Operation Deadlight

Strewn across the bottom of the North Atlantic lie 116 Second World War U-boat wrecks. Submarine expert Innes McCartney launched an ambitious expedition to find them.

When Germany capitulated in 1945, the U-boat arm of its navy, although bo...

When Germany capitulated in 1945, the U-boat arm of its navy, although bowed and bloodied was still carrying out its duty. In fact, there were more U-boats at sea on the last day of the war than on the first. The casualties they suffered were appalling, the worst of any armed wing in the European forces. However, as with submariners the world over, the stoicism and sense of duty of these brave men was as commendable as it was remarkable.

In the waters off Malin Head, County Donegal, lie 116 of these U-boats. They are not graves, but rather, the rump of the U-bootwaffe, dumped there at the end of the war. The wrecks of Operation Deadlight represent a remarkable memorial to the Battle of the Atlantic. Only four or five had ever been visited by divers. In 2000 I launched a three-year project to put the Deadlight U-boats back on the map. This is our expedition story.

Background to Operation Deadlight
When the dust of conflict had settled and the spoils of war were being shared out, the Allies kept a few U-boats for technical evaluation. But the majority (116 of them) were lying on exposed moorings in Loch Ryan near Stranraer, Scotland and at the US Navy quay at Lisahally near Londonderry, Northern Ireland.
Such a large number of submarines posed a problem for the Allies. The naval balance of power in Europe could have been upset if they had been adopted in large numbers by any of the victors. The Cold War was unfolding and at the Yalta conference at the end of 1945, the Tripartate Naval Commission, made up of Britain, the US and the USSR decided that the rump of the U-bootwaffe would have to be destroyed.

The Royal Navy was given the unenviable task of disposing of the U-boats at sea in more than 100m of water, by February 1946. With the stroke of a pen, the British Admiralty had been tasked with towing the U-boats into the teeth of the North Atlantic in winter. It isn’t particularly surprising, therefore, that Operation Deadlight (as this order became known) proved to be an embarrassing postscript to the victory at sea.

A dumping area was selected and planning for disposal began. It was clear early on that it would be impossible to transfer any crews to a surface vessel in the wintry Atlantic seas. This meant that the submarines would have to be towed unmanned. Experience had already told the Royal Navy that this was a very difficult undertaking, even on a calm day. Submarines on tow tended to over-strain tow cables, or simply founder. Explosive charges set inside each U-boat were wired to a buoy that was trailed behind them. The plan was that once in the allocated area; the buoy could be picked up and the charges then blown, sinking the submarine immediately.

However, things didn’t go entirely to plan. U-boats foundered on tow, the tow cables broke, demolition charges failed and towing ships ran aground. Bad weather hampered the whole operation. In all, only 58 (exactly half) of the U-boats managed to reach the disposal area. The rest lie scattered in a line across the north coast of Donegal and range in depth from 46m to 130m.

The table below compares the Operation’s plans with its results:

Method / Planned / Actual

Explosive charge 69 / 2
Air Attack 29 / 13
Submarine 13 / 8
Gunfire 5 / 73
Foundered nil / 20

The most interesting statistic is the number of submarines that had to be sunk by gunfire. In most cases, gunfire was used to sink the U-boats that had broken free of the towing vessel and as a substitute for the highly unreliable demolition system using explosive charges aboard the U-boats .

Perhaps the best thing that can be said about Operation Deadlight is the fact that the February 1946 deadline was met. I have recently made contact with the captain of one of the towing ships at Deadlight. In the light of the experiences he has shared with me, I have formed the view that under the circumstances, the Royal Navy made the best of a bad job. While some historians have labelled Deadlight a farce, I prefer to see it as difficult undertaking executed in the best possible way that the limited timeframe allowed.

Expedition planning
Of the many and varied expeditions I have been involved with over the years, Operation Deadlight is unique, simply because of the number of wrecks involved. Even picking out the U-boats from the many other wrecks lost off Donegal was a challenge.

Positional data from Operation Deadlight had to be co-related with survey information, trawler snags, shipwreck data of the Irish North coast and other positional sources. Finding the wrecks was one thing, identifying them was an even greater challenge. This is because many of them are of the same class. We estimate that there are 33 Type VIIC , five Type IXC, two Type XXI, one Type IID, one Type VIID and one Type IXD.

We were certain that we could easily identify the class of the submarine within a few minutes, even in poor visibility. As it was, the visibility that we encountered off Malin Head was so spectacular that quite often the class was identified as soon as the submarine came into view.

