The SS Richard Montgomery sank in the Thames Estuary in August 1944 (Picture: Christophe Trouillard via Pen News)

A ‘Doomsday wreck’ crammed with enough explosives to unleash a tidal wave up the Thames is deteriorating faster than feared, experts have warned.

The SS Richard Montgomery sank in the Thames Estuary in August 1944, coming to rest at a depth of 49ft with 1,400 tonnes of explosives still in her hold.

Her three masts can still be seen looming above the water’s surface and plans have long been made to remove them – along with the risk they could topple and trigger a potentially ‘catastrophic’ blast.

That remedial work is now being brought forward after a new assessment discovered the corrosion plaguing the masts is worse-than-expected.

Southend Labour councillor Lydia Hyde, who’s familiar with the latest findings, said things had reached a point where it was safer to act.

She said: ‘There was an assessment in the summer, and then there was a more detailed one in November, to basically go and look at the condition of the masts.

‘The concern is that corrosion means they catastrophically fail, their structural integrity goes, the mast falls down and then lands on the wreck, and then that could set off an explosion.

‘Following the dive, they’ve assessed it and they’ve gone “actually, no, we need to bring this forward because the corrosion was more than expected”.

‘So they’ve got to be taken down.’

The SS Richard Montgomery was an American vessel carrying munitions for the allies in the Second World War (Picture: Pen News)

Her three masts can still be seen looming above the water’s surface and plans have long been made to remove them (Picture: Christophe Trouillard via Pen News)

The SS Richard Montgomery was an American vessel carrying munitions for the allies in the Second World War.

It’s feared she still holds enough explosive power to unleash a tidal wave in the Thames, earning her the nickname “Doomsday wreck”.

Estimates vary as to the potential size of such a wave – some say 16ft high, some just three feet, and some say there wouldn’t even be a one at all.

But Ms Hyde believes the impact would be felt all the way in Southend, more five miles away.

She said: ‘If that blast was to go off then we’re talking about the windows blowing out on the seafront.

‘I don’t know what the risk to life is at that distance – it might be quite small directly from it.

‘But if it’s enough to blast out your windows, knock people over, and knock people into things, then things could fall on them, so it could be quite dangerous for pedestrians.’

She estimated it would be ‘more severe’ on the Isle of Sheppey – the wreck is less than two miles from Sheerness, the island’s second-largest town.

Plans to remove the masts were first made in 2020.

At the time, the Department for Transport said the masts could be ‘placing undue strain on the rest of the vessel’. But the work has been delayed for years and the masts still stand.

Plans to remove the masts were first made in 2020 (Picture: Christophe Trouillard via Pen News)

Ms Hyde said it is now slated for removal in March, adding: ‘It’s obviously been there for a number of decades now, but over time the metal is going to rust.

‘Even though it’s been fine up until now, over time it is degrading and it’s just tipped through that threshold now where the safe thing to do is remove the masts.

‘There’s significant planning and expertise that’s going into this so we don’t expect there to be a catastrophic incident.’

A Department for Transport spokesman said: ‘Our priority will always be to ensure the safety of the public and reduce any risk posed by the SS Richard Montgomery.

‘We commissioned experts to carry out vital surveying work to the wreckage.

‘Based on their findings, we are now reviewing and updating our plans to remove the ship’s masts as soon as safely as possible.’

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‘The concern is that corrosion means they catastrophically fail… and then that could set off an explosion.’