Locomotives of the Midland Railway

The Midland was fortunate in that George Stephenson had built its main lines with very shallow gradients, while its main rival the LNWR had to cope with the hilly country north of Lancaster. The Midland favoured building large numbers of relatively small, low-powered engines to standardised designs. Each engine was cheaper to build and run than a larger equivalent and while more locomotives were required, the Midland's Derby Works was able to achieve economies of scale. The Midland found that on the majority of its well-graded lines a single small engine was sufficient, and that it was more efficient to add either more trains of a shorter length to handle greater demand or to employ multiple small engines (two or three) when heavier trains were needed. This was deemed preferable to building a small number of large engines for the routes and duties that required them which did not fit into Derby's standardised production and risked being underutilised and incurring expensive running costs unnecessarily. Indeed, the Midland's operations were often based around keeping even its small engines lightly loaded at a time when other railways were not only building larger, more powerful locomotives but working them to their maximum capacity with the heaviest trains possible. The Midland's philosophy was to keep individual train weights as low as was practically possible and run more trains, providing short-term economies in fuel consumption and wear-and-tear on the locomotive, which in the long term meant that Midland locomotives generally enjoyed longer service lives than hard-worked contemporaries on other railways. This was one reason why the relatively undersized standard Midland axle bearing was successfully retained for so long into the 20th century - under Midland operating practices the loads imposed on the bearing by a low-powered locomotive working well within its capabilities were minimised.

The overall interlinked light-use design/operate philosophy was formalised in 1907 when, under chairman George Ernest Paget and Traffic Inspector John Follows, the Midland introduced a new traffic management system whereby every locomotive type was assigned a single standardised workload (in contrast to the system used by other railways, including the Midland's main competitor the London and North Western Railway, whereby new or freshly-overhauled locomotives were given higher workloads, with locomotives progressively being assigned less arduous tasks as their condition deteriorated towards the next overhaul). This required that the standard workload had to be, to a extent, a 'worst case' scenario of a worn-out locomotive immediately due an overhaul, with the result that train loads were kept low and engines in good condition were not worked to their maximum. This system also ensured the continuation of the Midland's practice of continuing to run shorter, lighter but more frequent trains (against the industry trend for longer, heavier but fewer services) since the Midland's service timings were calculated on the basis of relatively low power being available.

The advantages were in the lower maintenance and fuel costs in ensuring that most engines were not worked to their limit, the permitting of standardised maintenance and inspection intervals (since individual locomotives did not have to be regularly assessed to ascertain their suitability for the work assigned to them) and the simplicity of rostering engines for work, as Midland shed managers could be confident that every engine they had available would be capable of the duty assigned. This allowed the Midland to greatly improve its punctuality and timekeeping - which had been poor in the late 19th century and a source of bad publicity - since the timetables and train loads could be drawn to also assume the standard 'worst case' locomotive power available, while most of the engines actually in service were in better condition than that.

One upshot of the new management system was that the Midland followed the practice common on American railways of putting the role of Motive Power Superintendent (responsible for managing and allocating the railway's locomotive stock in service) under the authority of the Operating Department (with overall responsibility for managing the railway's services and timetables in response to demand) rather than the role being subordinate to the Chief Mechanical Engineer (responsible for providing and maintaining locomotives) as was usual in British railway companies. This had the effect of Midland locomotive policy from approximately 1910, further formalising the concept of more frequent, lighter trains hauled by relatively small locomotives - a situation which favoured the goal of the Operating Department (greater frequency, flexibility and overall volume of services) at the expense of the Motive Power Superintendent's natural preference for a smaller number of more powerful locomotives (a smaller number of more easily-managed, less labour-intensive assets performing the same work) or the ability of the Derby works (under the CME) to design such locomotives.

