HMS Ashanti (F117): The Frigate That Pioneered Steam-and-Gas Power

A New Kind of Engine Room

HMS Ashanti was built by Yarrow Shipbuilders at Scotstoun on the Clyde at a cost of just over £5.3 million, launched on 9 March 1959 and commissioned on 23 November 1961.

She holds a truly notable engineering distinction: she was the first Royal Navy warship commissioned with combined steam and gas turbine propulsion, known as COSAG, pairing a conventional steam turbine with a Metrovick gas turbine on a single shaft, a technology that would go on to influence Royal Navy propulsion design for years afterward, giving her a top speed of 27 knots and a range of around 4,500 nautical miles at a 12-knot cruise.

It is worth asking why anybody would want two entirely different kinds of engine on one shaft, because the answer is very practical. A steam plant is economical and reliable and will run all day, but it takes hours to raise steam from cold and needs a large department to keep it going. A gas turbine is thirsty and was, in 1961, not yet trusted to run continuously, but it can be started and brought up to full power in minutes. Put both in and you get a ship that cruises cheaply on steam, has a burst of speed available on demand, and, crucially for a ship on a distant station with nobody to help her, can get out of harbour in a hurry without warning. The County class destroyers took the same idea into a much larger hull a year later, and the whole fleet had gone over to gas turbines alone within two decades.

The class she belonged to was designed for a specific and now rather dated purpose. Seven Tribals were built, Ashanti, Nubian, Gurkha, Eskimo, Tartar, Mohawk and Zulu, and they were drawn up in the 1950s not as fleet escorts for a North Atlantic war but as self-contained general-purpose ships for what the papers of the day would have called colonial policing, chiefly east of Suez and in the Gulf. That shaped everything about them. They were air conditioned throughout at a time when that was a real luxury in a British warship, they gave every man a bunk rather than a hammock, and they were built to operate alone for long periods a very long way from a dockyard. Her record between 1963 and 1971, in the Gulf, the Arabian Sea, off Aden and on the Beira Patrol, is exactly the career the design brief describes.

She carried twin 4.5-inch guns, Bofors and Oerlikon cannon, two Sea Cat missile systems and a Limbo anti-submarine mortar, a solidly equipped frigate for her era.

She had been laid down on 15 January 1958 as Yard No. 2121, and at 360 feet long and 42.5 feet across the beam displaced 2,300 tons standard, rising to 2,700 tons fully loaded, with a complement of around 253 officers and ratings.

Her COSAG machinery was not her only first: the Tribal class were also the earliest Royal Navy frigates built with a hangar and flight deck for an embarked anti-submarine helicopter, a Westland Wasp in Ashanti's case, a design choice that anticipated the small ship's helicopter now standard across the fleet.

The helicopter was the other thing they got right early. A small ship with a hangar and a flight deck can put a sonar or a torpedo twenty miles away in ten minutes, which multiplies what one hull can cover to an extent that is difficult to overstate, and it gives her a way of reaching a casualty, a beach or a boarding party without launching anything. The Tribals were the first British frigates built with that from the start. Every frigate the Royal Navy has commissioned since has had one, and the argument about whether a small ship should carry an aircraft has never been reopened.

Being first with new technology came with the usual growing pains: Caribbean trials in 1962 uncovered a fault in her gas turbine blades, an early lesson in the practical challenges of combining two very different propulsion systems in a single working warship.

A Global Workload

Between 1963 and 1967, Ashanti served across the Persian Gulf, the Arabian Sea, the Beira Patrol enforcing the Rhodesian oil embargo, and Aden, a demanding and varied schedule typical of frigates maintaining Britain's remaining global commitments during the 1960s.

She returned to Beira Patrol duty in 1970, and was present in 1971 for the Royal Navy's withdrawal from Malta, a symbolically significant moment marking the beginning of the end of over a century and a half of British naval presence on the island.

The Malta business of 1971 was a good deal messier than a withdrawal, and it is worth setting out because Ashanti was there for it. Dom Mintoff won the Maltese election that June and asked, within days, for the British military base to be dismantled. What followed was six months of extremely bad-tempered negotiation. Britain offered nine and a half million pounds a year for the facilities; Malta wanted eighteen. British forces began packing up. In January 1972 Mintoff told the world that the conditions Edward Heath was imposing were more appropriate for a conquered enemy than for a friendly nation whose only blame was to have tolerated a British presence for a hundred and seventy-one years, which is the sort of line that ends up in the record whether the Foreign Office likes it or not.

A deal was struck in March 1972, for seven years, and the ships came back. Another treaty followed in December 1974, and the British base on Malta finally closed on 31 March 1979, a date the island still marks. So what Ashanti saw in 1971 was not the end of the Royal Navy in Malta but the moment it became certain there would be one. Malta had been in British hands since 1800 and the headquarters of the Mediterranean Fleet for most of that time, and the ships that had left Grand Harbour under that flag include very nearly every famous name in the modern Navy. A Tribal-class frigate lying at Malta in the autumn of 1971 was watching the last act of it.

