Maneuverability vs Speed

[Shortround6]

Yes, pretty much. The one thing that the Germans had going for them at that time though was a very professional U-Boat service. It wouldn't have been a walk in the park for the RN. They hadn't developed all of the technologies that later defeated the U-Boats.

Quite true but then there only about 50 something U-Boats total at the time, I believe they started the war with 56(?) and added some, however in 1939/40 the new boats just about offset the losses. And a fair number of the boats were the type IIs with three torpedo tubes and two spare torpedoes. They were small and suited to costal waters but they were also slow and lacking in underwater endurance. At four knots they had 1/2 the range of the Type VIIs

The RN had just proved it had a pretty decent submarine service (or lucky) off Norway.

And the RN can afford to take some losses if they destroy the invasion fleet.

 

[Gary Cain]

Quite true but then there only about 50 something U-Boats total at the time, I believe they started the war with 56(?) and added some, however in 1939/40 the new boats just about offset the losses. And a fair number of the boats were the type IIs with three torpedo tubes and two spare torpedoes. They were small and suited to costal waters but they were also slow and lacking in underwater endurance. At four knots they had 1/2 the range of the Type VIIs

The RN had just proved it had a pretty decent submarine service (or lucky) off Norway.

And the RN can afford to take some losses if they destroy the invasion fleet.

True, but in the event of an invasion you can rest assured that ALL of the U-boats would have been involved. And they still had their best commanders to captain them.

 

[Thumpalumpacus]

What did they achieve?, if you took them out of the war would anything have changed?. Look at the Spitfire and Hurricane, I bet every other country would have put the best engine in the Spitfire and left the Hurricane to it's fate, one great fighter and one ordinary one but not the British, they gave both the best chance and what happened, two great fighters resulted, that's how you win. Like the Germans the Japanese should have focused on steady design improvements keeping their equipment at the top instead of wasting time on wonder weapons.

They should have focused on a doctrine that made the best use of formidable assets. "Steady design improvements" is pretty much what they did, anyway.

If you want to talk about wasting time on wonder weapons, why might you exclude the Germans? Jets -- too late. V-2s -- sure, let's build tunnels to bombard a British public that's already given you two fingers. Me-163 -- about as useful as a pinholed condom. The Germans certainly chased silver-bullet nonsense. Indeed, the Japanese did focus on steady improvement of designs, eschewing Wunderwaffen unless it was donated from a submarine mission.

The Japanese problem was that they started what they thought would be a short war with a power that could decide it would be a long war. They did that not only with America, but in China as well.

 

[Gary Cain]

They should have focused on a doctrine that made the best use of formidable assets. "Steady design improvements" is pretty much what they did, anyway.

If you want to talk about wasting time on wonder weapons, why might you exclude the Germans? Jets -- too late. V-2s -- sure, let's build tunnels to bombard a British public that's already given you two fingers. Me-163 -- about as useful as a pinholed condom. The Germans certainly chased silver-bullet nonsense. Indeed, the Japanese did focus on steady improvement of designs, eschewing Wunderwaffen unless it was donated from a submarine mission.

The Japanese problem was that they started what they thought would be a short war with a power that could decide it would be a long war. They did that not only with America, but in China as well.

That gets to that quality versus quantity argument. The Me262 was a better airplane than anything else out there in many ways, but it wasn't THAT much better. Now if you had an F-4 Phantom versus the rest of the world that would be one thing, nothing on Earth at that time could touch it. But the 262 was catchable if the P-51 had altitude. That isn't happening if your target is an F-4.

 

[Thumpalumpacus]

That gets to that quality versus quantity argument. The Me262 was a better airplane than anything else out there in many ways, but it wasn't THAT much better. Now if you had an F-4 Phantom versus the rest of the world that would be one thing, nothing on Earth at that time could touch it. But the 262 was catchable if the P-51 had altitude. That isn't happening if your target is an F-4.

My point to P PAT303 was that the Japanese did not actually chase many hi-tech weapons systems. Even when they did, say with the Okha, they still used a trained human guidance device to steer the simple rocket. They didn't design ballistic missiles, cruise missiles, guided AA missiles, guided bombs, or most of the other stuff. They actually did what he urges, which is to incrementally improve standard designs.

 

[PAT303]

The Me262 was a better airplane than anything else out there in many ways, but it wasn't THAT much better.

Thats true, the war was over before it had matured into a dependable fighter.

 

[pbehn]

Yes, pretty much. The one thing that the Germans had going for them at that time though was a very professional U-Boat service. It wouldn't have been a walk in the park for the RN. They hadn't developed all of the technologies that later defeated the U-Boats.

