Availability of German U boats early in the war

[Shortround6]

Here is a list, as near as I can figure out, about what kinds of U-boats were available when in the first year to year and half of the war.

Sept 1939

Type I
2 type I boats, 6 torpedo tubes, 8 reloads, range 7900 N miles at 10kts.

2 type Is total

Type II
6 type IIa boats. 3 torpedo tubes, two reloads. range 1600 N miles at 8kts
14 type IIb boats. 3 torpedo tubes, two reloads. range 3100 N miles at 8kts
6 type IIc boats. 3 torpedo tubes, two reloads. range 3800 N miles at 8kts.

26 Type IIs total in Sept 1939

Type VII
10 type VIIa boats, 5 torpedo tubes, 6 reloads, range 6200 N miles at 10kts.
9 type VIIb boats, 5 torpedo tubes, 7 reloads, range 8700 N miles at 10kts.

19 Type VIIs total

Type IX
7 type IXa boats, 6 torpedo tubes, 6 reloads, range 10,500 N miles at 10kts.

7 type IXs total

54 U boats total in commision (doesn't mean worked up/operational)

Now for by month additions, again by commissioning not operational.

Sept 1939
1 Type VIIB range 8700 miles

Oct 1939
no new boats (?)

Nov 1939
U-55, type VIIb range 8700 N miles
U-44, type IXA range 10500 N miles.

Dec 1939
U-62, type IIc range 3800 miles
U-64 type IXb 6 tubes up to 16 reloads, 12,000 mile range

Jan 1940
U-63, type IIc

Feb 1940
U-65, type IXb

March 1940
None?

April 1940
U-120, type IIB ex Chinese

May 1940
U-121, type IIB ex Chinese

June 1940,
U-137, U, 138, type IId, still 3 tubes and 5 torpedoes but range increased to 5650 N miles at 8knts

July 1940
U-103 type IXb
U-139 type IId

Aug 1940
U-104 type IXd
U-140, U-141 type IId

Sept 1940
U-73 type VIIb
U-105, U-106 type IXb
U-142, U-143 type IId.

The Germans, prior to the capture of the French ports had 18 boats to start eh war with that could even reach the mid Atlantic, stay there for several days and get home.
By the time the war was one year old and they had the French ports they had "added" (have not counted losses) 9 "large" boats and 6 of the small boats with 5 torpedoes total whos capacity for war patrols in the mid Atlantic was a bit sketchy.

The need to close the "Atlantic" gap didn't really exist at this time.

 

[Shortround6]

Now please note that the top speed on the surface for the Type II boats was 13knots. The type VIIs could do 17kts and type IXs could 18 kts or 18 and fraction.

And in the early stage of the war the type IIs made up the majority of the U boats.

Put a U-boat underwater and it's search range drops considerably. It may never sight a convoy that it might have seen if it was on the surface.
The slow type IIs, even if they have spotted a convoy, if forced under for a few hours, may never regain contact.
A plane can radio the convoy of a sighting a number of miles ahead the convoy alter course to avoid the contact.

Please note that wiki claims a type IIc boat had a range of 1,900 nautical miles at 12 knots instead of 3800 nautical miles at 8 knots so a captain would have to use a little discretion in how hard he pushed his boat trying to make up for lost ground.

Granted the plane cannot do some of things at night but in 1940-41 the RAF wasn't doing anything at night except swanning about all over western europe dropping bombs on all and sundry, hitting a ship yard with even one bomb would be like hitting the lottery

This difference between killing U-boats and greatly lessing their effectiveness had been noted in WW I and the operations of aircraft in anti sub patrols then. It needed to be relearned in WW II.

If the goal is to get cargoes through with small losses then the number of U-boats actually killed is a side issue. It looks good in a Newspaper headline though.

