The Flandern U-boat bases and U-Bootflottille Flandern

by Johan Ryheul

Flandern U-boat bases

Starting half October 1914, the biggest part of the coastline of the Belgian province of West-Flanders became occupied by the German Marinedivision, the future Marinekorps Flandern. From the Dutch border till Lombardsijde was now occupied, including the important harbours of Zeebrugge, Oostende and Brugge. The Germans originally had hoped to come also into the possession of Dunkirk and Calais, but this finally had been nothing more than some serious wishful thinking.

The importance of the Belgian harbours was very quickly discovered by a number of personalities of the German admiralty who were looking at the possibilities of using the ports. The harbours of Zeebrugge and Oostende each had a canal leading to the port of Brugge in the hinterland of the province, making Brugge an ideal base for submarines and torpedo boats, destroyers.

On the 15th November a second Marine Division was added to the first one and the Marinekorps Flandern became a fact, under the command of Admiral Ludwig von Schröder, also called the 'Löwe von Flandern' or the Lion of Flanders, who was exactly 60 years old.

Already on the 9th of November a very first U-boat entered the harbour of Zeebrugge, which had been completely cleared of mines two days earlier. It was the U 12 which ran out again the next morning for an operation before Dover. On the 11th it sank the torpedo gunboat Niger near the Deal LV, returning the next day to Zeebrugge because of bad weather. The first victim of the U-boat offensive from a Belgian port was a fact. On the 16th U 12 ran out again towards Boulogne.

On the 26th also U 11 ran in about 1600 hours. The orders of her CO, von Suchodoletz, were very clear, he was to operate from Zeebrugge.

On the 11the December U 12 returned together with the U 5. In the mean time U 11 was already active on the North Sea and had not been heard of since some days before. The next day some Allied papers mentioned the sinking of a U-boat. It became very clear that this had to be the U 11. In fact she ran on a mine on the 9th while surfaced near the Oostende bank at 1335 hours. The wreck is located and identified.

On the 13th U 5 and U 12 ran out from Zeebrugge but had to return because of the weather.

On the 23rd December U 12 was at sea, but found no enemy activity. The next day also the U 24 entered Zeebrugge and ran out again on the 27th. She was to return on the 9th of January 1915 and this was a reason for celebrations as she sank the British battleship Formidable on the 1st off Portland Bill.

Another big success from the Flanders harbours and for von Schröder reasons enough to make a remark in the Kriegstagesbuch of the naval units of the Marinekorps Flandern, in fact asking for more U-boats and torpedo boats that were to operate from Flanders at the Admiralty staff in Berlin.

On the 10th U 12 ran out for a long distance operation but had to return after two days because of bad weather again. Clearly showing how vulnerable these early U-boats were at the time.

On the 14th U 24 was leaving for operations near Boulogne and U 12 near Wandelaar LV. On the 22nd both ships just escaped damage in the Zeebrugge harbour during a bombing raid. The next day U 12 returned to Helgoland.

On the 27th U 29 ran into the port of Zeebrugge and the next day U 24 ran out again. On the 30th U 29 was to operate in the Channel but had to return again because of the weather.

On the 11th of February von Schröder received some bad news. The Admiralty in Berlin had no plans at all to station any U-boats at Flanders ports. They found the harbours not safe enough, too close to the enemy and only to be used in case of need. In other words the U-boats operating from Flanders remained under the command of Berlin and not of von Schröder. The British seemed to confirm one of the arguments by paying a visit to the Belgian coast with a rather large fleet.

The 15th U 8 entered Oostende. Three days later the U-boat started war against merchant vessels near the British coast. U 8 ran out on the 21st, returning with the U 20 on the 26th.

The 4th March was a day with good and bad news. The Admiralty in Berlin had decided to start with the preparations to station a few smaller types of U-boats at Flanders. On the other hand U 8 was lost that day.