Identifying the class was the easy bit, identifying the U-number was a different matter entirely. This is because of the unreliability of the positional data from the reports of Operation Deadlight and because of the high proportion of Type VIIC wrecks in the area. Trips to, among others, the U-boat Archive, the Public Records Office and the Imperial War Museum photo archive helped us put together a comprehensive assortment of material on the Deadlight U-boats.

There was also the possibility that we might encounter U-boats that had been sunk in action. The waters off Malin Head had been an area in which U-boats operated in both world wars. A number of U-boats are known to have been destroyed in these waters. As it was, we examined two U-boats which were sunk during the Second World War, one of which we located for the first time.

Essentially, the wrecks of Operation Deadlight can be categorised into three main types: the classic U-boat designs (type VIIC and Type IX), the rare designs, and the late-war wonder weapons, or ‘electro boats’.

When Germany capitulated in 1945, the U-boat arm of its navy, although bowed and bloodied was still carrying out its duty. In fact, there were more U-boats at sea on the last day of the war than on the first. The casualties they suffered were appalling, the worst of any armed wing in the European forces. However, as with submariners the world over, the stoicism and sense of duty of these brave men was as commendable as it was remarkable.

In the waters off Malin Head, County Donegal, lie 116 of these U-boats. They are not graves, but rather, the rump of the U-bootwaffe, dumped there at the end of the war. The wrecks of Operation Deadlight represent a remarkable memorial to the Battle of the Atlantic. Only four or five had ever been visited by divers. In 2000 I launched a three-year project to put the Deadlight U-boats back on the map. This is our expedition story.

Background to Operation Deadlight
When the dust of conflict had settled and the spoils of war were being shared out, the Allies kept a few U-boats for technical evaluation. But the majority (116 of them) were lying on exposed moorings in Loch Ryan near Stranraer, Scotland and at the US Navy quay at Lisahally near Londonderry, Northern Ireland.
Such a large number of submarines posed a problem for the Allies. The naval balance of power in Europe could have been upset if they had been adopted in large numbers by any of the victors. The Cold War was unfolding and at the Yalta conference at the end of 1945, the Tripartate Naval Commission, made up of Britain, the US and the USSR decided that the rump of the U-bootwaffe would have to be destroyed.

The Royal Navy was given the unenviable task of disposing of the U-boats at sea in more than 100m of water, by February 1946. With the stroke of a pen, the British Admiralty had been tasked with towing the U-boats into the teeth of the North Atlantic in winter. It isn’t particularly surprising, therefore, that Operation Deadlight (as this order became known) proved to be an embarrassing postscript to the victory at sea.

A dumping area was selected and planning for disposal began. It was clear early on that it would be impossible to transfer any crews to a surface vessel in the wintry Atlantic seas. This meant that the submarines would have to be towed unmanned. Experience had already told the Royal Navy that this was a very difficult undertaking, even on a calm day. Submarines on tow tended to over-strain tow cables, or simply founder. Explosive charges set inside each U-boat were wired to a buoy that was trailed behind them. The plan was that once in the allocated area; the buoy could be picked up and the charges then blown, sinking the submarine immediately.

However, things didn’t go entirely to plan. U-boats foundered on tow, the tow cables broke, demolition charges failed and towing ships ran aground. Bad weather hampered the whole operation. In all, only 58 (exactly half) of the U-boats managed to reach the disposal area. The rest lie scattered in a line across the north coast of Donegal and range in depth from 46m to 130m.

The table below compares the Operation’s plans with its results:

Method / Planned / Actual

Explosive charge 69 / 2
Air Attack 29 / 13
Submarine 13 / 8
Gunfire 5 / 73
Foundered nil / 20

The most interesting statistic is the number of submarines that had to be sunk by gunfire. In most cases, gunfire was used to sink the U-boats that had broken free of the towing vessel and as a substitute for the highly unreliable demolition system using explosive charges aboard the U-boats .

Perhaps the best thing that can be said about Operation Deadlight is the fact that the February 1946 deadline was met. I have recently made contact with the captain of one of the towing ships at Deadlight. In the light of the experiences he has shared with me, I have formed the view that under the circumstances, the Royal Navy made the best of a bad job. While some historians have labelled Deadlight a farce, I prefer to see it as difficult undertaking executed in the best possible way that the limited timeframe allowed.

