AMTAB - Automatic Train and Vehicle Weighing Systems

AMTAB are committed to developing systems that improve the safety and efficiency of rail traffic. Among their innovative product range are automatic train and vehicle weighing systems, train detectors, wheel flat detectors and automatic rail weighbridges. With over a decade of experience in the design and manufacture of dynamic rail traffic monitoring systems and weighing devices AMTAB are in a strong position to work with customers to find the best technical solution to improve efficiency and safety. New developments include the direction-dependant speed indicator and the axle detector to measure the passage of axles.

AUTOMATIC TRAIN WEIGHING SYSTEMS

The weighing system works by weighing trains while they are in motion. It can also be used for calculating the number of passengers in carriages and for loading systems with automatic feedback to ensure that loading will be as optimized as possible. AMTAB's dynamic weighing systems offer a number of key benefits:

• Weighing trains and vehicles in motion over weighing sensors saves a great deal of working time
• Simple installation: no extra weighing tracks are required and installation does not affect traffic flow
• Only holes for the sensors need be drilled into the rails
• The analysis unit is located indoors

The weighing system improves safety by checking that the axle loads are not too high and that wagon loads are not unbalanced.

The weighing system is quality assured and is tested in cooperation with the Swedish National Testing and Research Institute (SP) and the Norwegian Metrology Accreditation Service (Justervesenet). Approval has been obtained for use within the speed range of 4-25km/h in accordance with OIML R106, Class 1.

RAIL RELAY UNIT FOR TRAIN DETECTION

The rail relay unit can detect that a vehicle has stopped so that, for example, route and level crossing barriers can be released. The relay unit has fixed settings for different types of rails meaning no calibration is needed for different installations. The unit consists of a sensor that is bolted to the rail and an electronic evaluation unit which is installed alongside the track. If the dynamic wheel pressure exceeds a preset limit a change over relay is energized for five seconds.

WHEEL FLAT DETECTOR

The wheel flat detector measures the wave induced in the rails caused by the wheels when a train passes. If there are irregularities in the wheel a variation in wave propagation will occur in the rail which will be recorded by the sensors. The signals from the sensors are saved for subsequent computer processing. By adjusting the measured signal for the attenuation of the wave induced in the rail, the number of sensors can be reduced and accuracy improved.

TRAIN SPEED DETECTOR

A new development from AMTAB is the train speed detector. The indicator enables level crossing barriers to be lowered at varying times before the train passes the crossing so road users will not have to wait unnecessarily long.

AXLE DETECTOR

Another new development the axle detector is used for detecting wheel passages. When a wheel rolls on the rail past the sensor a signal, that is proportional to the measured wheel load, will be recorded via a current loop. The direction of the travel of the wheels can also be detected by an evaluation unit.