Improved interwar RAF/RN ASW

[MikeMeech]

Hi
Reference books on aircraft and 'ASW' during WW1 (not counting information in the OH 'War in the Air' and general naval aviation books) includes:
'Anti-Submarine Warfare in World War I, British naval aviation and the defeat of the U-Boats' by John J Abbatiello, 'The Story of a North Sea Air Station' by C F Snowden Gamble, 'The Spider Web, The Romance of a Flying-Boat Flight in the First World War' by Sqn. Ldr. T D Hallam, and 'Battlebags, British Airships of the First World War' by C E S Mowthorpe.
On Inter-war and WW2, members may find 'The RAF and Trade Defence 1919-1945, Constant Endeavour' by John Buckley useful.
Regarding air attacks on U-Boats in WW2 there is 'Search Find and Kill, Coastal Command's U-Boat Successes' by Norman Franks, and also by that author and Eric Zimmerman 'U-Boat versus Aircraft, The dramatic story behind U-Boat claims in gun action with aircraft in World War II'.
Also relevant chapters in 'RAF Coastal Command 1936-1969' by Chris Ashworth, 'The Cinderella Service, RAF Coastal Command 1939-1945' by Andrew Hendrie.
Chapter Eleven in 'Bombs Gone' by MacBean and Hogben gives details on 'Airborne Weapons versus Submarines'.
For general ASW warfare during WW2 there is 'The Allied Convoy System 1939-1945, Its Organization, Defence and Operation' by Arnold Hague, has short chapters on many aspects of the campaign. Again the OH both RAF and RN of the conflict cover ASW as part of the history, also Richard Woodman's 'The Real Cruel Sea, The Merchant Navy in the Battle of the Atlantic, 1939-1943' may also be of interest. There are other books as well of course.

Mike

 

[Shortround6]

It is not as if the RAF didn't recognise the limitations of the Anson. In 1938 the RAF went looking for a replacement. The result? A June 1938 order for 200 Lockheed Hudson plus another 50 if initial deliveries could be made by 31 Dec 1939. Deliveries by sea began in Feb 1939 with 250 built by Oct and more orders placed.

In May 1939 224 squadron swapped its Ansons for Hudsons. 233 re-equipped between Aug and Oct 1939 followed by 220 in Nov and other squadrons into 1940.

Thank you.

I would also note that Beaufort was supposed to do Maritime recon but was running late.

They had put more fuel into the Blenheim in 1937 for recon work (not maritime).
The Longer nose was supposed to have been for a Canadian requirement for maritime recon? The long nose and extra fuel and a few changes hit the production lines in the Spring of of 1939.
You do have the whole Botha fiasco. Also late even if it had worked.

You had peaple that knew that the Anson wasn't what was wanted. Unfortunately some of the people in charge were not taking decisive enough steps in 1939 (give or take) and were allowing the Anson to fill slots in the establishment for far too long.

The Ansons could have done good work in training units and could have filled in somewhat on very close shore missions. Still had 6 squadrons in the summer of 1940, in part due to adding more squadrons in total.


Basically they are several stages in aircraft vs submarine.
1, Contact.
this can be a smoke trail, a report from another aircraft or ship, a radio bearing, or actual visual sighting, radar soon gets added. Radar showed up over the winter of 1939/40 but it was rare at first, didn't work well and had limited range and conditions, got better.


2, Sighting,
Basically the MK I eyeball in 1939 and much of the rest of the war. Somebody on the plane has a visual sighting of the U-boat. This is either first contact or confirmation of the radar or confirmation of another "clue" like running down a radio transmission if the plane has the radio direction gear (which did not give range)
You need the "sighting" to go the next step/s.

3. Report sighting to command or other forces that need to know. which can be done at the same time as an "attack" or instead of an attack. Can the aircraft shadow the sub while surface ship/s get closer? Are surface ships too far away to close the the distance and do an Asdic search in time? A 36 kt destroyer already running at full speed needs 15 minutes to cover 9NM and a 8kt sub can cover 2 miles in any direction from the submerge point in the same 15 minutes. Up to the sub Captains judgement as to how long he wants to run at full speed and when he needs to slow down. Most U-Boats could do about 8kts under water at full speed. But the batteries were only good for an hour or two (at best) , depends on type of U-Boat. however at 4 kts the U-bat was good for 10-20 hours depending on type and condition. If the sub spots the aircraft and dives the time it takes the plane to go to the dive site to drop a smoke float the greater the error in placement.

4. Attack,
Optional, depends on weapons/weapon state and other stores. You have to pretty much line the plane up with the U-boat and fly over it much like doing a bomb run even if just using the smoke float/s.
This was also usually a race. The Sub could usually see the airplane before the airplane sighted the sub. Using 20/20 hind sight we can find out that the White painted CC aircraft could, by test, get 20-25% closer to a sub before being spotted than a black painted BC aircraft, how well the prewar or early war aircraft showed up ?????