Expedition planning
Of the many and varied expeditions I have been involved with over the years, Operation Deadlight is unique, simply because of the number of wrecks involved. Even picking out the U-boats from the many other wrecks lost off Donegal was a challenge.

Positional data from Operation Deadlight had to be co-related with survey information, trawler snags, shipwreck data of the Irish North coast and other positional sources. Finding the wrecks was one thing, identifying them was an even greater challenge. This is because many of them are of the same class. We estimate that there are 33 Type VIIC , five Type IXC, two Type XXI, one Type IID, one Type VIID and one Type IXD.

We were certain that we could easily identify the class of the submarine within a few minutes, even in poor visibility. As it was, the visibility that we encountered off Malin Head was so spectacular that quite often the class was identified as soon as the submarine came into view.

Identifying the class was the easy bit, identifying the U-number was a different matter entirely. This is because of the unreliability of the positional data from the reports of Operation Deadlight and because of the high proportion of Type VIIC wrecks in the area. Trips to, among others, the U-boat Archive, the Public Records Office and the Imperial War Museum photo archive helped us put together a comprehensive assortment of material on the Deadlight U-boats.

There was also the possibility that we might encounter U-boats that had been sunk in action. The waters off Malin Head had been an area in which U-boats operated in both world wars. A number of U-boats are known to have been destroyed in these waters. As it was, we examined two U-boats which were sunk during the Second World War, one of which we located for the first time.

Essentially, the wrecks of Operation Deadlight can be categorised into three main types: the classic U-boat designs (type VIIC and Type IX), the rare designs, and the late-war wonder weapons, or ‘electro boats’.

116 Second World War U-boat wrecks

The veterans: Type VII and Type IX wrecks

U155
Adolph Piening’s U155 was the most successful U-boat to be disposed of during Deadlight. She sank 25 Allied ships during the war, including the aircraft carrier HMS Avenger, with the loss of more than 400 lives. This 1,150-ton U-boat was one of the three top priority targets for the expedition. In stunning visibility at 73m the unmistakable giant shape of the Type IXC U-boat was found sitting bolt-upright on the sea bed. The forward hydroplanes and torpedo tubes have fallen off to one side, but apart from this damage the wreck was intact. This included all of the outer cladding attached to the pressure hull.
We could see the schnorchel on the starboard side of the foredeck and the conning tower hatch was open, allowing divers a clear view of the control room via the opened lower hatch. The aft dinghy recess on the deck was empty and both external torpedo doors were shut. All of the external torpedo containers had been removed.

The most exceptional thing that one observes while diving on wrecks of the Type IX class is their immense width and flat-teak decks, like bowling alleys. Type IX dives are rare around the UK, since they mostly roamed into more distant waters, but a drop on such a wreck is a real treat. An utterly absorbing dive, we could still see the wreck during the first decompression stops. Sheer submarine-diving bliss!

U1003
While on the hunt for one of the electro boats, we located the war loss U1003. She was sunk in a collision with the frigate HMCS New Glasgow. A total of 18 crew members were killed, with 31 being picked up.

Drifting along the side of the wreck at 69m we found a submarine that had clearly been in a collision while schnorkeling. The wreck was that of an armed U-boat, fully equipped for war. In dark but clear conditions, we were able to identify key features including AA guns and ammunition (the Deadlight U-boats were stripped of ammunition and supplies), the broken schnorchel lying on the sand, and an extended but badly bent periscope.

The position was close enough to the reported historic sinking position for us to deduce that the wreck must be U1003. We checked certain minor design features with our resident expert and were able to confirm the discovery of a lost U-boat.

The other Type VIIs
To date, the expeditions have turned up several other Type VIIC U-boats. We are presently satisfied with the identities of: U1104, U637, U1271, U1009 and U778, and we have also dived three others of this class which could be any of U1010, U281, U369, U298, or U930. Through a process of elimination and further examination of the video footage taken we hope to clear up our uncertainties over the next year. We also dived and filmed the war loss U1014, off Portrush, Northern Ireland.

The rare designs

U861
U861 was used as a cargo carrier to bring unobtainable raw materials to Germany from Japan during the last year of the war. In fact, when U861 surrendered, she was laden with a cargo of wolfram, iodine and tin. These large, cargo-carrying Type IXs are extremely rare – this was certainly the only one that I have seen.
This large U-boat lies in only 45m of water and is by far the most visited of all of the Deadlight wrecks. We dived the wreck when conditions allowed us to dive further offshore. Although substantially broken up, the U861 was a great dive. The propellers, engines, conning tower are all exposed and can be closely examined. It is also possible to penetrate the central section of this wreck. Surprisingly, the visibility was superb. Another memorable dive.

