A documentary-maker has visited one of the two surviving examples of the same type of ship as the SS Richard Montgomery.

Ken Rowles went to Fisherman’s Walk in San Francisco, America, to film the SS Jeremiah O’Brien.

Along with the SS John W Brown in Baltimore, it is the only remaining operational Liberty class vessel from the Second World War.

It is a sister ship – meaning it is almost an exact replica – of the Montgomery, which was carrying thousands of tonnes of explosives when it ran aground, split in two and sank off the coast of Sheerness on August 20, 1944.

Mr Rowles, of Sittingbourne, is currently making a 54-minute documentary called The Wreck: A Disaster Waiting to Happen.

He flew to USA with cameraman Graham Fowler from March 5 to 11 on a fact-finding mission to see how Liberty ships were built.

They also went on board the ship, which now functions as a museum, and spoke with veterans to discuss what they knew about the Montgomery.

The 69-year-old said: “It [the SS Jeremiah O’Brien] was one of the main ships involved in the D-Day landings.

“It actually went past Sheerness for the anniversary of D-Day in 1994 and it went up the Thames.”

He added he was able to get some insights into the sunken ship itself. He said: “One of the things I discovered was that the early Liberty ships split in half quite easily. There was a modification they made of putting an additional bow into the structure which made future Liberty ships more seaworthy.”

Mr Rowles, who has been working on this subject since 2002, said he is in negotiations with a “well-known” actor to narrate the feature.

A short promotional video to market the documentary to major television companies has recently been edited.

It is hoped the film will be ready in time for the 70th anniversary of the sinking.