| Power Classification | 4P reclassified 4MT in 1948 |
| Introduced | 1945 – 1951 |
| Designer | Fairburn |
| Company | LMS |
| Weight | 85t 5cwt |
| Driving Wheels | 5ft 9ins |
| Boiler Pressure | 200psi superheated |
| Cylinders | Outside – 19⅝ in x 26in |
| Tractive Effort | 24,670lbf |
| Valve Gear | Walschaert (piston valve) |
The 2-6-4T design that was to become a BR standard many years later was first introduced on the LMS by Fowler in 1927 as a locomotive for general passenger train usage with the 42300 class. This was then developed by Stanier who introduced a three cylinder and taper boiler version in 1934 which became the 42500 class. In 1935 Stanier produced the 42425 class which had two cylinders.
The Fairburn version which had two cylinders was introduced in 1945 as the 42050 class engine.
Fairburn did not have a background of working with steam engines as he joined the LMS from English Electric Co in 1934 to be the Chief Electrical Engineer. He actively encouraged developments of design features to reduce shed servicing and increase the mileage between workshop visits to cope with the difficult conditions of wartime operations. Fairburn provided guidance later which aided the introduction of 0-6-0 diesel shunters.
The final development of this design was completed by Riddle with the introduction of the 80000 class BR standard locomotive in 1951.
 |
Fowler Tank – 42395 onwards of 1933 |
 |
Stanier 2 cylinder version – 1935
42425-94 and 42537-672 |
 |
Fairburn – 1945
42050-299 and 42673-99 |
 |
Riddle – 1951
80000-154 |
The Fairburn version introduced in 1945 was developed from the Stanier locomotives and had a shorter wheelbase and other minor modifications. They could be distinguished from Stanier’s engines by the gap in the running plate ahead of the cylinders. The Fairburn class continued to be built by BR until 1951 when the standard BR class was introduced.
The last few batches of engines (42066-42106) were built at Brighton railway works for service on the Southern Region of British Railways in 1950 and 1951, replacing earlier designs. The majority of these remained on the Southern Region throughout their working lives. Many of them were stationed at Stewarts Lane in Battersea, Dover and Ashford (Kent) for use on the South Eastern Section. One of the routes which became a favourite stamping ground was the Maidstone to Ashford line on which one notorious derailment of one of Maunsell’s River class had taken place at Bearsted.
Number in Service.
| Built | Withdrawals | No. in Service | ||
| BR Numbers | Quantity | |||
| 1945 | 42200-17 & 42673-99 |
45 |
45 |
|
| 1946 | 42218-64 |
47 |
92 |
|
| 1947 | 42187-89 & 42265-99 |
38 |
130 |
|
| 1948 | 42147-82 & 42190-99 |
46 |
176 |
|
| 1949 | 42107-32 & 42183-86 |
30 |
206 |
|
| 1950 | 42050-78, 42096-106 & 42133-46 |
54 |
260 |
|
| 1951 | 42079-95 |
17 |
277 |
|
| 1952-60 |
277 |
|||
| 1961 |
3 |
274 |
||
| 1962 |
43 |
231 |
||
| 1963 |
30 |
201 |
||
| 1964 |
57 |
144 |
||
| 1965 |
54 |
90 |
||
| 1966 |
48 |
42 |
||
| 1967 |
42 |
0 |
||
- 42066 – 106 were built at Brighton. The rest were built at Derby.
The 41 locomotives built at Brighton in 1950 and 1951 all entered service on the Southern Region allocated to five depots.
| Tunbridge Wells |
11 |
| Stewarts lane |
10 |
| Brighton |
9 |
| Ramsgate |
6 |
| Dover Marine |
5 |
These were the only engines of this class to be allocated to the Southern Region and they were all reallocated to other regions by the end of 1959. The first three (one each to York, Heaton and Middlesbrough) moved to the Eastern Region in 1952 with a further four going to Gateshead in 1954.