"Hans, look over here, there is a patch of spinach in that cloud!"

Many of the U-boats could submerge in under 30 seconds, sometimes as little as 20?
The plane commander did not have a lot of time to make decisions.
Also note that may of the weapons had restrictions of height and speed at which they could be dropped.

5, actual results of the attack,
successful placement of smoke float (which is subject to surface wave action and wind in addition to current).
Successful placement of weapon/s ( AS bomb, depth charge, GP bomb in the first few years) and a larger pattern of bombs was better than smaller number of bombs per attack.
how well the fuse worked and blast radius of bomb and depth of the fuse for non contact fuses.

There were a lot of things that went into a successful attack.

Just like there were a lot things that went into a successful surface ship attack.
British started the war with a 4 charge pattern, one off the stern rack, one fired off each side by the DCT and one more over stern for a diamond pattern. With more depth charges and more DCT's they went to a 7 charge pattern and then to 10 charge pattern and finally to a 14 charge pattern. When looking at the "kill" numbers as the war went on be aware they were using a lot more depth charges per attack.

 

[Geoffrey Sinclair]

I would also note that Beaufort was supposed to do Maritime recon but was running late.

They had put more fuel into the Blenheim in 1937 for recon work (not maritime).
The Longer nose was supposed to have been for a Canadian requirement for maritime recon? The long nose and extra fuel and a few changes hit the production lines in the Spring of of 1939.

The Bristol Bolingbroke saga.

The Bristol type 142M Blenheim I was ordered in 1935 with first production in March 1937. The Avro Anson was built to specification G.18/35. After that came specification G.24/35 which was for a more capable aircraft. Then came GR specification 11/36 issued 14 July 1936, as the response to the proposed Bristol Type 149, a 4 place General Reconnaissance development of the Blenheim mark I, the name Bolingbroke was allocated and an order placed with Bristol for 134 aircraft. Planned as an interim GR type to bridge the gap to types like the Beaufort.

The requirement for a fourth crew member meant "The nose portion of the fuselage is to be lengthened to provide accommodation for a bomb-aimer centrally in the nose with the necessary equipment for his duties as navigator. The existing folding seat by the side of the pilot will be retained as an alternative seat for the bomb aimer." In addition sections of the wings and fuselage were to be made watertight, dinghy stowage in the port engine nacelle, "Provision is to be made to carry and release 8 reconnaissance flares and 2 forced landing flares.", "Stowages are to be provided for sea markers and flame floats." "A station for a wireless operator is to be provided immediately forward of the gun turret with safety belt and parachute stowage. A window is to be provided in the fuselage side at this station." Plus other changes including more fuel. The result was a heavier aircraft.

Bristol used Blenheim K7072 (40th production example, built around August 1937) to test out new nose configurations but little to nothing else. The RAF cancelled the GR specification in December 1937, before Bristol could come up with a satisfactory lengthened nose, the 134 aircraft Bolingbroke order being added to the order for Blenheim mark I with the requirement that as many as possible built as the improved Blenheim as in mid 1938 the new Blenheim nose configuration was considered worthwhile enough to put it into service as the Bristol type 149 Blenheim mark IV (reusing the type number). Blenheim I L1222 tested the other main mark IV airframe change, the extra fuel tanks, in August 1938. This would explain reports of the early mark IV not having the extra fuel tanks fitted during production. The first production mark IV was built in January 1939 but it took until July for Bristol to end mark I production and September for the Rootes line to switch to mark IV and March 1940 for the Avro line.

The Australian order for Bolingbroke was changed to Beaufort, the Canadian order kept the name Bolingbroke for what was a Canadian built 3 place Bristol Type 149 Blenheim mark IV with some of the Bolingbroke GR requirements, like dinghy stowage and flares. The RAF ordered Hudsons for GR work. So did the RAAF, but also as bombers.

An online thesis https://apps.dtic.mil/sti/pdfs/ADA425512.pdf British Naval Aviation and the Anti-Submarine Campaign, 1917-18

 

[MikeMeech]

4. Attack,
Optional, depends on weapons/weapon state and other stores. You have to pretty much line the plane up with the U-boat and fly over it much like doing a bomb run even if just using the smoke float/s.
This was also usually a race. The Sub could usually see the airplane before the airplane sighted the sub. Using 20/20 hind sight we can find out that the White painted CC aircraft could, by test, get 20-25% closer to a sub before being spotted than a black painted BC aircraft, how well the prewar or early war aircraft showed up ?????

