fruits of his labour, because he was able to haul his logs quicker, more continuously, and cheaper by this means than were his rivals with their horses.

As this was the object for which he had striven he became completely satisfied with what he had accomplished. He proved that his locomotive could run and keep the track where an ordinary engine would fail completely. So he built additional improved engines, and in a short space of Ephraim Shay’s gear-driven locomotive became the talk of the American and Canadian lumber camps. Those who formerly had laughed at his efforts now wanted to avail themselves of similar facilities. In a short while Ephraim Shay became inundated with orders for similar machines.

Luckily he was a very shrewd man business. The gibes of his competitors did not dissuade him from protecting the salient points of his ideas by means of Patent Acts. Then inquiries began to roll in from other sources. Contractors who appreciated the advantages of mechanical haulage, but who were faced with similar conditions concerning primitiveness of track, banks and curves, having heard of the achievements of the Shay geared engine, wanted them for their works.

The designer not being able to meet these demands by his own efforts, transferred his patents to two concerns, the Carnes Agerter Company and the Lima Locomotive and Machine Company, since amalgamated and now known as the Lima Locomotive Corporation, of Lima, Ohio. The invention, now placed in the hands of experienced and expert engineers, was developed very rapidly along approved locomotive lines.

Colloquially it has become known as “The Hill Climber”, and the nickname is appropriate. Its range of workability is wide both as regards gradients and curvature. It will climb banks ranging from 1 in 33 to 1 in 7, and will negotiate curves of 50 to 100 feet radius, conditions which it is safe to assert could not be fulfilled by many other types of locomotives with ease.

SHAY GEARED LOCOMOTIVE ROUNDING HORSE-SHOE CURVE of 164 feet radius and rising 1 in 20 upon the Mount Arisan Railway, Formosa.

Although originally designed for service in lumber camps and upon contractors’ works, it has passed to other more useful spheres. Being built in all sizes from 10 to 160 tons weight, it is equally applicable to trunk line working where stiff banks and sharp curves abound. True, its speed capacity is limited, but that is a secondary consideration so long as it moves the loads imposed to and from the points required.

Its salient peculiarity is the enormous power developed at slow speed, and its extreme flexibility in negotiating the sharpest curves. On the Mount Arisan Railway in Formosa the banks run up to a maximum of 1 in 20, while the sharpest curves are only of 164 feet radius. Another interesting application is that upon the Mount Tamalpais Railway in California, where the heavy grades and sharp bends of this sight-seeing line are overcome by means of the geared locomotive.

The modern expression of the Shay geared locomotive differs very radically from its original prototype although the fund-amental characteristics are retained. The vertical boiler was discarded in favour of one of the conventional locomotive type, thereby bringing it into line with general practice. The locomotive is built on centre bearing trucks, including the tender, which carries both fuel and water. The frame is of the plain girder instead of the special locomotive type, because it has to provide a foundation of support and strength. The inverted engines, either two- or three-cylinder according to the size of the machine, are placed on one side of the centre line for balancing purposes, strongly supported on the frame, and immed-iately under the observation of the driver. Although two cylinders are sometimes used, three forms the usual practice, so as to bring the setting of the cranks to 120 degrees. The vertical engines drive on a crank-shaft, which in turn is connected with the main line shaft, which is built up in sections and rendered flexible by means of universal joints and extension couplings. This shaft drives pinions which mesh with bevel wheels attached to the outer face of the truck wheels. Each wheel, both of the engine and tender, is geared, so that every wheel, irrespective of number, is converted into a driver. The gear ratio is about 19 to 42. Although three cylinders are employed, each is driven by high-pressure steam, the pressure of the latter being 200 pounds per square inch. When viewed from the driving side the locomotive certainly presents a quaint and lop-sided appearance, but in its present form the locomotive represents the outcome of some 30 years’ experience, so that the unworkmanlike design is more apparent than real. The driver has absolute control when ascending and descending the steepest grades. The machine is fitted with all the latest and usual locomotive fittings, and can, if desired, be adapted to the consumption of oil fuel.

THE LARGEST AND MOST POWERFUL SHAY GEARED LOCOMOTIVE IN SERVICE. In running order it weighs 160 tons, develops a tractive effort of 74,400 pounds, and hauls a load of 200 tons up a bank of 1 in 14·28.

