lördag 7 juli 2018

The Stroudley legacy

These thoughts are prompted by the appearance of a range of Caledonian Railway locomotives for train simulators.

The story begins with William Stroudley, who had been in charge of locomotives at workshops of the poverty-stricken Highland Railway at Inverness for four years, when in 1870, at the early age of 37, he moved to the prestigious job of Locomotive Superintendent at the Brighton works of the London, Brighton and South Coast Railway (LBSC), taking with him his workshop manager, Dugald Drummond. Between them, they established a solid tradition of locomotive design which continued until the 1920s, with locomotives which remained in service until almost the very end of steam in Britain.

On arriving at Brighton, Stroudley initiated a programme of standardisation, based on a limited number of locomotive types with components common to the different classes. These included the famous A1‑type Terrier 0‑6‑0 tank locomotives for lightly laid lines, the G‑type 2‑2‑2 single driver express passenger locomotives, the C‑type 0‑6‑0 tender locomotives for freight, the D1‑type 0‑4‑2 tank locomotives for short distance passenger services, and the E1‑type 0‑6‑0 tank locomotives for freight.

The single driver locomotives soon proved to be unsuitable for the heavier express trains—there is a steep climb out of Victoria—and because Stroudley did not like bogies, he constructed a series of 0-4-2 tender locomotives, starting with a tender engine version of the D1, with successive enlargements of the type, of which the best known was the famous B1 ‘Gladstone’ class.

The 0-4-2 design was a dead end, no other railway using this type in any significant numbers. When, in 1875, Drummond moved took over responsibility for the locomotives of the North British Railway, he designed what was probably the first modern 4-4-0 tender locomotive type with inside cylinders, the ‘Abbotsford’ class, which entered service in 1876. These were the first of a breed that would continue to be developed for another forty years. In 1882, Drummond moved to the Caledonian Railway and enlarged and improved locomotives of the same general type, the ‘60’class, were brought into service on that railway. Drummond resigned from the Caledonian in 1890, and his successors, Lambie, and McIntosh, continued this line of development. McIntosh’s contribution was to fit the locomotives with a much larger boiler, and this was the famous 721 ‘Dunalastair’ class. The type went through four successive enlargements, the final version being the superheated ‘Dunalastair IV’, followed by yet another version by the successor to McIntosh, Pickersgill, who took over in 1914. The Pickersgill locomotives were constructed between 1916 and 1922, and although their performance was disappointing, all remained in service until 1959.

Most of the Dunalastairs, however, were not built for the Caledonian but for the Belgian State Railways, which put over 400 of the type into service between 1899 and 1912.

Tender freight locomotive design followed a parallel path, with successively larger 0-6-0 types being introduced in response to the need for greater power.

There was a similar development with tank engines. The 0-4-2 type D was stretched to create an 0-4-4 design and these went through a number of phases, the last of the Caledonian design entering service in 1925, in LMS days. They were still to be seen on Glasgow suburban routes in the late 1950s and there were normally a few at Beattock on standby for banking work.

Drummond himself took over at the London and South Western Railway in 1895 and again proceeded to equip the railway with locomotives of similar types to those he had provided for the Caledonian:  4-4-0 tender locomotives for express passenger services, of which the best known were the T9 for the main line and the S11, a small wheeled version for hilly routes in the west, an 0-6-0 tender locomotive for freight, and an 0-4-4 tank engine, the M7, for local passenger services. As on the Caledonian, the designs were successively enlarged, culminating in the D15 4-4-0, a class of ten locomotives introduced in 1912. All of these types were extraordinarily long-lived, no doubt because of their efficiency, ease of maintenance and very sturdy construction.

Stretching the design
The basic Drummond inside-cylinder 4-4-0 design had its limits. Trains became heavier and 4-4-0 locomotives were no longer adequate. On the Caledonian, the type was stretched to a 4-6-0 type, including the famous ‘Cardean’ class. These were elegant but disappointing in performance. The Caledonian never had a effective 4-6-0, though it could certainly have done with one. The Pickersgill 4-6-0s were elegant but feeble and spent their lives shuffling around the Glasgow area.

Drummond, on the London and South Western, put various types of 4-6-0 into service, some with four cylinders. The styling which suited the small 4-4-0 types looked monstrous on the huge 4-6-0 classes. Their performance was dismal. This was at a time when Churchward had produced the highly competent Saint and Star classes, following a long series of experiments leading to a range of designs which continued into production until the 1950s, since the same basic types were adopted for construction by the London Midland and Scottish Railway and by British Railways. The brilliant young Drummond had clearly got stuck in a rut, being well past retirement age when he started on his 4-6-0 designs; put plainly, Drummond just did not know how to design a 4-6-0 and at that time the type was still fairly novel.

The South Western at least did better than the Caledonian. When Drummond retired in 1912, he was succeeded by his works manager, Robert Urie, who produced a range of simple, sturdy and competent 4-6-0 designs with two outside cylinders: the H15 mixed traffic type, the S15 freight class and the N15 express passenger class. Their performance was not as good as it might have been due to the design of the valves, but after the grouping, the Southern Railway’s Chief Mechanical Engineer, Maunsell, applied the Swindon practice for valve design to the N15 (the ‘King Arthur’ class) and S15 types, to produce two classes of outstanding locomotives which remained in front line service almost to the end of steam; in preservation, the S15 class has proved to be remarkably competent at handling passenger trains.

As so often with the history of steam locomotive design, there are principles which apply to engineering generally.

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