"Hans, look over here, there is a patch of spinach in that cloud!"

Many of the U-boats could submerge in under 30 seconds, sometimes as little as 20?
The plane commander did not have a lot of time to make decisions.
Also note that may of the weapons had restrictions of height and speed at which they could be dropped.

Hi
Camouflage for CC aircraft in all situations was problematic, overview here in extract from 'RAF Camouflage of World War 2' (Airfix Magazine guide 11) by Michael J F Bowyer:

The book 'Operational Research in the RAF' by the Air Ministry, HMSO 1963, also has mention:

However, post war we see maritime patrol aircraft in rather darker colours again and not only in the RAF.

Mike

 

[Glider]

I agree and disagree with this. while the Anson was a good training aircraft with viceless handling characteristics, it might be worth pointing out that anti-submarine warfare had not graduated much beyond the Great War. Even by 1939 and the Sunderland having entered service, the human eye was still the most widely employed detection mechanism aboard aircraft. You state that the Anson was restricted in capability, I say how? It didn't need to carry thousands of pounds of bombs, when smoker markers is all it needs to highlight where a submarine is. A small bomb is all that's needed to cripple a submarine.

As I mentioned, the aerial element was to detect the submarine and radio assistance from a nearby warship. The two worked closely together, this was derived from techniques developed during the Great War. The ship would then speed toward the hopefully crippled submarine, or to at least where the aircraft last spotted it on the surface, and remember we are talking submersibles with a maximum speed underwater of less than 10 knots, so with a circling aircraft overhead having dropped marker flares, and a warship, equipped with ASDIC, the submarine is in for a rough time of it. The Anson's pilot was equipped with a forward firing Browning machine gun, so had a means by which to strafe the enemy submarine.

Let's also not forget that the Anson was built to satisfy a requirement for a General Coastal Reconnaissance Aircraft to specification 18/35, the emphasis being on coastal reconnaissance. It was designed for sea patrol; it wasn't specifically designed to hunt down and kill submarines, it was designed to detect, track and disable submarines until more powerful assets arrived at the scene.

That was the state of the art at the beginning of World War Two. The Anson didn't need to be a P-3 in 1939. It was perfectly capable of doing the job when it entered service and even at the outbreak of war as submarine technology and the means with which to detect and destroy them had not advanced much more than twenty years earlier. It had good visibility from its extensive glazing, it was slow enough to loiter around a slow-moving submarine and it could carry the requisite radio and navigational equipment to let a surface ship know where a possible contact was.

The radio operator's station, with the navigator's desk beyond. Note the extensive glazing. Excuse the modern Dave Clark headsets, the aircraft is airworthy.

View attachment 686000Anson interior

The biggest threat to the Anson was enemy aircraft of course, but who in 1936 could have predicted that the Germans were going to have invaded almost all of Western Europe by the end of 1940 and have friendly forces stretching from Spain to the very top of the continent? It was fitted with an unpowered Armstrong Whitworth gun turret fitted with a .303-in MG.

By the way, for the Blackburn Kangaroo to have done that much damage with only eight aircraft in service at any one time in 1918 is quite remarkable.

As is usual, in this thread we are projecting what we know has happened in the past eighty or so years against what was de rigeur back in the late 1930s and by consequence missing the point entirely.

The main problem with the Anson and the rest of Coastal Command at the start of the war was the lack of any effective AS weapons.

 

[Macandy]

Reality:

Even in the very worst days of early 1943, Allied Merchant Ship losses never exceeded 2% of Allied sailings

No Allied convoy was every destroyed in detail by U Boats

Thousands of merchant ships travelled alone outside convoys across the oceans from the start to the end of WWII

The Germans were never winning.

 

[Geoffrey Sinclair]

Even in the very worst days of early 1943, Allied Merchant Ship losses never exceeded 2% of Allied sailings

To put it one way according to the Bomber Command War Diaries some 3,775 Lancasters were lost during the war, or 2.36% of sorties, or to put it another way 56% of the 6,712 Lancasters officially built to the end of April 1945 were lost. One percentage figure tends to look more dramatic than the other.

Allied merchant ship losses of over 20,000,000 GRT can be compared with the merchant fleet strength of around 60,000,000 GRT at the end of the war or for more dramatic effect the smaller size in September 1939.

No Allied convoy was every destroyed in detail by U Boats

What does destroyed in detail mean? No 1940 Luftwaffe raid on Britain was destroyed in detail, so the RAF was never winning?

Thousands of merchant ships travelled alone outside convoys across the oceans from the start to the end of WWII

and were lost as a result.

The Germans were never winning.