 

[buffnut453]

Granted the plane cannot do some of things at night but in 1940-41 the RAF wasn't doing anything at night except swanning about all over western europe dropping bombs on all and sundry, hitting a ship yard with even one bomb would be like hitting the lottery

The problem is the British didn't KNOW their night bombing was ineffective until Sept 1941 courtesy of the Butt Report. ASV Mk I didn't have the range or reliability to do much of anything, day or night. The ASV Mk II was, primarily, a more reliable improvement on the Mk I and, although deliveries of the Mk II started arriving in the summer of 1940, by October of that year only 45 receivers had been delivered. Even then, the impact on U-boat losses wasn't significant.

This difference between killing U-boats and greatly lessing their effectiveness had been noted in WW I and the operations of aircraft in anti sub patrols then. It needed to be relearned in WW II.

I can't disagree with your last point but, sadly, the first point is tough to measure. How do you know that you're lessening the effectiveness of U-boats, particularly when you can't even determine whether they're there. Sorry but military leaders don't allocate substantial resources on the basis that they might do something. They allocate resources where they will have a known and quantifiable impact. And while a reduction in shipping losses is certainly measureable, there are so many other variables as to make direct association to aircraft operations impossible. You can't prove a negative.

If the goal is to get cargoes through with small losses then the number of U-boats actually killed is a side issue. It looks good in a Newspaper headline though.

That is ONE wartime goal but there are others as well, like striking back at the enemy which was driven by the need to bolster British morale after the Dunkirk debacle, and to demonstrate to America that Britain was going to remain in the fight. You aren't going to do either of those things by "swanning about" (to use your words) over the Atlantic.

Aside from heavy application of the retrospectroscope, you seem to be suggesting that aircraft flying over the ocean with little probability of finding a single U-boat was a better use of aircraft than dropping bombs on Germany...and this when the British thought their bombing campaign was believed to be successful. 'Fraid that logic dog doesn't hunt.

 

[Shortround6]

First, let me thank you for this information

1939: 9 0
1940: 24 3
1941: 35 4
1942: 87 40
1943: 244 146

Now lets throw in a few variables besides the radar.

In 1939 a fair number of CC aircraft were the Anson.
The standard AS weapon was the 100 anti-submarine bomb which would have been lucky to sink a sub if it exploded inside it. Yes a bit of hyperbole but one British sub survived getting hit with one (at least one of the planes dropping the bombs did not, Fragments/blast brought the plane/s down, the sub rescued the air men). A german sub made it back to germany after having a 100lb anti sub bomb hit and explode on the deck casing.

The Anson was slow making hard to press an attack (reach the position of the sub before it dove).and only carried two bombs which it dropped using the pilots best judgment, no bomb sight was fitted or at least not one that worked below 3000ft and with the type/trajectory of the 100lb bomb.

The Replacement of the Anson with the Hudson was Fairly rapid but you are talking about 10 squadrons using Ansons in Sept 1939, some squadrons were using Blenheims.
Getting proper bombsight and an intervalometer (device that will drop the bombs with an equal time between bombs instead of letting them go in a salvo) also took a bit of doing.
it took quite some time for the RAF to shift over to 250lb bombs let alone the 250lb depth charge for anti sub work with aircraft.
The Blenheim and Hudson could both turn a sighting into at least something resembling a successful attack due to their higher speeds.

Hudsons when they went into service were often loaded with 10 of the nearly useless 100lb anti submarine bombs. But I not sure if they dropped them in strings of 4 (or?) or just in pairs.

Radar alone was NOT responsible for the the much greater kill numbers in the later years although it was quite helpful in getting contacts.

 

[Shortround6]

Aside from heavy application of the retrospectroscope, you seem to be suggesting that aircraft flying over the ocean with little probability of finding a single U-boat was a better use of aircraft than dropping bombs on Germany...and this when the British thought their bombing campaign was believed to be successful. 'Fraid that logic dog doesn't hunt.

No, what I am suggesting is that aircraft be used to patrol known chokepoints, known convoy routes and to escort convoys themselves rather than fly about willie-nillie over vast areas of empty ocean (at least empty of allied ships).

