Technology

electronic guidance

Prompted by the growing interest in intermediate forms of public transport, and with investment from The National Endowment for Science, Technology and the Arts (NESTA), Minitram Systems has developed a new form of electronic guidance. Called ‘Safeguide’, the system majors on simplicity and above all safety. 

Safeguide is used in conjunction with rubber-tyred Minitrams which can operate within a segregated tram/bus lane on an existing highway or else along dedicated, paved alignments and in pedestrian areas. The electronic guidance system automatically steers the vehicle but in all other respects - including braking and acelerating - the driver remains in control.

Based around the concept of detecting low frequency signals generated through underground cables, the breakthrough with Safeguide is its unique, high integrity watchdog steering system. This patented device is designed to automatically take over from the primary system should an emergency condition be detected. Such an approach differs significantly from previous forms of electronic guidance, which have relied on the driver to take evasive action in the event of failure.

To ensure the highest possible level of safety integrity, Minitram Systems has designed Safeguide against very specific performance criteria identified in a safety case strategy. This strategy has been developed through painstaking consultation with industry experts and Her Majesty's Railway Inspectorate (HMRI).

In terms of infrastructure, Safeguide is extremely cost effective. A pair of signal cables are buried down the centre of the guideway approximately 75mm below the paved surface and 400mm apart. Signal generators and transponders are located at stations/stops. 

Aside from the obvious benefits of a fixed infrastructure transit system, the four-wheel steered Minitram, under Safeguide control, can improve on the performance of conventionally guided vehicles by achieving a virtually gapless, level boarding solution. This is of particular interest to operators and local authorities now faced with very stringent access requirements under DDA legislation. 

The guidance system can also ensure precise steering along narrow transit corridors. This is especially relevant in historic town centres where conventional bus lanes or tram lines would be impractical. 

Minitram Systems believe that Safeguide offers significant advantages over other forms of guidance such as O’bahn (kerb guidance). For example: the infrastructure is more or less invisible; it is inexpensive to install (a complete Minitram system inclusive of vehicles and infrastructure is estimated to cost around £1m per km); it will work in all weather conditions and there are no trip hazards for pedestrians.