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Anti Collision Devices

PostPosted: Wed Dec 11, 2013 6:24 pm
by Prasanth
The ACD Network is a Train Collision prevention system designed, developed and patented by Konkan Railway Corporation Limited (A Public Sector Undertaking of Ministry of Railways, Government of India). Its concept was first proposed by the former chairman of Konkan railways Mr. B raja ram in the 90s.Its patent was filed in the sept 1999 and the patent was granted in the year 2005. It is a self-acting microprocessor-based data communication device which when installed on locomotives (along with an auto-braking unit - ABU), guard vans, stations and level-crossing gates (both manned and unmanned), prevents high-speed collisions in mid-sections, station areas and at level-crossing gates.

The ACD uses both radio frequency and Global Positioning System (GPS) through satellites, whereby a train is automatically brought to a halt if the track ahead is not clear. The train starts braking 3 kms ahead of a blockade. The Anti-Collision Device (ACD), also called `Raksha Kavach,' envisages setting up a network of "self-acting" micro-processor based communication devices which automatically apply brakes on trains that are unknowingly getting into a "collision-like situation," including before stations and at mid-sections. "At the mid-sections, where neither the protection of signals nor guidance is available to the driver, the ACD makes the loco intelligent and extends its capability to detect any collision-like situations in a range of 3 km, which the driver cannot detect on his own. Situations like collision between two approaching trains or between a derailed train on one track and an approaching train on the adjacent tract can thus be prevented, according to the KRCL official.

The "silent" network of ACD systems can be installed on the locomotives, guard vans and at stations, which could ensure that trains do not collide at while travelling at high speeds. Further, if the ACD systems are provided at the level crossing gates (both manned as well as un-manned), the project could provide protection to the lives of road users also. "We have tested the commercial prototypes of ACD system, which has been developed indigenously for the first time in the world. It has been technically proven during joint field trials with Research Design and Standards Organization, nominated by the Railways," the official said. The ACDs are capable of multi functions.

For example, while approaching a station, the Loco ACD gives the "station approach" warning to the driver about 2 km in rear of the first STOP signal of the station and in case the driver ignores the warning it will automatically regulate the train speed. The pilot project implementation of ACD was successfully commissioned on the North-East Frontier Railway this year. Survey for expanding the system to another 10,000 km falling on the critical and busy sections of the network is almost complete.


Indian railways are the world's second-largest railway, with 6,853 stations, 63,028 kilometres of track, 37,840 passenger coaches and 222,147 freight cars. Annually it carries some 4.83 billion passengers and 492 million tons of freight. Of the 11 million passengers who climb aboard one of 8,520 trains each day, about 550,000 have reserved accommodations. Railways is an Eco- Friendly and Popular mode of Transport in almost all cities of the INDIA. It provides vital connectivity between major commercial system at low cost. It is also the most used method of long distance transportation in India. But with the increase in number of passengers and traffic during the last 10-15 years the frequency of train accidents has also increased rapidly. Out of total accidents around the world approximately 15% occur in India. These accidents take hundreds of lives, disable many people and causes high financial losses to the Indian Railways.

As the number of passengers is increasing day by day, the rail routes are getting busier. This increase in the traffic also increases the chances of accidents. In Mumbai during the peak hours trains reach at stations with an average time interval of 3-5 min. With this much close interval between the arrival of trains there are high chances of collisions between the trains. As these trains carry 6.94 million passengers per day, even small accidents will have catastrophic effect on the people of Mumbai. Although an Auxiliary Warning System (AWS), has been operational in Mumbai’s Central and Western Railways for the past 15 years and there have been very few major accidents. But a more advance and efficient systems was always needed.