From Page 31 "Aircraft VS Submarine" by Alfred Price.
"The sixth and final lesson was that if the convoy system was a powerful submarine countermeasure in it's own right, it was doubly so if the ships had air cover. During the final 18 months if the war, merchant ships made some 84,000 voyages in convoy. On these, only 257 were sunk while they were in convoy. But of the 257, only two were lost when the convoy enjoyed the protection of aircraft and warships. This was the remarkable measure of the success of the aircraft as an anti-submarine weapon during the First World War. Even though it could only rarely sink it's prey by itself, it ensured that only the bravest, or most foolhardy,of submarine captains attempted to sink the ships it protected."

Might be a bit overblown but shows the basic data and concepts were there had anyone chosen to look.

The British had tried to stop the WW I U-boats from transiting from the bases to their operational areas with little success, (and actually less success than first claimed) so that method already had some serious questions as to how useful it was.

Apparently preventing ships from getting sunk was not "offensive minded" enough.

If one wants to use the retrospectroscope then just look at the blimps. Not sure they even scored one kill but never lost a ship in a convoy they were protecting to submarines?

 

[buffnut453]

No, what I am suggesting is that aircraft be used to patrol known chokepoints, known convoy routes and to escort convoys themselves rather than fly about willie-nillie over vast areas of empty ocean (at least empty of allied ships).

From Page 31 "Aircraft VS Submarine" by Alfred Price.
"The sixth and final lesson was that if the convoy system was a powerful submarine countermeasure in it's own right, it was doubly so if the ships had air cover. During the final 18 months if the war, merchant ships made some 84,000 voyages in convoy. On these, only 257 were sunk while they were in convoy. But of the 257, only two were lost when the convoy enjoyed the protection of aircraft and warships. This was the remarkable measure of the success of the aircraft as an anti-submarine weapon during the First World War. Even though it could only rarely sink it's prey by itself, it ensured that only the bravest, or most foolhardy,of submarine captains attempted to sink the ships it protected."

Might be a bit overblown but shows the basic data and concepts were there had anyone chosen to look.

The British had tried to stop the WW I U-boats from transiting from the bases to their operational areas with little success, (and actually less success than first claimed) so that method already had some serious questions as to how useful it was.

Apparently preventing ships from getting sunk was not "offensive minded" enough.

If one wants to use the retrospectroscope then just look at the blimps. Not sure they even scored one kill but never lost a ship in a convoy they were protecting to submarines?

I understand the point you're making but the sheer areas to be covered were enormous. For example, the area covered by a single convoy, to include an hour's worth of approach distance at submarine speeds, is in excess of 250 square miles. One aircraft with a radar that, on the best of days, can only see 5 miles, simply isn't going to make a lot of difference. The chances of finding said submarine without radar are vanishingly small. Also, while aircraft may deter submarine attacks during daytime, they can't do anything at night.

You refer to choke points but you're still talking about trying to cover hundreds of miles of ocean. Again, without some technical system to help the crew find the submarine, the odds of doing anything substantive are nil.

Also, bear in mind that to maintain a single aircraft over a convoy pretty much takes an entire flight to be permanently assigned: one aircraft on-station, one heading out, one coming home, one prepped and ready to go, one that's being refueled and rearmed with a couple of spares to make up for maintenance failures. Keeping 2 aircraft permanently on-station over a convoy during daylight hours will take an entire squadron. Take a look at the number of routes and numbers of convoys on those routes (List of Allied convoys during World War II by region - Wikipedia). Where are all those squadrons going to come from, and where will they all be based? The logistical challenges would be immense to achieve your goal of "escorting convoys". It sounds simple but in practice would be incredibly difficult. Also bear in mind that, even if those 2 aircraft do succeed in suppressing submarine attacks during daytime, there's still the night period to cover. And bear in mind that many convoys were progressing at little more than 6-7kts.

As to the blimps, I'd need to see a lot more analysis of their efficacy before judging whether they had ANY impact on the survivability of convoys. Again, you can't prove a negative. Were the blimps successful or was it simply a case that no U-boats operated in the area at the times the blimps were operational? As previously stated,, military leaders want proof of effectiveness before expending resources. That's why Coastal Command WAS bolstered after the advent of radar...because senior officers could see that the resources dedicated would actually achieve something.

