Waggon- und Maschinenbau GmbH Donauwörth railbus

Waggon und Maschinenbau, G.m.b.H., of Donauworth railbus
Waggon und Maschinenbau railbus at Weybourne shed, North Norfolk Railway
In service	1958 - 1967
Manufacturer	(Waggon- und Maschinenbau GmbH Donauwörth ())
Number built	5
Formation	railbus
Capacity	56
Operator(s)	British Railways
Line(s) served	Witham–Maldon branch line, Braintree Branch Line, Saffron Walden Railway
Specifications
Car length	41 ft 10 in (12.75 m) (over body), 45 ft 9 3⁄4 in (13.964 m) (over buffers)
Width	41 ft 8 1⁄2 in (12.713 m) (over panels)
Height	11 ft 9 in (3.58 m)
Maximum speed	55 mph (89 km/h)
Weight	15 tonnes (14.8 long tons; 16.5 short tons)
Traction system	6-speed electro mechanical gearbox
Prime mover(s)	Buessing
Engine type	6-cylinder horizontal
Power output	150 hp (110 kW) at 1,900 r.p.m.
Track gauge	1,435 mm (4 ft 8 1⁄2 in) standard gauge

The British Railways railbuses were delivered in April 1958. They were based at Cambridge until 1964. They were withdrawn in 1966 and 1967.

The WMD railbuses were 5 of the total of 22 delivered in 1958 from five manufacturers (the rest British). They were planned to have "extensive trials". The underframe, power equipment, transmission and brake gear were similar to the Uerdingen railbus, common on the German Federal Railway. They were shipped via the Harwich-Zeebrugge train ferry. It was hoped they might be the answer to increasing losses on rural branch-lines. In the first year of the railbuses they saved £66,000 in operating costs, but the branches were still losing £4,000 a year (£85,000 at 2014 prices). However, at the time, such losses were unacceptable, and the lines they worked were closed.

The underframes were built of channel shaped cross-beams welded to flanged plate longitudinal girders. The corrugated steel floor was welded on top.

The body was formed of alloy panels rivetted on a light steel frame. Roof plates were crimped to increase rigidity. The body was suspended from four points on the frame, connected by hydraulic shock absorbers.

Unlike most BR diesel units, the accelerator was foot controlled. Also unusual at that time, were the power operated central doors and air powered disc brakes.

Initially the buses worked the Maldon, Braintree, and Saffron Walden lines. They had too few seats for the Braintree branch and were used on the Mildenhall line from July 1958. Mildenhall closed in 1962. E79961/3/4 had their Buessing engines replaced by AEC A220X engines, also of 150 hp, in 1962-3, due to the cost of importing replacements from Germany. Their other branches closed in 1964, after which they spent most of their time in store at Cambridge. In 1965 79963 and 79964 were trialled on the Alston Line, but couldn't haul parcels vans and had heating problems in winter. 79961 and 79964 were transferred to serve Millers Dale in 1966, but that branch closed in 1967. M79961 was the last to be withdrawn in August 1967 and was scrapped at Rotherham in 1968.