Alternative strategy in the Battle of the Atlantic

I speak from alot of experiance in shipboard damage control. I was in the Navy 27 years, attended firefighting schools (Shipboard and flight deck both) numerous times, qualified as DCPO, repair locker leader, and a bunch of other DC related stuff. The way I would have done it is have each team train on firefighting, shoring and, dewatering and then have them simply run drills with some crew helping each day while at sea. You can get a really good team that way in just a few weeks.
The best locker I was ever in was half nucs, half bosun's mates. Brains and brawn combined. The shoring team had the honor of being the only one ever to build a training shore the RefTra people couldn't knock down with 10 lbs sledge hammers. They were suitiably impressed.

 

Hey guys, looks like yet another great WI thread!

I have to say that I am quite impressed by the knowledge displayed here. As more of a tinkerer than an actual doer, I have a question for you fellows. I am strictly a land lover, but wouldn't a torpedo bulge filled by a vertical slab of ice (frozen in side an inflatable bag/bladder) and backed by a few feet of water (to augment the shock-absorbing potential of the ice be the cheapest, easiest to repair, and most resilient torpedo defense?

I remember reading a book about the difficulties of arctic subs had with 'hostile ice' and thinking that if ice were such bad-ass stuff, why didn't we just use the stuff ourselves to protect from torpedo's and icebergs?

How big were the warheads on the German torpedo's?
How thick a slab of ice (backed by a volume of water that could 'blow out' through designed for pressure release points) need to be to keep the hull from taking the brunt of the blow?

What if you had <ICE>Water<ICE> inside the 'torpedo bulge'?

The idea here is that the torpedo hits the outer ice barrier and detonates. The ice barrier shatters and bows inward, displacing the water
out the top hatches in the torpedo bulge, and the residual energy then hits the second (inner) ice barrier and doesn't make it to the hull itself.

Or is this another of my wacky ideas that could never work?

 

JAdams, I think you are correct.
It wasn't economical to slow down production to build tougher boats. Part of the problem was that it would take too long to replace the shipping supply, and due to convoy practices, it wouldn't help much.

At the outbreak of war, the US had about 5 million tons of ocean-going shipping, and the UK (& allies) about 21 million tons. (The US also had about 3 million tons of smaller Coastal, Great Lakes & Mississippi cargo ships) The UK was building about 1.8 million tons per year. The US built 1.9 million tons in 1941, and about 5.2 million tons in 1942.

Although the Liberties were made quickly using an existing older design, the Victory class was a new design (started Feb 1942) made to take into account war experience & needs, but the first ones wern't ready till the sping of '44. - Too late to have a great effect on the war, as regardless of the design for the Victory's, by that time the u-boat war would either be won or lost.
The other problem is, that the convoy practice was to put the larger more important ships (newest) in the center, with the smaller, older ones on the outside. So in a u-boat attack, the ships likely hit would be the older 3,000 & 4,000 tonners, not the newer 10,000 ton Liberties.

In a word - no.
In fact the u-boats were the most effective in 1939 - 1940 in terms of ships sunk vs U-boats lost, however they were handicapped by the shortage of u-boats.

Luckily for the Allies, Hitler didn't understand naval warfare, he concentrated resources on the big ticket "prestige" ships like the Bismarck, while ignoring U-boats.
The Bismarck & Tirpitz were both laid down in 1936, and launched in 1939. Although the Bismarck did provoke a huge reaction from the British, it didn't have much effect on the war, as it was sunk on it's maiden voyage. The Tirpitz never engaged the RN.
By contrast, in 1937 the KM produced a grand total of 1 - ONE! U-boat.
If they had produced 199 U-boats in 1937 (as they did in 1941) things would have been vastly different in the war.

Some facts:

Year . U-boats produced
1935....14
1936....21
1937....1
1938....9

Start of war : 57 U-boats operational

Year . U-boats produced .. U-boats sunk
1939 ....18 .......................9
1940 ....50 .......................24
1941 ....199 .....................35
1942 ....237 .....................86
1943 ....284 .....................238
1944 ....229 .....................235
1945 ....91 .......................129

{info from uboat.net}

Furthermore, of the approx 64 u-boats operational on "Alder Tag" (Aug 1940) about 35 or 40 were of the smaller, short range type II "coastal boats" that were used for training or used in the North Sea, Med, Black Sea. They didn't really have the range or endurance to opeate far out at sea, in the atlantic trade routes.