U Boats at periscope depth are very visible from the air. Using towed barges the German army would struggle to transport their army across the Channel in September October even if they were gifted a harbour and unopposed.

 

[Shortround6]

True, but in the event of an invasion you can rest assured that ALL of the U-boats would have been involved. And they still had their best commanders to captain them.

No you can't be assured of that.
It would leave all of the North Atlantic and Western Approaches devoid of U-Boats for a week or more before the invasion.
Boats weren't basing of the French ports except in scattered instances in the summer of 1940 while the repairs to port facilities were made.

The U boats can't block shipping bringing in munitions/supplies into the west of Britain and guard the Invasion fleet at the same time. If you want them fit, armed and fueled to take on the RN you have to slow down and stop the war patrols prior to the planed invasion.

This is beginning to sound like all those arguments where the Germans could invade England if the Luftwaffe did A, B, C, D, E and F, but they only had enough planes to do 3 of the jobs, not all six.
Same with the U-boats. Some people want them to help lay mines to block the invasion routes from British surface ships. And they want them to stop the british ships form leaving port and they want them torpedo the British ships on the way or just in prior to them getting to the invasion rafts.

The Type IIs do 12-13 knots top speed on the surface. They can run for about 5 hours at 4kts under water and about 1 hour at 8 kts under water. Once a surface ship gets passed them they can't catch it until it comes back. Even a clapped out R type battleship can make 19-20 knots.
The U-boats don't have radar.
The Type VIIs are faster, 16-17 knots on the surface which means they can out run a trawler. They can do about 8-10 hours at 4 kts under water.

 

[Reluctant Poster]

Quite true but then there only about 50 something U-Boats total at the time, I believe they started the war with 56(?) and added some, however in 1939/40 the new boats just about offset the losses. And a fair number of the boats were the type IIs with three torpedo tubes and two spare torpedoes. They were small and suited to costal waters but they were also slow and lacking in underwater endurance. At four knots they had 1/2 the range of the Type VIIs

The RN had just proved it had a pretty decent submarine service (or lucky) off Norway.

And the RN can afford to take some losses if they destroy the invasion fleet.

They also had issues with defective torpedoes, in particular depth keeping.

https://digitalcommons.georgiasouthern.edu/cgi/viewcontent.cgi?article=1599&context=etd

When attacking merchant vessels it can be compensated for by a second attack not so much with destroyers

 

[Gary Cain]

Thats true, the war was over before it had matured into a dependable fighter.

Even if it were a dependable fighter its performance isn't that much superior., Like I said, it could still be caught.

 

[Gary Cain]

No you can't be assured of that.
It would leave all of the North Atlantic and Western Approaches devoid of U-Boats for a week or more before the invasion.
Boats weren't basing of the French ports except in scattered instances in the summer of 1940 while the repairs to port facilities were made.

The U boats can't block shipping bringing in munitions/supplies into the west of Britain and guard the Invasion fleet at the same time. If you want them fit, armed and fueled to take on the RN you have to slow down and stop the war patrols prior to the planed invasion.

This is beginning to sound like all those arguments where the Germans could invade England if the Luftwaffe did A, B, C, D, E and F, but they only had enough planes to do 3 of the jobs, not all six.
Same with the U-boats. Some people want them to help lay mines to block the invasion routes from British surface ships. And they want them to stop the british ships form leaving port and they want them torpedo the British ships on the way or just in prior to them getting to the invasion rafts.

The Type IIs do 12-13 knots top speed on the surface. They can run for about 5 hours at 4kts under water and about 1 hour at 8 kts under water. Once a surface ship gets passed them they can't catch it until it comes back. Even a clapped out R type battleship can make 19-20 knots.
The U-boats don't have radar.
The Type VIIs are faster, 16-17 knots on the surface which means they can out run a trawler. They can do about 8-10 hours at 4 kts under water.

Yeah, I think you can. Raeder and Doenitz weren't dummies. They would have known that the U-Boat force would have been critical to the success of the operation. The speed of the U-boats isn't a factor because the British are coming to THEM. They would have been out screening the invasion fleet and it is a simple calculation to figure out where the RN ships MUST be to engage the invasion fleet. If the RN is going to engage, they MUST present themselves as targets.

Having a Topp, or a Prien coming after me is not something I would have enjoyd.

 

[PAT303]

No, they could have continued attacking the airfields. They chose not to, thankfully, because one of their Home cities got bombed by accident. Simply strafing the airfields would have been sufficient to keep the fighters down, which would have allowed an invasion to be launched.

