EMERGENCY crews are being mobilised to tackle a major disaster on the Thames involving a collision between two ships near Tower Bridge.

EMERGENCY crews are being mobilised to tackle a major disaster on the Thames involving a collision between two ships near Tower Bridge.

But they don’t go into action until late Thursday evening (Sept 30).

The exercise is aimed at preventing another Marchioness-type disaster when 51 people were drowned in a Thames collision in 1989.

A broken down commercial vessel and a damaged passenger boat are being used as a scenario for the search-and-rescue exercise in how to deal with major emergencies on the river.

It is 21 years since the night-time Marchioness tragedy when the pleasure cruiser was in collision with the Bowbelle dredger.

On Thursday, teams of river police, the fire brigade, ambulance service, Coastguard and Royal Lifeboat crews join the Port of London Authority and Passenger Boat Association to make sure they are ‘up to speed’ should such a disaster happen again.

But the full details of the operation are being kept secret from the rescue teams in advance, in order to retain an element of surprise.

“We are deliberately keeping information to a minimum,” the RNLI’s Andrew Ashton revealed. “Our lifeboat crew members would mentally prepare themselves if they know what’s coming.

“The purpose is to make it as realistic as possible, because in a real-life emergency you would have no prior warning.”

The ‘rehearsal’ is the first major rescue exercise during the hours of darkness. The last was in daylight four years ago.

The two-hour exercise begins at 8.30pm with a message to London Coastguard, which then coordinates all the emergency resources including RNLI lifeboats, the Met Police river patrols, the London Fire Brigade fireboat and the Coastguard.

The coordinated Thames ‘search and rescue’ service was set up after the Marchioness disaster near Blackfriars Bridge in the early hours of August 20, 1989, when it was hosting a private birthday with 131 crew and passengers on board.

Only 79 survived after she was hit amidship in the collision with the Bowbelle.

The Marchioness rolled over on impact and quickly filled with water while being pushed under by the dredger.

The entire superstructure became detached and took just 30 seconds to sink. Most of those drowned were trapped below deck.

A memorial was later set up in the nave of Southwark Cathedral, not far from the site of the disaster, where every year in August a remembrance service is held for the 51 who lost their lives.