The Germans/Axis were winning the tonnage war until around late 1942. On top of that comes the flow on effects, the bottleneck of merchant shipping then invasion shipping and their effects on allied operations. The high ship losses in 1942 caused the cancellation of many LST to be replaced by DE, more invasion shipping in 1944 would have enabled more allied operations, Overlord earlier plus Dragoon at the same time. The cost of allied ASW. Convoying cost cargo capacity, the wait times at either end increased, ships were idle for longer.

Figuring out how much shipping was lost in WWII runs into the lower tonnage limit used when compiling the figures otherwise think how many canoes make it as battle casualties, plus many histories only list the combat losses. In addition much officially neutral shipping was employed by the allies.

The book The Allied Convoy System by Arnold Hague seems to use 100 GRT as the lower limit, his figures are 6,428 ship losses, 2,775 to submarines, 753 to aircraft, 521 to mine, 326 to surface attack, other causes 411 (note the book says these include capture, being sunk by the explosion of another ship as the result of an attack, and unknown combat related causes), 307 foundered, 95 overdue presumed lost (some would be lost to submarine or surface raider), 226 fire and explosion, 312 collision and 702 wrecked. So the hazards of sailing in close proximity to other ships, without lights and lighthouses, sometimes more heavily loaded than normal, in weather that would usually be avoided in peace time meant that for every three losses related to enemy action there was one loss to marine causes.

The USN notes 302 marine losses in 1942, 620,266 GRT and 131 losses 278,269 GRT in the first 5 months of 1943, that loss rate over 5 years is about 3,000,000 GRT. The USSBS has the Japanese losing 116 ships, 308,386 GRT to marine causes.

Lloyds idea of losses, Total Shipping sunk by war related causes, are put at

1939 228 ships 781,747 GRT
1940 1,135 ships 3,993,198 GRT
1941 1,268 ships 3,964,111 GRT
1942 1,738 ships 7,645,339 GRT
1943 654 ships 3,235,378 GRT
1944 260 ships 1,175,797 GRT
1945 128 ships 519,078 GRT
Total 5,411 ships 21,314,648 GRT

Out of these neutral shipping sunk was,

1939 87 ships 252,135 GRT
1940 227 ships 678,368 GRT
1941 70 ships 214,248 GRT
1942 91 ships 267,988 GRT
1943 62 ships 82,137 GRT
1944 34 ships 26,051 GRT
1945 6 ships 1,505 GRT
Total 577 ships 1,522,432 GRT

Total captured ships (this is in addition to the sinkings above),

1939 15 ships 34,953 GRT
1940 205 ships 519,821 GRT
1941 375 ships 562,700 GRT
1942 133 ships 246,284 GRT
1943 9 ships 24,367 GRT
1944 13 ships 26,537 GRT
1945 3 ships 1,523 GRT
Total 753 ships 1,416,185 GRT

Out of which the neutral shipping captured was,

1939 13 ships 28,568 GRT
1940 63 ships 140,174 GRT
1941 13 ships 54,880 GRT
1942 1 ship 1,200 GRT
1943 1 ship 1,248 GRT
Total 91 ships 226,070 GRT

Lloyds list some 387 ships of 951,078 GRT as unknown reasons for loss. Cross referencing Axis Submarine Successes by Jurgen Rohwer accounts for half of these and most of the tonnage.

"British" tanker losses to end November 1941 were around 2.1 million tons, balanced by under 3.1 million tons of gains, mostly the tanker fleets of countries the Germans had invaded. (850,000 tons was new construction.). So the fleet was around 4.2 million tons then add the US fleet, though most of that was in US coastal trade. Allied tanker losses went to 1,859,000 DWT December 1941 to May 1942, another 754,000 DWT June to August 1942. The allied tanker fleet did not regain its November 1941 strength until around November 1943, the fleet spent most of 1942 to February 1943 down a nett 1.7 million GRT. That hurt allied operations. After 1943 the gains were more than a million tons per quarter more than the losses. Even so to help ease the shortage Independent voyages returning from Europe were used in 1944 and 1945.

Clay Blair has some of the best figures on Convoy losses, as opposed to independent sailings.

His figures for 1939 are 700 ships sailing from North America or Sierra Leone to Britain in convoy, 5 ships lost.

In 1940 5,434 ships sailing from North America or Sierra Leone to Britain in convoy, 133 ships lost.

In 1941 5,923 ships sailing from North America or Sierra Leone to Britain in convoy, 153 ships lost.

During this time period 19 convoys lost 6 or more ships, a total of 187 ships from the 19 convoys, worst hit was SC7 21 ships lost, in October 1940. So these 19 actions accounted for most of the 291 ships lost from convoys. Blair quotes US tenth fleet figures of North Atlantic convoys, 169 ships lost out of 7,558 in 1942, 139 out of 9,097 in 1943, 11 out of 12,907 in 1944 and 6 out of 5,857 in 1945. The carnage caused to HX229 and SC122 in March 1943 21 out of 94 ships sunk, 141,000 tons, made it look like the U-boats were able to break the convoy system.

