In 1908 Mr. Ivatt introduced a new class of six-coupled goods tender engines, with wheels of exceptionally large diameter, 5-ft. 8-in. These engines are, in respect to their boilers, cylinders, motion and wheels, practically interchangeable with the 0-6-2 suburban tank locomotives of the “190” class, and were intended to work express goods and mixed traffic on the main line. They are illustrated in Fig. 115. Following are the leading dimensions:
- Cylinders, 18-in. by 26-in.;
- diameter of coupled wheels, 5-ft. 8-in.; wheelbase: leading to driving 7-ft. 3-in., driving to trailing 9-ft., total 16-ft. 3-in.;
- boiler: length of barrel 10-ft. 5-in. between tube plates, diameter (outside) 4-ft. 8-in., height of centre above rails 8-ft. 0 3/8-in.; heating surface: firebox 120 sq. ft., tubes 1,130 sq. ft., total 1,250 sq. ft.; grate area, 19 sq. ft.; working pressure, 170 lb. per sq. in.
- The tender was of a new pattern with unequally spaced wheel-base, 7-ft. between leading and middle, and 6-ft. between middle and trailing wheels respectively, this arrangement bringing more weight to bear on the leading wheels; the capacity of the tender was 3,500 gallons of water and 61 tons of coal.
- In working order the engine weighed 46 tons 14 cwt., distributed as follows: on leading wheels, 16 tons; on driving wheels, 17 tons 4 cwt.; and on trailing wheels, 13 tons 10 cwt.; the tender weighed 43 tons 2 cwt.
- The total wheel-base of engine and tender was 37-ft. 8-in., and the extreme length over buffers 50-ft. 51-in.
So far fifteen engines of this class have been built at Doncaster, in the following order:
| Date. | Doncaster No. | Engine No. |
|---|---|---|
| 1908 | 1198 | 1 |
| .. | 1202-1215 | 2-15 |
