Author Topic: HM Submarine Onslaught (1960 - 1991)  (Read 1762 times)

Offline stuartwaters

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HM Submarine Onslaught (1960 - 1991)
« Reply #1 on: June 09, 2020, 07:02:55 AM »

Retrieved from the old forum using the Wayback Machine - with an addition.


HMS Onslaught was an Oberon class patrol submarine and was the penultimate submarine built for the Royal Navy at Chatham Dockyard.


The Oberon class were the quietest, most effective and deadly non-nuclear submarines to be built by any navy during the Cold War. They were designed to hunt down and destroy Soviet submarines in the North Atlantic and Barents Sea before they could break into the Atlantic Shipping lanes, leaving the nuclear powered submarines free to track and destroy Soviet ballistic missile submarines ('Boomers') beore they could launch their missiles in the event of war. They were the ultimate evolution of a design which could trace it's ancestry back to the L Class of 1917. The Oberon Class were very successful, in addition to the 13 boats built for the Royal Navy, they were also built for the navies of Canada, Australia, Brazil and Chile and 27 boats were built in total.


HMS Onslaught was laid down on No 7 slip on 8th April 1959 and was launched into the Medway on 24th September 1960. After fitting out, she commissioned at Chatham on 14th September 1962.


HMS Onslaught launch





On completion, she was 295 ft long and 18ft wide across the beam, She displaced 2030 tons surfaced and 2410 tons dived. She was armed with 8 21" torpedo tubes, 6 in the bow and 2 short tubes in the stern. She carried 18 reload torpedoes. She was powered by a pair of the Chatham designed Admiralty Standard Range diesel engines driving generators which both charged her batteries and fed her electric motors.


Her career is still shrouded in secrecy. She was continually updated during her career, the most significant modifications came in the late 1970s, when she was fitted to carry the Mk24 Tigerfish wire-guided torpedo. This enabled her stern torpedo tubes and all the associated gear to be removed and the former after torpedo room was converted to extra accomodation. She was also fitted with a towed array sonar and a new, more streamlined forward sonar dome.


Onslaught at sea





Onslaught in 1964





Onslaught leaving HMS Dolphin at Portsmouth





On 10th September 1964, she departed Portsmouth for the area off Cape Wrath to participate in Exercise Teamwork, along with HM Submarines Opossum, Otus, Osiris, Finwhale, Grampus, Rorqual, Totem, Alaric and the new nuclear powered submarine Dreadnought. This exercise also involved 14 frigates and 8 minesweepers and lasted until 2nd October.


In 1975 - 1976, she participated in a series of major exercises:


In September 1975, Exercise Highwood with Opossum, Ocelot, Oracle, Rorqual and the nuclear powered submarines Sovereign and Warspite.


In November 1975, Exercise Moby Dick with Opossum, Sovereign and 5 frigates


In February 1976, Exercise Gratitude with Opossum, Oracle and the nuclear submarines Valiant, Swiftsure and Courageous.


In 1976, HMS Onslaught participated in the Navy Days at Chatham. Here's her page in the programme:





By the mid-1980s, advancing submarine technology meant that the Oberon Class were beginning to lose their edge and plans were made to replace the class with the new, much more advanced Type 2400 Upholder Class of diesel-electric boats. Unlike their Canadian and Australian counterparts, no further improvements were made to the British boats in anticipation of the introduction of the Upholder Class. As things turned out, the Upholder Class fell victim to the post-Cold War defence cuts and despite the 13 Oberon class submarines being decommissioned, only 4 Upholder class boats were eventually built and those boats fell victim to further cost-cutting in the early 1990s and despite being brand new, were sold to the Royal Canadian Navy.


HMS Onslaught was decommissioned in 1990 and was broken up in Aliaga, Turkey in October 1991.
"I did not say the French would not come, I said they will not come by sea" - Admiral Sir John Jervis, 1st Earl St Vincent.