This decision needs some more background information. Fact is that the Belgian coast was very often the target of British ships, shelling the city of Oostende most of the time. However early 1915 was taken a start with the construction of a large number of coastal batteries between Raversijde and the Dutch border. Starting with smaller calibres such as the 5, 8.8 and 10.5 cm and ending with the enormous 38 cm guns of for example the Deutschland battery at Bredene or the Pommern at Koekelare. About 44 of these emplacements were to rise at the coast, protecting in a very effective way the coastline from further Allied shipping visits. And if it was the case, they were very short visits!

On the 10th of March the U 29 left Oostende, the ship of the famous Lt.z.S. Otto Weddingen who sank on the 22nd of September 1914 the British cruisers Aboukir, Hohue and Cressy in less than an hour. Eight days later U 29 became a victim of the HMS Dreadnought and the early U-boat weapon lost its first living legend.

The same day U 28 entered bringing along two Dutch 'Beuteschiffe'.

On the 21st and 24th March U 28 ran out for small operations. On the 27th of March, we read, underlined in pencil in the Kriegstagesbuch of von Schröder: UB 10 als Erste der kleine U-boote in Brugge. Two days later UB 4 followed. Von Schröder notes: ástu.

U-Bootflottille Flandern

In reality the U-Bootflottille Flandern was officially erected two days later, and Korvettenkapitän Karl Bartenbach became the unit's commanding officer.

Early 1915 were also made the plans to make of the Flemish harbours real war bases. In Brugge for example no less than 14.000 people worked at the harbour on the Kaiserliche Werft. Many of them were civilians (over 4000), German technical personnel and harbour specialists (over 5000). They started with laying electricity, construction of U-boat bunkers, bunkers, dry-docks, floating docks, storage hangars.

The U-boat bunkers were the most spectacular realisations together with the floating docks. Also in Zeebrugge and Oostende were constructed a number of U-boat shelters and in Oostende also some new dry-docks.

Needless to say that all these installations did attract a large number of enemy planes and bombardments. To give just an example, about 6000 bombs fell on Brugge, killing 123 civilians and wounding 243. About 700 civilian houses were destroyed or badly damaged. The damages in the harbour itself were most of the time null! In a number of cases some ships got damaged as did some smaller unimportant installations.

During April 1915 still other U-boats used the Flanders ports. U 24, U 28 and U 31 were amongst them. On the 2april UB 5 also arrived at Brugge. In fact these ships came from Germany in parts. They were reassembled at Hoboken, Antwerp and taken from there on pontoons to Brugge by the canals. The 8th of April also UB 15 arrived and the next day UB ran out towards the Noordhinder LV. On the 10th of April at 1024 hours it torpedoed a steamer which sank immediately. The first victim of the U-bootflottille Flandern was a fact. Two days later UB 15 was back in. The next day one of the most famous ships, not to say one of the legendary ships of the unit left port to operate on a line between Outer Gabbard and the Noordhinder LV, it was the UB 10. However this operation was not successful and they returned two days later. That same 15th of April UB 5 sank another steamer at 0715 hours and came back in the same afternoon.

More and more ships arrived. UB 13 on the 16th and on the 19th the UB 6. In may also arrived the first U-boats of the UC I class in Brugge. The very first minefield to be laid by these mine laying U-boats was located south of the Goodwin LV and was the so called Sperre 1. It was laid by the UC 11 on 31 May, 1915. Not even 24 hours later it took its very first victim, the British destroyer HMS Mohawk. The British admiralty was quite puzzled with the fact that they could not find out how this mine came here.

A whole number of other minefields followed in the three months to come, and the results were quite good as no less than 23 merchant vessels, 16 fishing boats and 2 British torpedo boats went to the bottom of the North Sea. Not talking about the 5 merchant vessels and 2 destroyers damaged! And the British Admiralty still remained with the same questions: where did these mines come from?

Only the accident with the UC 2 would change this matter. The U-boat sank on 2 July, 1915 by accident and was raised by the Royal Navy, who soon discovered that this was no ordinary submarine, but a complete new type of minelayers. So if you ever heard that British Intelligence and other spies did a tremendous work, forget about it!

In October 1915 no less than 16 U-boats were operational from the Zeebrugge and Oostende harbours. The ships came now directly over the sea from Germany to Flanders.