According to the RN official history from January 1942 to May 1943 inclusive 537 ships were sunk in convoys (411 to subs), versus 1067 ships sailing independently (934 to subs). Even in the first 5 months of 1943 the convoys lost 193 ships versus 105 sailing independently. These figures are for all theatres of war and come after the requirements, like top speed, for sailing independently were increased in 1941. Going independent was dangerous.

The US merchant marine notes it sustained a higher casualty rate than any branch of the US Armed forces, Marine Corps included.

The Allied Convoy System by Hague notes total UK merchant sailor deaths for the war notified to the registrar general was 29,180, plus 814 lost on fishing vessels, these figures exclude British losses on other nationality's or requisitioned merchant ships and "foreign" (Lascar etc.) casualties on UK merchant ships.

The UK history Merchant Shipping And The Demands Of War comes up with an estimated figure of 43,886 deaths or "permanent damage" from all causes when estimating the total merchant sailors lost to the end of 1944, then comes the 1945 deaths, about 317 direct deaths plus those ashore etc. So maybe 45,000 deaths and permanent damage, of which at least 32,000 were deaths, compared with 60,595 dead and 86,162 seriously injured civilians in the UK from enemy attack.

 

[Shortround6]

The main problem with the Anson and the rest of Coastal Command at the start of the war was the lack of any effective AS weapons.

it wasn't specifically designed to hunt down and kill submarines, it was designed to detect, track and disable submarines until more powerful assets arrived at the scene.

As has been pointed out the "detect" phase was dependent on human eyes and every body was pretty much at the same level.
The "Track" phase isn't much different either. It was somewhat weather dependent. In favorable conditions the Aircraft could see down into the water, this depended on lighting, sea color/depth and sea conditions (waves).

The "disable" phase was the hard part.
No homing torpedoes, no retro bombs, no rockets, etc.
The Hudsons were on order and were supposed to carry about 1000lbs of ordnance. Ten of 100lb anti-sub bombs which allowed for a large bomb pattern or repeat attacks or both. Or a fewer number of larger bombs.

It turned out the 100lb AS bomb was just about worthless so the "disable" part wasn't actually possible without a very great deal of luck. And if you can't "disable" the "more powerful assets" showing up "in time" becomes very rare.

The whole "smoke float" thing seems to have been more wishful thinking than working solution. A 20kt escort that sees the smoke float drop 5 NM from the escorts location is going to need 15 minutes to get there and an 8kt sub can cover 2 NM in any direction from the smoke floats location in the same 15 minutes. Sub can't keep goin at high speed without draining the batteries but the odds are not in the escorts favor without more help (plane drops another float on an oil slick or spots a shadow or periscope wake or?)

They had figured out in WW I that long endurance planes (not necessarily long ranged) gave a better return on investment that short endurance aircraft. You needed fewer of them to maintain the same number of patrol hours.

 

[nuuumannn]

As has been pointed out the "detect" phase was dependent on human eyes and every body was pretty much at the same level.
The "Track" phase isn't much different either. It was somewhat weather dependent. In favorable conditions the Aircraft could see down into the water, this depended on lighting, sea color/depth and sea conditions (waves).

The "disable" phase was the hard part.
No homing torpedoes, no retro bombs, no rockets, etc.
The Hudsons were on order and were supposed to carry about 1000lbs of ordnance. Ten of 100lb anti-sub bombs which allowed for a large bomb pattern or repeat attacks or both. Or a fewer number of larger bombs.

It turned out the 100lb AS bomb was just about worthless so the "disable" part wasn't actually possible without a very great deal of luck. And if you can't "disable" the "more powerful assets" showing up "in time" becomes very rare.

The whole "smoke float" thing seems to have been more wishful thinking than working solution. A 20kt escort that sees the smoke float drop 5 NM from the escorts location is going to need 15 minutes to get there and an 8kt sub can cover 2 NM in any direction from the smoke floats location in the same 15 minutes. Sub can't keep goin at high speed without draining the batteries but the odds are not in the escorts favor without more help (plane drops another float on an oil slick or spots a shadow or periscope wake or?)

They had figured out in WW I that long endurance planes (not necessarily long ranged) gave a better return on investment that short endurance aircraft. You needed fewer of them to maintain the same number of patrol hours.

Of course you're right about this SR, but those were the days and that was the tech they had. Nowt other way to do it until ASW arrives. The other thing worth remembering was that no one else did this any other way at the time. The Anson added nothing to the status quo but flying boats and maritime patrol aeroplanes with stations for observers and the carriage of smoke floats, depth bombs etc were the only way to do it from the air.