I hear your arguments but respectfully disagree, certainly up until 1943. Punching holes in the sky over the Atlantic, even if effective in daytime, will likely not do much to reduce losses to U-boats, particularly during the long winter nights. Also, such an approach didn't align strategically with Churchill's desire to show Britain fighting back, primarily in hopes of securing America's entry into the war on Britain's side. No realistic assessment would suggest

 

[Shortround6]

As to the blimps, I'd need to see a lot more analysis of their efficacy before judging whether they had ANY impact on the survivability of convoys. Again, you can't prove a negative. Were the blimps successful or was it simply a case that no U-boats operated in the area at the times the blimps were operational? As previously stated,, military leaders want proof of effectiveness before expending resources. That's why Coastal Command WAS bolstered after the advent of radar...because senior officers could see that the resources dedicated would actually achieve something.

It is also because some officers refused to look at the record of WW I.
In WW I between May 1st and Nov 12th 1918 there was an average of 190 land planes, 216 seaplanes, 85 large flying boats and 75 airships.
It is quite true that the actual "kills" were minimal but then the U-boats were not scoring a lot of successes either in the last six months of WW I.

Proving that ships got through (were not sunk) because of the presence of aircraft is quite difficult. It usually takes time and analysis of the statistics.
The US Blimps were under general orders not to attack themselves but to report contacts and updates to the surface escort.
The bulk of the blimps did not show up until after the U-boats had stopped coming to the coast of America in large (for U-boat) numbers so you are at least part right.

See Naval Airship Association, Inc. - World War II Era

Which may be a bit biased

1943 saw not only the introduction of new and better radars, it saw the introduction of rockets for anti-sub use, it saw the introduction of the MK 24 homing torpedo,
Better depth charges and better fuses. All meant that a higher percentage of contacts could be converted to kills. The better radar gave more contacts.

the whole endurance thing had been figured out in WW I too.

Point number 5 from the book psgr 30. and remember we are talking about WW I here.

"Fifthly, a patrol aircraft with a long endurance was able to the useful work of several short endurance ones. For example, an aircraft with an endurance of two hours, bases 35 miles form it's patrol area, would spend one hour flying to and from the patrol area, and one hour in it. An aircraft with the an endurance of six hours, on the other hand, flying form the same base to the same area, could spend five hours in the patrol area. Thus a flying machine with 3 times the endurance was able to spend 5 times as long on patrol (if the patrol area was further out , the difference became even more marked: for a 52 mile transit, the out and back flights took 1 1/2 hours and the aircraft with the longer endurance could spend nine times as long on patrol as the smaller one.)

Italics in the original and obviously the WW II planes were faster but the principle applies.

Early coastal command aircraft and weapons basicly sucked. However nicely the Anson flew or kept her crews from harm by an absence of nasty tricks or kept them warm (somewhat) in an enclosed cabin it was deficient in armament, short on endurance for the job required, slow in the attack.

as for the 250 square miles the 5 mile search radius, even a 2.5 mile search radius is good for just under 20 square miles.

a lot depends on visibility.

WW I search pattern

Later it was found that these spiderweb search patterns were not that effective in preventing U-boats from getting to the operational areas, and were, in effect, swanning about all over the ocean.
Say you had a convoy in the lower left area of the search pattern (outer ring at 7-8 o'clock and another one at 11 o'clock in the outer ring. Do you really care if there is a U-boat at 2 o'clock in the outer ring 50 miles away unless you were headed for Holland? convoy is doing 6-7 kts sub is cruising on the surface at 10kts. How long before he even spots the smoke from the convoy? (the visibility thing goes both ways)

Keeping the aircraft closer to the convoy's had been figured out after the end of the war with better analysis of losses. During the war they claimed 5 boats sunk in those spider web searches. truth was more like one.

