Major Naval blunders of WW2; kept secret

[Paul L]

If one looks at:

Losses in 39 are almost insignificant ~200 with ~half or less due to U-boats so hardly close in 29
In 40 the numbers go up ~1,000 with again around half due to U-boats and in 41 they increase to ~1,200
It's only in 42 that we see a spike to ~1,600 with 2/3 due to subs but by then US production is making up for over half the losses and produciton exceeds losses after that.
So the only time it could be anywhere close to the edge would be 1940-1942.

What matters is the ship tonnage, not the numbers of ships sunk. And more importantly, the cargo of the ship - oil, food, weapons.
The Germans didn't have to sink all the merchants, just enough to stop Britain from being able to carry out the war.

Cheers,

Yes this point is driven home in the Group 51 Operations research doc. That within two years the Germans had reduced the entire world wide shipping capacity by 1/5. Since the UK needed 30 million tons per year in peace time , when the world wide capacity was down to 33 million tons, it would soon require that entire world capacity to keep the UK functioning. Apparently 2/3 of the ships being targeted was tankers and the monthly consumption in the UK got to the point where the military functioning was threatened.


http://ibiblio.org/hyperwar/USN/rep/ASW-51/index.html

http://ibiblio.org/hyperwar/USN/rep/ASW-51/ASW-8.html

I got Mallmanns book on the German decryption code breaking efforts and even though its far from complete, its definitely illuminating.

In late 1940 German Intel knew the location of ½ of the major RN warship flotilla at sea [The rest would be at home ports?] and this was one of the low points, since the RN had just switched their naval cipher code from # 1 to #2. Intercept efforts would fluctuate between decoding ½ to ¼ of all message traffic until naval cipher code # 5 appeared in mid 1943, after that decoding was the exception rather than the rule. The Germans never broke naval cipher # 5. However the German situation was better than this. The British Merchant Navy had their own code cipher was broken and most of their traffic was decoded through out the war until the start of 1943. At this point they had shifted to “Merchant Ship code” and “Special Convoy Cipher”, and B Dienst was only able to decode a small bit of the traffic .

The joint allies made the situation easier with their codes, which allowed ¾ of the transmittions being decoded until late 1943, when the allies introduced a device similar to the German Enigma system. This allowed the Germans to locate most allied convoys general sailing and route through late 1943. However even at this late stage in the game, allied use of airpower over convoys and the surrounding communications that went between convoy and patrol plane , allowed the Germans to triangulate most allied convoys when they were under attack and thus issue reports. These intercept efforts allowed the Germans to get 10-24 hours warning on the departure of any allied convoy.

Unfortunately for the Germans a lot of this translated information was not used but it did give them an ability to find allied convoys despite the appalling lack of Luftwaffe air support the Uboat effort got during the war. Further the improving quality of German hydrophones allowed their Uboats to detect enemy convoys at considerable distance [100-150km] When this was combined with B-Dienst Convoy alerts, it allowed most allied convoys to be intercepted if the Uboats were within 200-400km of the port the Convoy departed from. Even when the allies drove the Germans below the surface, they were still able to get intercepts if they were within ~ 100km of the convoys.

[lwd]

If one looks at:

Losses in 39 are almost insignificant ~200 with ~half or less due to U-boats so hardly close in 29
In 40 the numbers go up ~1,000 with again around half due to U-boats and in 41 they increase to ~1,200
It's only in 42 that we see a spike to ~1,600 with 2/3 due to subs but by then US production is making up for over half the losses and produciton exceeds losses after that.
So the only time it could be anywhere close to the edge would be 1940-1942.

What matters is the ship tonnage, not the numbers of ships sunk. And more importantly, the cargo of the ship - oil, food, weapons.
The Germans didn't have to sink all the merchants, just enough to stop Britain from being able to carry out the war.

