The Parker Class D8 (GCR Class 6DB) 4-4-0 Locomotives
The Manchester Sheffield & Lincolnshire Railway's (MS&LR, later GCR) Class 6DB locomotives were a development of the MS&LR Class 6D 2-4-0 (LNER E2) design. The 6Ds were noted for poor riding which was blamed on the single carrying axle. The new Class 6DB locomotives replaced the single carrying axle with a leading two axle bogie. A total of three 6DBs were built at Gorton in 1888.
The D8s inherited a definite Sacre-look from the E2. It also inherited the hybrid nature of the E2 with double frames for the driving axles, but only a single frame for the carrying axles. There is some evidence to suggest that this look was due to Sacre continuing to remain at Gorton in an advisory capacity for a few years. In contrast, the D8s also had some Parker design elements such as the design of the chimney and cab windows.
The D8s succeeded as stop-gaps, and solved the E2 problem of poor riding. However, stop-gaps they were, and Parker was a firm believer in single framed designs. No more D8s were built.
Early in the 1900s, Robinson replaced the chimneys with his own design, and fitted new smokeboxes. The original round-topped firebox boilers were placed by Belpaire firebox boilers between 1910 and 1912. The new boilers were pitched slightly higher. At about the same time, the cab roofs were extended to cover the entire footplate.
The D8s were initially put to work on the MS&LR's fastest trains to King's Cross. This work was shared with the prototype D7, No. 561, but they were quickly replaced when the D7s went into volume production. The D8s were moved to Liverpool in 1893 where they operated the Liverpool to Hull services. Over time they were replaced by larger and more powerful locomotives. They moved to Lincolnshire and were allocated to either Lincoln or New Holland. During 1920, No. 510a was regularly seen on horse box specials from Newmarket to Haydock Park.
By 1922, all three were moved to Southport to work services to Liverpool and Manchester. All three continued at Southport until LNER ownership (1923), when two of the D8s were quickly withdrawn. The last D8 was withdrawn in 1926.
Technical Details
| Cylinders (x2): | (inside) | 18x26in. |
| Motion: | Stephenson | slide-valves |
| Boiler: | Max. Diameter: | 4ft 4in |
| Pressure: | 160psi | |
| Diagram No.: | 21 | |
| Heating Surface: | Total: | 1063 sq.ft. |
| Firebox: | 99 sq.ft. | |
| Tubes: | 964 sq.ft. (190x 1.75in) | |
| Grate Area: | 18.3 sq.ft. | |
| Wheels: | Leading: | 3ft 6.5in |
| Coupled: | 6ft 9.5in | |
| Tender: | 4ft 3.5in | |
| Tractive Effort: | 14,057lb | (@ 85% boiler pressure) |
| Wheelbase: | Total: | 44ft 5.5in |
| Engine: | 22ft 0in | |
| Tender: | 12ft 6in | |
| Weight (full): | Total: | 79 tons 7cwt |
| Engine: | 48 tons 4cwt | |
| Tender: | 31 tons 3cwt | |
| Max. Axle Load: | 15 tons 18cwt |
Preservation
The last D8 was withdrawn in 1926, and none survived into preservation.
Models
I am not aware of any models of the D8s in any scale.