 

Well, there was project Habbakuk. This was an Allied project that actually went so far as to prepare for actual construction. What they proposed building was a 1,000,000 ton aircraft carrier out of an ice-like substance called "Pyecrete"

Project Habakkuk: Interesting Thing of the Day

The US and Canada actually set up a huge plant just to make the materials. This included wood chipping /pulping plants, ice manufacturing facilities and the handling equipment to build the ship. Everything was set up and manufacturing was begun then the project was cancelled.

So, I guess ice could have been used to make an unsinkable ship....

 

I remember seeing something about the "ice ships" on TV a number of years ago, but didn't remember the name of the program. Thanks for the link!

I wonder how hard it would be to get a computer model of a torpedo warheads explosion and check that vs varying thicknesses of ice/water barriers to see where the {Useless/feasible/impervious} levels would be attained, and then cross check energy/weight factors and see if this could work for modern Nuc carriers.

Wouldn't it be interesting if this type of torpedo barrier proved effective in modern warships (or maybe it wouldn't be ice but a modern descendant to the Pyecrete)?

I think that unless the feasible thickness were to be measured in inches, the weight factor would prove to be prohibitive for a WWII merchant ship.

On a side note: Just what exactly was a 'torpedo bulge' filled with, anyway? From reading up on the Bismark I came away with the impression that perhaps a torpedo bulge was often used as additional fuel storage --- is this correct?

I remember reading that the force exerted by a torpedo warheads detonation was rapidly (and drastically) reduced by just a few feet, and that the concept of the torpedo bulge was to cause the detonation to take place away from the hull just for this purpose.

 

Mainly because by the summer of '44 the allies had won the "Battle of the Atlantic", with ASW advances the u-boats had little chance of sinking Allied ships.

Not true actually, the main problems were the Axis lack of understanding of naval war, and their inability to work together.

Consider this: Operation Drumbeat began a full 5 weeks after Pearl Harbor, with a grand total of FIVE U-boats attacking shipping in US waters. These 5 ships sank an average of 32,000 tons of shipping in their first tour (of about 6 weeks).
Suppose the Germans & Japanese had coordinated an attack to begin the morning of December 8, with Axis ships waiting in position in every major Allied port in the Pacific & Indian Oceans, and all the major US ports.
The damage would have been catastrophic, with all of the ports lacking ASW protection, and in peace-time mode.

The Allies could easily lose 6 to 8+ million tons in the first two months alone.
The following lock-down of Allied shipping would cripple the Allied supply line world-wide.

There were 50 DD's given to the British & Commonwealth, and far from "making Drumbeat more like a whimper", they would have had almost ZERO benefit to the US.

The "Bases for DD's" ships were of the older WWI era Caldwell, Wickes, and Clemson classes, and were totally unsuited for ASW duties.

Info from "destroyerHistory.Org"

Of the 38 DD's used by the British, by Dec 1941 - 23 had been converted by the UK for ASW use, 16 used for fleet duties, in process of conversion, or other purposes, and 3 had been sunk.
8 were transferred to the Royal Canadian Navy in 1940, with 4 more given to the RCN in 1942. In fact, many of these ex-US RCN ships ended up protecting convoys off the US Eastern Seaboard, as they took over convoy duties in the Jamaica - New York - Halifax route in 1942, when the US wasn't capable.

By comparison by Oct 1941, of the 120 remaining US WWI "Flush deck" destroyers, 48 had been or were in the process of upgrading, with only 19 completed.

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Lacking in sonar & effective depth charges, many of the the older "Flush deck" DD's were left sitting in port during Drumbeat, as they had little chance of effecting a successful attack against u-boats, and were more likely to become casualties.

The US didn't manage to sink even one single u-boat in the first 3 months of 1942, and in the 6 months from Dec 7 1941 - June 7, '42 had only managed to sink two U-boats. (During this time the British & Allies had sunk at least 25)

So to sum up, during drumbeat the US had about 200 destroyers - 85 modern destroyers, (Farragut - Bristol class), 48 upgraded "Flush deckers", and about 70 of the older, unconverted destroyers, yet were only able to sink 2 U-boats in the first 6 months of the war.

I seriously doubt that the addition of the 40 or so destroyers sent to operate by the Royal navy in european waters would have helped out much at all.

This is not a slam on the US Navy - they just didn't have the equipment & training in early '42 to combat the U-boats at sea.

