Part of Oxford University's Department of Physics has had to be dismantled to remove a huge storage tank.

Coming out: The gas cyclinder is extracted from the building in Banbury Road, Oxford

The department, in Banbury Road, was originally built around the 80-tonne tank, which can hold 100,000 cubic feet of gas, when it was installed in 1964 after a ten-day journey by road from Clydesdale.

But problems arose when the now-defunct 49ft 6in by 9ft 6in tank, part of a former vertical Van der Graff generator system, needed to be taken out of the building to make room for a new carbon dating unit for the archaeology unit.

It would not go through any of the existing doorways, so the only answer was to dismantle the end of the building.

The department's technical supervisor Mike Williams said: "It has been out of use for eight years and is the last bit of the Van der Graff left.

"This bit was particularly tricky to get out, so we had to take the ends of the concrete building off."

He said heat and lighting in that part of the building had had to be disconnected in the immediate area of the tank an operation which had taken several weeks.

Other parts of the generator have made it as far afield as Beijing and Strasbourg. This tank is understood to be destined for a second-hand tank dealer.

When in use, the tank housed an eight-million volt Van der Graff accelerator which acted as an injector to the 12-million volt accelerator installed in a basement below the fan-shaped concrete structure.

The former storage area for the tank will be reassembled as the carbon dating unit is constructed. Work is expected to finish this summer.