K4 2-6-0
K4 West Highland Moguls Gresley
Initially the K4s were mainly used on the Glasgow to Fort William stretch of the West Highland line. They handled the gradients and continuous curves with ease, but they were not designed for the 20 miles of level track near Glasgow, and the 8.5 miles stretch alongside Loch Eil. Vibration at speed was a problem on these stretches, and the middle big-end would require regular nut tightening. On one occasion, the middle connecting rod actually dropped off! Hence maintenance costs increased. The V4s with their slightly larger wheels were more popular with the enginemen but were lacking in power. Eventually the Thompson B1s appeared on the Glasgow to Fort William services from 1947, displacing the K4s to the Mallaig stretch. The new Thompson/Peppercorn K1s appeared in 1949 and were preferable due to their lack of a troublesome middle big-end. After Nationalisation, LMS 'Black 5' 4-6-0s were also moved to the line. From this point onwards, the K4s were concentrated at Eastfield and intended for use on West Highland goods trains only.
In 1959, the five K4s were transferred to Thornton Shed for use on goods trains until October 1961 when four were withdrawn. The last K4, No. 61994 The Great Marquess, was withdrawn in December 1961 and sold to Viscount Garnock and has survived into preservation.
Initially the K4s were mainly used on the Glasgow to Fort William stretch of the West Highland line. They handled the gradients and continuous curves with ease, but they were not designed for the 20 miles of level track near Glasgow, and the 8.5 miles stretch alongside Loch Eil. Vibration at speed was a problem on these stretches, and the middle big-end would require regular nut tightening. On one occasion, the middle connecting rod actually dropped off! Hence maintenance costs increased. The V4s with their slightly larger wheels were more popular with the enginemen but were lacking in power. Eventually the Thompson B1s appeared on the Glasgow to Fort William services from 1947, displacing the K4s to the Mallaig stretch. The new Thompson/Peppercorn K1s appeared in 1949 and were preferable due to their lack of a troublesome middle big-end. After Nationalisation, LMS 'Black 5' 4-6-0s were also moved to the line. From this point onwards, the K4s were concentrated at Eastfield and intended for use on West Highland goods trains only.
In 1959, the five K4s were transferred to Thornton Shed for use on goods trains until October 1961 when four were withdrawn. The last K4, No. 61994 The Great Marquess, was withdrawn in December 1961 and sold to Viscount Garnock and has survived into preservation.