| LMS Ivatt Class 4 | |
|---|---|
| LMS Ivatt Class 4 2-6-0 M3009 (later 43009) as built with double chimney, at Horwich Works in 1948 | |
| Power type | Steam |
| Designer | H.G. Ivatt |
| Builder | Horwich Works (75) Doncaster Works (50) Darlington Works (37) |
| Build date | 1947-1952 |
| Total produced | 162 |
| Configuration | 2-6-0 |
| UIC classification | 1'Ch |
| Gauge | 4 ft 8 1⁄2 in (1,435 mm) |
| Leading wheel diameter |
36 in (0.914 m) |
| Driver diameter | 63 in (1.600 m) |
| Length | 55 ft 11 in (17.04 m) |
| Locomotive weight | 59.1 long tons (60.0 t) |
| Fuel type | Coal |
| Fuel capacity | 4 long tons (4.1 t) |
| Water capacity | 3,500 imp gal (16,000 l; 4,200 US gal) |
| Boiler | LMS 4D |
| Boiler pressure | 225 psi (1.55 MPa) |
| Firegrate area | 23 sq ft (2.1 m2) |
| Cylinders | Two, outside |
| Cylinder size | 171⁄2 × 26 in (440 × 660 mm) |
| Valve gear | Walschaerts |
| Tractive effort | 24,170 lbf (107.51 kN) |
| Career | London, Midland & Scottish British Railways |
| Class | LMS: 4F, later 4 BR: 4MT |
| Nicknames | Mucky Ducks, Pigs |
| Axle load class | Route Availability 4 |
| Retired | 1963–68 |
The LMS Ivatt Class 4 2-6-0 is a class of steam locomotive primarily designed for medium freight work but also widely used on secondary passenger services. The London Midland and Scottish Railway (LMS) built 162 of this type between 1947 and 1952, but only three were built by the LMS before nationalisation in 1948. Designed by H.G. Ivatt, they were classified 4F by the LMS and 4MT by BR. In BR days they were used extensively across the system, being prevalent on the London Midland region and to a lesser extent elsewhere, notably on the Midland and Great Northern Joint Railway, an East Anglian line that had previously been joint owned by the LMS and LNER, where they became the dominant locomotive type. They were also used for a short period on the Somerset and Dorset Joint Railway, but were quickly transferred elsewhere, never to return, because of poor steaming on the line's long and steep gradients – this was before modifications were made to the design which improved steaming notably.
Contents |
The first three engines were numbered 3000–2 by the LMS, but became 43000–2 when renumbered by BR – 40000 was added to the running number to indicate an ex-LMS locomotive. The remaining 159, built by BR, continued the number sequence: 43003–161. Construction was divided between different locations, 75 were completed at Horwich Works, 50 at Doncaster Works and 37 at Darlington Works. The class was also sometimes called 'mucky ducks' or 'doodle-bugs' or even ‘Flying Pigs’.
The design was noted for its American looks – the running-plates were positioned at a high level and a gap left ahead of the cylinders. Because of this many people considered it to be the ugliest British locomotive produced, especially those locomotives outshopped with double chimneys (the first 50 engines); however, these gave poor performance and were quickly replaced with single chimneys. The locomotives also incorporated new mechanical features intended to reduce maintenance costs.
The BR Standard Class 4 2-6-0 was based on this design. Its looks were improved somewhat by the re-design of the outside foot-plating, to include a sloping plate to fill the gap ahead of the cylinders.
Only one example survived into preservation, No 43106, the final member of the class in service, which was based at Lostock Hall depot, near Preston. It was steamed for the final time on 1 August 1968 and departed initially towards Bescot MPD and then on to a new life in preservation on the Severn Valley Railway where it is affectionately known as the Flying Pig.
The locomotive has had a major overhaul recently finished and is currently operational after having damage repaired that it received during a derailment at Hampton Loade.
A OO gauge model of 43106 is produced by Bachmann Branchline, who also produce many other models of the Class 4, as well as the LMS Ivatt Class 2 2-6-0 and LMS Ivatt Class 2 2-6-2T.
|
|||||||||||||||||||||||