Smaller, less powerful engines also allowed savings in civil engineering upgrades as they permitted lighter-laid track and cheaper bridges to be retained for longer into the 20th century - thus there is an interaction with Route Availability - primarily based on axle loadings - although this concept was not formalised into classifications in Midland or LMS days (contrast to the Great Western Railway, q.v.). In turn this acted against the widespread adoption of larger, heavier engines as this would require a simultaneous large-scale civil engineering programme to improve the Midland's permanent way and associated structures. Similarly, the Midland was unusual among British railways by continuing to favour roundhouses to stable and service its locomotives instead of the more common longitudinal shed. While a shed could be relatively easy expanded and lengthened to accommodate larger locomotives, the roundhouses could not, further adding a secondary cost to adopting large engines. Another such factor was that decades of running light, short trains meant that the Midland's network featured shorter-than-average sidings and passing loops - if more powerful locomotives were to be procured and used to the full, these would have to be rebuilt to work with longer trains.

The small engine policy served the Midland well when its network was confined to the English Midlands, which is largely free of steep gradients. As the company expanded into other parts of Britain the policy's downsides began to cause problems. The company's own main line to Scotland (the Settle-Carlisle Line) and the Somerset and Dorset Joint Railway (where the Midland was responsible for providing locomotives) were renowned for their steep gradients and the company's locomotive stock proved badly suited to the task. Nonetheless the small engine policy remained and double-heading or banking was used to make up for the shortfall in power. The policy also greatly reduced capacity on the Midland's network as not only were there more (but smaller) trains than there would have been on another railway but further capacity was taken up by the need to accommodate light engines that had been used for piloting or banking duties that were returning to their depots. The small engine policy was a contributing factor to two fatal accidents on the Settle-Carlisle Line, at Hawes Junction and Ais Gill. In the former case it was due to excessive light-engine movements and in the latter due to a train stalling on the main line due to a lack of power.

The small engine policy remained in place into the 1920s and remained an influence during the early years of the Midland's successor the London, Midland and Scottish Railway, its Chief Mechanical Engineer for most of the 1920s being Henry Fowler, a long-standing Midland engineer and former CME of that company. James Anderson was made Chief Motive Power Superintendent of the new LMS. Anderson was also from the Midland, was a trained locomotive engineer, had been draughtsman and works manager at Derby Works and had been appointed temporary CME of the Midland when Fowler was seconded to the British government to manage wartime production of munitions and aircraft. The corporate management structure of the Midland, with the Operating Department overseeing the role of the Motive Power Superintendent, continued in a somewhat de facto fashion in the early years of the LMS.

Midland-era standard designs were continued or lightly updated and constructed for use across the new LMS network. Many of these types proved ill-suited or inadequate for routes and operating practices away from ex-Midland territory - while ex-Midland locomotives were imposed on the new LMS, the operational practices that went with them were not, on top of still-rising demands with regard to train speeds and weights. This left Midland-designed 'small engines' being worked to the full on heavy trains by crews used to working their engines as hard as possible. Under these conditions many of the designs proved inadequate in terms of both performance and reliability (such as the frequent axle bearing failures afflicting many ex-Midland LMS engines in the 1920s) and this left the LMS with a shortage of modern motive power by the late 1920s. Fowler oversaw the introduction of the Royal Scot class locomotives in 1927, which effectively ended the Midland small engine tradition - they were in fact built by the North British Locomotive Company which also had a large part in the design process, further assisted by plans of the Southern Railway's Lord Nelson class being provided to the LMS. Fowler was superseded by William Stanier in 1932 who brought in a new generation of modern 'large engine' designs, greatly influenced by his previous employer, the Great Western Railway.

In 1912 the Midland bought the London, Tilbury and Southend Railway, but this continued to be operated more or less separately. The Midland, and the LMS subsequently built some LT&SR designs.

• Baxter, Bertram (1982). Baxter, David (ed.). British Locomotive Catalogue 1825–1923. Vol. 3A: Midland Railway and its constituent companies. Ashbourne, Derbyshire: Moorland Publishing Company. ISBN 9780903485524.
• Casserley, H.C. (1960). Historic locomotive pocket book. London: Batsford.