Kriegsmarine frogmen, high speed explosive boats and one-man submarines?

[Sid Guttridge]

I have just found a passing reference to the German Navy's only special forces unit, comprising frogmen, high speed explosive boats and one-man submarines.

Does anyone have anything on its operations?

The explosive boats were apparently called "Linsen" (Lentil), which is a bugger to Google in English amongst the millions of vegetarian and vegan recipes on the interweb.

Does anyone know any more about these Linsen?

Many thanks in advance,

Sid.

[Waleed Y. Majeed]

Some info on the “kleinkampfverbände“.
https://historisches-marinearchiv.de/pr ... eibung.php
The “linsen” mentioned
https://www.axishistory.com/books/369-g ... rfahrzeuge
https://www.axishistory.com/books/369-g ... fverbaende
Youtube clips of the linsen in action etc.
https://m.youtube.com/watch?v=gRb1U18CJ20&t=1077
https://m.youtube.com/watch?v=gRb1U18CJ20

Look for the kleinkampfverbände and/or sprengboot Linse and you’ll avoid all the veggies.

Waleed

[Natter]

See viewtopic.php?p=2309631#p2309631

For technical information on the K-verband vessels (midget submarines and explosive boats), Fock is by far the best source:
* Wehrwissenschaftliche Berichte Herausgeben vom Arbeitskreis für Wehrforschung Band 3 - Marinekleinkampfmittel (Harald Fock, 1968. J.F. Lehmanns Verlag)
* Marine-Kleinkampf-Mittel (Harald Fock, 1996. Koehler. ISBN 3-930656-34-5 ) - This is a new and improved edition of the original from 1968.

[Waleed Y. Majeed]

Thanks Natter

Waleed

[Simon Trew 1]

Hi Waleed,

Below I have reproduced an extract from my forthcoming self-published source guide to the German perspective on the Normandy campaign. Obviously enough, it comes from the Kriegsmarine chapter. The work is unfinished so there are still things to add. But I guess my point is to suggest that there is a vast amount of material out there, much of it in primary sources (especially Allied intelligence records) - and a surprising amount of it not yet used in the (sometimes quite impressive) secondary accounts. My focus is on Normandy, but I have seen many records from the Italian campaign so I know there are abundant resources there too.

In addition to the things mentioned below there are many sources that discuss the small battle units as part of wider coverage of maritime aspects of the Normandy campaign - notably part of Hinsley's history of British Intelligence (in Vol. 3 Pt. 2) and relevant sections of the German official history of WWII (Rahn, Werner: “Die Deutsche Seekriegführung 1943 bis 1945”, in Boog, Horst et al: Das Deutsche Reich und der Zweite Weltkrieg, Band 10/1: Die Militärische Niederwerfung der Wehrmacht (Militärgeschichtlichen Forschungsamt, Deutsche Verlags-Anstalt, Munich 2008, pp.3-276).

See also:

War Diary, German Naval Staff Operations Division, Part A: Volume 60, August 1944 (Naval History Division, Washington D.C., 1955, 688pp.). This is the English-language translation of the principal war diary of the German naval command for August 1944. It describes various aspects of the Normandy campaign, including operations by U-boats, surface craft and the Kriegsmarine’s ‘small battle units’. The complete text of the original German-language document (published by Verlag E.S. Mittler & Sohn in 1995) is accessible at http://uboatdata.ussleahy.com/SKL/60-1/04001949.pdf (1-15 August) and http://uboatdata.ussleahy.com/SKL/60-2/04001950.pdf (16-31 August).

I would also add that the DEFE 3 records from the UK National Archives (downloadable for free from their website) contain extensive information about the small battle units, based on intercepted, deciphered and translated German signals. You have to plough through mountains of extraneous material, admittedly, but the effort is still worthwhile.