Cheers,

Yes this point is driven home in the Group 51 Operations research doc. That within two years the Germans had reduced the entire world wide shipping capacity by 1/5. Since the UK needed 30 million tons per year in peace time , when the world wide capacity was down to 33 million tons, it would soon require that entire world capacity to keep the UK functioning. Apparently 2/3 of the ships being targeted was tankers and the monthly consumption in the UK got to the point where the military functioning was threatened.
...
http://ibiblio.org/hyperwar/USN/rep/ASW-51/ASW-8.html
....

Tonnage and numbers of cargo ships are reasonably well correlated. Looking at the document above I get a rather different picutre. I didn't see where it stated that the UK required 30 million tons/year in peace time but in any case that's not necessarily it's war time requirement. Also looking at the table in the above document the Uboats account for ~1 million tons between 1939 and Sept 42 when the 33 million ton capacity is mentioned. I simply don't see the case for Britain being near defeat by the U-boats.

[Paul L]

What matters is the ship tonnage, not the numbers of ships sunk. And more importantly, the cargo of the ship - oil, food, weapons.
The Germans didn't have to sink all the merchants, just enough to stop Britain from being able to carry out the war.

Cheers,

Yes this point is driven home in the Group 51 Operations research doc. That within two years the Germans had reduced the entire world wide shipping capacity by 1/5. Since the UK needed 30 million tons per year in peace time , when the world wide capacity was down to 33 million tons, it would soon require that entire world capacity to keep the UK functioning. Apparently 2/3 of the ships being targeted was tankers and the monthly consumption in the UK got to the point where the military functioning was threatened.
...
http://ibiblio.org/hyperwar/USN/rep/ASW-51/ASW-8.html
....

Tonnage and numbers of cargo ships are reasonably well correlated. Looking at the document above I get a rather different picutre. I didn't see where it stated that the UK required 30 million tons/year in peace time but in any case that's not necessarily it's war time requirement. Also looking at the table in the above document the Uboats account for ~1 million tons between 1939 and Sept 42 when the 33 million ton capacity is mentioned. I simply don't see the case for Britain being near defeat by the U-boats.

The 30 million tons comes from Churchill and is much quoted. But that was peace time , actual wartime consumption reached as high as 64 million tons per year by 1944, so it was a big deal. All it would take is the neutal shipping to refuse to risk losing their ships in a 'lost cause' and/or Lloylds refusing to insure charters; to collapse the UK war economy. Its the kind of event that historians would agnoize over for decades after [Why did they do that?], but it can happen.

[hammy]

You are missing that certain vital imports were being heavily predated , for which there were no available substitutes AT THAT TIME .
Mineral oil and refined fuels are , I suppose , the obvious example . All imported ( bar a dribble , still produced onshore somewhere or other here - Kent , or is it Leicestershire ? ) , and no chance of synthesising more than token quantities from the (abundant) coal supply here for 30 months , because of the Lead time needed to set up such an industry from scratch .

We could do without Argentine Beef , New Zealand Mutton , etc , by comparison , and eat mainly potatoes , but tanks and spitfires cant .

You also are missing the Morale effect of sinkings on the Merchant seamen , a very real worry at the time was that crews would at some point refuse to sail , to the stage that at least one freighter was crossing the North Atlantic with a crew of "volunteers" made up from convicts from Barlinnie prison , Glasgow .
( I wouldn't fancy being third officer on her ! )
Up till mid 1941 Escort vessels only operated out into the Western Approaches , some way west of Ireland , were very few in number , and without Radar or lights frequently lost contact with their charges in bad weather or at night . Thereafter , the convoy , assuming you were even in one , would be accompanied only by an armed merchant cruiser ( if you were lucky ) or without any protection at all , ( save that of being in a "shoal" like sardines ) .
I would have low morale in those circumstances .

