The

Caledonian Railway The Caledonian Railway (CR) was one of the two biggest of the five major Scottish railway companies prior to the 1923 Grouping. It was formed in 1845 with the objective of forming a link between English railways and Glasgow. It progressively ex ...

49 Class and 903 Class were

4-6-0 A 4-6-0 steam locomotive, under the Whyte notation for the classification of steam locomotives by wheel arrangement, has four leading wheels on two axles in a leading bogie and six powered and coupled driving wheels on three axles with the abs ...

express passenger locomotives designed by John F. McIntosh and built at the Caledonian Railway's own St. Rollox Works in 1903 and 1906 respectively.

49 Class

In 1903, the Caledonian Railway had no passenger locomotives larger than 4-4-0s, and the heaviest trains over its main line between Glasgow and Carlisle required to be double headed, even in the less demanding southbound ('up') direction. Northbound ('down') trains also required banking assistance on the climb to

Beattock Summit Beattock Summit is the highest point of the West Coast Main Line (WCML) railway and of the A74(M) motorway as they cross between Dumfries and Galloway and South Lanarkshire in south west Scotland. The height of the summit reached by the A74(M) ...

. In an effort to avoid these requirements, McIntosh designed a large 4-6-0 based on his 'Dunalastair' series of 4-4-0s. Two locomotives were built in 1903, and immediately became the Caledonian's flagship locomotives. Nonetheless, their performance did not live up to expectations, and it was soon clear that banking assistance was still required over Beattock. Until 1906 the Caledonian railway had no

turntables A phonograph, later called a gramophone, and since the 1940s a record player, or more recently a turntable, is a device for the mechanical and analogue reproduction of sound. The sound vibration Waveform, waveforms are recorded as correspond ...

long enough for the 49 Class, and arrangements for turning them included use of the Cathcart Circle or turning locomotive and tender separately.

903 Class

By 1906, experience with the 49 Class had enabled McIntosh to design an improved version, and the installation of new turntables at major engine sheds presaged the arrival of five new locomotives. The first of these, number 903, was named ''"Cardean"'' after the country estate of one of the CR directors, and immediately became the company's new flagship locomotive, with its name becoming a nickname for the whole class. The Caledonian gave the new locomotives a great deal of publicity and ''"Cardean"'' thus achieved some fame. Even so, the performance of the 903s was still unremarkable.

Rebuilding and subsequent service

Neither class was equipped with

superheating In thermodynamics, superheating (sometimes referred to as boiling retardation, or boiling delay) is the phenomenon in which a liquid is heated to a temperature higher than its boiling point, without boiling. This is a so-called ''metastable state ...

when built, but all seven locomotives were rebuilt with Schmidt superheaters and new cylinders during 1911. These modifications reduced coal consumption but made little difference to the locomotives' performance, and McIntosh built no more large passenger 4-6-0s (although he did build smaller 4-6-0s for goods traffic). His successor

William Pickersgill William Pickersgill (1861 – 2 May 1928) was an English railway engineer, and was chief mechanical engineer of the Caledonian Railway from 1914 until Railways Act 1921, Grouping in 1923. He was appointed locomotive superintendent of the Nor ...

had no greater success with his inadequate, outside-cylindered 60 Class or the highly unsuccessful three-cylinder 956 Class, so the Caledonian Railway continued to rely heavily upon 4-4-0s for express passenger traffic until the

Grouping Grouping generally refers to the creation of one or more groups, or to the groups themselves. More specifically, grouping may refer to: * Shot grouping in shooting sports and other uses of firearms * the use of symbols of grouping in mathemati ...

. One 903 class locomotive was withdrawn in 1915 due to accident damage, but the other six locomotives passed to the

London, Midland and Scottish Railway The London, Midland and Scottish Railway (LMSIt has been argued that the initials LMSR should be used to be consistent with London and North Eastern Railway, LNER, Great Western Railway, GWR and Southern Railway (UK), SR. The London, Midland an ...

in 1923. The two 49 class locomotives were extensively renewed around 1924 with new frames and cylinders, but all of the Caledonian passenger 4-6-0s were quickly eclipsed by new

LMS Compound 4-4-0 The London, Midland and Scottish Railway Compound 4-4-0 was a class of steam locomotive designed for passenger work. Overview One hundred and ninety five engines were built by the LMS, adding to the 45 Midland Railway 1000 Class, to which ...

and Royal Scot 4-6-0s. The four surviving 903s were withdrawn in 1927–30, whilst the two 49s lasted until 1933. All were scrapped.

Accidents and incidents

*On 2 April 1909, locomotive No. 903 ''Cardean'' was hauling a passenger train that became divided and was derailed at ,

Lanarkshire Lanarkshire, also called the County of Lanark (; ), is a Counties of Scotland, historic county, Lieutenancy areas of Scotland, lieutenancy area and registration county in the Central Lowlands and Southern Uplands of Scotland. The county is no l ...

due to the failure of the crank axle of the locomotive. A few passengers suffered minor injuries. * On 22 May 1915, locomotive No. 907 was hauling a local passenger train involved in Britain's worst ever railway accident, the double collision and fire at Quintinshill,

Dumfriesshire Dumfriesshire or the County of Dumfries or Shire of Dumfries () is a Counties of Scotland, historic county and registration county in southern Scotland. The Dumfries lieutenancy areas of Scotland, lieutenancy area covers a similar area to the hi ...

in which at least 226 people were killed. The locomotive was taken to St Rollox works to be repaired, but due to the extent of the damage its rebuilding was abandoned and 907 was withdrawn and scrapped. :

Numbering and locomotive histories

References