Another direction to look at this is from the point of view of the Allies, who had to defend against attacks by Linsen etc. I guess the starting place is the relevant volume of Roskill's official history (Roskill, S. W.: The War at Sea 1939-1945, Volume III: The Offensive, Part II (1st June 1944 – 14th August 1945) (Her Majesty’s Stationery Office, London 1961; xvi + 502pp; see pp.124-6). But there is a massive amount of material in Allied naval records, memoir literature etc too.

Anyway, the following extract from my source guide may prove interesting and relevant, at least insofar as the Normandy campaign is concerned.

6.1. Primary sources, interrogation reports and other official records:

‘Command of the Small Battle Units’ (12pp.). This Allied intelligence report is in the UK National Archives, ADM 223/609 (ULTRA/ZIP/ZG/314, 6 September 1944). The document summarises the Kleinkampfverbände’s organisation and activities during summer 1944. There is a detailed list of operations by manned torpedoes, explosive motor boats and naval frogmen. Much of the information appears to be based on top secret intelligence sources (i.e. deciphered signals), to which material provided by prisoners was added.

‘Floating mines’. This short British intelligence report describes a German attempt to blow up a bridge across the River Orne, using a floating mine. The incident was linked to the capture of a Kriegsmarine frogman in the river on 2 July. See Part II of British Second Army’s Intelligence Summary No.31, issued 6 July 1944 (UK National Archives, WO 171/221).

‘Floating mines’. This report describes the features of the floating mine used in the attack on the Orne river bridge on 2 July (see above). Details are contained in Part II of British Second Army’s Intelligence Summary No.32, issued 7 July 1944 (UK National Archives, WO 171/221).

‘German Naval Organisation commanding “Small Battle Units”’ (18pp.). This detailed intelligence report is in the UK National Archives, ADM 223/609 (ULTRA/ZIP/ZG/309, 19 July 1944). It collates a large amount of information about the organisation of the Kleinkampfverbände, much of it provided by top secret sources. In addition to information about personnel, command structure and training schools, there are accounts of several operations carried out against the Allied invasion forces off the coast of Normandy.

Griffiths, L.: Government Code and Cipher School Naval History, Volume XIV: The German Navy – Small Battle Units (128pp.). This British official post-war study of the Kleinkampfverbände is based mostly on deciphered German signals and prisoner interrogations. It is in the UK National Archives, HW 11/27. The report provides a detailed history of the origins, development and use of small battle units, as well as related topics such as training and administration. Operations in all theatres are discussed. There is not a great deal of information about the Normandy campaign, but the account is still of some interest. There are eight appendices, which provide flotilla histories, technical details of weapons used and information about unit strengths and losses. There is a detailed glossary and a comprehensive index.

‘Human Torpedo (midget submarine)’. This intelligence report describes the German manned torpedoes used in two attacks on Allied shipping (on 6 and 8 July), and provides some information about their employment. The information is derived partly from the interrogation of prisoners. See Part I of British XXX Corps’ Intelligence Summary No.450, issued 17 July 1944 (UK National Archives, WO 171/337).

‘Human Torpedoes’. This is an account of an attack on British shipping by a large group of manned torpedoes and explosive motor boats that took place on the morning of 3 August 1944. The information came from some of the 25 prisoners captured by the British during the attack. It appears in Appendix B to Part II of British Second Army’s Intelligence Summary No.61, issued 5 August 1944 (UK National Archives, WO 171/222).

‘Human Torpedoes’. This is a translation of an order issued by a Kriegsmarine officer on 12 August 1944. It provides detailed instructions for an attack on Allied shipping in the Seine Bay on the night of 13-14 August, using manned torpedoes. The document is in Part II of First Canadian Army’s Intelligence Summary No.57, issued 25 August 1944 (UK National Archives, WO 179/2606A).

‘Human Torpedoes’ (6pp.). This is the transcript of a conversation between two German prisoners, whose discussion was secretly recorded by the British in January 1945. It is in the UK National Archives, ADM 223/609 (CSDIC(Main)/X114, 5 January 1945). One of the prisoners had participated in a manned torpedo attack in the English Channel in mid-August 1944. The transcript casts light on his personal experiences, as well as the equipment and tactics used during these operations.

