Not a very successful engine and badly proportioned, but certainly big for her time. Master Mechanic AJ Stevens sought to get still more adhesive weight on the track by adding another axle.
Stevens installed valve gear of his own design -- the so-called monkey motion -- that included two valves for each cylinder. The Locomotive Engineers Journal article described it thusly:
"Each cylinder of the engine is fitted with two rotary-balanced valves, placed as near each end of the cylinder as possible, to save clearance of space that would otherwise be filled and exhausted uselessly by live steam. The valves are driven by the A. J. Stevens valve gear, employing but one eccentric on a side and reversing from the rocker."
The author then reported on the merits of this layout: "The Stevens valve motion has given great satisfaction where it has been used. For freight service especially it is greatly superior to the old link motion in the economical manner in which it handles steam at the shorter points of cut-off."
To give the long-wheelbase engine any hope of negotiating CP curves, the journal reported, "The engine truck is of the "swing-beam" order, allowing the center pin of the saddle to play an inch and a half each side of the center. The back pair of drivers have also a transverse play of one-half inch each way from the center line of the engine, which
reduces the rigid wheel base to the first and fourth axis. This allows the engine to take, a fifteen-degree curve, which is shorter than the maximum curve on the Central Pacific. The first, fourth and fifth pair of drivers have 'flanged tires, the second and third being blind."
Although it was steamed up and paraded in front of passengers, the engine simply was too big to be of much use at the time. Boiler tubes were much too short and total evaporative heating surface laughably meager. Possessed of one of the longest cylinder strokes ever put into a conventional steam locomotive, the engine's cylinder volume overwhelmed the boiler.
She was scrapped, it is believed, in 1894.
|Specifications by Steve Llanso of Sweat House Media|
|Number in Class||1|
|Locomotive Length and Weight|
|Ratio of driving wheelbase to overall engine wheebase||0.68|
|Overall Wheelbase (engine & tender)||65.42'|
|Axle Loading (Maximum Weight per Axle)||26750 lbs|
|Weight on Drivers||121600 lbs|
|Engine Weight||154000 lbs|
|Tender Light Weight||85650 lbs|
|Total Engine and Tender Weight||239650 lbs|
|Tender Water Capacity||3000 gals|
|Tender Fuel Capacity (oil/coal)||5 tons|
|Minimum weight of rail (calculated)||41 lb/yard|
|Geometry Relating to Tractive Effort|
|Boiler Pressure||135 psi|
|Cylinders (dia x stroke)||21" x 36"|
|Tractive Effort||31961 lbs|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||3.80|
|Firebox Area||210 sq. ft|
|Grate Area||29.75 sq. ft|
|Evaporative Heating Surface||1364 sq. ft|
|Combined Heating Surface||1364 sq. ft|
|Evaporative Heating Surface/Cylinder Volume||94.51|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||4016|
|Same as above plus superheater percentage||4016|
|Same as above but substitute firebox area for grate area||28350|