During the early months of 1971, along with some 26 diesels of varying type, power and age, twelve steam locomotives remained at Corby Works. Survivors after the earlier partial dieselisation, and originally part of a larger stock built up by Stewarts and Lloyds from the 1930’s, the engines are, with one exception mentioned later, a group of Hawthorn Leslie 0-6-0 saddle tanks, with 16in x 24in outside cylinders. Built to their manufacturer’s then standard specification the first six of these locos were delivered new at the works in 1934, to coincide with the completion of the expansion programme decided on in 1932 – a development which was the first step in taking Corby from a smallish village, with three blast furnaces fed by local ironstone, to the sprawling town and steel works complex.
Further locomotives followed in batches and singly until 1941 when HL’s successor, Robert Stephenson & Hawthorns, despatched number 23. A similar locomotive, 40, built much earlier in 1919, had been taken over from the North Lincolnshire Iron Co Ltd in 1931; as it was supplied to NLI when Stewarts & Lloyds controlled that Company (1918-1931) it was probably nominally owned by S&L at the time of acquisition. Experience with this locomotive may have led to the adoption of the updated 16in design as a standard for the Works traffic at Corby, a design which even now is still very well thought of by the drivers. As might be expected of a works with a large number of locomotives and good engineering facilities, the practical experience of operating and maintaining the engines over the years has resulted in a good many detail alterations to the original design; the more obvious external differences can be determined from the accompanying illustrations, though mention may be made here of the cab windows. The enlarged timber framed openings to the front of the cab and the additional side ones were provided some time after World War 2 to provide better all-round visibility. The rear windows were also enlarged and fined with internal sliding glazed frames. One locomotive, 13, acquired a chime whistle in place of the more standard type.
By far the most interesting alteration, however, was the fitting of some of the engines with oil-burning equipment. An original experiment, in the 50’s, involved converting IRONWORKS No.1, a 1911 Barclay 0-6-0 saddle tank and one of the first Corby Ironworks locomotives to burn tar; this does not seem to have been particularly promising and it reverted to coal-firing. In the late summer of 1960, however, alterations made to Hawthorn Leslie 23 were more successful, and after some nine months’ experience seven of the standard locomotives (12, 14, 15, 16, 18, 23 and 32) were treated similarly over the succeeding two years.
The system, devised at Corby Works, consisted of a burner mounted in the bottom of the existing ashpan. This was fed with oil, from a tank mounted in the original coal bunker, and with steam, to distribute the oil within the firebox; the steam supply was taken from the dome through a lagged pipe running across the top of the saddle tank and into the cab. A brick arch protected the tube ends from the fierce heat and provided a better circulation of gases in the firebox; the base of the box was also bricked round to a height of twelve inches or so.
Two steam supplies, separately controlled, were provided at the burner, one to atomise the oil on entering the fitting, and the other to jet the spray around the firebox. Controlling the amount of steam at these valves gave varying intensities of fire. Steam was also provided to heat the oil tank (it was not always necessary to use this) and to clean out the oil feed pipe and fitting. The oil fuel tank contained 600 gallons and was fitted between and below the rear cab windows, the bunker being extended rearwards slightly to provide the necessary volume. Before the fire could be lit steam pressure had to be available for atomisation of the oil within the firebox. A supply was therefore provided at the loco shed (from a reduced works supply of 50lb) which was connected by flexible pipe into the control fitting, whilst a valve on the supply pipe from the loco boiler was turned off. This stationary source was therefore used until a sufficient pressure has been reached (50lb) for the engine’s own boiler to take over.
To light the fire, burning cotton waste was thrown into the firebox; it was then possible to ignite the burner by opening the steam valve and jetting valve and then the oil source, after first making sure the firedoors were shut and the blower was on! An air line was provided at the shed in place of the blower until the engine has its own steam. Heated and lagged elevated tanks at the “diesel end’ of the shed formed the fuelling point, the oil itself being Victaulic. The conversions were reasonably successful, but the locomotives became somewhat heavy consumers of water and could not be left for long without losing pressure, due to the transient nature of an oil fire compared with a coal one.
From the 1950’s all locos, steam and diesel, were painted buttercup yellow, with red wheels and coupling rods and black fittings, and, in the case of steamers, lettered S&L in black on the saddle tank: the 16in locos as a class seem to be known as the “the S&L’s” by the enginemen, other locos not generally having been so adorned. There were variations in the detail of the painting, mostly with regard to the extent, or existence, of black and yellow dazzle striping. This livery was adopted to make them more easily visible in the works, but owing to the dirty conditions which eroded the paint, the colour gradually deteriorated to a “steelworks black”. In the autumn of 1970, 21 received an overhaul involving the fitting of a new boiler which had been standing spare for a number of years. The axle boxes were renewed, attention given to the motion, etc. and presumably she was the last loco to have such repairs and renewals. 21 was repainted and lettered BSC, probably the only steam locomotive in British Steel Corporation ownership to achieve this distinction.
By April 1971, there were only two regular steam jobs, although three further engines were steamed as standby for diesel failures or for occasional or extra duties, three or four engines would usually be at work at any one time. This was out of a total of eight in more or less regular usage, although in March 1971 one of those, 19, was put to one side with slight accident damage. A further four were dumped at the loco shed in various stages of abandonment.
– Information from the Archives of IRS http://www.irsociety.co.uk