Road-rail vehicle

From Wikipedia, the free encyclopedia

Three British diggers

HiRail wheel (retracted) on a small truck

Buckingham Branch Railroad's HiRail Chevy Suburban.

A Road-rail vehicle is a self-propelled vehicle that can be legally used on both roads and rails. They are sometimes referred to as a Hy-rail or HiRail. They are normally converted rubber tired road vehicles that have additional steel wheels for running on rails. Because one set of wheels would normally foul the other if both were down, a pneumatic, or hydraulic system is employed to lower and raise the rail wheels.

1 Overview
2 Road Rail buses
3 Road Transferable Locomotive
4 Maintenance and shunting
5 See also
6 External links

[edit] Overview

Such vehicles are normally used for permanent way maintenance during engineering possessions of the line. They can be driven on roads to near the site and then convert to rail vehicle for the final journey to the worksite. This avoids both the complex manouevres that would be associated with a rail vehicle, and the problem with a road vehicle of accessing the worksite if the worksite is not near a road. Since they are normally converted road vehicles, they would not fare well in a collision with a heavy rolling stock and therefore can only drive on railways under an engineering possession. Their light weight also means they may not correctly operate track circuits for signalling.

However, there have been other uses for road-rail vehicles. The Canadian company Brandt has converted large truck tractor units for use as locomotives that can move by road to where they are needed. [1], [2]. Still mostly used for permanent way maintenance, they can also be employed as thunderbird locomotives or even used in normal service, where they are suitable for smaller operators.

[edit] Road Rail buses

Attempts have been made over the years to try and design buses and coaches that could operate on both roads and railway tracks. These attempts were never particularly successful. Some were carried out in Britain during the 1930s, on the Nicky Line by LMS and The New South Wales Railways tried during the 1970s on New South Wales routes.

The Deutsche Bundesbahn operated a number of buses, called the Schi-Stra-Bus, that could be fitted with separate bogies in the Koblenz area from the 1950s to 1970s.[3]

[edit] Road Transferable Locomotive

The RTL is a truck prime mover with railway wheels that can be lowered when operating on the railway tracks. It was developed in Victoria in the 1990s. The idea was to have a locomotive that could transfer from one branch line carrying mainly wheat to another parallel branch line, where the rail connection is very roundabout. The RTL suffered a number of disadvantages. Loads were severely limited when the track was steeply graded. The rubber traction wheels slipped on the steel rails when wet. The life of the rubber tyres was not very long.

[edit] Maintenance and shunting

Self propelled maintenance vehicles for maintenance of the track and for shunting wagons are much more convenient to use if they can transfer to the road to reposition or otherwise get out of the way. Because relatively light loads are involved, the problems plaguing the Road Transferable Locomotive are avoided.

An example would be a forklift truck fitted with railway wheels and a coupling to shunt a wagon or two with.