Southern 2-8-8-2 "Chesapeake" Locomotives of the USA


Class Details by Steve Llanso of Sweat House Media

Class Ls-1 (Locobase 327)

Some data from Southern Railway diagrams hosted on southern.railfan.net/images/archive/southern/steam_loco_diagrams (viewed September 2002). See also Baldwin's Record of Recent Construction #92 (1918), which celebrates the production of the company's 50,000th locomotive and DeGolyer, Vol 56, pp. 394.

Works numbers were

1918

June 49081; July 49237, 49350; August 49488, 49644; September 50000; October 50132, 50346, November 50674; December 50786, 50991

1919

January 51081

These 23 engines were built as Mallet compounds with 39-inch LP cylinders; all four cylinders were served by 14" (356 mm) piston valves. Articulation of the vanadium-steel frame allowed the engines to take 16-deg radius curves, despite the provision of flanges on all drivers. (The front pair in each group used flange lubricators.) Erecting a brick wall (similar to if not identical with a Gaines wall) across the firebox's throat separated the grate from the combustion chamber, which contributed 109-sq ft (10.1 sq m) to the firebox heating surface area.. . Even with the five-foot long combustion chamber, however, the tube length still stretched out to 24 feet (7.3 metres).

According to the April 1919 Railway and Locomotive Engineering, the Appalachia Division for which they were headed presented "... an undulating profile with frequent grades of one to two percent." The article especially highlighted 8 miles near the Bristol end of the Division: "The most difficult section of the line is between Philips and Mountain. From mile-post 57 to mile-post 65 southbound, the average grade is 1.7 per cent with a maximum, for short distances, of 3.4 per cent. This portion of the line is an almost

constant succession of curves, many of them of over 10 degrees."

Eleven locomotives that were produced in 1924 had fewer tubes and more flues; see Locobase 11083.

The others were not converted because of lack of funds. Six were scrapped in 1937-1939, the remainder in 1949-1950.


Class Ls-1 (Locobase 11083)

Data from SRY 5 - 1929 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. See also DeGolyer, Vol 68, pp. 288+ and Vol 74, pp 172+. The first ten locomotives are described in Locobase 327. Works numbers were July 57864, 57895, 57899-57901 in July 1924 and 59282; July 59296-59298; 59373-59374 in June 1926.

Five years after the Southern bought the first batch of Ls-1 Mallets, it went back to Baldwin for more. Baldwin took the opportunity to reallocate boiler space by reducing the number of tubes and increase the number of flues. The result was a high percentage of superheater area as part of the overall combined heating surface. More direct heating surface area was supplied by the 112 sq ft (10.4 sq m) of the combustion chamber.

Three -- 4018, 4021, 4025 -- were later rebuilt with four 23" diameter HP cylinders after the success of the new-construction Ls-2 became evident in the late 1920s. The others were not converted because of lack of funds. Six were scrapped in 1937-1939, the remainder in 1949-1950.


Class Ls-2 (Locobase 328)

Some data from Southern Railway diagrams hosted on southern.railfan.net/images/archive/southern/steam_loco_diagrams (viewed September 2002). See also DeGolyer, Vol 80, pp. 746+. Works numbers were 60495 in May 1928, 60516-22 in June.

Firebox heating surface included 109 sq ft (10.1 sq m) of combustion chamber and 97 sq ft (9 sq m) of thermic syphons, boiler fitted with exhaust steam injectors. The 12" (305 mm) piston valves had a 7" (177 mm) travel with 1 5/8"(41.28 mm) lap and 3/16" (4.76 mm) lead.

The detailed roster in Prince (1965) shows that 4050 (see separate entry) was the prototype for simple-expansion Southern Mallets. Obviously successful, the single engine was joined by 8 others that were built to a slightly enlarged design and delivered in 1928. One major difference was the addition of thermic syphons, which significantly enhanced the firebox's contribution to overall heating efficiency.

These engines were the largest and most powerful locomotives the Southern ever purchased and operated on the 4.7% Saluda grade in North Carolina until retirement in 1951. They were simple-expansion variants of the earlier Ls-1 Mallet compounds; four of the latter were later converted to simple-expansion operation.


Class Ls-2 (Locobase 5136)

Some data from Southern Railway diagrams hosted on southern.railfan.net/images/archive/southern/steam_loco_diagrams (viewed September 2002). See also DeGolyer, Vol 75, pp. 159+.

Firebox heating surface included 109 sq ft (10.1 sq m) of combustion chamber, boiler fitted with exhaust steam injectors. The 12" (305 mm) piston valves had a 7" (229 mm) travel with 1 5/8" (41.275 mm) lap and 3/16" (4.77 mm) lead. As delivered, the boiler had 216 tubes; six were later deleted or blocked off.

The detailed roster in Prince (1965) shows that 4050 was the trial horse for simple-expansion Mallets. Its design was based on the compound locomotives delivered at the same time (see Locobase 11083). The boiler was a bit smaller, however, and did not provide the pattern for the eight Ls-2 that followed in 1928. (See Locobase 328.)

Specifications by Steve Llanso of Sweat House Media
ClassLs-1Ls-1Ls-2Ls-2
Locobase ID327 11,083 328 5136
RailroadSouthern (SRS)Southern (SRS)Southern (SRS)Southern (SRS)
CountryUSAUSAUSAUSA
Whyte2-8-8-22-8-8-22-8-8-22-8-8-2
Number in Class101181
Road Numbers4004-40154016-40264051-40584050
GaugeStdStdStdStd
Number Built101181
BuilderBaldwinBaldwinBaldwinBaldwin
Year1918192419281926
Valve GearSouthernBakerBakerBaker
Locomotive Length and Weight
Driver Wheelbase (ft)15.5015.5015.5015.50
Engine Wheelbase (ft)56.2556.7556.7556.75
Ratio of driving wheelbase to overall engine wheebase 0.28 0.27 0.27 0.27
Overall Wheelbase (engine & tender) (ft)86.9887.8787.8595.64
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)374,000374,000409,000390,000
Engine Weight (lbs)427,000427,000469,000448,000
Tender Loaded Weight (lbs)176,000191,400191,400261,600
Total Engine and Tender Weight (lbs)603,000618,400660,400709,600
Tender Water Capacity (gals)900010,00010,00014,000
Tender Fuel Capacity (oil/coal) (gals/tons)12161616
Minimum weight of rail (calculated) (lb/yd)78788581
Geometry Relating to Tractive Effort
Driver Diameter (in)56565757
Boiler Pressure (psi)210210210210
High Pressure Cylinders (dia x stroke) (in)25" x 30"25" x 30"23" x 30" (4)23" x 30" (4)
Low Pressure Cylinders (dia x stroke) (in)39" x 30"39" x 30"
Tractive Effort (lbs)84,71984,71999,39699,396
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.41 4.41 4.11 3.92
Heating Ability
Firebox Area (sq ft)335335436335
Grate Area (sq ft)82.8082.8082.8083
Evaporative Heating Surface (sq ft)4990492549764825
Superheating Surface (sq ft)1260135014201350
Combined Heating Surface (sq ft)6250627563966175
Evaporative Heating Surface/Cylinder Volume292.77288.95172.46167.23
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation17,38817,38817,38817,430
Same as above plus superheater percentage20,86621,21321,21321,265
Same as above but substitute firebox area for grate area84,42085,827111,70385,827
Power L18508886013,78512,896
Power MT401.22417.82594.44583.20

Reference


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