On the 6th of November would also be the first U-boat crew interned in the Netherlands. The UC 8 of W. Schmidt ran on a sandbank off Terschelling due to bad navigation and the Dutch thankfully took over the U-boat in service of their own majesty, the queen as the M1.

Three days later the UB 17 sank the French destroyer Branlebas. Even after the war the French and British were convinced that it had ran on a mine and that in no way a torpedo did sink it!

Also worth mentioning meanwhile is the fact that the U-boats were escorted by the seaplanes of the Seeflugstation Flandern at Zeebrugge when they entered or left the harbours at Flanders. This gave them the necessary protection against enemy planes and was able to warn them in case of enemy naval activity in the area.

In the beginning days of the submarine war, things very often were still very chivalresque, as the crews of merchant vessels very often did get some time to leave their vessel, after which it was or torpedoed or blown to pieces with charges if it was a smaller ship, as torpedoes were after all still very expensive weapons, not to waste on any kind of ship. Sometimes this knightly behaviour went even further as the sloops often received emergency rations and sometimes even were towed into the neighbourhood of friendly coasts.

Some commanders did have a very good reputation on that matter; others had a one that was really bad.

In 1916 the U-boat war started to gain speed from the Flemish harbours and this can also clearly be remarked by the numbers of losses concerning BRT's.

On the 24th March the UB 29 torpedoed the packet-boat Sussex, but the ship didn't sink very fast and was able to reach a safe harbour. First they had thought that they had run onto a mine, but once they could inspect the damage it became very clear that they had been hit by a torpedo which had led to the loss of 50 human lives and a whole bunch of protests followed immediately at the address of Germany. Also from the side of US president Wilson over the loss of American lives on the ship. The result was that from the 27 March only military targets could be attacked by submarines. This kind of doing and the yes you did, no I did not mentality between Germany and the US still went on for some time until in 1917 the unlimited U-boat war was declared.

Otto SteinbrinckOn March the 29th, the very first anniversary of the U-Flottille Flandern, one of the most reknown U-boat commanders ever, Kap.Lt. Otto Steinbrinck (left) received the Pour le Mérite, Germany's highest decoration from the emperor Wilhelm II.

On the 27th of April a quasi completely intact UC-boat fell in British hands. The sources vary on what really happened. Some say that the U-boat had stranded on a sandbank, other say that the boats was floating adrift because of damage sustained from running on a sandbank. Whatever may be the truth, fact is that the HMS Firedrake took the whole crew prisoner. The last man on board had still tried to blow up the ship but all he achieved was blowing a hole in the hull, and the fact that the mines came loose in their racks. UC5 was towed to a dry-dock at Harwich for restoration and finally was displayed to the public at Temple Pier on the Thames river for propaganda purposes. Later the U-boat even was moved to New York, and stood there in three pieces exhibitioned again for propaganda purposes and more especially to sell more Liberty Bonds.

Sometimes U-boat crews were very inventive in times of need. On the 25th of July the UC 6 experienced engine trouble and still had 90 miles to go to Zeebrugge. They started sailing home with a self constructed mast and sail! UB 19 took them on tow for the last part of their journey.

On the 14th August the merchant ship war retook and neutral and other vessels could again be attacked.

In September also new U-boats were delivered in Flanders from the UCII type. Not only had these more storage room for mines (18 instead of 12) but they also were armed with torpedoes. Nothing luxurious as already half of the UCI type submarines had been lost, in most of the cases due to the fact that these were as good as unable to defend themselves. On the other hand the successes booked with the mines were too big to stop this kind of warfare. Statistics showed clearly that in the period from May to July 1916, about 49.700 BRT were lost and from August till September again 60.000 BRT.

In the same time the chivalry at sea started to disappear. And this had its very good reasons. The British made more and more use of the so called Special Service Ships and Q-ships. Very often smaller vessels, looking quite helplessly so that the U-boat commanders decided not to waste a torpedo on them but to sink them by other means. So they went quite closely to them to finish them with charges or the deck gun. Once in range a sloop was no sloop, or a construction on the deck was nothing else than a well camouflaged gun. Some carried even a few guns.