‘Interrogation report on one German naval PW’ (15pp.). This is a detailed record of an interrogation of a German naval rating who participated in a manned torpedo attack against the Normandy invasion fleet in August 1944, and who was captured in the Mediterranean several months later. It is in the UK National Archives, ADM 223/609 (CSDIC(Main) CMF/N/16, 10 January 1945). The report provides a considerable amount of information about the unit involved in the operation and the equipment used.

‘Small Battle Units (Kleinkampfverbaende)’ (10pp.). This naval intelligence report was produced in November 1944. It is in the UK National Archives, ADM 223/609 (N.I.D. U.C. Report No.553, 6 November 1944). The document summarises the organisation of German small battle units and lists operations against Allied invasion forces off Normandy during summer 1944.

In addition to this material, some interesting documents are in the UK National Archives, ADM 223/594. The papers in this file relate to Kleinkampfverbaende operations near Anzio during early 1944. The information was passed on to recipients in the U.K. partly to prepare them to face similar attacks during the invasion of France.

6.2. Secondary sources:

Bekker, Cajus: K-Men: The Story of the German Frogmen and Midget Submarines (William Kimber and Co. Ltd., London 1955; 202pp., illustrations). Among other things, this book tells (not altogether reliably) the story of German attempts to use special naval units to hamper the Allied build-up in Normandy (pp.44-61), to destroy bridges captured by the British on D-Day (pp.73-81), and to sabotage a German artillery position in eastern Normandy after it fell into enemy hands (pp.82-90).

Blocksdorf, Helmut: Das Kommando Kleinkampfverbände der Kriegsmarine (Motorbuch, 2003; 200pp., illustrations). Unfortunately, I was unable to see a copy of this German-language book before completing this bibliography. Apparently, chapters 3, 9 and 12 describe one-man torpedo, explosive motor boat and frogmen operations carried out by the Kriegsmarine during the Normandy campaign.

Brüning, Robert and Buchner, Alex: Unteroffiziere entscheiden ein Gefecht (Verlag E. S. Mittler & Sohn GmbH, Herford 1981; 144pp., maps, illustrations). This is a German-language compendium of tales of military heroism displayed by German NCOs throughout the war. Pages 37-40 describe the achievement of a one-man torpedo crewman, who claimed to have sunk a cruiser off the Normandy coast (in fact, it was a minesweeper).

Jung, Michael (trans. Johnston, David): German Combat Divers in World War II (Schiffer Publishing Ltd., Atglen 2008; 159pp., illustrations). This is the English-language edition of the author’s 2004 Die deutschen Kampfschwimmer im Zweiten Weltkrieg (Verlag E. S. Mittler & Sohn GmbH, Hamburg). Among other things, the book describes (pp.106-15) operations carried out by German naval frogmen during the Normandy campaign, including attempts to destroy bridges over the Canal de Caen and River Orne, lock gates at the mouth of the Orne, and an artillery battery at Vasouy.

Kemp, Paul: Midget Submarines of the Second World War (Chatham Publishing, London 1999; 125pp., illustrations). Pages 42-9 of this book provide technical details of German submersibles developed for anti-shipping operations during the Second World War and describe their involvement in attacks against the invasion forces during July and August 1944.

Paterson, Lawrence: Weapons of Desperation: German Frogmen and Midget Submarines of World War II (Chatham Publishing/Greenhill Books, London 2006, xv + 256pp., maps, illustrations). This is a well-researched history of the Kleinkampfverbände. The book describes the origins and evolution of these units and their use in various theatres of war from April 1944 to May 1945. Attacks against Allied shipping in the Bay of the Seine, and by naval frogmen against bridges and other targets in Normandy, are covered on pp.35-79.