As I've mentioned in a previous post, until ASW and better explosive thingies come along, the only really effective way of countering submarines between the wars from the air was increasing the number of patrol aircraft.

 

[Shortround6]

The opening question was this

Is there anything Britain could have done between the wars to better prepare the RAF and RN to tackle the ASW needs of 1939-41?

Short of coming up with escort carriers several years early or advanced long range aircraft or advanced electronics or??????

the options do become limited.

1. Increase the number of patrol aircraft, but there is a limit, a somewhat artificial one but it was there.
2. Increase the effectiveness of the patrol aircraft. Also limited by the politics of the time. It was being worked on.
The was a big difference between an Anson and a Sunderland , even a 1939 Sunderland with no radar and AS bombs with less than ideal explosive thingies. Sunderlands were too expensive to become the standard aircraft.

However there were improvements in the aircraft mix that could have been made and improvements in AS armament that could have been made. There were also improvements in aircraft that could have been made to reduce operational losses (non combat related).

An aircraft with an endurance of 8 hours instead of 4 hours can either extend the air coverage range from shore or can stay on station at closer range for more time. At close range it can reduce the number of aircraft (and crews) needed for the same coverage. This was known in 1918.

The whole 100lb AS bomb fiasco could/should have been avoided. Again we don't need to come up with Torpex early. Just figure out what size bomb using exiting explosives (not the the cheapest one available) offers a decent chance of "disabling" a U-boat. And how many need to be dropped in a pattern to improve the chances of getting "a" hit.
Spending a little time/money on some sort of bombsight might have been beneficial. Or spending more sooner? Something may have been in the works but few planes had anything at the start of the war.
In 1938-40 getting planes that would hold several thousand pounds of AS bombs was not going to happen, too big and too expensive. So what was the minimum bomb load?
two 250lb bombs?
four 250lbs bombs?
more?
500lb bombs or something in-between 250lbs and 500lbs?
BTW the standard 250lb GP bomb only held about 27-29% explosive by weight (63-68lbs) so it isn't a very good substitute.
When better explosives (like Torpex) showed up the 100lb AS bomb got priority which shows that poor decisions early on continued to have effects for quite some time. They couldn't shut down production of the 100lb AS bomb and switch to a bigger bomb (even a 250lb bomb) without running into some sort of shortage. It happened eventually.

The aircraft anti-sub bombs don't have to "kill" but they should offer a reasonable chance of disabling or inconvincing the U-boat. Crack a fuel tank, cause a leak or battery out gassing, damage a diving plane, damage a propeller shaft.
Do something that could limit the U-boats mobility over the next few hours to either allow the convoy to escape or to allow surface ships to more effectively search for the U-boat (trailing oil slick?)




Smoke floats may not have been useless but they had very serious limitations. The surface ships had to have exercised with them or understood them to make the best use.
The slower the escort the closer the smoke float had to be dropped to convoy/escort or the "marker" covers too much ocean.

There were things that could have been done in 1938-41 to improve things. Not saying turn the U-boat war on it's head but make things harder for the U-boats while waiting for the better sensors and weapons to show up. Lets remember that hundreds of radar sets were repurposed from naval search radars to Air-to- air radars in 1940-41.

No one thing was going to make a huge change but several small changes could total up to a significant change.

 

[MikeMeech]

There were things that could have been done in 1938-41 to improve things. Not saying turn the U-boat war on it's head but make things harder for the U-boats while waiting for the better sensors and weapons to show up. Lets remember that hundreds of radar sets were repurposed from naval search radars to Air-to- air radars in 1940-41.

Hi
Radar (RDF) development pre-war and early war years was not as simple as that. The first 'ASV' radar was flown in 1937 in Anson K6260 (the Anson was the RAF's first land monoplane with a retractable undercarriage, so modern in its day). There were radar priorities, which constantly changed depending on the war situation, between ASV, AI, CH and CHL. Air defence systems had the main priority pre-war, but that changed in November 1939 when ASV became a higher priority (mainly to search for German Navy surface vessels) and scientists like (Sir) Bernard Lovell were moved from AI work to the fitment of ASV to Hudson's. During 1940, for obvious reasons, AI had a priority over ASV, however, another factor in the mix was the urgent requirement for the fitment of radar to destroyers and other small ships (for the detection of U-Boats and E-Boats). This resulted in the use of ASV I sets followed by the use of ASV II, about 32 ships were fitted by the end of 1940 and many more the following year, this became the Type 286. This came in a number of variants: Type 286 - ASV Mk. I with fixed antenna, mid to end of 1940; Type 286M - ASV Mk. II with fixed antenna, January to mid-1941; Type 286P - ASV Mk. II with rotating antenna, February 1941 to early 1942; Type 286PQ - ASV Mk. II with higher power and rotating antenna, late 1941 into 1942. The ASV II fitted to aircraft also came in different variants. Along with AI radars these used many of the same components so there would obviously be a strain on production to get all the radars needed to those that required them, not to mention trying to increase their reliability. The US later produced the ASV II as they had no counterpart to it, ordering 7000 from Philco as the ASE, but not available in the early war period.