However the Q-ships were not always as successful as they are shown in many books and other stories. Very often it came to a gun battle between the subs and the Q-ships, very often undecided, and in a number of cases a torpedo was fired at the target, eliminating the small vessel. In a number of cases the Q-ships were sunk by gunfire also. Still quite a considerable number of U-boats were sunk by the Q-ships. In a number of cases the U-boat crews were really slaughtered by the crews of these ships, even personnel that were drifting helpless in the water. It looks clear that way that on both sides of the front there were war criminals active that were never brought to justice.

For the U-boat commanders the solution was very simple. No more mister nice guy, no more warnings so no more time for the ship crews to leave safely their vessel that was about to be sunk. It just made the war even more inhuman then before. Just the way the U-boat war had started. The British had decided to block Germany and especially all shipping to Germany, starving the German population and what was more the civilians, the result was that the Germans started to use fully the potential of their U-boat weapon. This only resulting in still more casualties, not only on the front, but also in the homes of those who were not fighting. Thanks to the Q-ships more victims fell at sea also.

In the mean time the U-boats of Zeebrugge and Oostende started to operate further and further away from their home bases. The Gulf of Biscay and the southern Irish sea were no longer exceptions.

In the winter of 1916-1917 more and more subs of the UC type arrived at the Flemish harbours. 1917 would become a wonderful year concerning the results booked from the ports in Flanders. More ships clearly meant more possibilities and in January 1917 the Flandern Flottille had at its disposal no less than 22 submarines and in March already 38. Also to keep in mind was the unlimited submarine war that Germany had declared on the 1st of January 1917!

However, the same year the German U-boat weapon would also have to pay a toll. Between January and April 1917 only 4 submarines were lost in Flanders. But starting from the month of May these figures became more dramatic and sometimes 4 submarines were lost each month! Fact was that the torpedo boats of the Flandern Flottille spent already most of their time in clearing and destroying minefields, laid by the British. Not only minefields had to be destroyed but also a large number of net barrages. For these last ones a special torpedo had been developed from German side to enable the submarine to get free when trapped in one. There was also a net cutter on the bow of the submarines.

In April 1917 alone no less than 621.645 BRT was sunk by the U-boats. Needless to say that for the Allies it became more then time to do something about it if they still wanted to win the war.

The British commander Haig, had the idea that it had to be possible to start a new offensive in Flanders, his favourite territory to do so, break through the German lines and grasp the Flemish harbours or at least Oostende, leaving Zeebrugge also too close to the Allies to be still of use to the German imperial navy. Anyone would and could have known that such a plan was pure madness, except the British command, which was nothing else then the result of all kind of political games were each and everyone was trying to put his good friends on high military posts. In the night of the 6th on the 7th of June 1917 all hell broke loose and the ridges of Mesen and Wijtschate were taken by the Allies. On the 12th of July the Allies tried to force another breakthrough with the use of mustard gas, however without any results. On the 15th Allied artillery started to batter the German lines. On the 31st an offensive was started between Dieksmuide and Leie, but it was doomed to fail as it was and had been raining cats and dogs. The third battle of Ypres became a catastrophe. On the 30th of October started the famous battle of Passendale, which was taken on the Germans on the 6th of November. Four days later the offensive came to an end, with a result of maximum 10 kilometres advance in only one small area! Haig had failed deeply!

Between June and September more and more new U-boats arrived in the mean time in Flanders. Also a number of the brand-new UB III class, the numbers 54 till 57. Also the rest of the year new subs kept arriving, most of them being UB types who came in newly build or from other units. However in the same period many submarines were lost and also many famous names of U-boot commanders who often had become also living legends in their ranks. And with them also the knowledge disappeared that they otherwise were sharing with the many newcomers.

On the 1st of October 1917 also a second U-Flottille Flandern followed, and from that moment on Korv.Kap. Bartenbach could call himself Führer der Unterseeboote Flandern. His work was clearly appreciated in the fatherland as he received Germany's highest decoration, the Pour le Mérite on the 17th of October the same year. It has to be said that Bartenbach was very respected by his men and commanders; especially this was the case in the early war years. Later it became more difficult to get to know his crews, as some of them disappeared after only one or a few missions, not allowing them to get to know each other.