On the other hand, with the bases deal, the US was able to upgrade & use the facilities at the western hemisphere bases, Bahamas, Bermuda, Newfoundland, Antigua, Jamaica etc, which had far more benefit to the Western hemisphere ASW efforts than a bunch of obsolete WWI destroyers would.
And ultimately, it was the ability to project ASW aircraft everywhere in the N. Atlantic, from bases in Newfoundland, Bermuda, Antigua etc. that allowed the Allies to finally defeat the u-boat menace.

 

Reading further, I came across these two articles....

Re: The rise and fall Torpedo bulges

Anti-torpedo bulge - Wikipedia, the free encyclopedia

It seems that the Torpedo Bulge was water/air filled, and the latter successors did indeed use (among other things) fuel oil as buffers.

Nobody tired ice that I can tell so far...

 

freebird,

A few points of note.

You forget that the Germans had two years of submarining experience behind them, the Japanese did not. The Japanese achieved poor results when they had some nine submarines off the West Coast in mid-late December, 1941. See here Axis submarine successes of World ... - Google Books and "I-Boat Captain" by Zenji Orita and Joseph D. Harrington. The Japanese were still using the old pre-war tactic of staying submerged most of the time. These Japanese submarines reported few sightings and fewer sinkings. With the Japanese submariners still learning "the tricks of the trade," it will be a while before the reach the quality of Germany's submariners.

Also, since the British had, at that time, "cracked" ENIGMA, they would likely know that something was in the wind. How would they react? Let the Americans know that they were about to be attacked by Germany and Japan? The British had picked up the German submarines headed to American shores, but their warning went unheeded by the US. IIRC, this was made by direction finding and not through ENIGMA. Still, contact was made and the German submarines tracked.

Be fair now! A good half of your "200" US destroyers were posted to areas where they would never encounter German U-boats! See Axis History Forum &bull; View topic - US Navy Destroyers While still a poor showing, it is at least more honest.

 

Most Uboat attacks were with there guns not there torpedos.

 

I know that it started off that way (much cheaper to sink a ship with a few shells of the many they carried) than to expend a much larger and costlier torpedo (that they had far fewer of), but at what point did the surface action give way to submerged torpedo attack (or did it)?

 

uboat.net seems to think otherwise, see uboat.net - Special Sections - Attack Analysis

Now even if all of the gun only attacks were during Operation Drumbeat, which is unlikely, they still only account for roughly half of the ships lost in the first six months of said Operation. I don't see this as meeting the definition of the term "most."


@Shadow Master,

Yes, it was a cheaper way to sink ships, however sinking a ship, especially a good sized ship, requires a lot of time spent on the surface. Only the small ships would sink after a few shells, the larger ones could take up to several hours to sink. As the war progressed the U-boats did not have the luxury of spending a lot of time on the surface and by 1943 most of the guns had been removed. The exception to this was the Type IXs which were head to South Africa and the Indian Ocean, since these waters were less heavily patrolled by Allied ASW units. See uboat.net - Technical pages - U-boat Deck guns

 

The problem wasn't so much a lack of understanding how to run a Guerre de Course but rather the German's selection of submarine characteristics and design. Prewar, the KM looked at England and France as their primary potential adversaries in a future war. That view colored what sort of ships they built from capital units down to submarines and everything in between.
Because of their strategic view the KM only built shorter ranged, smaller boats almost up to the actual start of the war. For a commerce war in waters around Britain the Type VII was a good design. It was a handy boat with properties that made it good for that sort of operation.
Only the Type IX boats that had only recently started production were capable of carrying the war into the Middle and Western Atlantic. These few boats were also the only ones capable of reaching the US and operating in US waters.
So, for the Germans to really make Drumbeat effective they would have had to plan well before the war construction of U-boats suitable for use in distant waters. This would have also meant that they would have to consider the US a potential enemy in strategic planning as carrying such a war far from Europe and close to US shores would provoke the US even if they were not actively in the war.

That is until the British, and then the US, modified them. The typical modifications included removal of the boilers from the forward boiler room and making that space into additional fuel tankage. This gave these ships the range necessary for Atlantic escort duty. It did cut their speed to about 22 knots or so max but that was more than sufficent for ASW work.
Then they removed half or all of the torpedo tubes. The gun armament was cut down to 4 4"/50 guns and in some cases more so a few AA guns could be mounted. The reductions in armament allowed for two DC racks and 6 or 8 K guns to be fitted with an appropriate amount of depth charges.

This belies the idea that they were "totally unsuited" for ASW work. That was true only before conversion.

