Edward Thompson (engineer)

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Edward Thompson (1881-1949) was Chief Mechanical Engineer of the London and North Eastern Railway between 1941 and 1946.

1 Biography
2 Practices
3 Locomotives
4 External links

[edit] Biography

Edward Thompson came from an academic background having taken Mechanical Science Tripos at Pembroke College, Cambridge, unlike his predecessor Nigel Gresley who gained practical experience as a pupil at Horwich Works. After graduation Thompson worked in both industry and the railways for a while, when in 1912 he was appointed Carriage and Wagon Superintendent for GNR. He remained at this post for 18 years until he became Workshop Manager at Stratford works in 1930. This was his final post before becoming CME of LNER in 1941 after the untimely death of Nigel Gresley. Edward Thompson retired from the post of CME in 1946.

It is widely known that Gresley and Thompson disagreed on a number of issues. Many have interpreted this bitterness as NER (Thompson) vs. GNR (Gresley). Thompson happened to be the son-in-law of Sir Vincent Raven. The biggest disagreement between the two was on Gresley’s 3-cylinder conjugated valve gear. While this valve gear arrangement worked well during peace-time, it experienced problems due to low maintenance during World War 2. This did give Thompson some justification for the criticism of the design.

[edit] Practices

When Thompson was appointed CME of the LNER he started a much needed standardisation program. This program demonstrated Thompson's dislike for Gresley’s engineering practices. Many notable Gresley designs were rebuilt under this practice including the P2 Mikados, V2 Express goods and A1 Pacifics. The A1 chosen for rebuilding was none other than ‘Great Northern’, this being the original Gresley prototype for the class. Some have stated that this rebuild was sheer vindictiveness on Thompson’s part towards his old chief.

While Thompson criticised many of Gresley’s practices, equivalent comment can be made about many of Thompson’s designs. His Pacific rebuilds were not the best of designs. They all retained 3 cylinders, but with divided drive and 3 sets of independent Walschaerts valve gear. Thompson attached great importance to having connecting rods equal in length. This was not necessary, and as a result the outside cylinders were placed behind the front bogie with the inside cylinder well forward. This arrangement created long exhaust channels and encouraged flexing and fracture of the loco frames. All of his Pacifics were particularly prone to wheel slips. Such were the problems with his Pacifics that they preceded many of their older counterparts to the scrapheap.

Thompson’s L1 class suburban tanks also left a lot to be desired - they were a mechanical disaster. The 5ft 2in wheels were too small for the fast outer suburban services and they quickly knocked themselves apart. The axle boxes suffered, water tanks split, oil pipes broke off, and crossheads wore rapidly.

On the other hand Thompson built one of the most successful LNER designs, the Thompson B1. This was a simple two-cylinder design mixed traffic engine, with a 4-6-0 wheel arrangement. Over 400 of these locos were built between 1946 and 1952 four years after Thompson's death / in a total of 8 batches. The boiler used in the class formed the basis for the rebuilding of many pre-grouping classes, including the ex-GCR O4 2-8-0 freight locos. The Thompson B1 compared equally with the LMS Black Five engines during the BR exchange trials. It could be argued that the B1 is a better engine than the Black Five due to its cheaper cost of manufacture.

Thompson died three and a half years later in 1949, three years after his retirement from being CME of the LNER.