Info sourced from:
'Airborne Maritime Surveillance Radar Volume I' by Simon Watts.
'The History of Air Intercept Radar & the British Nightfighter 1935-1959' by Ian White.
'Echos of War' by Sir Bernard Lovell.
'Radar at Sea' by Derek Howse.
'The Development of Radar Equipments for the Royal Navy 1939-45' edited by F A Kingsley.
'A Radar History of World War II' by Louis Brown.

Mike

 

[GTX]

May not be relevant thread but I will ask anyway (feel free to move to another thread if need be): Does anyone have photos and details of the first sonobuoys used?

 

[ThomasP]

Hey GTX,

Do a search on the "AN/CRT" or "AN/CRT-1" sonobuoy. IIRC that was the first operational system used by the Allies.

Here is a link to start you out: "Firefly - CRT-1 Sonobuoy"

 

[GTX]

Hey GTX,

Do a search on the "AN/CRT" or "AN/CRT-1" sonobuoy. IIRC that was the first operational system used by the Allies.

Here is a link to start you out: "Firefly - CRT-1 Sonobuoy"

Thank you

 

[EwenS]

Thank you

I posted this earlier in the thread

https://apps.dtic.mil/sti/pdfs/ADA597432.pdf

 

[nuuumannn]

No one thing was going to make a huge change but several small changes could total up to a significant change.

Which takes time and a whole lot of effort that no individual country could have done without the effort of collective experience brought about through wartime. There was no easy fix and the rapidity that pre-war equipment and techniques were dispensed with during the war reflects this. War equals money and resources. Britain had all the latent capability to do what needed to be done in 1939, including producing more and better aircraft, better munitions, better technology, e.g. radar but without a war it takes a lot longer. Again, though, it's worth remembering that no one else was doing this any different and the same lessons the British had to learn had to be learned by everyone else.

 

[Shortround6]

Which takes time and a whole lot of effort that no individual country could have done without the effort of collective experience brought about through wartime. There was no easy fix and the rapidity that pre-war equipment and techniques were dispensed with during the war reflects this. War equals money and resources. Britain had all the latent capability to do what needed to be done in 1939, including producing more and better aircraft, better munitions, better technology, e.g. radar but without a war it takes a lot longer. Again, though, it's worth remembering that no one else was doing this any different and the same lessons the British had to learn had to be learned by everyone else.

The thing is that the British had the most experience with ASW of any country in the world as result of WW I and they didn't start back up in 1939 with the standard they had at the end of 1918. They added asdic but then regressed backwards in some areas. Relearning what they knew in WW I and having to fight the same battles in Whitehall instead of fighting the Germans wasted time and effort.

I am not expecting sono-bouys and homing torpedoes in 1939-40.

However it seems like a air dropped weapon (bomb or depth charge) that will actually make a U-boat leak with direct hit is too much to ask. Not even asking for rapid destruction, just l decent leak.
Aircraft that could patrol for two hours at 400 miles from base doesn't seem like a big ask. And guess what? some other countries had planes that could do that.

 

[nuuumannn]

The thing is that the British had the most experience with ASW of any country in the world as result of WW I and they didn't start back up in 1939 with the standard they had at the end of 1918. They added asdic but then regressed backwards in some areas. Relearning what they knew in WW I and having to fight the same battles in Whitehall instead of fighting the Germans wasted time and effort.

So, the British are stupid for not doing this. There, do you feel vindicated?

You're forgetting one little thing, peacetime. No one wanted to go to war again, so investment in the armed forces was run on a shoestring. Everywhere. Britain was not the only country that forgot the lessons of the Great War. Resources, knowledge, experience etc was lost over that intervening 20 years as the RAF went from thousands of aircraft and men strong to a mere hand full. Specifically, the Royal Naval Air Service no longer existed and while a few former RNAS bodies stayed on in the post-war RAF, emphasis changed and anti-submarine took a back seat, while all branches of the armed forces squabbled over resources. After all, which countries had submarines that were likely to pose a direct threat to the British Isles in the 1920s and 30s?

