The longest bridge-building machine in Europe being used to construct to Mersey Gateway has been christened.

The colossal movable scaffolding system has been named Trinity at a special launching event at Catalyst Trade Park in Widnes.

Staff working on the tolled crossing were invited to suggest ideas in a competition.

Lynn Jeary, a member of the project’s communication team, chose the name Trinity as she felt it symbolised the three bridge pylons and the three partners in the construction joint venture -Kier Infrastructure and Overseas Limited, Samsung C&T Corporation and FCC Construcción S.A.

As Merseylink is also sponsored by three major companies - Macquarie Capital, BBGI, and FCC - Trinity was deemed to be a perfect fit.

Martin Buckley, operations director at Merseylink, said: "According to engineering tradition, a machine cannot start work until it is given a name, and the name is usually female.

“The tradition is carried on throughout the world as a sign of good luck for the project ahead.

“The competition really captured the imagination of our staff team and we've had some brilliant suggestions."

It has taken construction teams three months to assemble the bright orange machine.

This is no mean feat considering it includes approximately 1,200 components, 3,000 actual parts and is held together by over 60,000 bolts.

Now fully built, Trinity measures an impressive 157m long - the length of around one and a half football pitches - and weighs around 1,700 tonnes.

The machine will now build the elevated road viaducts over the Mersey estuary on both sides of the river, beginning with the north approach viaduct from the launch site at Catalyst Trade Park in Widnes.

Halton Council leader Cllr Rob Polhill and chairman of the Mersey Gateway Crossings Board, said: "This is a special day as it marks another key milestone for the Mersey Gateway project.

“The size and scale of this machine is truly spectacular and it's going to be fascinating to see Trinity in action in the estuary over the next few months."