Saturday 21 September 2019

Rail buses developed at Dundalk GNR Works

IT EMERGED in December, 1952 that rail buses, adapted for low density traffic routes, which were being exported from the CIE works in Inchicore in Dublin were developed at the Great Northern Railway (GNR) Works in Dundalk by local engineering staff.

With a sparse rural population and a sometimes struggling economy, Irish railways sought economies of operation starting in the 1930's by eliminating branch line passenger trains and replacing them with railway operated buses or ' bus cabs' as there were sometimes called. This took place both before and after nationalisation in the Irish Republic. The buses called at the same stations the trains formerly did.

There was a problem however in the development of the rail buses in that a great part of the comfort afforded by bus was due to its pneumatic tyres.

At the time, in several parts of the world, particularly France rail cars were running on pneumatic tyres, but since the narrow head of the rail reduces the bearing area of the tyre, a cumbersome and costly multiplying of wheels had to be installed.

After some research and experiment, the G.N.R. solved the problem in a simple way by applying the steel tyre outside of the rubber one. The solution was reached by the General Manager at the Works, Mr. George W. Howden and the then Works Manager, Mr. R.W. Merdith and became known as the Howden-Merdeith patent.

The principles were that the rubber tyre was formed with the usual ridges on the other side of the outer surface and into the groves fitted two annular projections of the inner surface of the steel tyres so that the pneumatic tyre when inflated gripped securely to its outer steel rim which was made concave to suit the profile of the rubber tyre.

The front wheels of the bus did not swivel as steering was unnecessary on the rails. It was found that the track width of the standard bus was close to the gauge of the track, 5ft. 3 inches so that little alteration in dimension was needed. The cost of converting a bus to a rail bus was no more than £100.

The rail-bus proved a great success when introduced by the G.N.R. for it meant that a rail service could be provided in areas where traffic was so meagre as not to justify even the relatively low cost of working a rail car, not to mention the more expensive light stream train.

The vehicles came into service on November 17th, 1934 when the first one went into service on the Dundalk- Clones section. The rail-buses ran a total of 1,340,537 miles since they were introduced until December, 1952.

C.I.E. adopted the HowdenMerdeith patent. for operation in various areas of the country and also exported the idea