Her service was not without tragedy: in 1974, some 80 miles east of Hamilton, Bermuda, and returning from the Caribbean, a large wave struck the ship, killing one sailor outright and fatally injuring a second who died aboard, a stark reminder that even routine peacetime deployments carried genuine danger for the sailors involved.

Garbled early reports of the incident were picked up by Bermudian radio and passed on as confirmation that Ashanti herself had gone down, and for a few anxious hours British television news was reporting the frigate lost before the Royal Navy could correct the record.

The false report of her loss is worth a moment, because it says something about how news travelled in 1974. A garbled account went out on Bermudian radio, was picked up and repeated, and for several hours British television was reporting a Royal Navy frigate sunk in the Atlantic. Every family with a man aboard heard it. There was no way for the ship to reach them directly and no way for the Navy to get a correction out any faster than the original error had travelled. Two men had in fact died, which is bad enough, and several hundred families spent an afternoon believing they had lost somebody they had not.

The two men should be named, because the news that afternoon was wrong about the ship and right about the men. Ordinary Seaman Nigel K. Rogers went over the side and was never recovered. Petty Officer John B. Taws was recovered and died aboard. It was 5 February 1974, some eighty miles east of Bermuda, in the open Atlantic, and it happened in the time it takes a sea to come aboard.

And they are not the whole of her roll. Able Seaman James P. White was killed in a diving accident at Portland on 27 July 1964, when the ship was less than three years old; Mechanician 1st Class Graham R. Taylor died on 19 March 1979. Seven men in eighteen years, on a ship that was never once in action, in what the record would describe as peacetime service. One was lost in a diving accident off Dorset, two were taken by a wave, three were killed by an invisible gas in a boiler room, and one more died in a way the lists do not record. That is the actual cost of keeping a frigate at sea, and it is the part that never appears in a class specification or a defence review.

Three years later, in March 1977, an even worse disaster struck when fire broke out in a boiler room while Ashanti was in the Bristol Channel, filling the compartment with carbon monoxide. Timothy Burton, David Little and James Wardle were killed; Wardle, who had not himself been in the boiler room when the fire started, had gone back in with a foam extinguisher trying to reach his trapped shipmates.

The boiler room fire three years later deserves to be read slowly. Carbon monoxide is colourless, has no smell, and kills by taking the place of oxygen in the blood, so a man walking into a compartment full of it has no warning at all and very little time. Timothy Burton, David Little and James Wardle died. Wardle was not in the boiler room when it started. He went back in with a foam extinguisher to try to reach the two who were, knowing what was in there, and that is the whole of the story: a man went into a space he understood perfectly well would probably kill him, because his shipmates were in it.

The ship was extensively damaged, repaired and returned to service in 1978, before finally paying off to reserve and becoming a harbour training ship at Portsmouth in 1981, a much quieter final posting ahead of the fate that awaited her seven years later.

A Target for the Submarine Fleet

Ashanti's career ended, as it did for a number of retired frigates, as a live target rather than a quiet scrapping.

In 1988 she was sunk in a torpedo and missile exercise by the submarines HMS Sceptre and HMS Spartan, which used both conventional torpedoes and Sub Harpoon missiles against her, a final, practical contribution from a ship whose very first claim to fame had been an engineering innovation that helped shape the frigates that came after her.

She was the last of the seven, which is worth saying plainly. The Tribals were all decommissioned between 1975 and 1979, killed off by a manpower crisis and by inflation making them too expensive to maintain, and then in 1982 three of them, Gurkha, Tartar and Zulu, were hauled out of mothballs to hold the line at home while the fleet went to the South Atlantic. That done, all three were sold to Indonesia in 1984, refitted at Woolston by Vosper Thornycroft, and recommissioned under Indonesian names between 1985 and 1986. Mohawk was scrapped in 1982. HMS Eskimo (F119) was sunk as a target in 1986 and Nubian in 1987, which left Ashanti, the ship that gave the class its name and the last of it to go.

Being expended as a target is not the indignity it sounds. There is no other way to learn what a modern warhead does to a real hull with real bulkheads and real welds, and a navy that has never found out is a navy guessing. Britain sank her own ships for that purpose for as long as she had ships to spare, a practice that continued until HMS Boxer (F92) and HMS Brave went down together in the Western Approaches in July 2004. Ashanti spent her career finding out whether things worked: two kinds of engine on one shaft, a helicopter on a small ship, air conditioning throughout, a hull designed for the Gulf rather than the Atlantic. It is entirely in character that she spent her last afternoon finding out one more thing.