Hope this helps

Simon

[Sid Guttridge]

Hi Simon,

Brilliant!

That is precisely the sort of informed and sourced contribution that justifies the existence of internet fora like AHF.

Many thanks,

Sid.

[Sid Guttridge]

Hi Waleed,

A belated many thanks. I shall work through all your suggested links,

I appreciation,

Sid.

[Darius333]

Thanks Simon for your list.


Regards

Darius

[Simon Trew 1]

Hello all,

No problem. I was looking again at Hinsley (Hinsley, F. H. (‘Harry’); Thomas, E.; Simkins, C.; and Ransom, C.: British Intelligence in the Second World War, Its Influence on Strategy and Operations: Volume Three, Part II (Her Majesty’s Stationery Office, London 1988; xvi + 1038pp., maps) & am reminded that it really is an excellent place to find relevant information. Pages 457-61 provide a focused summary of the use of small battle units in the West during 1944, based mostly on intelligence material found in ADM 223/196, /198, /227, /200-/204, /312, /313 & /315. But there is also extensive information about their operations in the Mediterranean (pp.877-84) & about their final operations in the West in 1945 (pp.633-40).

I haven't yet been able to look at the ADM 223 files used by Hinsley (though I have seen other ADM 223 files, as indicated by my list above). But I note the very large quantity of signals sent to Allied commands in the West & Mediterranean that are in DEFE 3 (based, fairly clearly, on the same sources that Hinsley used). Leaving aside the special naval series in DEFE 3 (which is huge), even the 'main series' is pretty substantial. There is a very large amount of material about operations in the Mediterranean (units based in Italian ports, and operations against 'Dragoon'). There is rather less about KdK operations off the Normandy coast, but a summary of signals I have extracted includes the following. The first piece of information is the signal number, the second is the time and date it was sent to Allied field commands, and the final information is my summary of the text.