You sound like the Axis powers, if we do this they will do that and we will win.

 

[Gary Cain]

U Boats at periscope depth are very visible from the air. Using towed barges the German army would struggle to transport their army across the Channel in September October even if they were gifted a harbour and unopposed.

Yes, they are. But remember, there is still a viable Luftwaffe fighter force. A patrol craft like a Sunderland isn't going to have a very nice time hunting for the sub. A sub which only needs to break surface with its periscope for a very short time. It would use its sonar to position itself for the attack. The periscope only pops up for the torpedo launch. Figure you have five minutes, on a good day, to spot it.

 

[Gary Cain]

You sound like the Axis powers, if we do this they will do that and we will win.

No, not at all. But I have studied the war a lot, and it isn't just a simple our planes are better so we will win scenario. There is a reason why the Germans did so damned good, with so little.

 

[Reluctant Poster]

Combat strength of the U-boat Force - Kriegsmarine U-boat Operations - uboat.net

The U-boat War in World War Two (Kriegsmarine, 1939-1945) and World War One (Kaiserliche Marine, 1914-1918) and the Allied efforts to counter the threat. Over 40.000 pages on the officers, the boats, technology and the Allied efforts to counter the U-boat threat.

uboat.net

The number of uboats at sea never exceeded 20 during 1940 except for the Norwegian campaign.

 

[PAT303]

. Simply straffing airfields sounds great, the airfields were not defenceless and straffing them incurred losses.

Ju88's attacked an airfield at low level at one point and were butchered, reading up on Luftwaffe pilots they were becoming increasingly dismayed at the ability of RAF fighters to find and intercept them in any weather, they knew the truth and knew they couldn't win because they were there

 

[pbehn]

No, not at all. But I have studied the war a lot, and it isn't just a simple our planes are better so we will win scenario. There is a reason why the Germans did so damned good, with so little.

Inn 1939-40 they had the biggest airforce in the world but that was changing quickly

Yes, they are. But remember, there is still a viable Luftwaffe fighter force. A patrol craft like a Sunderland isn't going to have a very nice time hunting for the sub. A sub which only needs to break surface with its periscope for a very short time. It would use its sonar to position itself for the attack. The periscope only pops up for the torpedo launch. Figure you have five minutes, on a good day, to spot it.

They only do 4 kts underwater if you know where they are they arent a problem, coming anywhere near the surface leaves them open to being rammed or depth charged. A completely different situation to the open Atlantic.

 

[PAT303]

True, but in the event of an invasion you can rest assured that ALL of the U-boats would have been involved. And they still had their best commanders to captain them.

What happens at night when the Luftwaffe isn't around, the Royal Navy happens. Here's a scenario, what stops the RN from sailing across and parking a few battleships off the French ports and plastering them with 15''-16'' shells a few nights a week?.

 

[SaparotRob]

Drachinifel did a video on a "stealth battleship". It brings up your scenario, sorta'.

 

[Shortround6]

Yeah, I think you can. Raeder and Doenitz weren't dummies. They would have known that the U-Boat force would have been critical to the success of the operation. The speed of the U-boats isn't a factor because the British are coming to THEM. They would have been out screening the invasion fleet and it is a simple calculation to figure out where the RN ships MUST be to engage the invasion fleet. If the RN is going to engage, they MUST present themselves as targets.

Having a Topp, or a Prien coming after me is not something I would have enjoyd.

And that means the RN can use anti sub craft to sweep for the U-boats using sonar in a layered manner.
Like a bunch of trawlers and the like going first because invasion barges sure don't have the fire power to stop them, Perhaps you can torpedo them and perhaps you can's. small and shallow draft, then the older destroyers, Can't use sonar at much over 15knts but at some point stop the sonar wind them up to 25-30knots and zig zag, even Prien would have a hard time with that. And they can afford to loose some old destroyers and trawlers. Then the newer destroyers and old light cruisers show up, The RN has the choice of attacking at night or during the day. They have the choice of attacking on the rafts first day at sea or the 2nd or the 3rd or even the 4th (first Germans get ashore, RN shows up, smashes the bulk of the transport on it's home, Germans ashore run out of ammo and food.)
British aren't dummies either. There were several hundred costal escorts/trawlers (not all with sonar) just in the Channel. A few hundred more in Western Approaches.

The RN will take losses, but they can afford to. The Germans can loose some U-boats, they can afford that.
The Germans cannot loose the invasion barges/rafts. The Germans have fewer than 1/2 dozen ships that are destroyer size or larger, They can't afford to loose them.
British have around as many subs as the Germans do. Germans just about zero anti-sub capability.