Southern Railway Ss class

The Southern Railway Ss was a class of 2-10-2 "Santa Fe" type steam locomotives built in 1917 and 1918 for the Southern Railway (SOU). They were assigned to haul and bank heavy freight trains over the Saluda Grade and Old Fort Loops in the Blue Ridge Mountains of North Carolina.

Southern Railway Ss class
Southern Railway No. 5016, constructed new in 1917
Type and origin References: Power type Steam Builder Baldwin Locomotive Works ALCO's Richmond Works Build date 1917-1918 Total produced 80
Specifications Configuration: ​  • Whyte 2-10-2 Gauge 4 ft 8+1⁄2 in (1,435 mm) standard gauge Leading dia. 33 in (838 mm) Driver dia. 57 in (1,448 mm) Trailing dia. 42 in (1,067 mm) Wheelbase 20 ft 7 in (6.274 m) Length 84 ft 3.5 in (25.69 m) Loco weight 378,000 lb (171,000 kg) Tender weight 176,000 lb (80,000 kg) Tender type 2 axle bogie Fuel type Coal Fuel capacity 16 t (16 long tons; 18 short tons), formerly 12 t (12 long tons; 13 short tons) Water cap. 9,000 US gal (34,000 L; 7,500 imp gal) Firebox: ​  • Grate area 88 sq ft (8.2 m2) Boiler pressure 200 psi (1.38 MPa), formerly 190 psi (1.31 MPa) Feedwater heater Worthington (added in the 1940s) Cylinders Two, outside Cylinder size 28 in × 32 in (711 mm × 813 mm) Valve gear Southern Valve type 14-inch (356 mm) piston valves
Performance figures Tractive effort 74,000 lbf (329.2 kN), formerly 71,000 lbf (315.8 kN)
Career Operators Southern Railway Cincinnati, New Orleans and Texas Pacific Railway (1918 only) Class Ss Numbers SOU No. 5000-5054 CNO&TP No. 6350-6374→SOU No. 5055-5079 Withdrawn 1951-1952 Disposition All scrapped

History

Ever since the Santa Fe Railway develop the 2-10-2 wheel arrangement (hence the Railroad's namesake) in 1903, the Southern Railway (SOU) began placing a new order of their own 2-10-2s; the Ss class were built with 57 in (1,448 mm) driving wheels, duplex stokers, 71,000 lb (32.2 tonnes) of tractive effort, and an operating boiler pressure of 190 psi (1.31 MPa). The first batches of fifty-five locomotives (Nos. 5000-5054) were built in 1917 by the Baldwin Locomotive Works in Philadelphia, Pennsylvania. In 1918, the second batches of twenty-five 2-10-2s (Nos. 6350-6374) were built by the American Locomotive Company (ALCO) of Richmond, Virginia for SOU's Cincinnati, New Orleans and Texas Pacific (CNO&TP) division, but were later renumbered to 5055-5079 when being moved to Southern's main division.

These locomotives were designed to haul heavy freight trains, but were proven too slow to work on the Southern Railway's Washington, D.C. to Atlanta main line and too big for the CNO&TP tunnels' tight clearances. However, the Ss locomotives were very efficient on handling the mountain grades in North and South Carolina, Georgia, and Tennessee. Eventually, they were moved to Southern's Asheville and Knoxville divisions to bank and haul heavy freight trains, especially on Saluda Grade between Asheville, North Carolina and Spartanburg, South Carolina and the Old Fort Loops between Asheville and Salisbury, North Carolina in the Blue Ridge Mountains.

To work on the Asheville division, the Ss locomotives were modified with two water gauges made longer for the engineer and fireman to safely measure the water level in the boiler while going up and down the railway grades. Additionally, the Ss locomotives were equipped with a second air pump due to the excessive use of air brakes. While they were used to bank the head end passenger trains, the Ss locomotives were given cab signals and steam brake connection; and the water pipes were added to cool down the driving wheels' tires while descending the mountains.

By the late 1940s, the Southern Railway began to dieselize with the Ss steam locomotives' duties taken over by the EMD F7 diesel locomotives. All of the Ss steam locomotives were retired and scrapped by the early 1950s, with none surviving into preservation.

See also

• USRA Light Santa Fe

Bibliography

• Prince, Richard E. (1970). Steam Locomotives and Boats: Southern Railway System (2nd ed.). Wheelwright Lithographing Company. ISBN 0-9600088-4-5.
• Tillotson Jr., Curt (2000). Classic Steam Trains of the South (1st ed.). TLC Publishing. ISBN 1-883089-55-7.

Further reading

• Schafer, Bill, ed. (2019). "First Quarter, 2019". TIES. Vol. 33, no. 1. White River Productions.
• Tillotson Jr., Curt (2005). Southern Railway Steam Trains Volume 2 - Freight (1st ed.). TLC Publishing. ISBN 0-9766201-5-4.

External links

• Southern 2-10-2 "Santa Fe" Locomotives in the USA