When the Wolgan Valley Railway was carried some 30½ miles inland from Newnes Junction, on the New South Wales Government system, in order to tap the shale oil fields, the fact that some 1,760 feet difference in altitude had to be overcome in this distance offered a somewhat perplexing problem to the surveyors. The location gave banks of 1 in 22, and curves of 330 feet radius, which could not be eased owing to the configuration of the country. The operation of such a railway also occasioned considerable anxiety, as ordinary adhesion working was quite out of the question. The issue was closely investigated and after examining the Mount Tamalpais Railway and its Shay locomotives, which have to run over similar grades, and where the curves range between 70 and 80 feet radius, and also the Canadian Pacific Railway, where the Shay geared locomotives have to overcome curves of 230 feet radius, this system was adopted. In one particular case where Shay locomotives are at work it was found that whereas the maximum load capable of being hauled by the geared engine was 5,781 tons on the level, it could pull 1,556 tons up a bank of 1 in 100, 852 tons up 1 in 50, 484 tons up 1 in 25, and 235 tons up 1 in 16·66. The latter grade is quite impossible to ordinary adhesion working. The only alternative to the Shay geared locomotive was the rack system or the Fell centre rail such as worked the mail traffic over Mont Cenis during the boring of the tunnel. Seeing that the conditions fulfilled in this instance were closely allied to those which had to be faced in Australia, twp 70- and one 90-ton Shay geared locomotives were acquired for the Wolgan Valley line, this decision being influenced by its flexibility in conjunction and the enormous adhesion.

In the country of its origin the Shay geared locomotive has been adopted extensively and many striking machines of this type have been built. The latest and most remarkable is that designed for the Kansas City Southern Railway in connection with the operation of the new terminals of this system which have been completed on the north side of Kansas City, Missouri. This is the largest and most powerful geared locomotive in operation in the world to-day. It is of standard gauge with three cylinders, each of 18 inches diameter by a stroke of 20 inches, and 48-inch drivers. The boiler diameter varies from 67⅜ to 79¼ inches, and steam is used at a pressure of 200 pounds. There arc 347 two-inch boiler tubes 16 feet 4¾ inches in length between tube sheets with an aggregate heating surface of 2,910 square feet. The fire-box measures 120 by 68½ inches, and has a heating surface of 185 square feet, so that the total heating surface is 3,095 square feet. The grate area is 57·1 square feet. The rigid wheel base is of 6 feet, and the total wheel base 52 feet 11 inches, while the over-all width is 11 feet 4 inches by 15 feet in height. The tender carries 5,000 gallons of water and 2,200 gallons of oil. In running order the locomotive weighs 160 tons.

The duty which this engine has to fulfil is of a very exacting character, and demonstrates very conclusively the enormous power developed by this geared system. Owing to every wheel being a driver and available for adhesion the locomotive is able to develop a tractive effort of 74,400 pounds. It was designed to haul a train load of 200 tons up a grade of 1 in 14·28 on which there are some sharp curves, and upon reaching the top of the bank to negotiate curves of 95·5 feet radius in order to move the cars to and from the various warehouses.

Despite the fact that this huge geared locomotive was built 30 years after the inventor, Mr. Ephraim Shay, contrived his first crude engine to facilitate his logging operations, strict adherence has been made to the original Shay idea - the vertical cylinders are placed on the side, and are geared with each wheel by a flexible shaft, so that each wheel becomes a driver, and all the weight of the locomotive and tender is disposed over the driving wheels. Since Mr. Shay evolved his unique solution for overcoming an exasperating difficulty in the backwoods of Michigan several different types of geared loco-motives have appeared, but it is interesting to observe that the Shay has more than held its own, over 2,000 locomotives of this type being in daily use throughout the world. Although the Mallet articulated, Fairlie, Garrett and other duplex forms have appeared since, the Shay geared locomotive still is preferred for service under conditions closely analogous to those for which it was first designed.

THE SHAY GEARED LOCOMOTIVE AT WORK UPON THE MOUNT TAMALPAIS RAILWAY IN CALIFORNIA.

You can read more on

“The Mount Tamalpais Railway”,

“Rack Rail Locomotives” and

“Unconventional Locomotives”

on this website.