|THE INDUSTRIAL RAILWAY RECORD
© DECEMBER 1968
As mentioned in RECORD 13, The Irish Peat Commission (Bord na Mona) operates extensive narrow gauge railway systems in those parts of Eire where peat is found, the majority of the lines being laid to aft in gauge. For several years the motive power was principally the Ruston & Hornsby 4-wheeled diesel locomotive, but it was decided that more powerful machines could be advantageously employed. A batch of locos was later obtained from Deutz of Germany, and in 1961 Bord na Mona constructed a prototype 0−4−0 diesel loco to satisfy its own particular requirements.
After extensive proving trials the Hunslet Engine Company was successful in obtaining an order on 23rd January 1962 to supply locomotives of this "Wagonmaster" design. The first locomotive was despatched from Leeds fully erected on 8th November 1962, and the initial batch of twenty-five was completed just over twelve months later. A second batch of twenty-eight was ordered on 30th December 1963 and delivered between 30th June 1964 and 30th September 1965. The Hunslet works numbers are 6232 - 6236 (1962), 6237 - 6256 (1963), 6304 - 6311 (1964) and 6312 - 6331 (1965).
Weighing some 72 tons in working order, these 0−4−0 diesel hydraulic locomotives are driven by a 6-cylinder Ford 590E diesel engine developing 80hp at 2,250rpm. The 4−speed Ford synchromesh gearbox was removed from the engine on delivery from Fordís and a Vulcan-Sinclair fluid coupling complete with housing was mounted on the rear of the engine; the gearbox was then fitted on the rear of the housing. A Hardy-Spicer universal drive shaft takes the drive to a forward and reverse gearbox mounted in the frame. Final drive to the wheels is through a jackshaft, fly cranks, coupling and connecting rods. It will be noted that the coupling rod is of an unusual shape with a lug towards one end where the connecting rod is pinned.
Forward and reverse speeds of 2.4, 4.95, 9.1 and 15..3 mph are available, and the locomotives are fitted with handbrake only which operates on all four wheels. They have a maximum axle load of 4 tons 18 cwts, can traverse curves of 60ft radius, and have a maximum tractive effort of 6,300lbs. Assuming the train to have a starting resistance of 18lbs per ton, they are capable of starting a 90-ton train on a 1 in 50 grade or 340 tons on level track, and can be used on track laid with rails as light as 25 lbs per yard.
When new the "Wagonmasters" were painted as follows: lower half of the cab, inside and outside - dark brown B.S.C. 412); upper half of the cab, inside and outside - deep cream B.S.C. 353); frames and running gear - black.
We are indebted to Mr G. Horsman and the Hunslet Engine Co Ltd for much of the above information and the photograph. The drawing, by Ken Fleming, is based on general arrangement drawing M.7087E kindly supplied by Bord na Mona and loaned by Mr D. Semmens.