HTP Submarines - Life's a bleach and then you dive.
A pod of Hedgehog round? That's something that's never occurred to me. Sounds like it might be a good idea.I was thinking of contact detonated sink grenades.
What if the Krigesmarine gets the type 21 in 1943? Would the battle of the Atlantic go worse for the allies?
I agree.While eliminating the advantages of HF/DF, code breaking and centimetric radar will help the U-boats, it still wont let them win the Battle of the Atlantic.
The German U-boaters pinned their hopes on their 1943 variant of pre WW II US deep sonar attack tactics. Creep into ambush, lie in wait for the target to overrun them and then launch a barrage of pattern seeking and acoustic torpedoes. This was the emergent U-boater convoy attack doctrine that comes into use with Type VIIs and Type IXs when the improved torpedoes arrive. GsG and GsF multi-channel sonar helps with the convoy location problem but the U-boaters are still at the mercy of their endurance limited G7 family of weapons. 140 degrees offset angle solution and 500 run seconds means a weapon functionally no better than the Mark XIV, and that is not good enough for "mobile minefield" tactics.Without the informational advantage, the allies won't be able to route evasively as OTL. This will result in more convoy battles and more merchant ships sunk. But it will also result in more U-boats sunk.
Mr. Snort is not radar proof.Radar was most efficient in Biscay, against subs entering and leaving port. With radar warning kit, those losses will be reduced (not eliminated, luck and errors also play a part). But it does mean a lot more time submerged, so shorter time on station for the U-boats.
Uhm… the British were terrible at ASW in the Falklands crisis. This is not because they were lacking in the skills. They did not have enough assets. Some people forget that the key aspect of the Battle of the North Atlantic and the allied victory is sensor saturation and sheer numbers of launch platforms with the needed profundity of weaponry to throw at each U-boat. By 1944, whole CVE task forces were deployed to chase 1 lousy U-boat. That is one (small) aircraft carrier with 25-30 aircraft, 4-6 destroyers and hundreds of depth charges and dozens of ASW mortars and plane dropped acoustic torpedoes, not to mention the air dropped sono-buoys, and the dozen or so active pingers and magnetic anomaly detectors, working like mad (pun) to develop a return off the 1 U-boat.Regarding the efficiency of allied efforts against a better U-boat. Well, the Loch/Squid combination was coming in 44, it would be feasible to speed up the squid/sonar part and put it into River class escorts as a priority. That combo was an effective sub killer until the mid-50's, against boats which are better and quieter than a Type XXI. So the allies aren't as helpless as you may think.
It is a numbers war. Can the attacker saturate the defense? Nope. Too late.Remember that a Type XXI still has to get quite close to launch a torpedo, and the escorts are there listening for you. And the faster you go underwater, the noisier you are. More shipping losses, yes. A winning BoA, no.
While eliminating the advantages of HF/DF, code breaking and centimetric radar will help the U-boats, it still wont let them win the Battle of the Atlantic.
Without the informational advantage, the allies wont be able to route evasively as OTL. This will result in more convoy battles and more merchant ships sunk. But it will also result in more U-boats sunk.
Radar was most efficient in Biscay, against subs entering and leaving port. With radar warning kit, those losses will be reduced (not eliminated, luck and errors also play a part). But it does mean a lot more time submerged, so shorter time on station for the U-boats.
Uhm… the British were terrible at ASW in the Falklands crisis. This is not because they were lacking in the skills. They did not have enough assets. Some people forget that the key aspect of the Battle of the North Atlantic and the allied victory is sensor saturation and sheer numbers of launch platforms with the needed profundity of weaponry to throw at each U-boat. By 1944, whole CVE task forces were deployed to chase 1 lousy U-boat. That is one (small) aircraft carrier with 25-30 aircraft, 4-6 destroyers and hundreds of depth charges and dozens of ASW mortars and plane dropped acoustic torpedoes, not to mention the air dropped sono-buoys, and the dozen or so active pingers and magnetic anomaly detectors, working like mad (pun) to develop a return off the 1 U-boat.
It is a numbers war. Can the attacker saturate the defense? Nope. Too late.
Nope it would not matter, the whole point about the XXI was that it was invisible to radar. The 10 cm radar sets available in 1943 had a very hard time picking up the large ball valve snorkel head of the XXI. The smaller T-valve heads which were in development could not be seen by 1943 radar and were very hard to find with 1945 radar. The XXI was virtually invisible on the march.
Now assume the XXI project is two years ahead of itself. This is not a simple premise since the 1943 XXI would not be the same as the 1945 XXI which was the product of the prevailing chaotic conditions. The workmanship would be better and the mess with the hydraulic system would probably not have happened since the 1943 XXI would still have used electric motors. It would have been a higher quality boat with a lot less problems. Further, the crew training program would have been undisturbed by enemy ASW in the Baltic. Also not that snorkel technology would have to be 2 years ahead of itself, so there was scope for a small, radar invisible T-valve snorkel down the road.