 

[fubar57]

A nifty little U-Boat book...

 

[The Basket]

The Germans had the Z plan for naval expansion.

More battleships and less u boats.

The Kriegsmarine wanted Jutland 2 not commerce raiding.

 

[Shortround6]

I understand the point you're making but the sheer areas to be covered were enormous. For example, the area covered by a single convoy, to include an hour's worth of approach distance at submarine speeds, is in excess of 250 square miles. One aircraft with a radar that, on the best of days, can only see 5 miles, simply isn't going to make a lot of difference. The chances of finding said submarine without radar are vanishingly small. Also, while aircraft may deter submarine attacks during daytime, they can't do anything at night.

The plane is not stationary over the convoy but flying an orbit around the convoy. For argument's sake call it a 40 mile orbit so a 160mph airplane would make 4 orbits an hour and quite a bit of ocean would be scanned every hour. Adjust as needed. Yes weather and visibility play a big part but that goes both ways. As to the not being able to anything at night? While most U-boat attacks were performed at night most convoy sightings were done during the day with the U-boat trailing the convoy and attacking at night. The whole visibility going both ways thing.

If they sub can only see 6 miles, and yes, in good conditions they can see much better, in bad ones? When did subs get radar? A sub under water has a very short search range.

A submerged sub does not have the speed/endurance to make an intercept of the convoy in the 'surfaced approach and tracking zone". Depending on how long the sub is forced to stay down in that zone it may never regain contact with the convoy again as the convoy zig zags away. A sub that has lost contact with a convoy during the day is not much of threat at night. Most subs were good for around an hour or a bit more at max underwater speeds, but were good for over 15-20 hours at 1/2 speed. But half speed means even a slow convoy is moving 3 kts faster than the sub.

Also, bear in mind that to maintain a single aircraft over a convoy pretty much takes an entire flight to be permanently assigned: one aircraft on-station, one heading out, one coming home, one prepped and ready to go, one that's being refueled and rearmed with a couple of spares to make up for maintenance failures. Keeping 2 aircraft permanently on-station over a convoy during daylight hours will take an entire squadron. Take a look at the number of routes and numbers of convoys on those routes (List of Allied convoys during World War II by region - Wikipedia). Where are all those squadrons going to come from, and where will they all be based? The logistical challenges would be immense to achieve your goal of "escorting convoys". It sounds simple but in practice would be incredibly difficult. Also bear in mind that, even if those 2 aircraft do succeed in suppressing submarine attacks during daytime, there's still the night period to cover. And bear in mind that many convoys were progressing at little more than 6-7kts.

Again it is not so much suppressing U boat attacks during the day, but preventing the U-boat from getting into firing position. Few U-boats did surface attacks during the day during the early war years. the Attack, unless they were lucky enough to have the convoy almost run over them while they were running submerged, was to spot the convoy while avoid being spotted, (neither U boats or escorts having much for radar in the early years), figure out the course, run parallel to convoy on one side or the other then cut in front of it, submerge in ambush position and wait for the convoy to reach it. That is daylight, the other method was just shadow the convoy, wait until night and then approach on the surface, make the attack and either escape on the surface in the dark or submerge and evade.

The Aircraft's job/mission was to keep the U-boats underwater with a much diminished search radius (they don't spot convoy to begin with) or to disrupt their shadowing/getting into ambush position. If they can direct a convoy escort or two to make the u-boats life miserable for an hour or two so much the better.

I hear your arguments but respectfully disagree, certainly up until 1943. Punching holes in the sky over the Atlantic, even if effective in daytime, will likely not do much to reduce losses to U-boats, particularly during the long winter nights.

No punching holes in the sky, but escorting convoys.

I think you give a bit too much credit to the radar.

there are 4 things that make for an effective attack (high likelihood of a kill) on a submarine.
1. getting a contact.
2. getting a sighting (not always the same thing)
3. making the attack
4. using a weapon with a decent chance of killing the sub.

