Since most rails laid for use on logging railways were often uneven and rough to ride on, it was important that the locomotives logging companies used were capable of negotiating them. This resulted in many unconventional articulated locomotive designs with the most popular being shayes and climaxes. The issue was the Shayes were somewhat shoddy and the climaxes weren't as great as they were built up to be. What loggers needed was something strong but also smooth running. And thanks to a misadressed letter, they got it. In 1891, a Mr. Addington of Little Washington, North Carolina, was in need of a locomotive to work on his logging railway capable of handling grades of 1 in 10 and bends with a 95 ft radius. He wrote to Edward Nicole's, president of the Brooks Locomotive Works in New York, to put in an order to be completed within 60 days, but accidentally addressed the letter to the Dunkerk Engineering Company. The confusion likely coming from the fact that Nicole's owned both companies. Despite mostly manufacturing hydraulic equipment and specialist machine parts, the Dunkirk Engineering Company also built a few engines of their own. Given Addington only wanted a small 10-tonon locomotive when the inquiry ended up in the hands of the company's mechanical superintendent, Charles L. Heisler, Heisler requested they accept the order, but on the condition that he be given an extra 30 days to come up with a satisfactory design. Addington agreed and so Heisler set to work. Rather than design a new engine from scratch, it seems he instead set about refining and improving the class B Gilbert type locomotives that the Dunkerk Engineering Company already produced. These engines were quite similar to the geared locomotives built by Climax, mostly because the gearing they used was designed by George D. Gilbert, one of the many people who had a hand in developing the Climax design. However, rather than having the cylinders mounted near the front, powering a shaft, which then connected to the main drive shaft, the cylinders were mounted in the cab in a sort of Vshape pointing downwards, connecting to the drive shaft directly. Heisler altered the Dunkirk Gilbert engines primarily by changing the gearing on the wheels. The old design had the drive shaft power both axles on each bogey directly via a series of gears. Meanwhile, his new design had only one axle receive power from the drive shaft. The other axle being powered by a set of external side rods connected to the driven one. One end of the shaft was also designed to slide a little to help negotiate corners better with the gears on the bogeies being submerged in an oil bath. The gears were positioned just so that they meshed perfectly, required little maintenance, and ran smoothly and nolessly. Heisler also repositioned the cylinders from inside of the cab to threequarters of the way along the boiler to help better distribute the locomotive's weight onto its wheels. And each component from the boiler to the cylinders was designed so they could be removed easily and individually, making maintenance and replacing parts that much easier. The drive shaft being set between the engine's frames also meant it was better protected from the weather and debris. Two separate sanding gears were fitted which could be operated either automatically or manually. One towards the front and one towards the rear which dropped sand before the outermost wheels ensuring all wheels were sanded regardless of which direction the engine traveled. To keep the rest of the engine cheap and simple, it was fitted with a cylindrical boiler and an internal firebox. With the design complete, the engine was built, tested, and sent to Addington, who responded favorably to this unique design. With other companies showing an interest in the engine, Heisler patented the design, and the Dunkirk Engineering Company began to build more of these engines until 1893 when Nicole's died. With no place left to build his engines, Heisler was approached by George Burnham, then president of the Baldwin Locomotive Works, who displayed a keen interest in the design. After having his team of technicians report favorably on Heisler's design, Burnham expressed a great interest in manufacturing the locomotive in some of the smaller private shops he owned around Erie. Heistler agreed and the Sterns manufacturing company began building more of Heistler's engines, even developing a three bogey variant until Burnham's death in 1904. Once again, without a company to build his engines, Heistler production was put on hold until the design was picked up once more by a Mr. FF Curtsy and Roy Swab. And in 1907, the trio founded the Heistler Locomotive Works. During this time, Heistler took the opportunity to refine and improve his machines, making adjustments to the gearing, boosting the engine's overall power, swapping the wooden cabs for steel, and implementing a suggestion of swabs, which greatly improved the flexibility of the engine's truck frames. The brakes, too, were intricate, but effective. One small cylinder and one large cylinder was used to provide braking, these being controlled by a three-way valve. Putting the brakes in the first position, steam would be sent to the small cylinder, which applied a moderate amount of braking power. In the second position, the larger cylinder would receive steam, providing much stronger braking, while any steam in the smaller one would be exhausted. Finally, in the third position, both cylinders would fill and the brakes would come hard on and setting the lever to a neutral position would release the steam and then by extension the brakes. This system ensured that all wheels would be braced evenly, and the settings meant the driver had finer control over the engine speed when traversing a constant gradient. Aside from the brakes, Heistler wanted to keep the rest of his engine as short and as simple as possible, guaranteeing it would not only be able to tackle the sharpest bends, but also having less moving parts meant less points of failure, and that his engines could be sold cheaper than other geared engines on the market. Their smooth running nature combined with their ease of maintenance and reliability made Heislers very popular among many logging railroads and supposedly were much faster compared to Sha and Climaxes. Likely why some ended up being used to pull passenger trains on mountainous roads. Their customizability was also greatly appealing as not only could the design be modified to burn wood, coal, or oil easily, but changing a locomotive's gauge was as simple as swapping out their bogeies, and should the engine need to carry more water, a saddle tank could be easily fitted to accommodate. Despite the positive press, the Heislers had one major drawback compared to other geared locomotives on the market. This being their fireboxes. Because the drive shaft ran under the boiler, it greatly limited the maximum size of the firebox. Heistler compensated for this by primarily using ram's bottom boilers as the firebox was contained in the boiler shell, but stated the boiler type could be swapped out if desired. This problem, however, didn't seem to dissuade customers, as the Heistler's strength, speed, and ride quality more than made up for its shortcomings. Not only were they used coast to coast in both the US and Canada, but they were even used abroad in booming logging countries like New Zealand. What added to the longevity of Heisler's design was that when internal combustion engines became more affordable, the layout made it very easy to replace the boiler and cylinders with an engine block, allowing companies to upgrade and modify their redundant rolling stock as opposed to just flatout scrapping them. Even with their flexibility and great performance, however, the demand for logging locomotives eventually died down. With the well finally drying up, the Heisler locomotive company ceased production in 1941, having produced a total of 625 engines. Funnily enough, the final Heistler to ever be built was constructed 2 years after the company closed in New Zealand in 1943 by AMG Price. with this engine surviving into preservation along with 34 other US-built Heislers. It's tragic really. Despite its seemingly superior performance compared to the Shayes and Climaxes, the Heisler being the last of the trio to be developed, combined with its on andoff production left it lagging behind in terms of numbers built. All the same, the fact that Heistler managed to cement his design as a staple of logging railroads long after so many other geared locomotives had flooded the market just goes to show that even if you're late to the party, you can still leave a big impression. Subscribe for more. [Music]