Steam Locomotives of a More Leisurely Era
1920 – 3-Cylinder 2-6-0
Great Northern Railway
1935 as running in 1947
A powerful class of mixed traffic locomotives introduced by Gresley in 1920. Ten engines were constructed for the GNR, Nos. 1000-9, and after grouping another 183 were built between 1924 and 1937, with slight modifications. At the time of their appearance these engines had the largest boilers, 6’ 0” in diameter, yet seen in this country. They were the first of Gresley’s engines to employ the rocking shaft device whereby the piston valve of the inside cylinder is actuated by levers connected with the tail rods of the Walschaert’s valve gear of the two outside cylinders, thus dispensing with the need for a separate eccentric or valve gear for the inside cylinders. This arrangement was later used most successfully by Gresley for his ‘Pacifics’ and several other classes, and worked very well when kept in good order. It is inclined, however, to become uncertain under conditions of poor maintenance so frequently met with towards the end of the steam era.
The GNR built engines became Nos. 4000-9 after the grouping, and the post-amalgamation ones had scattered numbers over the LNER range, between 17 and 3832. At the 1946 renumbering the whole class became 1800-1992, and subsequently BR 61800-61922.
In 1945 No. 206 (now No. 61863) was rebuilt with two cylinders, and increased boiler pressure, but no further conversions took place. Scrapping of the class commenced in 1959.
The general class – Driving wheels – 5’ 8”, Cylinders (3) 18½”x 26”, Pressure – 180 lb., Tractive effort – 30030 lb., Weight – 72 tons 12 cwt, GNR classification – H4, LNER classification – K3, BR classification – 5P6F
Engine 61863 -Driving wheels – 5’ 8”, Cylinders (2) 20”x 26”, Pressure – 225 lb., Tractive effort – 29250 lb., Weight – 71 tons 5 cwt, GNR classification – N/A, LNER classification – K5, BR classification – 5P6F