Without radar a contact and a sighting are the same thing. With radar a contact is not enough information to make an attack with. The radar may/will give you more contacts but you still need a visual to conduct the attack, a big reason for the Leigh light.

Even with a visual not all sightings could be turned into attacks, the sighting could be lost as the plane turned to make the attack or the u-boat submerged before the aircraft got into weapons dropping range.

having effective weapons increases the probability of success. Bigger bombs/depth charges have a greater lethal radius, converting a near miss to a kill. More bombs dropped per attack means a greater danger area to the U boat. rockets and retro rockets expand the attack envelope. Homing torpedoes (Introduced in 1943) means a weapon can be dropped on the "swirl" with a much greater chance of success than a salvo of bombs. Swirl being where the U-boat was a number of seconds before the weapons were dropped.

Better radars were important, very important, but to credit the improved radars with the much improved success rate of U-boat attacks neglects the improved weapons and greater capacity of the aircraft.

For an early period in the war Aircraft made 55 sightings/contacts and made 44 attacks of which 8 were judged successful (kill or damaged claimed) it turns out from German records that NO U-boats were lost due to air attack and one made it home with a lot of it's stern decking torn up by a direct hit by one of those, oh so wonderful, 100lb anti-sub bombs.

Better aircraft might have converted a few more sightings into attacks but not all sightings/contacts are ever going to be converted to 100% attacks. however the 44 attacks for zero kills was a pretty dismal result. Granted they thought they were doing better at the time.

 

[JAG88]

Aircraft would have been a wise solution, but I think the main issue is that the RN believed the Uboats to be nothing special, rehashed WW1 stuff, and that the ASDIC had solved that problem for good thus not requiring much effort to defeat, plus the Germans didnt have that many and very few large ones and no cruiser ones which were their main concern.

"In May 1936, the German decision to build additional 250-ton boats
(substantiating NID's thesis about mass training) and their determination
to press on with four more 500-ton Type VII U-boats before
operational experience had been gained with the first six, surprised
Admiral Troup.89 The German Naval High Command's U-boat strategy
became clear to the Admiralty's technical assessors: the potential
quality of the new U-boat arm was being sacrificed to the dictates of
mass production. Rather than pioneering revolutionary prototypes by
years of experimentation, time, money and resources were being
expended to put into place the industrial infrastructure necessary to
fabricate large quantities of merely adequate types.90 Once that fixed
infrastructure was in place, it would be extremely difficult to introduce
novel designs without jeopardizing the output of large numbers. Like
the Ford Motor Company, which was rolling millions of identical Model
Ts off its Detroit assembly lines, the technical assessors imagined that
the German Navy planned to mass produce in wartime hundreds of
standardized U-boats. These boats would be tough and reliable, but
they would not be revolutionary victory-winning machines. Indeed, it
surprised Goodall that German naval strategists had decided so readily
to invest in the plant required to produce the existing models. In
November 1935, a technical analysis of the three current types concluded
that 'anti-submarine measures since the war has had little effect
on German ideas . . . [and shows] but a slight advance on those of the
[1914-18] period'.91 In the summer of 1936, therefore, Goodall summed
up NID's official appraisal of the U-boat menace as 'Don't worry they're
rotten' submarines.

...

In the 1920s, they had been conditioned to expect German constructors to move in this direction by
intelligence about plans for a 'submarine cruiser' capable of carrying
eight to 16 aircraft or a large minelayer armed with a 6-inch gun.94 In
1935-36, Krüger and other sources had reported rumours about plans
for large U-boats of 1,000 to 1,550 tons, but no corroborating evidence
ever emerged.95 The 712-ton Type I design, however, with its reported
surface endurance of 12,500 miles at 10 knots,96 was probably perceived
to be a precursor to U-cruisers. Still, although there were features of
the new U-boats that were considered 'dangerous', Goodall wrote in
October 1936 'that there was nothing outstanding in the design'.97 In
December, the introduction of the 740-ton Type IX aroused curiosity,
but Krüger was unable to supply drawings of the boat until the summer
of 1937, when Turkey placed an order for a variation of it through IvS.98
In contrast to the concern about the largest U-boats, Dönitz's prize
boats, the 500-ton Type VIIs, received passing attention. Unlike
the relatively accurate appraisal of the 700-ton Type I and IX boats, the
assessors grossly underestimated the endurance of the 500-ton Type
VII.

