FORTY-THREE years ago one of the most dramatic rescues took place more than 1,500ft below the Irish Sea.

In the summer of 1973 Roger Chapman and Roger Mallinson were working for Barrow-based Vickers Oceanics laying deep-sea telephone cables.

On August 29 the two men were working 150 miles south west of Cork, Ireland, in the Pisces III submersible.

After working underwater, the two men surfaced to be taken aboard their support vessel, the Vickers Voyager.

During the course of docking, the thick cable used to tow the boat in ripped a section of the hatch from Pisces III, causing water to flood in.

The submarine quickly sank, snapping the attached tow line at a depth of 170ft, before hitting the sea bed 1,575 ft down.

Mr Chapman and Mr Mallinson knew not to panic, both being experienced submariners.

Taking stock of their situation almost 500 metres underwater, the men knew their actions could mean life or death.

After checking the submarine for leaks, they settled in to wait for rescue, aiming to conserve as little oxygen as possible.

On the surface, rescue plans were put into action, with teams from across the world mobilised to help the trapped men.

Vickers dispatched the submarine's mothership, the Vickers Venturer, to the area, picking up two rescue subs along the way from Cork.

The Barrow-built submarine HMS Valiant was sent to help with the rescue, along with a vessel from the US navy.

However, the rescue effort was severely hampered by the deteriorating weather.

Gale force winds and 35ft swells set back rescue attempts as the oxygen supply aboard Pisces III continued to go down.

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The first attempt to locate the men using the submarine Pisces II failed.

It developed a mechanical fault and was taken out of action.

Another vessel, Pisces V, was sent below in an attempt to locate the men.

Chapman sang a song in an attempt to help the sub locate them on the sea bed.

The two men sank on Wednesday morning, and it was now Friday.

By this point they had only 24 hours of oxygen left.

However, they were finally found by Pisces V, and the first rescue line was attached.

But problems still blighted the rescue operation.

Initial attempts to raise the stricken submarine were foiled by mechanical problems and the increasingly poor weather.

The men below had now been trapped for almost 100 hours, and their oxygen was becoming more and more contaminated with carbon dioxide.

Finally, with the help of a US Curv submarine and a Canadian coastguard vessel, the John Cabot, Pisces III was winched to the surface after 85 hours below.

Miraculously, the two men walked away from their ordeal relatively unscathed, suffering from sleep deprivation and a lack of food and water.

For Mr Chapman, the experience proved to be a transformative one.

He set Rumic, a Dalton-based company that offered sub-sea services to offshore and defence industries.

Through his company he became one of the world's leading experts on rescue submarines.

He was mobilised by the Royal Navy during the Kursk disaster in 2000, and was instrumental in rescuing seven stranded Russian submariners in 2005.

Mr Mallinson continued to work for Vickers until 1978.

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