UK-based Silvertip Design has an exciting new project that it hopes will revolutionise freight and passenger travel. After years of research and development Mechanical Engineer and head of Silvertip Design Carl Henderson has produced the "Blade Runner", a dual-mode vehicle that could transport passengers or freight over long distances on rail or road.robinSimilar in concept to the JR Hokkaido vehicle train/bus concept recently featured in Gizmo, the potential benefits of an affordable dual-mode vehicle are immense, especially in areas of government economic and civil planning, as well as the commercial sector. Aware of the potential of this innovative idea, the dual-mode project is currently being backed by freight trailer and body builder Don Bur, Stoke-on-Trent, and the government's Department of Trade and Industry.
Although the load-carrying portion can be either a lorry or a bus, the dual-mode vehicle resembles an articulated truck up to 16.5 metres long. The fundamental departure is that both the powered front section and the bogie of the trailed vehicle have special wheels for aligning the vehicle on railway or tram tracks. These flanged wheels are fully retractable when driving on normal roads.
Although this idea is not entirely a new one, other attempts have been complicated and expensive because of the proposal to drive the vehicle with rail wheels.
The Silvertip dual-mode vehicle approaches this problem in a different manner. The driving and braking power comes directly from the road tyres, as they are in contact with the rails. Weight sharing between the flanged rail and regular road wheels is automatically varied by sophisticated systems that determine the required power transmission needs. More weight can be distributed on the rail wheels when cruising, or more on the road wheels when braking, accelerating and climbing hills.
When on rails, only light contact is needed for normal driving motion because the rolling resistance on rail is a fifth of that on road, so much less power is needed, resulting in less consumption of fuel overall. Regular stopping distance is more than halved because of the enhanced grip when weight is transferred to the tyres when braking. According to Silvertip, emergency stopping distance could be cut by about 75 per cent, representing a positive leap in safety in avoiding rail collisions.
One real advantage of being able to change from rail to road during transit is that the dual-mode vehicle can go off rail and steer past another vehicle or obstruction on a tramway. Therefore the Blade Runner can change route at junctions without relying on a specific railway points system.
Furthermore, the dual-mode vehicle can easily deviate from a railway and carry on by road to deliver or pick up passengers or cargo much like an ordinary bus or lorry would. Thus, no added time need be wasted in transferring goods or people from one mode of transport to another. Another interesting feature proposed in conjunction with the dual-mode vehicle is that conventional two-track railways are not required. The cost of maintaining regular rail track is immense, as tracks undergo huge dynamic forces causing deformation and cracking of the rail itself.
A purpose-built single-ribbon track could be laid down in existing highways and the load carrying wear on this track would be minimal. Special areas would not be needed to be put aside to lay down this track, like train tracks require, as the dual-mode vehicle could operate like a train but take up the same road as normal vehicles. This results in a huge economic saving in industrial planning.
The exclusive routing, speed and fuel economy of rail is combined with the convenience and organisational economy of road. Although the capital cost is understandably greater than that of a pure road vehicle, the overall operating costs are much less.
