L-series Mallet compounds came in 3 batches, all of which had the same simple (as listed) and compound TE (105,600 lb).
L1s (901-910) put 451,800 lb on the drivers and had a total engine weight of 506,500 lb.
L1-a (911-915) drivers supported 455,600 lb and total weight was 503,100 lb.
The L2 class numbered 916-925 and are shown in Locobase 8888.
Locobase is struck by the timing of this contract. Lima had entered the market for full-size mainline power in 1911; for the builder to be offering such a large engine--its first sale of a Mallet--indicates the determination to compete that underlay the decision. Its October 1916 ad for the L class in Railway Mechanical Engineer staked Lima's claim to ride on the leading edge:
"Today's Locomotives Must Be Different
"To carry peak load of modern railroad operation puts locomotive designers to the test.
"Rules and ratios of ten years ago [i.e., 1906] are now obsolete.
"Capacity increasing factors and economy devices have opened a new era and created new possibilities.
"Lima appreciates its responsibility to apply these factors to peak and normal loads.
"This locomotive is a case in point."
The design was in fact competitive with the other US 2-8-8-2 classes then in service, although its cylinder volume was among the smallest. Its mixed valve outfit had 14" (356 mm) piston valves serving the HP cylinders and double-ported slide valves feeding the LPs. Lima's ground-breaking superpower would appear 10 years later.
Drury's (1993) wry comment on the effect on top speed of 52" drivers and 40" LP cylinders suggests the limits of at least this early approach to superpower: "...the freight timetables must have listed days instead of hours and minutes."
Lima's third batch of big Mallets weighed a bit more than the L1s (for which, see Locobase 331), but were otherwise almost identical. Some of the class had Baker valve gear, some were fitted with Walschaert valve gear; all of this class had converted to Walschaert valve gear by 1 February 1938, according to a letter in Volume 41 of the DeGolyer specification bookRaildata collection at SMU.
At some later date, several of the L1s and L2s had their grates stretched from 120" (3.048 m) to 150" (3.81 m), which increased the grate area to 100 sq ft (9.3 sq m) and the firebox to 530 sq ft (49.2 sq m). Locobase suspects this was a result of eliminating a combustion chamber ahead of the firebox, especially as the arch tubes had been deleted.
|Specifications by Steve Llanso of Sweat House Media|
|Class||L1||L1/L2 with larger grate|
|Railroad||Western Maryland (WM)||Western Maryland (WM)|
|Number in Class||15||10|
|Locomotive Length and Weight|
|Driver Wheelbase (ft)||15||15|
|Engine Wheelbase (ft)||56.67||56.67|
|Ratio of driving wheelbase to overall engine wheebase||0.26||0.26|
|Overall Wheelbase (engine & tender) (ft)||91.14||91.14|
|Axle Loading (Maximum Weight per Axle) (lbs)||58,700||60,300|
|Weight on Drivers (lbs)||451,800||469,900|
|Engine Weight (lbs)||506,500||504,900|
|Tender Loaded Weight (lbs)||209,500||224,600|
|Total Engine and Tender Weight (lbs)||716,000||729,500|
|Tender Water Capacity (gals)||10,500||12,500|
|Tender Fuel Capacity (oil/coal) (gals/tons)||20||20|
|Minimum weight of rail (calculated) (lb/yd)||94||98|
|Geometry Relating to Tractive Effort|
|Driver Diameter (in)||52||52|
|Boiler Pressure (psi)||210||210|
|High Pressure Cylinders (dia x stroke) (in)||26" x 30"||26" x 30"|
|Low Pressure Cylinders (dia x stroke) (in)||40" x 30"||40" x 30"|
|Tractive Effort (lbs)||97,877||97,877|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||4.62||4.80|
|Firebox Area (sq ft)||404||530|
|Grate Area (sq ft)||80||100|
|Evaporative Heating Surface (sq ft)||5693||5768|
|Superheating Surface (sq ft)||1264||1380|
|Combined Heating Surface (sq ft)||6957||7148|
|Evaporative Heating Surface/Cylinder Volume||308.81||312.88|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||16,800||21,000|
|Same as above plus superheater percentage||19,824||24,990|
|Same as above but substitute firebox area for grate area||100,111||132,447|