ONE of the longest surviving working features of the North-East's industrial heritage was removed yesterday in an attempt to breathe new life into a dock.

The operation to remove the 200-ton dock gates proved as much of an engineering challenge as when they were installed almost 160 years ago.

When the first gates were installed at Middlesbrough Dock in 1842, the main dock users were sailing ships bound for the Continent with cargoes of coal.

It could scarcely have been imagined that, five sets of gates later, the dock is still maintained.

While it was closed to commercial trade in 1980, it still caters for the occasional craft.

Now, in the first stage of an £18m regeneration project for the area, the gates will be replaced to allow the passage of many more vessels.

The decision to remove the gates was taken because they no longer maintained a constant water level.

But moving them proved more troublesome than expected, with an initial attempt to float them out leaving one gate lopsided in the water.

This time, no chances were being taken, with a 1,000-ton mobile crane being used to winch the gates above the River Tees.

Colin Embleton, a site manager for Harbour and General, which performed the task, said it was a mammoth undertaking.

"It was a massive operation, but we were 100 per cent confident that it would work," he said.

"An incredible amount of planning went into this."

The entrance to the dock had to be impounded with a wall to ensure that the water level was not affected.

And such is the scale of the operation, due to last until Friday, that an entrance to a car park at the neighbouring Riverside Stadium has had to be closed.

John Navaratnam, a senior project manager at English Partnerships, one of the agencies behind the scheme, said the regeneration of the dock's Middlehaven site will have lasting benefits.

"The reclamation of Middlehaven is a vital first step in the regeneration of central Middlesbrough, which will have an impact in the wider region too," said Mr Navaratnam.

But for local historians such as David Pattenden, the changes mark another step away from a golden age when the dock was Middlesbrough's focal point.

He said: "Middlesbrough Dock was dug out by navvies in the late 1830s and was called a puddle in a railway yard.

"It created the first railway town.