The Robinson Class B5 (GCR Class 8) 4-6-0s
The Great Central Railway's (GCR) Class 8 (LNER Class B5) was the first of Robinson's 4-6-0 designs, and would become a basis for his Atlantics as well as other 4-6-0 designs. Robinson design both the B5 and a special kind of bogie fish van for a new fast fish service from Grimsby. Although they were also later used for passenger traffic, they were known as "fish engines" throughout their lives.
The design was relatively straight-forward with 6ft driving wheels and two outside 19in x 26in cylinders. The boiler was of a saturated 4ft 9in type. Many of the parts including the cylinders were interchangeable with other GCR locomotives including the Q4 0-8-0. The 4-6-0 arrangement forced the firebox to be shallow, but otherwise the boiler was similar to types already in use by the GCR.
Two batches were built. The first batch of six was built in 1902 by Neilson & Co, whilst the second batch of eight was built by Beyer Peacock & Co in 1904.
When they were designed, the B5s were not intended to run long distances without stopping for water and they were fitted with the GCR's standard 3,250 gallon tender was fitted. Longer non-stop running became more common after 1903 when the GCR started to introduce water troughs. The small tenders quickly became a handicap, and between 1905 and 1906 4,000 gallon tenders were substituted. Various tender swaps would continue to occur until 1925 when No. 181 was the last B5 to lose its 3,250 gallon tender for the last time.
The boilers remained saturated during GCR ownership, but superheating was under consideration at the time of Grouping (1923). No. 184 was fitted with a 5ft diameter O4 superheated boiler, pitched 9.5in higher so that the deeper firebox cleared the rear driving axle. Between 1926 and 1936, all fourteen B5s (including No. 184) were rebuilt with superheated boilers of the original 4ft 9in diameter.
The B5 class was subdivided from 1925. B5/1 referred to unrebuilt locomotives whilst B5/2 referred to No. 184 with the 5ft diameter boiler. Locomotives were reclassified as B5/2 as they were rebuilt with the 4ft 9in diameter superheated boiler. The subdivisions were abolished in 1936 when all of the B5s were fitted with superheated boilers.
Between 1926 and 1937, seven of the B5s had O4-pattern cylinders and piston valves fitted. The new cylinders were 21in diameter, and the new piston valves were 10in diameter.
The initial B5 batch was allocated to Grimsby and Neasden to haul the fish trains for which they were designed. The second batch was allocated to Gorton, and were often used to haul express passenger trains between Marylebone and Leicester. This allocation might seem unusual, but the B5s were the largest GCR locomotive type at the time.
By Grouping (1923), the B5s were divided between Gorton, Immingham, and Mexborough. The Mexborough B5s regularly hauled fish trains onto the Great Western Railway (GWR) via Banbury. The Mexborough B5s were moved to Doncaster in 1924. During the next ten years, both Lincoln and Woodford would receive B5s for use on fish trains, stopping passenger trains, and as station pilot at Lincoln Central.
No. 6070 was the first to be withdrawn in 1939. A year later, and all of the remaining B5s were at Mexborough although three moved to Sheffield in 1943. During World War 2, the B5s mainly worked trains between Sheffield and Hull, easily handling the heavy wartime traffic over this difficult route. They also assisted with banking between Wath and Dunford Bridge.
The B5s started to be displaced by the Thompson B1s from 1946. The B5s worked on the Cheshire lines out of Trafford Park for the next two years, as well as traffic out of Lincoln. Withdrawals started in 1947. The remaining engines spent their last years banking at Dunford Bridge, with the last B5 withdrawn from service in 1950.
Technical Details
Tender weight is for the 4000 gallon tender. The B5s were also fitted with 3,250 gallon tenders that had the same coal capacity and wheelbase.
| Cylinders: | (2x outside) | 19x26in. |
| Motion: | Gear: | Stephenson |
| Valves: | Slide | |
| Boiler: | Max. Diameter: | 4ft 9in |
| Pressure: | 180psi | |
| Diagram No.: | 17 | |
| Heating Surface: | Total: | 1795 sq.ft. |
| Firebox: | 130 sq.ft. | |
| Tubes: | 1665 sq.ft. (207x 2in dia) | |
| Grate Area: | 23.5 sq.ft. | |
| Wheels: | Leading: | 3ft 6in |
| Coupled: | 6ft 1in | |
| Tender: | 4ft 4in | |
| Tractive Effort: | (@ 85%) | 19,672lb |
| Wheelbase: | Total: | 50ft 8in |
| Engine: | 26ft 1.5in | |
| Tender: | 13ft 0in | |
| Weight (full): | Total: | 113 tons 8cwt |
| Engine: | 65 tons 2cwt | |
| Tender: | 48 tons 6cwt | |
| Max. Axle Load: | 18 tons |
Preservation
The last B5 was scrapped in 1950, and none of the B5s survived into preservation.
Models
Great Central Models produce 4mm (P4,EM) scale etched brass kits for both the large and small boiler variants of the B5. In the past, Millholme have also produced a OO gauge (4mm scale) kit of the B5, but this is no longer available.
An O gauge (7mm scale) kit is available from Gladiator.
Acknowledgements
Thank you to Malcolm Peirson for the above photograph of B4 GCR No. 186.