The previous point about the imminent collapse being an economic one is also well made . Having parted with all our foreign currency , and most of our Gold , and having sold off most of our Foreign Stocks,Shares,Bonds etc ( at knock-down prices ) , and having given the USA long leases on many of our bases ( like Bermuda ) , there was very little left to sell or give away in exchange for arms (of sometimes dubious quality).
Hence the "Whisky Galore" episode , based on a true event , the wreck of a freighter bound out of the Clyde for the US , laden with Old mature whisky , which came to grief in bad weather on one of the Hebrides Islands off Scotland . The bottles and casks of fine old whisky were an asset having value , to be sold and exchanged for arms from the US . The Hebridean Islanders , a savage race even today , promptly looted as much of the cargo as could be got out of her and squirrelled away from the view of His Majesty's Reciever of Wrecks , and I have every sympathy .
The point being , that the country was down to desperate economic measures like that to keep the war going .

[lwd]

... The 30 million tons comes from Churchill and is much quoted.

That may be but what does it mean and how accurate is it?

But that was peace time , actual wartime consumption reached as high as 64 million tons per year by 1944, so it was a big deal.

Note that consumption is not the same as capacity. If you have a capacity of 30 million tons and you can make 2 trips a year you have 60 million tons available for consumption. If it's 4 trips a lyear then you have 120 million.

All it would take is the neutal shipping to refuse to risk losing their ships in a 'lost cause' and/or Lloylds refusing to insure charters; to collapse the UK war economy. Its the kind of event that historians would agnoize over for decades after [Why did they do that?], but it can happen.

But most of the shipping was hardly neutral.

Certainly there was a period where the trend was very bad for the British. However they were never in danger of immenent collapse from the Uboats.

[lwd]

You are missing that certain vital imports were being heavily predated , ....

Was I? At what point did Britains supply of petrol go critical? Sure they put conservation measures in effect but I've never read that they didn't send fighters up intercept German aircraft because of a lack of fuel.

From a somewhat different slant this is being discussed over at:
http://www.ww2f.com/what-if/37319-alter ... antic.html
Here's a quote of relevance from there by :

... According to Clay Blair, in "Hitler's U-boat War" Vol. 2, (page 708), of 657 total convoys on the critical North Atlantic convoy route between September, 1942, and May, 1945, comprised of 31,111 ships, just 247 (less than 1%) ships were lost. Those figures hold up for all periods and for the totals of all convoys in all areas. Less than 1% of ships transiting areas patrolled by Axis submarines were lost to submarine attack. So going to great lengths to protect merchant vessels against torpedo attack does not seem to make much sense. When actual losses are plotted against replacement tonnage it's clear neither German U-boats or Japanese subs ever had much of a chance of winning the "tonnage war"."

In terms of cargo sunk, or the total embarked for the UK the loss ammounted to around 4% - 7% annually. There was a surge to over 10% cargo lost in 1942 which is connected to Operation Drumbeat off the East Coast of the US and the related Carribian submarine operations. In 1943 when the Battle of The Atlantic' was at its crisis height loss of cargo embarked & destined for the UK started well below 10% at the start of the year and dropped to below 5% by midyear. ...

[Bgile]

lwd,

What you seem to be saying is the ASW effort wasn't worthwhile because losses were sustainable. Do you really believe that if the escorts were withdrawn and their crews were transferred to the army, that all would be fine? Because if you don't believe that, then you almost have to believe that the reason the losses didn't become prohibitive was the increasing allied ASW effort.

[Paul L]

LWD on that link I gave you , you will see that convoying ends up with 1/2 capacity after year since the accumulated delay adds up to that much ....compared to unescorted shipping, so when the WORLD WIDE shipping is 32 million tons the actual amount through conovys is only going to be about 16 million, so they will actually have to make 4 trips just to keep up the peace time needs to say nothing of the additional wartime needs. Also since Uboats operated in campaigns there were surges when the accumulated losses in tankers meant the fuel supply in the UK was down to a couple of months forcing severe rationing.