The allocation of the class between regions of British Railway for the period when all of the class were in service shows the impact of the transfers from the Southern Region.
| December 1951 |
December 1960 |
|
| Western |
0 |
1 |
| Southern |
41 |
0 |
| Eastern |
47 |
37 |
| Scottish |
93 |
87 |
|
181 |
125 |
|
| Midland |
96 |
152 |
|
277 |
277 |
The one locomotive (42182) allocated to the Western Region spent some time at Landore, Swansea after arriving there from Chester in 1960. It moved on to Swansea East Dock the following year before having a brief period at Leamington Spa in 1962 before returning to the Midland Region at Willesden later that year.
The engines shown as allocated to the Eastern Region in 1951 includes depots in Yorkshire (mainly around Bradford and Leeds) that were then part of the Midland Region but later transferred to the Eastern Region. In addition to this there were 16 locomotives allocated to Tilbury, Plaistow and Shoeburyness. These remained the main areas on the Eastern where members of this class were based but they made brief visits to Newcastle and the North East coast at Whitby and Scarborough.
The Scottish based locomotives were largely based in the Glasgow area (including the Ayrshire Coast and along the West Coast main line). The largest allocation was to Polmadie in Glasgow. A few were allocated to St Margarets and Dalry Road in Edinburgh. The furthest north they were allocated were Perth and Aviemore where a small number were based for a very short time.
The Midland Region locomotives were to be found right across the region.
Withdrawals began in 1961 with the last 90 retired from service in 1966 and 1967.
| Withdrawn From | 1966 |
1967 |
|
| Midland | Bank Hall |
2 |
|
| Barrow |
1 |
||
| Birkenhead |
3 |
1 |
|
| Bolton |
4 |
||
| Bushbury |
1 |
||
| Tebay |
4 |
3 |
|
| Lostock Hall |
2 |
3 |
|
| Newton Heath |
1 |
||
| Trafford Park |
1 |
6 |
|
| Wigan Springs Branch |
1 |
||
| Eastern | Huddersfield |
1 |
|
| Leeds Holbeck |
2 |
2 |
|
| Low Moor |
5 |
14 |
|
| Normanton |
8 |
||
| Wakefield |
4 |
3 |
|
| Scottish | Beattock |
2 |
|
| Carstairs |
5 |
||
| Greenock Ladyburn |
5 |
||
| Motherwell |
1 |
||
| Polmadie |
3 |
||
| St Margarets |
2 |
||
|
48 |
42 |
This class was amongst the last of the tank engines still to be working on the BR system. 42152 hauled the last steam train on the Eastern Region when it was in charge of the 4:18pm Bradford to Leeds passenger train on 1st October 1967. It reported touched a top speed of 74mph whilst doing so.
By the end of 1966 there were still 42 in use which represented about 44% of the total number of tank engines of all classes still in service. In addition to those included in the table below one J72 survived until withdrawn in October 1967 from Tyne Dock shed. This locomotive was a departmental service engine used for de-icing (69005 Dep58)
|
Class |
Number Built | When Built |
Number in Service |
|
41200 |
130 | 1946-52 | 8 |
|
42050 |
277 | 1945-51 |
42 |
|
42425 |
206 | 1935-43 |
15 |
|
47260 |
417 | 1924-31 |
4 |
| 80000 | 155 | 1951-57 |
25 |
|
82000 |
45 | 1952-55 |
2 |
|
96 |
Accidents and Incidents
On 19 April 1955, locomotive 42073 was in collision with V2 60968 at Newcastle Central station, Northumberland. Both locomotives were derailed.
 |
42134 on Workington shed-January 1965.The locomotive was based at Barrow at this time before moving to Tebay in December 1966. It was withdrawn from service at Tebay in April 1967 and scrapped in December 1967. |
 |
42252 on former Furness Railway territory at Egremont-June 1966. The locomotive was allocated to Tebay in June 1966 before being transferred to Low Moor in April 1967. It was withdrawn from service in September 1967 and scrapped in April 1968
|
 |
42055 on Low Moor shed where it was then based-May 1966. It remained at Low Moor until withdrawn from service in June 1967. It was scrapped in November 1967. |
