| Power Classification | 4P |
| Introduced | 1905 – 1909, 1902 – 1903 rebuilt by Deeley 1914 – 1919 |
| Designer | Deeley and Johnson |
| Company | MR |
| Weight – Loco | 61t 14cwt |
| Tender | 42t 14cwt |
| Driving Wheels | 7ft 0ins |
| Boiler Pressure | 200psi superheated |
| Cylinders | One inside high pressure cylinder – 19in x 26in – and two outside low pressure cylinders – 21in x 26in |
| Tractive Effort | 21,840lbf (TE of low pressure cylinders at 80% of boiler pressure) |
| Valve Gear | Stephenson (slide valve on low pressure cylinders and piston valves on high pressure cylinder) |
These engines are considered by some to have been the only really successful compound locomotives ever to work in this country. Originally the process was seen as a method of fully utilising ssteam that, because of inadequate valve performance, was exhausted before all of its potential power had been extracted.
Compound engines use the steam produced by the boiler twice, firstly in high-pressure cylinders, and secondly in low-pressure cylinders. Several railways had experimented with compound engines in the latter part of the 19th century. But with somewhat indifferent results. The benefit of the compound design was that it reduced the coal consumption at a time when the price of coal had risen sharply. The use of compound engines goes back to the middle of the 19th century but these were static engines
Johnson based his compounds on a system invented by the chief draughtsman of the North Eastern Railway, William Smith. One inside high-pressure cylinder and two outside low-pressure cylinders were used. A second regulator was fitted to allow live steam to be admitted directly to the low-pressure cylinders which was a great help when starting. Five locomotives were built in 1902-1903 and they were numbered 2631-2635. They put up some fine work on the mountainous Settle and Carlisle line.
When Deeley succeeded Johnson he decided to build more engines of the same basic design but with some important differences. The Smith type valve gear was replaced with a simpler system. The engines always started as non-compound engines, with live steam in the low-pressure cylinders, and as the regulator was opened further, the engines automatically switched over to compound working. There were also some differences in external appearance with the running plate being raised clear of the coupling rods and the rectangular rear splasher being replaced with a quarter circle, which merged into the cab side sheet. The boiler pressure was also raised to 220psi although it was later reduced to 200psi.
Thirty of Deeley’s new engines were built in 1905-1906, numbered 1000-1029. In the 1907 Midland Railway re-numbering scheme these became 1005-1034, and the original Johnson engines became 1000-1004. A further ten locomotives numbered 1035-1044 came out in 1908-1909.
Between 1914 and 1919 1000-1004 were rebuilt in line with the Deeley engines, and at the same time they were superheated. 1040 was superheated in 1913, and the rest of the class was superheated from 1919 onwards.
No more engines of the class were built by the Midland, but the design was adapted as a standard design by the LMS and 195 engines were turned out between 1924 and 1932, numbered 1045-1199, and 900-939. This was the Fowler 40900 class of compounds which had 6ft 9in driving wheels in place of the 7ft wheels of the original engines and 200psi boiler pressure. They were superheated from new.
Both classes did magnificent work, not only on the Midland Railway, but also on the Caledonian and Glasgow & South Western main lines. They also worked well on the former London & North Western Railway, where they worked the Birmingham two-hour expresses, for which they were ideally suited. However, they were always viewed with some suspicion on LNWR lines, due to a mistrust of compound engines in general dating back to the unsuccessful experiments with compounds in Webb days.
In 1924 and 1925 a number of trials were held over the routes from Carlisle to Leeds over Aisgill and Carlisle to Preston over Shap. The trials involved MR 4-4-0 compounds, the LNWR 4-6-0 locomotives and Caledonian 4-4-0 engines. At this time the LMS had a Chief General Superintendent (Follows) and a Superintendent of Motive Power (Anderson) who both came from the Midland Railway. The MR tended to operate lighter loaded trains at more frequent intervals which contrasted with the LNWR which operated heavier trains. The compound outperformed the other locomotives although the mechanical state of the various engines may have contributed towards this. The coal consumption of the compound was significantly better than the other classes used.
