The jaws of a crane grab which crushed a worker at Shoreham Harbour could have been shut off as a safety measure, the Old Bailey heard.

An expert on lifting machinery told jurors yesterday it took just five minutes to switch off the clamshell grab which accidentally snapped shut on the head of Simon Jones, 24.

The Sussex University student, from Banbury, Oxfordshire, had been loading bags of road-building stone from the hold of a ship.

It was his first day as a casual worker for shipping firm Euromin which, together with its general manager, Richard Martell, is charged with his killing.

Ronald Stalard, who runs a firm which tests machinery and offers safety consultations, told the court he was asked by Euromin for advice on how to improve its method of lifting two months before the tragedy.

He said the old system was unsafe and the company wanted a simpler, safer and quicker method.

Mr Stalard confirmed it was the company's intention for cargo to be loaded on to hooks by staff working beneath the open grab jaws.

He said: "My understanding was that the grab would be open.

"You could cut off the shut valve so it couldn't possibly move. I know the shut-off valve was working properly because I actually tested the grab.

"It takes about five minutes to shut off the valves."

Jurors have heard the grab attachment did not need to be connected while unloading bags of stone.

The prosecution claims the company, under the instructions of its manager, put workers' lives at risk after ignoring several Health and Safety Executive measures.

It was thought an operator accidentally nudged the lever which shuts the claw, the jury has heard.

Martell, of Jubilee House, Aldingbourne Drive, Crockerhill, near Chichester, denies manslaughter.

Dutch-owned Euromin, of the Glassmill, Battersea Bridge Road, Battersea, London, denies manslaughter and six charges under Health and Safety regulations.

The trial continues.