Experts say there have been no surprises in the most recent survey on the wreck of the SS Richard Montgomery. However, it has shown one of the mast stays has become detached. Reporter Emma Grove spoke to the Maritime and Coastguard Agency’s Receiver of Wreck to find out what this means...

Surveys are carried out most years on the SS Richard Montgomery – the American Liberty ship which was carrying thousands of tons of explosives when it ran aground, split in two and sank off Sheerness on August 20, 1944.

For decades it has been speculated what would happen if its cargo exploded, with parts of Sheppey and Sittingbourne likely to be badly affected.

A report from 2012’s sonar survey was published last week and there are a few changes which have been noted, although it says overall the site remains stable.

There has been an increase of about 16cm to 2.69m in a crack on the port side of one of the holds since 2011 and the deck plating on the same hold has dropped by 30cm since 2010.

One of the mast stays, which attach the mast to the deck, has come off completely.

Receiver of Wreck for the Maritime and Coastguard Agency Alison Kentuck, who oversaw the report, said the change was not unexpected.

Since the multibeam sonar survey was carried out in October 2012, divers have been back down to study the thickness of the masts and the hull.

This most recent visit in the summer showed the mast stay is now totally detached and sitting on the deck.

“It’s something we can expect given that the masts in particular all go all the way up through the water column and through the tidal range so they are subject to wind, rain and tidal change,” Ms Kentuck said.

“We would expect them to be subject to deterioration and given it’s only the most forward mast which has stays, it’s not completely unexpected one might have snapped off.”

She said there was a lot of trimming done to the masts in about 2000 to reduce stress on the hull and there has always been the possibility this could be done again, but Ministry of Defence advice will be sought on this.

Ms Kentuck said the masts still seem to be in exactly the same position.

“It’s a possibility the masts could collapse completely but we are not anticipating it happening any time soon,” she added.

As recommended in the 2011 report, a smaller vessel was used to carry out the latest investigation which meant it could travel right over the top of the wreck and take clearer pictures from above.

“The main outcomes from this and the previous reports are that at the moment there are no surprises,” Mr Kentuck said.

“There is slow deterioration as you would expect but it does seem to be slow and it seems the wreck itself is in reasonably good condition given its age. It’s standing up to its environment very well.”

As for what happens next, Ms Kentuck said this year’s survey was supposed to be carried out last week but the wind prevented this from happening so it is hoped it will take place this week.

Once that has been done, the results from both the 2012 and 2013 reports will be considered along with the divers’ hull/mast investigation from this summer, although that is unlikely to happen this year.

“The Department of Transport has always said monitoring with non-intervention is the best way forward,” she added. “It’s always kept under review.”

MP Gordon Henderson said he was reassured to read that as a whole the wreck site appeared to be stable.

But he has written to transport minister Stephen Hammond to point out that the report doesn’t give any indication of the current state of the munitions on board and asking if there is any intention to use a different technique to check for deterioration in that area.