A SENIOR Mass Transit Railway official has said a comprehensive review of the MTR safety system urged by legislators would not be necessary, even though drivers would apparently not be alerted if carriage couplings came loose.
An inquiry into Tuesday's MTR incident is aimed at finding out whether any warning signals were given to the driver when a train split in two in the tunnel between Tai Wo Hau and Tsuen Wan.
Operations director Mr Bill Donald said yesterday there were reports of passengers triggering the alarm to try to talk to the driver but the message was not understood.
After the carriages separated, both sections of the train were brought to a halt by a central computer.
Mr Donald said, under normal circumstances, the train operator would need instructions from the central control room to start a train on manual mode after an automatic brake.
''The train operator would not have started the train had he known of the couplings failure,'' he said.