The reference for locomotives and railcars
Southern Railway (USA) class Ls-2
United States | 1926 | 9 produced
No. 4050 in August 1948 in Knoxville, Tennessee
No. 4050 in August 1948 in Knoxville, Tennessee
collection Harold K. Vollrath

Based on the Ls-1 class Mallets, the Southern had the No. 4050 built in 1926 with simple expansion and a slightly smaller boiler. Since this proved its worth, four Ls-1 were also converted to simple expansion and in 1928 a further eight locomotives were built again with a larger boiler. This was more efficient mainly because of the thermic syphons. They also received larger tenders and now formed the Ls-2 class. They were the Southern's most powerful locomotives and were also used on the almost five percent steep Saluda Grade.

Axle config2-8-8-2 (Mikado Mallet) 
Gauge4 ft 8 1/2 in (Standard gauge)
Dimensions and Weights
Wheelbase56 ft 9 in
Fixed wheelbase15 ft 5 in
Service weight448,000 lbs469,000 lbs
Adhesive weight390,000 lbs409,000 lbs
Total weight709,600 lbs660,400 lbs
Water capacity10,000 us gal14,000 us gal
Fuel capacity32,000 lbs (coal)
Power sourcesteam
Estimated power3,200 hp (2,386 kW)3,500 hp (2,610 kW)
Optimal speed21 mph22 mph
Starting effort99,396 lbf
Power Plant
Driver diameter57 in
Boiler pressure210 psi
Expansion typesimple
Cylindersfour, 23 x 30 in
Grate area83 sq ft82.8 sq ft
Firebox area335 sq ft436 sq ft
Tube heating area4,490 sq ft4,540 sq ft
Evaporative heating area4,825 sq ft4,976 sq ft
Superheater area1,350 sq ft1,420 sq ft
Total heating area6,175 sq ft6,396 sq ft
Calculated Values
steam locomotive
last changed: 07/2023

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