...

The pre-war judgement of NID and the DNC was sound; with the exception of better
speed, diving capacity, and communications, First World War German
submariners would have found few novelties in the second generation
U-boats; mass production did mean a reliance-on standard designs of
adequate quality. Dönitz, the composer of the 'wolf packs,' however,
dubbed it a reliance upon 'proven' types. Unfortunately for the Royal
Navy, the innovation that finally shaped Germany's approach to war at
sea in the 1940s was not technical but tactical."

From: 'I believe the Hun is cheating': British admiralty technical intelligence and the German Navy, 1936–39
Joseph A. Maiolo

"
ASDIC research had produced
promising results in the late 1920s, but operational sets were not in general
use. By the mid-1930s, however, the situation had changed. ASDIC was in
general service on British warships and submarines.30 Moreover, exercises
in 1936 appeared to demonstrate that ASDIC-guided destroyer attacks were
'decisive' in six out of ten cases.31 In other words, by the mid-1930s, the
Royal Navy's top planners had become convinced that ASDIC's real
capabilities provided the foundations for a plausible projection of an
operational performance far greater than actual. More remarkably, this
confidence translated into a willingness to influence the submarine policies
of potential foes by co-ordinating the inflated image of ASDIC as presented
in Parliament with direct action at sea."

From: "Deception and intelligence failure: Anglo‐German preparations for U‐boat warfare in the 1930s"
Joseph A. Maiolo

Hard to invest on additional protective measures when you believe the threat isnt there and have many other deficit areas.

 

[Shortround6]

Hard to invest on additional protective measures when you believe the threat isnt there and have many other deficit areas.

It also required the almost wilful ignoring of the lessons learned in WW I.

In the late 30s a large sum of money, but not as large as was really needed, was spent on aircraft and the formation of coastal command squadrons. Money was finally freed up to spend on weapons (actual bombs instead on plans/designs on paper) and orders placed for the production of anti-sub bombs. Without ever testing the bombs in live shots (with explosives) for destructive effect against any sort of target.

Unfortunately the lessons of WW I were again ignored or glossed over. Short range, low endurance aircraft equipped most of the squadrons meaning many more of the "cheap" aircraft were required (along with aircrew and ground crew) to get the same number of "patrol/escort" hours than a somewhat more expensive airplane.

It was known at the end of WW I that a plane with 6 hours of endurance could spend 5-9 times the amount of time on station depending on distance from base as a plane with 2 hours of endurance. The same principles/arithmetic (not even math) applied in the 1930s but apparently were not used. Or not used until 1938 which was a bit late for equipping squadrons in 1939, early 1940.

Here is a chart using data from Aug to Dec 1942 which obviously requires a bit of foresight to use in the late 30s.

With 8 hours of air cover the losses were about 30% of what they were with no air cover. Fast convoys have lower losses in general. 18-24 hour air cover is not required to achieve a significant reduction in sinkings (average wolf pack size attacking the convoys in this data set was 4.9-5.5)
It was well known at the end of WWI that convoys with aircover suffered much lower losses than convoys without air cover, even though sinkings of U-boats by aircraft alone were non existent. Perhaps that was the justification for the Use of the Anson and those worthless 100lb anti sub bombs?

 

[JAG88]

My favorites are the RAF torpedo bombers, two models, none worked, none were in service, which was kind of lucky since there were no torpedoes for them either.

It is mind boggling what you learn once you get past of the regular histories, so many mistakes, so many astounding failures that seem imposible considering we are talking about professional soldiers and sailors...

Didnt they consider something along the lines of MAC ships between wars?

I know they toyed around with a trade protection carrier but since they wanted them armored as well it wasnt cost effective, or something along those lines.