South African Class 15CA 4-8-2

South African Class 15CA 4-8-2
No. 2802 at Esselen Park, 21 September 2009
Type and origin ♠ With 57 inch (1,448 mm) coupled wheels ♥ With 60 inch (1,524 mm) coupled wheels ♣ 23x28 Cylinders - ♦ 24x28 Cylinders - ʘ Reboilered ʘ No. 2039-2059, 2072-2073 ʘ No. 2074-2077, 2801-2839 - ʘ No. 2840-2857 Power type Steam Designer South African Railways (Col F.R. Collins DSO) Builder American Locomotive Company Baldwin Locomotive Works Società Italiana Ernesto Breda North British Locomotive Company Serial number ALCO 66986-67008, Baldwin 60828-60831, Breda 2236-2245, NBL 23774-23802, 24008-24025 Model Class 15CA Build date 1926-1929 Total produced 84
Specifications Configuration: ​  • Whyte 4-8-2 (Mountain)  • UIC 2'D1'h2 Driver 2nd coupled axle Gauge 3 ft 6 in (1,067 mm) Cape gauge Leading dia. 30 in (762 mm) Coupled dia. ♠ 57 in (1,448 mm) ♥ 60 in (1,524 mm) Trailing dia. ʘʘ 33 in (838 mm) ʘ 34 in (864 mm) Tender wheels 34 in (864 mm) Wheelbase 65 ft 3 1⁄4 in (19,895 mm)  • Engine 35 ft 8 in (10,871 mm)  • Leading 6 ft 10 in (2,083 mm)  • Coupled 15 ft 9 in (4,801 mm)  • Tender 20 ft 5 in (6,223 mm)  • Tender bogie 6 ft 2 in (1,880 mm) Length: ​  • Over couplers 73 ft 3 1⁄4 in (22,333 mm) Height ♠ 12 ft 10 in (3,912 mm) ♥ 12 ft 11 1⁄2 in (3,950 mm) Frame type Bar Axle load ♠ʘ 17 LT 9 cwt (17,730 kg) ♠ʘ 17 LT 12 cwt (17,880 kg) ♠ʘ 17 LT 10 cwt (17,780 kg) ♥ʘ 17 LT 15 cwt (18,030 kg) ♥ʘ 17 LT 18 cwt (18,190 kg) ♥ʘ 17 LT 16 cwt (18,090 kg)  • Leading ♠ʘ 19 LT 12 cwt (19,910 kg) ♠ʘ 19 LT 7 cwt (19,660 kg) ♠ʘ 21 LT 7 cwt (21,690 kg) ♥ʘ 19 LT 12 cwt (19,910 kg) ♥ʘ 19 LT 7 cwt (19,660 kg) ♥ʘ 21 LT 7 cwt (21,690 kg)  • 1st coupled ♠ʘ 17 LT 6 cwt (17,580 kg) ♠ʘ 17 LT 10 cwt (17,780 kg) ♠ʘ 17 LT 6 cwt (17,580 kg) ♥ʘ 17 LT 9 cwt (17,730 kg) ♥ʘ 17 LT 13 cwt (17,930 kg) ♥ʘ 17 LT 9 cwt (17,730 kg)  • 2nd coupled ♠ʘ 17 LT 9 cwt (17,730 kg) ♠ʘ 17 LT 12 cwt (17,880 kg) ♠ʘ 17 LT 10 cwt (17,780 kg) ♥ʘ 17 LT 15 cwt (18,030 kg) ♥ʘ 17 LT 18 cwt (18,190 kg) ♥ʘ 17 LT 16 cwt (18,090 kg)  • 3rd coupled ♠ʘ 17 LT 7 cwt (17,630 kg) ♠ʘ 17 LT 11 cwt (17,830 kg) ♠ʘ 17 LT 6 cwt (17,580 kg) ♥ʘ 17 LT 13 cwt (17,930 kg) ♥ʘ 17 LT 17 cwt (18,140 kg) ♥ʘ 17 LT 12 cwt (17,880 kg)  • 4th coupled ♠ʘ 17 LT 4 cwt (17,480 kg) ♠ʘ 17 LT 7 cwt (17,630 kg) ♠ʘ 17 LT 3 cwt (17,430 kg) ♥ʘ 17 LT 10 cwt (17,780 kg) ♥ʘ 17 LT 13 cwt (17,930 kg) ♥ʘ 17 LT 9 cwt (17,730 kg)  • Trailing ♠ʘ 14 LT 9 cwt (14,680 kg) ♠ʘ 14 LT 16 cwt (15,040 kg) ♠ʘ 14 LT 13 cwt (14,890 kg) ♥ʘ 14 LT 9 cwt (14,680 kg) ♥ʘ 14 LT 16 cwt (15,040 kg) ♥ʘ 14 LT 13 cwt (14,890 kg)  • Tender bogie Bogie 1: 33 LT 18 cwt (34,440 kg) Bogie 2: 35 LT 10 cwt (36,070 kg)  • Tender axle 17 LT 15 cwt (18,030 kg) Adhesive weight ♠ʘ 69 LT 6 cwt (70,410 kg) ♠ʘ 70 LT (71,120 kg) ♠ʘ 69 LT 5 cwt (70,360 kg) ♥ʘ 70 LT 7 cwt (71,480 kg) ♥ʘ 71 LT 1 cwt (72,190 kg) ♥ʘ 70 LT 6 cwt (71,430 kg) Loco weight ♠ʘ 103 LT 7 cwt (105,000 kg) ♠ʘ 104 LT 3 cwt (105,800 kg) ♠ʘ 105 LT 5 cwt (106,900 kg) ♥ʘ 104 LT 8 cwt (106,100 kg) ♥ʘ 105 LT 4 cwt (106,900 kg) ♥ʘ 106 LT 6 cwt (108,000 kg) Tender weight 69 LT 8 cwt (70,510 kg) Total weight ♠ʘ 172 LT 15 cwt (175,500 kg) ♠ʘ 173 LT 11 cwt (176,300 kg) ♠ʘ 174 LT 13 cwt (177,500 kg) ♥ʘ 173 LT 16 cwt (176,600 kg) ♥ʘ 174 LT 12 cwt (177,400 kg) ♥ʘ 175 LT 14 cwt (178,500 kg) Tender type KT (2-axle bogies) Fuel type Coal Fuel capacity 14 LT (14.2 t) Water cap 6,000 imp gal (27,300 l) Firebox type Round-top  • Firegrate area 48 sq ft (4.5 m2) Boiler: ​  • Pitch ♠ 8 ft 6 in (2,591 mm) ♥ 8 ft 7 1⁄2 in (2,629 mm)  • Diameter 6 ft 2 1⁄4 in (1,886 mm)  • Tube plates 20 ft 1⁄2 in (6,109 mm)  • Small tubes ♠♥ 143: 2 1⁄4 in (57 mm) ʘ 117: 2 1⁄4 in (57 mm)  • Large tubes ♠♥ 30: 5 1⁄2 in (140 mm) ʘ 34: 5 1⁄2 in (140 mm) Boiler pressure ♠ 200 psi (1,379 kPa) ♥ 210 psi (1,448 kPa) Safety valve Pop Heating surface ♠♥ 2,777 sq ft (258.0 m2) ʘ 2,584 sq ft (240.1 m2)  • Tubes ♠♥ 2,554 sq ft (237.3 m2) ʘ 2,361 sq ft (219.3 m2)  • Arch tubes 23 sq ft (2.1 m2)  • Firebox 200 sq ft (19 m2) Superheater: ​  • Type Schmidt  • Heating area ♠♥ 716 sq ft (66.5 m2) ʘ 670 sq ft (62 m2) Cylinders Two Cylinder size ♣ 23 in (584 mm) bore ♦ 24 in (610 mm) bore ♣♦ 28 in (711 mm) stroke Valve gear Walschaerts Valve type Piston Couplers Johnston link-and-pin AAR knuckle (1930s)
Performance figures Tractive effort ♠♣ 38,980 lbf (173.4 kN) @ 75% ♠♦ 42,440 lbf (188.8 kN) @ 75% ♥♣ 38,880 lbf (172.9 kN) @ 75% ♥♦ 42,340 lbf (188.3 kN) @ 75%
Career Operators South African Railways Class Class 15CA Number in class 84 Numbers 2039–2059, 2072-2077, 2801-2857 Delivered 1926-1930 First run 1926 Withdrawn 1980s
♠ The leading coupled axle had flangeless wheels

