HMS Onslaught, 1960-1991

D832 "Onslaught" nameplate

Isn’t it strange to know that something is historically significant, but that most of us may never find out exactly why?

Today I enjoyed a ride behind the only currently operational ex-British Railways “Warship” Class locomotive – no. D832 Onslaught – at the East Lancashire Railway, a heritage railway centred on the town of Bury, roughly 10 miles north of Manchester.

The “Warships” were born out of the British Railways Modernisation Plan of the mid-1950s – directly replacing steam traction on the routes of the former Great Western Railway – and were essentially a scaled down version of the highly successful West German V200 class.  In the best tradition of the GWR, they all carried names on a theme – in this case, Royal Navy vessels – the irony being that these locomotives of impeccable German pedigree were named after a number of particularly renowned ships that, just 15 years previously, had played key roles in the defeat of Germany in World War 2.  Indeed, the destroyer HMS Onslaught herself was a veteran of convoys both in the Atlantic and off Scandinavia (where she was credited with putting the finishing touches to the destruction of the U-boat U-472 which scuttled itself in March 1944) and also of the D-Day landings in Normandy.

Following the sale of the destroyer HMS Onslaught to the Pakistani Navy in 1951, the name has been re-used by the Royal Navy just once – for an Oberon class submarine, pennant number S14 – which was coincidentally launched from Chatham Dockyard exactly 56 years ago today: Saturday 24th September 1960 – is of the same vintage as the locomotive, and is the subject of these ramblings.


The Oberon class were conventionally (i.e. non-nuclear) powered patrol submarines and were designed as a key British weapon for the Cold War.  At 295ft in length – equivalent to the proverbial football pitch – and carrying a crew of 65, they were sizeable enough beasts, yet intended to be stealthy, hunting down their Russian peers preferably without being detected.  Being both smaller and quieter than their nuclear counterparts, these diesel-electric submarines were deemed more appropriate for this type of work.  A total of 27 were built – 13 for the Royal Navy, with others for Canada, Australia, Brazil and Chile.

Following commissioning in 1962, HMS Onslaught first saw active service from Singapore during the Borneo confrontation (when fighting broke out after the creation of Malaysia in 1963) then during the British withdrawal from Singapore later in the decade.

However, it is what happened later in her life which is open to conjecture – the details remain classified information.  What is commonly accepted is that HMS Onslaught and her sisters spent a considerable amount of time in the Baltic Sea in the late 1970s and throughout the 1980s, engaged in clandestine operations against the Soviets at the height of the Cold War.  Iain Ballantyne in his book “Hunter Killers” recounts how HMS Onslaught once spent seven weeks in the Baltic with 17 intelligence specialists crowded on board, alongside her usual crew.  It has even been reported fairly extensively that British submarines even sent commandos ashore in the Soviet Union.  That in itself would be interesting enough, but it has also been suggested that commandos were secretly sent ashore to neutral nations on the other side of the Baltic – Finland and, particularly, Sweden.  These two countries formed a buffer between NATO and the Soviet Union and therefore were, usually passively, politically volatile during the Cold War.  They would definitely have been a target for Soviet invasion if they decided to mount an offensive heading West.  Sweden was aware that there were submarine incursions into its territorial waters on an increasingly frequent basis as the 1980s progressed – these were generally accepted as being of Soviet origin – but could they in fact have been Royal Navy?  Perhaps they were testing Sweden’s responses and anti-submarine infrastructure, to investigate what may happen if the Soviets did actually attempt an invasion?  The entire Cold War was shrouded in mystery and (particularly) suspicion, even of one’s own “friends”.

Britain has apparently publicly maintained that its Oberons were never in the Baltic.  They certainly have not admitted to any such covert operations within Scandinavia.  But the very fact that any information on the broad subject remains top secret, might be taken by the cynics among us as a hint that there remains something worth hiding…

What might HMS Onslaught and her sister vessels have been looking for?  More importantly, what might they have found?  It is possible that we will never find out, but equally, it is possible that our entire understanding of the Cold War may shift if we do.

HMS Onslaught was decommissioned in 1990 and scrapped in Turkey in 1991.  However, eight Oberons have survived in various forms around the world, and a number can be visited – although just one of them is in the UK.  Whereas HMS Onslaught was the penultimate Navy warship manufactured in Chatham, and did not survive; the final one, HMS Ocelot (S17), has returned “home” to the Kentish town, to form an important part of the Historic Dockyard Chatham attraction.  HMS Ocelot, too, retains her Cold War secrets – one day, we may know more about the service life of these enigmatic vessels.