XL 2177 1720 hrs 15 July Information dated 5 July describes intended operations by special forces (‘human torpedoes’) against bridges over Canal de Caen & River Orne. Discouraging response on 6 July.
XL 2442 1458 hrs 17 July Italian report 15 July refers to use of personnel of small battle units in attempt to sabotage Orne bridges.
XL 2992 2243 hrs 21 July On 15 July LXXXVI Corps notes that the ‘Orne River mining operation’ has been postponed for a fortnight.
XL 3450 1048 hrs 26 July Provides detailed review of movements & projected operations by small battle units. Notes ‘human torpedo’ operations in Seine Bay by two flotillas, one on night of 5-6 July & another the following night. First unit involved is returning to Lübeck via Paris. Another flotilla will arrive in Paris area during week beginning 9 July. Also reviews operations in Mediterranean.
XL 4194 1729 hrs 31 July Provides details of a planned naval operation by small battle units in Seine Bay. Special communications to be set up by 30 July by the unit involved. On 29 July naval special forces in Le Havre – Rouen area are tasked to investigate a possible raid on the occupied French coast to capture enemy ciphers from an enemy naval signals station.
XL 5121 1826 hrs 7 Aug Raises possibility of small battle unit based in Italy re-locating to France.
XL 5365 1452 hrs 9 Aug Describes attack by small battle units on Allied shipping in Seine Bay on night 2-3 [probably] August. 58 human torpedoes used of which 17 returned. 20 explosive motor boats & 12 control craft also used, organized in 12 sub-divisions (of which 10 returned). Late on 3 August Germans appreciate that only a “mass operation” by explosive boats can succeed.
XL 5378 1558 hrs 9 Aug By 0530 hrs 9 August Navy requests Luftwaffe air cover against enemy fighter-bombers in order to protect small battle units returning into Trouville harbour.
XL 5494 1117 hrs 10 Aug Describes possible move of small battle unit elements from Mediterranean to ‘the West’.
XL 6046 1819 hrs 13 Aug Describes details of an operation involving “swimming saboteurs” that was being planned on 8 August. Operation to begin from Cabourg. Notes need for information provided by direction-finding & also Luftwaffe reconnaissance before operation can begin.
XL 6047 1829 hrs 13 Aug On 9 August preparations begin for destruction of Ouistreham locks by “swimming saboteurs”. Describes details of explosives required & method of conveyance to objective. Operation resembles failed attack on Orne & Canal de Caen bridges on night 4-5 July.
XL 6174 1350 hrs 14 Aug On 10 August Mediterranean small battle units HQ identifies boats being sent to Paris a week later.
XL 6577 1617 hrs 16 Aug On night 15-16 August a special operation involving 53 “weapons” was due to take place but only 11 started owing to heavy rain. Remaining weapons due to be used night 16-17 August, Luftwaffe illumination requested.
XL 6608 2056 hrs 16 Aug Clarifies XL 6577 (see above) by suggesting that operations referred to involve human torpedoes & explosive boats.
XL 7216 1736 hrs 20 Aug On 19 August Small Battle Units HQ mentions departure of a detachment to the “Western area”. If it is impossible to use it there, it should be diverted south.
XL 7974 1111 hrs 26 Aug Report that an operation is to be carried out from Fécamp on the night of 29-30 August, using a flotilla of special craft (submersibles).
XL 8060 2208 hrs 26 Aug Report 24 August summarises activities of small battle units up to that date. 211th Flotilla operated in Seine bay on nights of 5-6 July & 8-9 August, & has returned to Germany. 212th Flotilla has not yet operated but will be ready to leave Baltic around 31 August. According to HQ of small battle units on 17 August, it is to operate in the West or – if this is impossible – the Mediterranean. 261st Flotilla has not yet operated & was expected to leave Germany for West on 21 August. It is to carry out an operation from Fécamp on 29-30 August. 361st Flotilla operated in Seine bay on night 7-8 July & appears to have returned to Germany. 362nd Flotilla operated in Seine bay on night 2-3 August, is now in Tournai probably returning to Baltic. 363rd Flotilla operated in Seine bay on nights 15-16 & 16-17 August. Now moving via Le Havre to Baltic. 364th Flotilla has not yet operated. It was to do so in Le Havre area but intention given up on 23 August & HQ states it will go to Mediterranean.
XL 8136 1029 hrs 27 Aug Describes situation in NW France up to 0700 hrs 27 August, according to German naval sources. Brief reference to special operation from Fécamp.
XL 8196 2009 hrs 27 Aug On 23 August a group of swimming saboteurs leaves Tournai for Venice.
XL 8212 2253 hrs 27 Aug On/about 25 August 364th Flotilla (small battle units) leaves Tournai by rail for Genoa.
XL 8359 2111 hrs 28 Aug On 26 August 24 “special craft” for operation due to be carried out on night 29-30 August from Fécamp are en route to the port. Operation is against Normandy landing area & craft are to return to Le Havre. (Admiralty believes craft are one-man U-boats.)
XL 8505 0405 hrs 30 Aug 24 craft (probably midget submarines) & 48 explosive motor boats loaded at Lübeck on 26-27 August were intended to operate from Fécamp against invasion shipping in Bay of the Seine, returning to Fécamp. Increase in range is facilitated by carrying reserve fuel drums. Fuel & lubricating oil for operations is being moved from Strasbourg & is expected to arrive at Tournai for onward transport at 1400 hrs 28 August. Owing to shortage of cranes at Fécamp only 16 explosive boats can be launched each hour. Therefore only 32-36 can be launched by midnight (fewer if the crane doesn't work) & later sailing makes it impossible to return by night. 50 additional craft (probably midget submarines) are leaving on 30 August by rail for Tournai, also to operate from Fécamp against Seine bay.
XL 8513 0434 hrs 30 Aug Report on 26 August states that special weapons embarked for the West are to be withdrawn to the south only when there are no prospects for success in the West. No one-man torpedo operations are to be carried out in the Channel for the present.
XL 8614 2123 hrs 30 Aug Owing to the land situation, approval has been requested for operation of explosive motor boats & other craft from Calais or Boulogne (instead of Fécamp) against convoys off the English coast.
XL 8615 2248 hrs 30 Aug At 2200 hrs 29 August it is reported that the operation of 24 special craft from Fécamp that night is postponed for 24 hours owing to launching difficulties.
XL 8633 2309 hrs 30 Aug By 0930 hrs 30 August lorries transporting 48 explosive motor boats from Lübeck arrive 45 km SW of Brussels. It is intended they remain there in a well camouflaged position until needed for operations.