[Paul L]

The editing function on this forum is really limited!

What I was trying to add to my post was ...

The Oil crisis for the allies lasted from 1940-43 reaching several peaks during that period. In Early 1942 the loss rate on tankers was reaching 200,000 tons per month and the allies concluded they would lose 1/2 of their tanker fleet within a year if this kept up. Further at this time the RN complained they only had 2 months supply of bunkerfuel while stockpiles of Gasoline for the Army was down to 5 weeks. "Oil & War" pp 106 & 111 Goralski & Freeburg. The Allied ASW breakthroughs of 1942 and Decoding break throughs into 1943, could not have come at a better time. Certainly as long as the Axis could keep the allied fuel supplies in crisis , the allies would be very hard pressed to build up any major second front needed to defeat Hitlers Wehrmacht.

[RF]

I am not aware of a fuel crisis in Britain during any part of WW2, either from official records or from the memories of my parents and grandparents who lived in Britain throughout the war.
Fuel was very tightly rationed, especially for civilian use, where use was only allowed on an essential basis. Remember that at that time coal was still the main fuel for power and electricity, which did not need to be imported as Britain was a major coal producer.
As I understand it the main problem from 1940 to 1942 was of available shipping space, rather than a shortage of ships' cargoes arriving.

[lwd]

lwd,

What you seem to be saying is the ASW effort wasn't worthwhile because losses were sustainable. ....

Not at all. The U-boats (E-boats, surface ships, and aircraft) were a serious threat to Britain. If the British had done nothing about them they might well have lost. That's not the same thing as "coming close to defeating Britain". Indeed in 41 the situation looked bad but defeat wasn't immenent and there was clearly time to prevent if from becoming so.

[lwd]

....compared to unescorted shipping, so when the WORLD WIDE shipping is 32 million tons the actual amount through conovys is only going to be about 16 million, so they will actually have to make 4 trips just to keep up the peace time needs to say nothing of the additional wartime needs.

But we aren't at all sure of what these "peace time needs" are. Indeed some of them could and were considered luxuries and were cut. Britian went to rationing pretty early and kept it up until well after the war. So it's not at all clear that the "wartime needs" were greater than the peace time ones. Furthermore there's still the question of just what the 30 million tons represented. For things like fuel supply there are many ways to calculate it and they can yield considerably different reserves. Without knowing the details it's hard to say just what the critical reserves were (I would define these as the fuel required to defend Britian).

[Byron Angel]

The editing function on this forum is really limited!

What I was trying to add to my post was ...

The Oil crisis for the allies lasted from 1940-43 reaching several peaks during that period. In Early 1942 the loss rate on tankers was reaching 200,000 tons per month and the allies concluded they would lose 1/2 of their tanker fleet within a year if this kept up. Further at this time the RN complained they only had 2 months supply of bunkerfuel while stockpiles of Gasoline for the Army was down to 5 weeks. "Oil & War" pp 106 & 111 Goralski & Freeburg. The Allied ASW breakthroughs of 1942 and Decoding break throughs into 1943, could not have come at a better time. Certainly as long as the Axis could keep the allied fuel supplies in crisis , the allies would be very hard pressed to build up any major second front needed to defeat Hitlers Wehrmacht.

..... Blair discusses the heavy attrition of allied oil tankers in early 1942 (see"Hitler's U-Boat War", Vol 1, from pg. 588).

