German U-Boat Statistics

[Borden Battery]

I have done a quick search of the Great War Forum site, however, I have not been able to locate any summary statistics on the impact of the German U-boat fleet on Allied shipping.

Given there was unrestricted activity, and the pressure from Haig and Jellicoe through the Battle of Passchendaele, there must be some summary statistics on the number of ships sunk and the associated tonnages.

Can someone direct me to these summary statistics? I am interested in detailed statistics with source references.

Regards

- Borden Battery

[Stebie9173]

I know there are. Some monthly tonnage statistics were on the Great War programme today. I'll check it tomorrow morning on video if it hasn't been taped over it!

Not detailed, I know but a start...

Steve.

[Adrian Roberts]

Try www.uboat.net

A very comprehensive site. Apparently in WW1 a total of 375 U boats sank 6596 merchant ships, a total of 12,800,000 tons. Not sure if this included sinkings by mines laid by u-boat

Adrian

[Borden Battery]

Thanks Adrian

I have reviewed the U-Boat site and it contains a lot of high quality information and articles. I note there is even a small but specialized discussion forum on this site as well.

The CEF Study Group will be adding this site to its recommended website list.

Thanks Again.

Borden Battery

[Michael Lowrey]

Bordon,

The figures Adrian gives would include losses to U-boat laid mine. These account for approximately 10% of the total.

I actually handle much of the WWI material for Uboat.net; thank you the recommendation. If you have any questions of this topic, fire away...

Best wishes,

Michael

[Borden Battery]

Hello Michael

15 April 2005

When you have the time, I would appreciate it if you could post a good summary of the role and actions of the German U-Boat fleet during the Great War.

While we tend to focus on the land-based actions of the Western Front on this discussion forum, there were several other theatres and forces involved in this conflict.

Regards

Borden Battery

[historydavid]

Borden,

The Naval History site (www.naval-history.net) has some detailed figures for British merchant vessels, by individual vessel, tonnage, where sunk, how sunk etc. (but I believe that these are based on British Vessels Lost at Sea, which is not a complete listing)

You would have to get the calculator out to assemble some totals.

For more rounded totals the following may suffice:

The information for this table is from Arthur J Marders book "From the Dreadnought to Scapa Flow. Volume V" p.111.

1914 British World Total

August 40,254 62,767

September 88,219 98,378

October 77,805 87,917

November 8,888 19,413

December 26,035 44,197

Yearly Totals 241,201 312,672

1915

January 32,054 47,981

February 36,372 59,921

March 71,479 80,775

April 22,453 55,725

May 84,025 120,058

June 83,198 131,428

July 52,847 109,640

August 148,464 185,866

September 101,690 151,884

October 54,156 88,534

November 94,493 153,043

December 74,490 123,141

Yearly Totals 855,721 1,307,996

1916

January 62,288 81,259

February 75,860 117,547

March 99,089 167,097

April 141,193 191,667

May 64,521 129,175

June 36,976 108,855

July 82,432 118,215

August 43,354 162,744

September 104,572 230,460

October 176,248 353,660

November 168,809 311,508

December 182,292 355,139

Yearly Totals 1,237,634 2,327,326

1917

January 153,666 368,521

February 313,486 540,006

March 353,478 593,841

April 545,282 881,027

May 352,289 596,629

June 417,925 687,507

July 364,858 557,988

August 329,810 511,730

September 196,212 351,748

October 276,132 458,558

November 173,560 289,212

December 253,087 399,111

Yearly Totals 3,729,785 6,235,878

1918

January 179,973 306,658

February 226,896 318,957

March 199,458 342,597

April 215,543 278,719

May 192,436 295,520

June 162,990 255,587

July 165,449 260,967

August 145,721 283,815

September 136,859 187,881

October 59,229 118,559

November 10,195 17,682

Yearly Totals 1,694,749 2,666,942

Grand Total 7,759,090 12,850,814

The same figures appear in John Terraine's "Business in Great Waters - The U-boat Wars 1916-1945" published 1989.

The are introduced with the following comments:

These figures exclude Commissioned Auxiliaries.

The British figures include merchant vessels only; the world total includes British & foreign fishing vessels.

The figures include steam & sailing vessels of all sizes.

Borden, the above totals are probably as accurate as you will get, bearing in mind that the tonnage of some of the vessels sunk by U-boats is unknown and it is still possible that some vessel losses that have been attributed to other causes may have been due to U-boats.

I think that definitive totals are impossible to attain.

Hoping at least some of this will shed light on your search and not be too disheartening.

Best wishes

David

ps hope the formatting works ok.

[historydavid]

whoops, I screwed up.

The format for the tonnages should be:

Month British tonnage World Total tonnage

Hope you sort it out.

David

[Michael Lowrey]

The question of exact tonnage sunk is an interesting one. I am working on a database of all cases of ships sunk, damaged or captured by German and Austrian U-boats in WWI. For 1918, for example, I have 1329 vessels of 2,821,398 tons sunk. This includes some warships with about 50,000 tons of displacment tonnage (Britannia, San Diego, a French cruiser, some destroyers, sloops, and purpose-built minesweepers) and merchant ships taken into naval service. The official German estimate for 1918 (Germany-only) is 2,754,152 grt for mercantile tonnage sunk.

