Willamettes were different....
Geared Steam Locomotive Works ©
The Willamette locomotive, while very similar to
Lima's Shay, did have notable differences. Some of these differences
disappeared in 1927 when Lima introduced their "Pacific Coast" model which
virtually "copied" what Willamette had begun 5 years earlier.
Unlike Lima, Willamette's engineers chose the best, most practical, and most logical components and technology available at the time for the manufacture of their locomotive. This same component technology was also available to Lima, but for one reason or another, they resisted change and didn't implement these until they woke up to the reality that Willamette had a better idea..... but even that took them 5 years. West coast loggers were buying the Willamette and cutting into Lima's profits.
Piston valves were utilized on Willamette locomotives built with superheaters.
Like Lima, Willamette manufactured both standard "saturated steam" and "superheated steam" locomotive models. The companys differed in the valve systems used on the superheated models. Operating problems in the field with one of the only two Willamette superheated locomotives built with slide valves was quickly recognized by the company as a design flaw. Both units were retrofitted with piston valves. With all subsequent superheated Willamettes the piston valve system became standard. They quickly learned a practical lesson that Lima denied was causing their customers a problem.
The slide valve system was used on all standard and superheated Shays built up until the introduction of the improved "Pacific Coast" model in 1927. One function of the slide valve system is to provide lubrication to the valves themselves. On the basic Shay, the steam used in the cylinders was termed "saturated" steam..... meaning it contained a certain amount of water droplets. These droplets provided some lubrication of the valves in addition to the primary lubrication source, the slide valve system. Superheaters were added to locomotives to make the steam hotter. The steam being hotter meant more power from the same amount of fuel expended. This "super heated" steam was also drier, with virtually no water droplets as is the case of "saturated" steam. This fact translated to less or no lubrication being supplied by the steam and more being required by the valve system.
The Lima engineers failed to give adequate credit to the lubrication being provided by the "saturated" steam when they decided to install superheaters on the Shay locomotives. They chose to continue the use of the slide valve system. This resulting lubrication loss often contributed to burnt valve faces and may have contributed to other mechanical problems. In spite of the continual urging by their field representatives, the company's engineers stodgily refused to admit their superheated locomotives and the slide valves were the cause of the problems. They insisted the valve system provided adequate lubrication. Owners continued to have the valve problems.
Walschaert Valve Gear
The superior Walschaert valve gear was used on all Willamettes manufactured. Lima, who predominately utilized the Stephenson valve gear, had manufactured some Class "B" locomotives with Walschaerts, but never fully embraced the gear.
Valve chests were turned outward.
The square valve chest covers on those units with slide valves and the rounded covers on those with piston valves were turned or positioned facing outward, away from the boiler. This change was made possible by the nature of the Walschaert gear design and the smart thinking Willamette engineers.
The Shay had those corresponding components turned sideways, paralleling the boiler. The Shay's front most two cylinder chests faced forward and the remaining third cylinder's faced toward the rear of the locomotive.
Outward facing chests proved beneficial to the Willamette company and their locomotive owners in at least two respects.
- The positioning made the chests covers readily accessible for any maintenance required. The Shay's proved more challenging with one chest cover blocking the access to the other and the shroud over the cylinders blocking access to the same on the outer most cylinders.
- The other benefit from the design was, unlike the Shay's, all three cylinders were identical for all practical purposes. This meant they were interchangeable, thus reducing design and manufacturing costs.
Cylinders moved forward of the cab.
All three cylinders were moved forward such that the third or rear most cylinder was in front of the crew cab. On the Shay, this cylinder was located physically behind the cab's front edge. Many Shay photos show this cylinder almost protruding into the cab. This change was not replicated in Pacific Coast Shay.
Truck springs were inclined toward the bolster.
Willamette improved on the basic Shay's design by their inclining the truck springs toward the center of the bolster. This reduced the sway of the locomotive over uneven rail or roadbed. Needless to say, this improved the ride and may have reduced the wear and tear on the remainder of the locomotive.
Ultra tight boilers.
Being in the boiler making business for many years prior to entry into locomotive manufacturing, Willamette had perfected the art of manufacturing boilers that were extremely tight. This translated into less steam leakage and thus higher fuel efficiency.
Better pulling power and considerably less fuel consumption.
There are stories of claims by Willamette owners and operating engineers about "Willies" having better pulling power and the fuel consumption being superior to comparably sized Shays.
There is at least one documented instance of a practical comparison being made by a well seasoned engineer on a road that just happened to own a Willamette and a Shay, as close to identical as was possible. Over the same trackage with empty cars, the Willamette could pull 29 to the Shay's 27 while utilizing 40% less fuel. 1
The only component on the Willamette that was truly unique was the casting that carried the crosshead guides and supported the crankshaft. A patent was received on August 14, 1923 for this part.
1The Willamette Locomotive
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Page changed: Monday August 01, 2005 09:21:20 PM