U218
This is the only located example of the rare Type VIID minelayer U-boat. Only six of these were built and U218 was the only one to have survived the war. This class is characterised by a series of five vertical mine chutes, located in a section behind the control room. The chutes of U218 were examined in detail by the Allies and are thought to have been influential in the later design of the Polaris missile launch system. Only on this wreck can the technology be studied. Clearly this made U218 a major target for the expedition.

At a depth of 60m in excellent visibility and much ambient light, the wreck of U218 was found first time at the location, we thought it would be at. The superb conditions made for high-quality video and stills images of the wreck. It was an incredible sight.

U218 lies on a 45-degree list to port. Apart from minor damage to bow and stern, this wreck is completely intact. The five-chute mine section behind the conning tower made this wreck easily indentifiable. Such a rare U-boat was a treat for the diving team, and a fantastic way to begin the expedition, as it was the first Deadlight dive we conducted.

Wonder weapons: the type XXI U-boats
The Type XXI U-boat represents one of the greatest and most revolutionary submarine designs ever. The quantum leap in technology which these submarines represented came too late to avoid defeat for Germany. The Type XXI was essentially the world’s first true submarine, designed to operate entirely underwater. It also sported a range of new technologies from torpedoes to sonar. Fortunately for the Allies only one was at sea on the last day of the war, while another 90 were being prepared.
Type XXI wrecks are rare, but at Deadlight we now have two. The one found in 2002 is completely intact.

U2506
Under the command of Knight’s Cross holder Horst von Schroeter, U2506 was still in operation, right up to when the war ended.

After a lengthy search we located and dived the wreck in 2002. U2506 is completely intact and represents the finest example of a Type XXI that
can be seen anywhere. Even the features which we would have expected to have been removed, such as the flak armament are present. The hull is perfect, as is the conning tower, retractable hydroplanes, periscopes schnorchel and so on. We dived this wreck three times and were awestruck by what we had found. I doubt that I’ll ever see a more impressive submarine wreck.

On return from Deadlight, I traced Horst von Schroeter and sent him some images of his command. Within a week I had received an enthusiastic reply from him. The annual reunion of his crew was held in September 2002 and they all were able to view the source video footage of their boat and the official expedition video. This proved to be one of the most rewarding aspects of the Deadlight expeditions so far.

Horst von Schroeter retired as an admiral from the Bundesmarine in 1979. At the age of 82, I don’t think he thought he’d see U2506 again. Hopefully he will be attending the Deadlight reunion we are planning for 2003.

U2511
Adi Schnee was one of the great personalities of the U-boat arm. By all reports he was a great character. A Knight’s Cross holder, he was returned to front line service at the end of the war to take command of U2511. As it was, he was the only commander to approach an Allied convoy in this new weapon. Schnee did not attack HMS Norfolk, because he had already received the surrender order.

Diving at midday in bright sunshine, the wreck was visible from 45m on our descent. It was possible to see the entire submarine lying on a sand bottom, clearly recognisable as Adalbert Schnee’s U2511.

U2511 was sunk by gunfire, after her towing cable broke. There is a sizeable blast hole in the starboard side, alongside the tower. Swimming into this hole reveals a mass of cabling and many batteries all along the keel section of the wreck. Looking forward, the divers could see the open bulkhead door leading to the forward compartment.

This was one of the most spectacular U-boat dives I have ever done (I have dived more than 55). It is a rare sight indeed to have the visibility to see an entire submarine in view at 69m. This was made all the more significant by the fact that the wreck was U2511, the only Type XXI to approach an Allied Navy convoy.
U2511 is perhaps the most historically important U-boat wreck of the Deadlight fleet. The wreck has now been photographed and filmed for posterity. A spectacular, if salutary reminder of the massive jump in submarine design and technology made during the Second World War.

In total we carried out 320 man dives over 20 days of diving with 45 different divers taking part. We dived at depths between 45–85m and no diving incidents occured. So far we have have identified 14 new U-boat wrecks – three of them being the rarest U-boats ever dived. We have also located a further four U-boats for later exploration.

• To order a copy of the official expedition video see the website www.periscopepublishing.com.