In short, I think that getting hold of Hinsley, downloading the DEFE 3 files from the UK National Archives website and maybe buying one or more of the better secondary sources (e.g. Paterson), would probably provide you with a fairly substantial proportion of the information that is likely to interest you.

Happy new year,

Simon

[Sid Guttridge]

Hi Simon,

Thanks.

I used to use the PRO regularly, but in recent years, especially the last year, I haven't been able to do so. Indeed, my readers card may now be due for renewal.

I will try to follow up on ADM223/---- next time I get to go there.

Cheers,

Sid.

[thaddeus_c]

they had the example of FL-Boats from WWI, and were experimenting with different forms of guidance, wonder why they were so late to launch anything?

could include manned torpedoes and minisubs in that too? only with Seehund did they launch a really viable platform.

[Roelie]

Dear Simon,
In your searches of these materials did you come across any mentions of the Wal kleinschnellboot?
I cannot access the archives, but maybe in the future I can travel there. I hope you can give me a hint!
Thank you for listing all this information!
Really wonderful job.
Regards,
Roel

[Simon Trew 1]

Hello Roel,

I'm sorry, but I don't remember coming across anything like this. But it is important to emphasise that my interests are quite focused and selfish. When I was looking at the things listed above (especially Admiralty intelligence files in the UK National Archives), I was looking only for Normandy material. Of course, I saw other things too but if it wasn't Normandy-related, I quickly moved on. Since the type of vessel that interests you wasn't introduced until after the Normandy campaign was over (I had to look it up!), even if there is something in the files about it, I don't think it would have lodged in my memory.

All I can say is that some of the Admiralty intelligence files are packed with fascinating things and I wouldn't be surprised if there is material about the Wal Kleinschnellboot. Certainly, if the British eventually captured examples, I'm pretty sure they would have evaluated them and produced technical reports.

Do any of the secondary sources indicate material in their bibliography that might help you find out where to look? I am not an expert on Admiralty records and my usual way of finding stuff is to do long trawls through indexes and then start ordering the files. Sometimes I strike lucky and often I do not. I'm luckier than many in living close to TNA but for various reasons I don't get there often. Partly owing to Covid restrictions, I have managed precisely one visit in the last year. I'm not going to find much that way!

Good luck, sorry I can't be more helpful.

Simon

[sailorsam]

thanks for all the info
I had always wondered about such forces in the Kreigsmarine.
I'm guessing they weren't used more because most of their maritime conflict was open ocean.
IIRC there were some barge / river operations involving the schnellboots. never heard of anything involving divers etc.

[Roelie]

Dear Simon,
Thank you for your prompt reply!!!
As far as I could find out until now, they where captured by the British. There are three photos on the web showing British troops inspecting them. I was in touch with the owner of the photos. He told me his father had photographed the Wal as a member of the Vernon mine department and that they could have been taken to Scotland for inspection, where the department had been relocated. Some photos he told me where labeled as secret. He gave the photos to a curator at the naval museum. I have the curators name, but not found a way to get in contact with them. These photos show great details of this vessel. Only a very limited amount was produced and I am extremely curious what happened to them:)
One other thing I found is that there are also movies about the kleinkampfmittel which have not been digitized yet.
I cannot wait to jump on a boat or plane to go through these records.
Thank you again,
Regards,
Roel