HMS Opportune (S20): A Collision With Her Own Sister Ship in Portsmouth Harbour

Built at Greenock

HMS Opportune was built by Scotts Shipbuilding and Engineering Company at Greenock, launched on 14 February 1964 and commissioned on 29 December that year, an Oberon-class submarine measuring 241 feet between perpendiculars and displacing 2,410 tons submerged, armed with eight 21-inch torpedo tubes.

She was laid down at Greenock on 26 October 1962 and took just over two years to build, which was brisk work for a submarine even then. Scotts had been on that stretch of the lower Clyde since 1711 and had a fair claim to being the oldest shipbuilders in the world; they also built HMS Cachalot a few years earlier, and within a few years of finishing Opportune they had been merged into Scott Lithgow as the Clyde shrank. She was one of the last submarines they ever launched. What the Oberons were and why they were as quiet as they were is set out with HMS Oberon, the boat that named the class.

A Collision in Heavy Weather

On 15 February 1967, Opportune collided with her own sister submarine HMS Orpheus in Portsmouth harbour during night operations in heavy weather, a properly serious mishap between two boats of the same class that resulted in a court martial for Orpheus's commanding officer, who was convicted of hazarding his vessel and given a reprimand.

There is an apparent contradiction in that account worth clearing up, because the damage to the two boats was in fact minor. A court martial and a conviction sound like the aftermath of something catastrophic, and this was two submarines touching in the dark in a gale off Portsmouth and going on to their berths. The explanation is that hazarding is not an offence about damage. It is an offence about risk.

Under naval discipline a commanding officer is answerable for putting his ship in danger, whether or not the danger comes off. The test is whether a competent officer would have taken the ship where he took her in the conditions that obtained, and if the answer is no then he has hazarded her, even if nothing worse happens than scraped paint. It is a deliberately hard rule and it exists because the alternative, judging officers only on outcomes, would reward luck. A captain who does something reckless and gets away with it would be untouchable, and the man who does the same thing on a worse night would carry the whole weight of it.

The sentence tells you where the court put it. A reprimand is the mildest formal punishment available and it is not the end of a career, but it goes on the record permanently and it is read by every selection board thereafter. The court had decided that the standard had been missed and that the consequences had been kind, and it wrote both of those things down. HMS Orpheus carries the rest of her own story, which included an altogether more cheerful record set in the Mediterranean.

Opportune suffered a second serious incident in 1971 when she struck a merchant vessel, sustaining damage to her fin and both periscopes, a costly reminder of just how crowded and hazardous busy shipping lanes could be for a submarine operating near the surface.

Both periscopes and the fin is a revealing pattern of damage. It means she was at periscope depth with her masts up when it happened, and that whatever hit her hit the only part of her that was near the surface. A submarine at periscope depth is at her most vulnerable and her most useful at the same time: she can see and hear and transmit, and she is also a few feet below the keels of everything moving above her, looking at a busy seaway through a tube roughly the width of a wrist for a few seconds at a time before dipping it again. Every submarine navy has a list of these. HMS Ambush put one on hers as recently as 2016, in a nuclear boat with sonar the 1971 fleet could not have imagined.

A Silver Jubilee and a Quiet Retirement

Opportune took her place in the 1977 Silver Jubilee Fleet Review at Spithead, before paying off on 2 June 1993. She subsequently spent several years at Pounds scrapyard in Portsmouth before finally being broken up, though her former crew went on to establish an annual reunion tradition, a warm testament to the bonds forged among submariners who had served aboard her.

One of the Last Three

That date deserves more than a clause. Opportune was one of the last three conventional submarines the Royal Navy ever ran. She, HMS Opossum and HMS Oracle all paid off in 1993, and when they went the diesel-electric flotilla went with them. Britain has operated nothing but nuclear submarines from that year to this, which makes it one of only a handful of navies in the world with no conventional boats at all.

The reasoning was the reasoning of the whole period. The Cold War had ended, the defence budget was being cut, and a fleet of ageing diesel boats designed to sit quietly in the Norwegian Sea listening for Soviet submarines had lost the thing it was listening for. Keeping two kinds of submarine means two kinds of crew, two training pipelines and two sets of spares, and when the money went the conventional half of it was the half that could be given up. There is a decent argument that Britain has missed them since, because a small quiet boat that can lie on the bottom in shallow water does things a nuclear submarine cannot, and it is an argument that has been had at intervals ever since without changing anything.

Twenty-nine years is a full career and she was worked hard for all of them. She had two collisions, both in her first seven years, and then two decades in which nothing went wrong that anybody has published, which is what a well-run submarine looks like from the outside.

Pounds of Tipner is worth knowing about if you have ever driven past Portsmouth on the M275 and wondered what the yard full of grey hulls was. The firm had been in scrap since the 1860s and started taking ships apart in 1921, beginning with surrendered German U-boats, and its position next door to the dockyard meant it ended up with a remarkable share of the Royal Navy's cast-offs: submarines, frigates, minesweepers, landing craft, lightships and a good deal of army equipment besides.

The reason Opportune sat there for years rather than being cut up promptly is that Pounds was never purely a breaker. A great deal of the business was trading: a landing craft resold as a ferry, a minesweeper sold on to become a Mediterranean pleasure boat, a lightship turned into a floating restaurant. Hulls were kept because a buyer might appear, and a submarine is a harder thing to find a second use for than most. She lay at Tipner on the mud with the rest of it until it became clear that nobody was coming.

The yard itself has now gone the same way. The Tipner site is being redeveloped for housing and sea defences, so the last physical trace of a great many British warships is a piece of reclaimed ground with flats on it. Three of her sisters did better: HMS Ocelot is preserved at Chatham, and HMS Onyx and HMS Otus both survived as museum boats. The rest, Opportune among them, went for scrap, which is the ordinary ending and the reason the reunions matter.