MANCHESTER'S tram system ground to a halt for four hours following a power failure which hit its key operations centre.

Some Metrolink commuters had to be helped by ladder from trams to ground level when they came to an abrupt standstill between stations.

Other angry passengers complained that they waited in vain at stations, not knowing that the trams had stopped.

One said: "Nobody had the faintest idea what was going on. You would have thought that Metrolink could have got staff out to tell people - or at the very least put up a poster at each station."

Trams on the entire system were immobilised around 10am yesterday and there was no service on the system until 2pm when it finally resumed.

Problems began on Sunday night with a power failure which hit the area around Queens Road, Cheetham Hill. United Utilities were able to restore connections - but not to the Metrolink nerve centre.

Power was available to overhead lines which supply trams but there was no power for services including vital signalling and communications systems.

The tram company said it was able to make use of a stand-by generator which it said got them through yesterday's commuter rush-hour period.

But then it began struggling to cope with demand before ceasing to work, bringing services on the entire system to a halt.

Metrolink was able to bring in a second, more powerful generator but it was around four hours before any kind of service was re-introduced.

A spokesman said: "We are unsure of the precise nature of the problem which led to the loss of power. United Utilities was informed and we did what we could to keep trams running.

"We managed to get through the peak morning rush-hour but the first generator was just not powerful enough to cope with demands on it, and eventually stopped. We didn't put out notices warning passengers of problems because up to that point we believed we could keep the system going.

"Once the generator failed, we had no means of operating signalling equipment on the network, communicating with our drivers, or operating passenger information systems at stations."

One traveller said: "We were stuck outside Cornbrook for up to two hours and in the end were brought down on ladders from the tram to the ground.

"Somebody's wheelchair had to be dismantled and carried down the ladders while the person who was in it was helped down."

A grandfather from Sale said: "I sat on the tram outside Stretford station for about an hour. It slowly moved into the station and we were allowed off.

"I ended up walking into Manchester and was more than two hours late for work."

United Utilities said it took a while to locate the source of the fault on a high voltage cable. Once that had been done engineers began immediate repair work.

A spokesman said: "We were prepared to work right into the night if necessary. We have been in constant touch with Metrolink to appraise them of developments."

Services are back to normal.

Were you affected by the power failure? Have your say.