External video

South African Steam: 15CA 2850 around Pretoria. (18.09 minutes)

The South African Railways Class 15CA 4-8-2 of 1926 was a steam locomotive.

In 1926, the South African Railways placed 23 Class 15CA steam locomotives with a 4-8-2 Mountain type wheel arrangement in service. Another 61 engines were ordered and delivered from three manufacturers in 1929 and 1930.

After the twelve Class 15C Big Bill 4-8-2 Mountain type locomotives which were delivered by Baldwin Locomotive Works in 1925 had been in service a short while, it was discovered that the frames under the front of the firebox had a tendency to crack, necessitating heavy repairs.

To overcome this, a new modified design was prepared by Col F.R. Collins DSO, the Chief Mechanical Engineer (CME) of the South African Railways (SAR), for an almost identical locomotive but with the frames shortened to the front of the firebox and widened under the firebox by means of a bridle casting.

The first batch of 23 of these redesigned locomotives were built for the SAR by the American Locomotive Company (ALCO). They were delivered in 1926, numbered in the range from 2039 to 2059, 2072 and 2073, and designated Class 15CA. The "A" supposedly indicated the manufacturer ALCO rather than, as was usual SAR practice, a different version of an existing locomotive type.

The earlier Baldwin-built Class 15C was then reclassified to Class 15CB for no good reason, since the "B" merely indicated the manufacturer Baldwin and not, as was usual practice, a branchline locomotive.

Another 61 Class 15CA locomotives were acquired in four batches from three other manufacturers in 1929 and 1930. Like the 23 ALCO-built locomotives, all except the last batch were built with 23 inches (584 millimetres) bore cylinders.

Apart from the redesigned frame under the firebox, these locomotives were very similar to the Class 15C in proportions and appearance. They also had Coale pop type safety valves, a Schmidt type superheater and a combustion chamber in the firebox, which was equipped with flexible side stays and water siphon arch tubes. Their coupled wheel axleboxes, crank pins and connecting rod big ends were grease lubricated. These engines used the same Type KT tenders with a coal capacity of 14 long tons (14.2 tonnes) and a water capacity of 6,000 imperial gallons (27,300 litres).