Around the time the trials ended Hughes retired as Chief Mechanical Engineer and was replaced by Fowler. Fowler moved the CME headquarters from Horwich to Derby and the design staff at Derby became more immersed in plans to build more compound locomotives – even up to a pacific. In January 1926 Fowler attended a meeting of the Graduates Section of the Institute of Mechanical Engineers. One of his former pupils (E L Diamond) presented a paper investigating the steam losses in compound locomotives. The conclusion was that the performance of all locomotives could be significantly improved by modifying the valves in the cylinders to restrict the steam passage. Follower incorporated these changes into the 2-6-4T engines (2300 class) which were being designed.
The Crewe workshops were working on an improved Claughton 4-6-0 design at this time and the Operating Department succeeded in impressing the Chairman to the extent that Fowler was instructed to stop all work on compound pacifics.
It has to be remembered that at this time there was much rivalry between the MR and the LNWR. One quote which reflects some of the views of MR locomotives is reproduced below.
“The nice little engines were made pets of. They were housed in nice clean sheds, and they were never overloaded.”
Lowering standards of maintenance during and after the Second World War took a toll on these locomotives and they later fell into disrepute. They were gradually put to work on local trains, duties for which they were unsuitable and in consequence they got a poor reputation.
Number in Service.
| Built | Withdrawals | No. in Service | ||
| BR Numbers | Quantity | |||
| 1902 | 41000-1 | 2 | 2 | |
| 1903 | 41002-4 | 3 | 5 | |
| 1905 | 41005-14 | 10 | 15 | |
| 1906 | 41015-34 | 20 | 35 | |
| 1908 | 41035-39 | 5 | 40 | |
| 1909 | 41040-44 | 5 | 45 | |
| 1910-47 | 45 | |||
| 1948 | 8 | 37 | ||
| 1949 | 5 | 32 | ||
| 1950 | 4 | 28 | ||
| 1951 | 17 | 11 | ||
| 1952 | 10 | 1 | ||
| 1953 | 1 | 0 | ||
- The last locomotive withdrawn was 41025 which was taken out of service at Gloucester Barnwood in January 1953
Allocation of locomotives in service as at 1st of January.
| Depot | 1948 | 1952 |
| Bedford | 8 | 2 |
| Bournville | 1 | |
| Bristol Barrow Road | 2 | |
| Chester | 4 | |
| Derby | 4 | 1 |
| Gloucester Barnwood | 5 | 2 |
| Hellefield | 1 | |
| Kentish Town | 2 | |
| Kettering | 1 | |
| Lancaster | 2 | |
| Leeds Holbeck | 2 | 1 |
| Leicester Midland | 4 | |
| Manningham | 2 | 1 |
| Millhouses | 6 | |
| Nottingham | 4 | 3 |
| Saltley | 2 | |
| 45 | 11 |
Accidents and Incidents
- On 23 December 1904, locomotive 1040 was hauling an express passenger train that was derailed at Aylesbury, Buckinghamshire due to excessive speed on a curve. Locomotive 1042 was hauling an express passenger train that collided with the wreckage at low speed. Four people were killed.
- On 19 January 1918, locomotive 1010 was hauling an express passenger train that was derailed when it ran into a landslip obstructing the line between Little Salkeld and Lazonby railway stations in Long Meg cutting on the Settle-Carlisle Line.
- As the 11 carriage 08:50 London St Pancras to Glasgow express approached the cutting a heavy landslip caused by a sudden thaw blocked both roads ahead of the train. Just five minutes earlier a platelayer had walked past the spot and seen nothing amiss. The engine ploughed into the mass of clay at a speed of 60 mph, telescoping the front two carriages and killing seven passengers and injuring 46.
- On 10 July 1933, locomotive 1010 was hauling an express passenger train that was in a side-long collision with a freight train at Little Salkeld due to a signalman’s error. One person was killed and about 30 were injured, one seriously.
- On 12 April 1947, locomotive No. 1004 was hauling a passenger train which was derailed near Keighley, Yorkshire when a bridge collapsed under it.
- On 21 April 1952, locomotive 41040 was one of two hauling the Thames-Clyde Express that was derailed at Blea Moor Loops, West Riding of Yorkshire. The front end of a brake rod on the tender of the leading engine became detached and, after bouncing on the sleepers and ballast between the rails for a distance of over two miles, it struck the stretcher bar of the first facing points. The closed switch of the points was wrenched open and the derailment of the second engine and the following coaches was inevitable. The brake rod came adrift because of bad maintenance of the engine.
Preservation
Preserved British Steam Locomotives 