Look how quickly the navy downsized, from having the world's largest number of battleships to not very many by the early 1930s. Many of the aviation advances that entered RAF service in the 20s and 30s were first pioneered by private companies, not necessarily funded by the government. It's so easy to say, "why did they not do this or that", but we forget, when looking at our books on World War Two how the Great War had a cumulative impact that affected everyone. Let's put it this way, I bet that even in 1936 no one (who mattered) in Britain was able to foresee that before the end of the decade the country was going to be at war with Germany again.

 

[Shortround6]

Perhaps the biggest advance the US had over Europe was propeller design. That's it. All metal aircraft were in production and service in Europe across the board.

Actually the US was building some advanced commercial planes, to the extent that many airlines, companies and countries were buying American aircraft.
Or looking to the US for innovations. Not all "all metal" aircraft were created equal. The US was working on 3 different airliners that were larger/ higher capacity than the DC-3 and was working cabin pressurization. The US had also worked on a number of large flying boats over the years The Boeing 314 beating the Short "G" 26 class into the air by about year.

The B-18 Bolo was the US' predominant frontline bomber in the first couple of years of the war and it had poorer performance, defensive armament and bomb load compared to British and German bombers.

It might help if we actually compared like to like.
The Douglas DB-1 bomber prototype actually was flying in the summer of 1935. About 1 year before the Wellington and the Hampden and about 9 months before the Whitley. Yes, it took a while to get into production but guess what, the first production B-18 was delivered Feb 23rd 1937, one full day before 2nd prototype Whitley ((K4587) flew. And about 10 months before the first production Wellington. First production Hampden flew in Aug 1938, 3-4 months after the 1st B-18A or about 4 months after Douglas had completed the initial
contract/s for 133 aircraft.
Production was slow and it took until Jan 1940 to complete the 350th B-18. However in the meantime Douglas had competed the XB-23 prototype (using DC-3 components) in July 1939 and the Army issued a change order for the last of the B-18s and the last 38 (not counted in the 350 number) were completed as B-23s from Feb through Sept of 1940.
A B-23 vs Ju-88A-4 comparison is interesting.
However these were just a holding action as the Army had already placed orders for the NA B-25 and Martin B-26 off the drawing board from a requirement issued on March 11th 1939.
the contracts were placed on Sept 10th 1939 for 184 B-25s and 201 Martin B-26s.

Now, unlike the early Tiger powered Whitleys, you could actually use the B-18s over water.

For more modern American bombers the Douglas DB-7 first flew on Aug 17th 1939. The Martin 167F first also flew in Aug 1939.
The prototype B-24 first flew Dec 29th 1939 (yes it need more work)

Yes the B-18 was obsolete in 1940 (or in 1939) but then it had entered service before the British medium bombers and it was more a contemporary of the early Step nose He 111s.
The US had a number of aircraft in the pipeline to replace it.

 

[EwenS]

Actually the US was building some advanced commercial planes, to the extent that many airlines, companies and countries were buying American aircraft.

I sometimes wonder if those in the US actually understand the differences in distances involved and transport networks available in Europe compared to the USA both now and in the past.

Mainland Britain is about 600 miles north to south (Or about the same distance between Washington DC and Chicago) and about half that across. London to Berlin is about 600 miles. London to Moscow is only 1,600. London to Istanbul, the famous Orient Express Rail Route, is only 1,550 miles. And how many major centres of population in between?

In the first half of the 20th century Britain alone had 19-20,000 miles of railway. And it had nearly 7,000 stations on that network, connecting up virtually every town and village in the country. And most mail goods travelled by this means. People travelled less often and less far. Internal air travel had to compete with that and was considered a largely luxury service.

Travel across the Empire was largely by ship due to the distances involved, and Britain had many shipping lines comfortably transporting people across the world. Air travel on those routes was developed on those Empire routes in the 1930s but again was a luxury service. The distances involved required, with the aircraft technology of the day, many stopping off points. And many of the routes were designed to use flying boat services to negate the cost of building airports in far flung parts of the world.

The USA is about 3,000 miles coast to coast. And the USA was not so well served with railways west of about Kansas City. So the US Govt started promoting the aviation industry by subsidising Air mail services to link the two coasts in 1925. That served to really kick start the US aviation industry.

So there was just not the same perceived need to develop civilian air transportation in Britain or Europe between the wars. Add to that, Europe was not a single market. And each country had its own, often nationalised, airlines and aircraft companies which they naturally wished to promote.

So with a much smaller demand, more competition from surface transport, and a much more fragmented market, for both aircraft and passengers, there was no way British, or European, aircraft companies were going to invest capital and take a risk on building the same types of civil aircraft and on the same scale that US companies did during the 1930s.

So, as I see it, aviation in Europe between the wars is more driven by military than civil needs. And the question is then how to get from the biplanes of 1930 to the Superfortress of 1942.