Chariots Of War, Robert W Hobson (Ulric Publishing £29.95)

IT all began with a double loss. In May 1989, Robert Hobson's mother died. Six months later, his father suffered a fatal stroke while asleep in bed.

Robert, who lives near Bromley in Kent, had the unhappy task of sorting through the contents of his parents' neat red brick bungalow. In a dim cupboard in the hall he found a stack of battered suitcases - and, right at the bottom, a small blue suitcase covered in dust.

Inside were naval documents from the Second World War stamped Top Secret in bright red letters. Alongside them was a list signed by his father headed 'Missing on Special Operation', and hundreds of photographs and newspaper cuttings reporting the navy's wartime use of 'human torpedoes'.

"It seemed my father, a lieutenant-commander in the Royal Naval Volunteer Reserve (RNVR), had been involved with covert naval operations during the Second World War, a subject he had never discussed with me," writes Robert in the introduction to his new book, Chariots Of War.

"The documents were totally meaningless but the newspaper cuttings dated June 1944 reported the British navy using 'chariots': small, rocket-shaped submersibles that divers sat astride, dressed like men from outer space."

Robert had stumbled across an almost-forgotten episode of the war, one with which his father had been closely associated. He had to find out more.

So began 12 years of research in which Robert set out to discover the story of his father and his fellow 'human torpedoes'.

He trawled through public libraries and records offices for information about the 'chariots', and attempted to trace some of the people in his father's photographs and letters. Eventually, he made a breakthrough.

"Quite by accident, while thumbing through my father's address book, I found a name that corresponded with one on a 20-year-old letter," he writes. "I anxiously dialled the Buckingham-shire telephone number, and to my great joy Mr O'Sullivan answered and confirmed he had served in the navy with my father."

Mr O'Sullivan had been transferred out of chariots into mini-submarines, and so what he knew was limited.

Through him, however, Robert was able to contact other members of his father's former unit, including 'charioteers' (which is what the human torpedoes were known as) Len Berey and Geoff Larkin. What emerged was the forgotten story of war heroes who were almost James Bond-like in their daring and exploits.

In one sense it is a story that, thanks to Robert, has already been told. He was the driving force behind the human torpedo exhibition at Eden Camp near Malton, which was opened by Prince Philip in December 2002. The popular exhibition features replica Italian and British chariots, and a restored British Mark II chariot.

Chariots Of War takes the story much further, however: recounting how that exhibition came to be set up, and going into vivid detail about some of the charioteers' most daring raids in the North Sea and the Mediterranean.

The charioteers were crack units of specially-trained frogmen who sat astride a 30ft-long torpedo which they steered into enemy harbours. The units were set up on the orders of Prime Minister Winston Churchill after the Italians, who invented the 'human torpedoes', used them to devastating effect on December 9 1941, sinking a British tanker and seriously damaging the battleships HMS Queen Elizabeth and HMS Valiant in Alexandria harbour.

Despite the name, the 'human torpedoes' were not suicide missions.

Charioteers would steer towards their targets with just their head and shoulders above water until, 60 feet out, they would dive to a depth of about 30 feet. Once underneath the target ship's hull, they would blow the chariot's main tank, so it rose beneath the ship. Magnets would then be used to attach the torpedo's warhead to the ship's hull, and the charioteers would attempt to make their escape.

They may not have been suicide missions, but they were desperately dangerous. The British chariots were first used at the end of 1942 in an abortive attempt to sink the German battleship Tirpitz, holed up in a Norwegian fjord.

Chariots were carried to Norway strapped beneath a Norwegian fishing boat: but the mission ended in disaster when the chariots broke away from their moorings beneath the boat and were lost.

With little fuel left, the fishing boat's skipper decided the only option was to try to escape overland to neutral Sweden. One of the charioteers was shot and injured by Germans in the ensuing escape - and subsequently executed as a spy.

At the end of December, the charioteers tried again. On December 28 the British submarine P-311 left Malta with three chariots and ten charioteers to attack ships in the port of Maddalena, Sardinia. The sub's course took her through the straits of Sicily, after which she disappeared and was never heard from again.

Two more British subs, Thunderbolt and Trooper, left Malta on December 30, heading for Palermo harbour. Five chariots were launched into the harbour's dark waters, where the new Italian cruiser Ulpio Traiano was moored.

One managed to negotiate the harbour's torpedo nets and attach a warhead to the cruiser's hull, and attach magnetic mines to other ships.

Another chariot fixed its warhead to the hull of the luxury passenger ship SS Viminale. The two charioteers hid their diving suits and walked into Palermo, but were promptly arrested by the carabinieri.

Others were less lucky. One pair, Miln and Simpson, were struggling towards the harbour when the batteries of their chariot exploded, causing it to dive.

"Miln reported that Simpson had become entangled with the chariot and was unable to break free as the machine plummeted to the sea floor," Robert writes. The Italian navy also discovered another charioteer's lifeless body floating in the harbour. He, too, had drowned.

Thanks to faulty fuses, the Italians were also able to retrieve the unexploded mines that had been successfully placed on vessels' hulls.

There were, however, successes for the charioteers, including the sinking of the German-controlled cruiser Bolzano in La Spezia harbour - the force of the explosion lifted the huge cruiser completely out of the water.

Len Berey was involved in that attack, making a daring escape through Italy with the help of the Partisans, following goat tracks through the mountains and surviving by eating wild cherries. Sadly, his companion was killed by a hand grenade during the escape.

Chariots Of War, Robert W Hobson (Ulric Publishing £29.95)

Updated: 08:52 Wednesday, March 24, 2004