The more dangerous U-boats became the greater the emphsis the US and Britian / Commonwealth would have put on ASW operations. So, there would be a trade-off. That is, if the Germans sink more ships and operate more subs the Allies respond with more merchant construction, alternatives to shipping (like the Texas - Pennslyvania pipeline the US built to move oil by land rather than tanker), and additional ASW equipment. One side cannot be consdered to have radically changed their strategy and equipment without the other responding to those changes.

These got the same types of sonar / asdic other ASW escorts got. Typically, a QC or the British equivalent asdic set along with HF/DF whenever possible. What they generally lacked through about 1942 was radar. Aside from that, just being able to drive a U-boat off the surface and keep it submerged for an hour or two is enough to prevent an attack or continuation of an attack.

This doesn't preclude them getting better faster and putting more effort into ASW if sinkings increased. In fact, I would argue they would simply because they would have no choice and do have the resources to put into it.

Equipment, yes. Training and tactics, no. That was the problem. A large part of that problem can squarely be put on Admiral King for not taking a greater interest in ASW operations in the Atlantic initially. He didn't order convoying. He didn't force merchant ships to black out or take other measures to avoid submarine attack. He didn't order up additional patrol aircraft. He had a fight going with the USAAC over aircraft allocation. In short, he was a primary cause of alot of the success of Drumbeat.

 

More U-boats off the US coast doesn't necessarily make things worse in the long term either. While short term sinkings would increase U-boat losses would also be likely to increase. If the US instituted convoying and blackouts quicker that could cut the losses significantly. As could a shift of air assets to anti U-boat work.

 

The original armament of the flush-deck/four-piper destroyers was four 4"/50 cal guns, one 3"/23 AA, and four triple 21" torpedo tube mounts. By WWII they also carried depth-charge racks and several water-cooled .50-caliber machine guns. They had four boilers in two boiler rooms.

In 1941, 48 were in service in other roles:
18 DMS minesweepers
8 DM minelayers
14 AVD seaplane tenders
6 APD fast transports
2 training/experimental: Semmes attached to Submarine School, Dahlgren to Key West Sound (sonar) School

Many had already been scrapped including the first generation of DMs.

DMs, DMSs, and the later antisubmarine conversions had #4 boiler replaced by fuel tanks; being close to amidships, this was the best location for a variable weight not originally provided for. AVDs and APDs had the forward boiler room converted to accommodations, storage, and gas tanks in the AVDs. This was more convenient since it was adjacent to existing living and working spaces; the deck immediately above, between the bridge and the midships deckhouse, was also filled in to provide additional space.

The destroyers-for-bases deal left 71 flush-deck DDs, 37 in the Atlantic (reduced to 36 by the loss of Reuben James in October 1941), 21 Pacific, 13 Far East. Most of the Atlantic and Pacific ships were assigned by division or squadron to naval districts, as was the one remaining older destroyer, the "thousand-tonner" Allen (DD-66) at Pearl Harbor. Prior to hostilities, 27 of the Atlantic units were modified for escort duties, with six 3"/50 DP guns replacing the four 4" and the aft pair of torpedo tubes. The 3"/23 was also dispensed with and six depth charge throwers added.

Wartime modifications were less extensive, although the replacement of #4 boiler by fuel tankage was common. Some ships including the eight survivors of the Asiatic Fleet had the aft torpedo tubes replaced by DC throwers but retained 4" armament. Up to six 20mm guns were added, replacing .50s. Many of the converted types like DMSs and APDs received 3"/50s in place of 4"; this was particularly important in the Pacific where they faced air attack. Some also received 40mms, either one twin power-operated mount or two manually operated singles.

The only major wartime conversions were additional APDs which proved very useful. Approximately 20 DDs and several AVDs were converted.

Blair's Hitler's U-Boat War lists 92 destroyers in the Atlantic Fleet on 12/7/41: 55 modern types including all 28 of the new Bensons then in commission and 37 flush-deckers including Dahlgren. The number remained relatively consistent over the next few months although individual ships transferred to the Pacific and new ones were commissioned in East Coast yards. The Pacific (including Asiatic) had 46 modern and 35 older DDs, total 81.

Armament note: the Clemson class, last of the flush-deckers, were made capable of mounting four 5"/51 guns, and five of them actually did so. This was in response to the German U-cruisers with 5.9" deck guns. The aft 5-incher had to be carried on the fantail, whereas a 4" was usually atop the aft deckhouse. Two ships carried experimental twin 4" mounts for a total of eight guns. AFAIK none served in these configurations in WWII.

Most data from Friedman's US Destroyers, Illustrated Design History.