AN INGENIOUS TRAIN.

New Zealand Herald, Volume LXVI, Issue 20420, 23 November 1929, Page 3 (Supplement)

AN INGENIOUS TRAIN.

TRACK-RENEWAL SYSTEM.

MILE EVERY THREE NIGHTS.

JHE LATEST AID OF SCIENCE

For mof,e than a hundred years there has been no change in the method of relaying Britain's rail tracks, which cover 51,500 miles and cost ovpr £13.000,0C0 annually to maintain and renew. The materials used (rails, chairs, keys, sleepers, and bolts) have been greatly improved in quality and design, but owing to the ijvw-increasing weight of trains the renewal of tracks becomes a subject cf primary importance to railways.

The present method of relaying js that rails, chairs, sleepers, and fastenings, weighing something in the neighbourhood of 400 tons for every mile of track, are placed alongside a stretch to be renewed until the'relaying gang takes possession and " opens up" the line. Hie old track is removed from the " road" by hand, loaded into waggons by hand, and discharged at the depots for distribution, for sale, or re-use. The relaying of any length of,track means that the new and old materials have to be transferred by hand'seven times.

Science, however, has come definitely to the aid of the railway engineer in the thape of /the latest Morris track-laying system, which is virtually a rail track on a train. At a central depot the new track is assembled iri complete units to the length of tlie rails, and loaded by overhead electric crane on to an ingenious train known as the track-layer. Along the train, at the extreme outside width, runs an outer rail, on which a transporter or,train trolley runs from end to end.

This transporter' conveys a complete length of built-up track from one end of the train to the oilier, ami when it reaches the Tear end of the train it is taken over by the track-layer, which consists of a rectangular cantilever steel fiame mounted on a bogie truck, one end of the frame projecting beyond the track.

On arrival at the site ol the relaying, the first length of old track is lifted out by the cantilever frame and is passed back to the transporter, because the new track is run forward on to the projecting end of the cantilever when dropped on to the ballast in proper line and position, the near ends of 111e rail being 111 contact with the rails on which the train is

standing. In the interval the ballast has been broken up ready for the new rails, and after the joints between the old and new rails have been connected, the train moves forward ready for the next transfer. The cantilever and transporter are .worked electrically from a power van Which receives its energy from the steam engine of the train. The track-layer does roost of its work by searchlight during the night, and one-third of a mile of track can be renewed in a night's work. Ihe track-laying train does not in any Way interfere with trains passing on the opposite line, and there is little interference with the services. As soon as the •relaying is completed, the track-layer with its transporter is left in a convenient, siding and the material waggons return to the depot for unloading and reloading for the next night.