There are an additional 104 cases ships listed as sunk that are not as yet attributed to a specific submarine and not counted in the above (some of these cases probably aren't real sinkings, some maybe non-U-boat related, a few are simply bizarre in that they appear in BVLAS and LLoyd's War Losses but no submarine claims them, some clearly are and I just haven't tracked down the vessel responsible).

12 vessels were taken as prizes in 1918, and at least five retained. These should be regarded as the equivalent of sunk for these purposes. 176 ships of 865,124 tons were damged; the are seven additional cases of ships damaged that are as yet unattributed.

And if I ran these numbers again in a month, they'd likely be slightly different, as it's entirely possible that I might have solved a previously unattributed sinking or been able to dismiss a case as being non-u-boat related. There are some cases that will produce to clear answer regardless how much I or anyone researches the...

Also note that the 1917 sinking total is almost exactly the same as 1942, the top year for u-boats in WWII. April 1917 is the best month of either war for U-boats.

Best wishes,

Michael

[Borden Battery]

Hello Michael

17 April 2005

I find your work interesting and surprised it taking until 2005+ to consoliate the information on U-Boats and their confirmed targets.

Placing the data into a database will force you and others to review and allocate information for each ship and should lead to a more rigourous compilation. Are you doing this work alone or are you able to coordinate a small team of persons?

How many U-Boats were lost which might have also sunk a ship while on that specific cruise: this might be a factor in any final consolidation of the data.

For myself, I am working with another person on the transcribing of some of the detailed daily war diaries from some Canadian Expeditionary Force units and some select British Expeditionary Forces.

Regards

Dwight Mercer / Borden Battery

[Michael Lowrey]

Dwight,

I do have a research partner plus lost of other contacts. The list of people doing WWI U-boat research is rather short.

To be fair, the German official history series, Handelskrieg mit U-Booten by Admiral Arno Spindler attributes out 96 to 97 percent of the cases. Of course, when you're dealing with a population of +/- 7,500 ships sunk, damaged, or captured, that last 3 or 4 percent is still several hundred sinkings/ships damaged that are unexplained. Spindler is probably 99.8% accurate is his attributions; I've found only a very few errors when comparing the sinkings he credits to a specific submarine to that boats KTB (Kriegstagebuch = war diary) and British Vessels Sunk at Sea and Lloyd's War Losses.

As for why no one has tried to work out the remaining cases, a lot of it is timing. The fourth volume of Spindler covering February to December 1917 was published during WWII. The fifth volume covering 1918 was released in 1966(!), nearly half a century after the fact. By then, the focus of naval research and interest was focused on the more recent world war.

Of the ships sunk or damaged not explained by Spindler, many cases are simply ommissions. Sometimes a ship is even identified by name as being sunk in a KTB but for some reason was over looked when Spindler and his team prepared the official history. In other cases, it's possible to find a date and location match in a KTB for a torpedo or gunnary attack.

Spindler also missed a fair number of submarine-laid mine hits. Given that mine can sink a vessel months after it was laid, these can be a bit trickiery to sort out, especially in the most heavily mined areas. Complicating things is somethings that are labeled mines hits where really torpedo hits and vise versa.

One major problem in attributing out a number of cases is simply a lack of a precise position for a loss. It's hard to know what to look for in a case like the steamer Virent which is listed as torpedoed in the Mediterranean on July 17, 1917. I think I've found a match-- there is an U-boat that claimed a hit in the Med on that day -- but without knowing exactly where in the Med it's hard to be sure. (Kew awaits eventually but many cases like this don't involve British vessels.)

Spindler does try to assign sinkings to U-boats lost of patrol. Obviously, you have to be careful of these and be alert for alternative explainations or possible errors. I have found among the unexplained post-Spindler, a very few cases of ships sunk or damaged by a submarine that was lost later on that patrol. In one case, it does disprove the commonly accepted sinking claim for that submarine.

In another case, noted submarine diver Innes McCartney unexpectedly found an UBIII wreck of Padstow, Cornwall. He was able to identify the boat as UB 65 two years ago through markings on the propellers. The U-boat was lost through some sort of accident; there's no obvious damage to the boat. A buddy of mine did the historical research and found an unexplained sinking nearby at a time consistant with when UB 65 should have been in the area... I should add that there are major methodological problems in the U-boat loss record, so a case like this comes as no surprise. (I also work with divers to locate and identify submarine wrecks and plan to write a book on U-boat losses.)

Best wishes,

Michael

[Borden Battery]

It would appear the topic and research are in very good hands. I commend you on your work and thank you for the informative narrative you provided on your research.

With your permission, I would like to re-post your answer on the CEF Study Group site [with reference to the Great War Forum] and again reference the uboat.net website. I think some additional researchers would be interested in this aspect of the Great War.

Dwight Mercer

[Michael Lowrey]

Dwight,

No problem what so ever.

Best wishes,

Michael