U-2511 Submarine (Malin Head — 210 fsw)

(Lead Photo Credit : Ben Lair)

Introduction

This was my last dive in Malin Head and it proved to be a great one.

The U-2511 was a Type XXI submarine that was built near the end of WW II. But — that alone doesn’t make it special.

What makes this submarine special is that it was a “diesel-electric Elektroboot” submarine that was designed and built during the later stages of WW II and rapidly increased the technology inside the submarine to allow it to operate much longer underwater thus providing more stealth and deadliness. Fortunately, the war in Europe ended just as these beasts were starting to get deployed.

There were apparently 118 completed (more than I head initially heard about) but only 4 were combat ready and only two were put into active service (but they did not see combat).

Type XXI Submarines

These submarines were the first that were designed to operate primarily submerged. Previously, submarines operated on the surface and submerged when necessary. These submarines incorporate a lot of batteries in order to extend their time underwater. They would need to come within periscope depth every few days in order to recharge the batteries with fresh air. These submarines could travel at 5 knots underwater for 75 hours without surfacing.

Below is photo of the U-2540 at the Maritime Museum in Bremerhaven. It is the only floating example of a Type XXI U-Boat. The fascinating fact about this sub is that she was scuttled by the crew in 1945, salvaged in 1957 and then refurbished and used actively until she was retired in 1982. She was then modified to appear in a wartime configuration and put on exhibit.

For the era, the boat was pretty big but not in length. When I saw the sub, I was surprised on how “bulky” it was. They were 251 feet long and had a beam of 26 feet. Similar subs in WW II had a beam of about the same, but for some reason, this sub seemed very “chunky” across the middle. Maybe it was all the batteries. This class of submarine had 6 torpedo tubes in the bow and carried either 17 or 23 torpedoes depending upon whether she was also carrying mines. She had 5 officers and 52 enlisted sailors.

Below is a picture of three Elektroboat Type XXI submarines in Bergen, Norway in 1945. The center sub is U-2511.

The Type XXI submarines were literally ahead of their time but had the right idea that they had the most value when they were submerged. Nowadays, nuclear submarines can stay submerged for months (maybe a year or more) at a time. This new class of submarines had an advanced electric-drive engine that it allowed it to achieve greater speeds underwater for longer periods of time — thus allowing it to go undetected longer and find more enemy ships to sink.

Wikipedia has a good history of the submarine along with some interesting photos. They were apparently pre-built in prefabricated sections that would be assembled at the shipyard.

Below is a diagram of the sub from the US Navy archives:

Also interesting is that the U-2513 is 70 miles west of Key West, Florida in 215 feet (65m) of water as a result of being sunk as a target on 7 October 1951. We had acquired her after the war and operated her in the Atlantic ocean. Another crazy story about the U-2513 is that President Harry Truman visited the sub and dived to 440 feet in her! I might have to add that to the project list. 🙂

U-2511 Sinking

The U-2511 was originally assigned to service at Bergen, Norway in March 1945. She conducted one patrol and was headed to the Caribbean on the night (30 April 1945) that Hitler shot himself. She received the order to abort on 4 May and the captain claimed that he had the British cruiser Norfolk in her sights when he got the cease fire order.

She returned Londonderry Port on 21 June 1945 and was part of the Operation Deadlight. She was surrendered on 9 May 1945 at Bergen, Norway.

Operation Deadlight was the codename for the Royal Navy project from late 1945 to early 1946 to scuttle the German U-boats that were surrendered to the Allies. In total, the Germans surrendered 156 submarines and 116 of them were scuttled as part of the operation. The remaining submarines were claimed by the UK, France, Norway, etc. and used for various purposes such as museums and some were re-used under the new flag.

The U-2511 was being towed out to one of the areas designated for scuttling when the tow cable broke due to bad weather. Instead of trying to continue towing her, she was sunk by gunfire on 7 Jan 1946. She is largely intact other than a large blast hole caused by the shellfire.

The Wreck

The wreck is a 2-3 hour boat ride off the coast of Ireland and was located in 1999 by local diver Al Wright.

The wreck is very unique and very important historically. The Operation Deadlight Expedition 2001 summarized it well:

U2511 is perhaps the most historically important U-boat wreck of the Deadlight fleet. She has now been photographed and filmed for posterity. A spectacular, if salutary reminder of the massive jump in submarine design and technology made during World War Two.

The wreck lies on her port side and is largely intact. She has a large hole on her starboard side near the conning tower. This is where the main blast occurred that sank the ship. Ben went inside and witnessed the tangle of cables, batteries, etc. I will post a few of his photos below.

It is really a spectacular dive since she sits in white sand, the visibility was amazing, and is nearly intact and very big.

Photogrammetry Model

I didn’t think I would have enough time on the wreck with one dive to build a complete photogrammetry model. Instead, I had a plan to essentially build a “2D” model that would show the submarine from the top-down view. We had the downline right by bow so I started taking photos and swimming down the length of the wreck. I covered the top of the conning tower, then down to the stern and then went back along the length of the ship adding photos until I got to the bow.

In reality, I probably could have got more of the sides of the wreck and around the conning tower and maybe built a more complete model but I’m happy with the results. Below are some screen captures along with a link to the on-line model.

This is the “top down” overall view with the bow at the right and the stern at the left.

In the bottom photo shown in the gallery below, you can see the large hole “below” the conning tower. It is a little obscured, but there is a scuba tank right below the hole that was a bailout tank left by Ben Lair when he took a little tour inside that hole. 🙂

Below is a link to the on-line model (keep in mind that it is “mostly” a 2D model):

Photos

Since all of my photos were used for photogrammetry, I don’t have any photos with good composition. However, Ben Lair took some really great photos and has been kind enough to allow me to use them.

As mentioned above, Ben went into the interior through the explosion hole and saw the tangle of cables, along with a passageway and some batteries. Very cool!

The conning tower is very striking and the periscope tube has a very cool and interesting glass dome on it that you can see some of the elements inside if you scrape away some of the debris:

And below is a photo that gives a good sense of the size of the wreck and the amazing visibility we had:

Below is a photo that I took of the large prop & rudder on the starboard side:

And, for fun, here is a photo I took with Ben’s bailout tank sitting outside the large hole he entered to explore the inside a little bit:

Thanks To …

• Ben for letting me use some of his great photos for the post
• Dean & team for safely getting us out to the wreck and the amazing placement of the downline. Always a pleasure to dive with him!

References

Wikipedia U-2511

Type XXI Submarine

Wikipedia Operation Deadlight

Operation Deadlight Expedition 2001