Early 1918 can be suspected also some battle fatigue. Some U-boats and their crews surrender rather easily while others have themselves interned for not very clear or not really dramatic reasons. Spain seemed to have been quite popular for this.

In April 1918 the most successful and most renowned U-boat commander of the Flandern Flottille retired from active service at sea. Otto Steinbrinck was near complete physical exhaustion and became 1st Admiralstaff officer with the Führer der U-Boote Flandern, Bartenbach.

Many other U-boat commanders received Germany's highest decoration the Pour le Mérite as Steinbrinck had doe before them. Amongst them was Paul Hundius on the 18th August 1918, Oblt.z.S. Reinhold Saltzwedel on the 20th August 1917, Obt.z.S. Johannes Lohs in April 1918, Ralph Wenninger on the 30th March 1918. Wenninger was also the only one of these to survive the war…

It is clear that more and more losses were suffered. On the 23rd of April 1918 there was the famous raid of St.-George's Day by the British, in which was attempted to block the harbours of Zeebrugge and Oostende by sinking block ships in the harbour mouths. At Oostende this failed catastrophically while Zeebrugge became partly blocked. Also a second attempt on the 10th of May in the harbour of Oostende ended in catastrophe with the HMS Vindictive.

It is and remains one of the holy houses what concerns the Zeebrugge story in Great-Britain. The British spend so much propaganda on the matter that the inventors of it started to believe themselves that they had succeeded. Even nowadays the Imperial War Museum has a top secret list with propaganda books on which also a few on Zeebrugge are mentioned. The very best example of this way of doing is The Glory of Zeebrugge by Keeble Howard, published in London by Chatto and Windus in 1918. The so called Official Narratives mentioned in it are indeed authentical and nothing else then pure propaganda.

Fact is also that when Admiral Keyes returned with his fleet at Dover harbour, the medals and decorations were already official even on a moment that it was not know if the operation was a success and what exactly had happened at Oostende! In one operation more Victoria Crosses were awarded than that had received some units during the complete duration of the war! It is unbelievable this could happen, the more as that the day following the first raid, one of the smaller U-boats left en re-entered the Zeebrugge harbour!

Fact however was also that Germany was winning the war at that moment on the land front and that the British and the Allies needed very desperately a victory. Zeebrugge most certainly was a moral victory, so the real facts of what happened at Zeebrugge were to be forgotten. They even went that far in their story telling that they claimed that even of the harbour of Oostende was completely blocked; the German ships all were trapped in the harbour of Brugge. They even went further saying that the German commanders had forged their logbooks when they wrote down their operations from the Zeebrugge and Oostende harbours after St.-George's Day.

However anybody with a little brains could quickly start demanding himself why the Allies continued bombing the locks at Zeebrugge, other parts of the harbour and the harbour at Brugge. After the war it became even more difficult explaining how the destroyers and U-boats that were trapped at Zeebrugge possibly could have returned to Germany. Seems that they all of a sudden had vanished into the air of Flanders…

By the end of September 1918 the subs from the U-Flottille Flandern 1 and II started indeed to return to Germany. Shortly afterwards the installations of the ports of Zeebrugge, Oostende and Brugge were destroyed by the German's while retreating.

No less than 2554 merchant vessels (or about 4.5 million BRT) were destroyed by the U-boats of the both Flandern Flotillas, not even mentioning the warships that they had taken out of action or destroyed.

It is the more unbelievable that the story of these U-boat crews is almost forgotten although they were more successful concerning number of ships sunk then the crews of WW II.

This article was published on 1 Sep 2002.

Zeebrugge and Ostend Raids 1918, The

Lake, Deborah

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Books dealing with this subject include

Alarm ! Tauchen !. Fürbringer, Werner, 1933.
Marinekorps Flandern. Ryheul, Johan, 1997.
Raiders of the Deep. Thomas, Lowell, 1995. (transl.)
World War One - Marinekorps Flandern. Ryheul, Johan, 2002.
WW I - Marinekorps Flandern. Ryheul, Johan, 2002.
The Zeebrugge and Ostend Raids 1918. Lake, Deborah, 2002.

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