The short story is that Doenitz took advantage of US/Allied tactical and operational unpreparedness in the Caribbean and along the Atlantic seaboard to inflict heavy losses. Overall tankers sunk in American and Caribbean waters totalled 129 for the period Jan-Jun 1942. These losses, coupled with the need of Britain to detach about 50 units of its tanker fleet from servicing the Home Islands to support ongoing miltary operations in the Mediterranean and Indian theaters, did raise serious concerns about the ability to maintain adequate petroleum products reserves in Great Britain. However, events soon dispelled British concerns on this front. First, proper convoy procedures finally implemented in Caribbean and American coastal waters ended the easy 'Paukenschlag' pickings and tanker losses dramatically plummeted by mid-1942 . Secondly, in response to a British request for the loan of 700,000 DWT of tanker capacity to tide them over during their period of concern, the US was able to immediately provide Britain with 854,000 DWT (about 20% more capacity than had been requested!). Allied shipbuilding programs rapidly accelerated from there to the point where carrying capacity on the Atlantic routes was being added faster than German U-Boat efforts could sink it. Once that condition was reached, the U-Boat war could fairly be deemed a strategic failure.


Happy New Year to all,

Byron

[hammy]

You are missing that certain vital imports were being heavily predated , ....

Was I? At what point did Britains supply of petrol go critical? Sure they put conservation measures in effect but I've never read that they didn't send fighters up intercept German aircraft because of a lack of fuel.

Well of course you havent because that would probably be the ultimate cut of all . Lot of RAF Ground Crews riding around the aerodromes on bicycles though , weren't there !
Dont forget that it isnt just petrol . At the other end of the refining ladder it's Asphalt . Hence all those concrete runways , and wooden blocks in the bombholes in the roads . And all the petrochemical products in between , including things like vaseline .
A further point is that if tankers are being sunk then it screws production up , because the Tank Farm at the loading point can only hold so much , and bearing in mind that some crude oils have to be kept warm to prevent them from solidifying , once the tanks are all full you cant just add capacity without some fairly intensive engineering effort .If your tankers dont arrive , load , and depart to schedule then you have a big problem .

From a somewhat different slant this is being discussed over at:
http://www.ww2f.com/what-if/37319-alter ... antic.html
Here's a quote of relevance from there by :

... According to Clay Blair, in "Hitler's U-boat War" Vol. 2, (page 708), of 657 total convoys on the critical North Atlantic convoy route between September, 1942, and May, 1945, comprised of 31,111 ships, just 247 (less than 1%) ships were lost. Those figures hold up for all periods and for the totals of all convoys in all areas. Less than 1% of ships transiting areas patrolled by Axis submarines were lost to submarine attack. So going to great lengths to protect merchant vessels against torpedo attack does not seem to make much sense. When actual losses are plotted against replacement tonnage it's clear neither German U-boats or Japanese subs ever had much of a chance of winning the "tonnage war"."

In terms of cargo sunk, or the total embarked for the UK the loss ammounted to around 4% - 7% annually. There was a surge to over 10% cargo lost in 1942 which is connected to Operation Drumbeat off the East Coast of the US and the related Carribian submarine operations. In 1943 when the Battle of The Atlantic' was at its crisis height loss of cargo embarked & destined for the UK started well below 10% at the start of the year and dropped to below 5% by midyear. ...

Dead right old boy , but you are reading the wrong lesson from this .
What this is , is proof positive that Convoys work , even when the escort is less than the optimum size , the case up to mid 1942 or so . Many ships were NOT sailing in convoy though or only for part of their route . Fast ships , those on unfrequented passages , or those proceeding to/fro Convoy assembly points would be covered only by patrolling warships or aircraft looking at sea areas , not accompanying the shipping .
Thats exactly the mistake that the worlds navies are making today in the seas around the Horn of Africa , with entirely predictable results . ( AGAIN TODAY I see .)
In WW2 the situation was (probably) unavoidable , your forces can never be strong enough everywhere to completely rule out losses .
Churchill had some pretty bad failures during WW2 , but the Operational Research Department he promoted in the Admiralty , and which was responsible for the studies proving that an efficient convoy system was the least worst way of maintaining supply was bang on target .

[Byron Angel]

What this is , is proof positive that Convoys work , even when the escort is less than the optimum size , the case up to mid 1942 or so .

..... Agree 100 pct ..... provided that the opponent is not reading your mail.


Byron