What would have happened if about 100 of these 1943 XXI had been operational by the summer of 1943? They would have sunk a lot of ships and would probably have torn up the odd convoy. If we assume a production of 20 XXI/month and a loss rate of 10 - 15 per million tons sunk, we wind up being able to sink 1.3 - 2 million tons per month and still keep up the number of U-boats in the field. The loss rate of 10 - 15 per million tons is reasonable when one considers the way the XXI would operate. It would be invisible to radar since it never surfaces and the snorkel head is very hard to find, so losses while enroute to station would be minimal. It carried 23 torpedoes and had a fast reload system which would have allowed at least two attacks on a convoy before being found. So the XXI gets in something like 6 kills with 12 torpedoes before it has to dive away. With some luck, they could get off 18 torpedoes which would give around 9 kills. A single XXI attack would result in the sinking of 30,000 - 50,000 tons and the XXI probably has an even chance to get away. Note it can run for 11 hours at 10 knots, which is more than adequate for keeping up with a slow convoy. So far we are working with standard torpedoes, no Lerche.
The big problem with winning the Battle of the Atlantic becomes finding the convoys. The XXI was capable of finding its own targets out to a distance of around 30 NM using sonar and it could probably hear a battle 60 or even 90 NM away. The best way to use them would have been under radio silence for the whole voyage and that would have been the end of ULTRA. However, it is doubtful that Doenitz would have done that. He would most likely have continued on with all the chit chat, although that may have tipped him off to ULTRA since a lot of XXI would have survived the attempts to sink them enroute and also they would have picked up the attempts to reroute convoys. I would think that given a year, Doenitz would have found ways to minimize the effect of both HF-DF and ULTRA. Since the XXI could have operated in a high threat area, it could have operated close to the western approaches and picked up its targets relatively easily.
This does not answer the question of how many ships get sunk. In order to win the Battle of the Atlantic, the objective would have had to be 15 - 20 million tons per year, which was Allied production plus a modest reduction in the total pool. Historically, the U-boats sank 5.8 million tons in 1942, their best year, out of total Allied losses of 8.2 million tons. The XXI would have had to manage about 3 times that, rather unlikely given only the XXI. If we throw in wire guided torpedoes like Lerche, the numbers start to look better since the XXI can now bite back hard against pursuing ships. And so we find ourselves on that slippery slope of “What ifs”.
The XXI by itself in 1943 would most likely not have resulted in a draw or a German win, but in a longer war. However, it was a vital ingredient in any German draw/win scenario. The other vital ingredients were an earlier appearance of jet aircraft, notably the Me 262, and the death of Hitler by 1943. With the Me262 in control of the air over the Reich in 1943, the XXI doing major damage in the Atlantic and the generals running the war without Hitler’s interference, a draw was quite possible. In this sort of scenario, the Americans would have had a tough time delivering an atomic bomb in the face of German air superiority.
And yet the RN had exactly zero ships damaged or sunk by submarines in the Falklands...
Part of the problem is an A/S screen has quite a different configuration to an AA one. Given the losses, concentrating less on the A/S screen seems sensible.
That's just it. With FIDO only capable of 12 kn for 10 min, you're looking at a Type XXI able to evade for over 8h: it only has to maintain 12kt to keep distance, & only do it for 10-12 min at a time...at 17 knots it's going to rapidly run out of juice if it came under a sustained attack and had to keep running
Am I being dense? Because I don't see anything "radical" about the idea of the Type XXI. Take a Type IX pressure hull, put in a 5m plug for more battery, sheathe it in a new casing (which sholdn't take too long to design), tank test a bit, & deploy. Knowing the Germans, the first batches probably have a lot of complicated & buggy gewgaws the crews will hate, & those will get deleted in the later batches, but maybe not, if you keep the internal gear to OEM Type IX.To design the type XXI you need to first learn from something what needs to be changed. ...And in this timeline they need to do ALL of that in something like 30 months from first WW2 submarine combat to type XXI entering combat. Presumably it takes at least 6 months to go from a finished design to the first production unit entering service as you need to built tooling and such to get it into production. If you assume 12 months of combat to learn you have a problem with existing equipment and what the problem is that leaves you about 1 year to design a radically new submarine. I think your going to end up with a LOT of design and manufacturing issues.
That's just it. With FIDO only capable of 12 kn for 10 min, you're looking at a Type XXI able to evade for over 8h: it only has to maintain 12kt to keep distance, & only do it for 10-12 min at a time...
Am I being dense? Because I don't see anything "radical" about the idea of the Type XXI. Take a Type IX pressure hull, put in a 5m plug for more battery, sheathe it in a new casing (which sholdn't take too long to design), tank test a bit, & deploy. Knowing the Germans, the first batches probably have a lot of complicated & buggy gewgaws the crews will hate, & those will get deleted in the later batches, but maybe not, if you keep the internal gear to OEM Type IX.
That's just it. With FIDO only capable of 12 kn for 10 min, you're looking at a Type XXI able to evade for over 8h: it only has to maintain 12kt to keep distance, & only do it for 10-12 min at a time...
I entirely agree with the final proposition. Prosecute to kill wasn't required; I follow RN/RCN on that: keeping a U-boat down & away from the convoy will do nicely.Some U-boat hunts took place over the course of a day or more till a successful prosecution with DC and Hedgehog - FIDO simply made attacking them easier
And even if a U-boat did ultimately evade destruction and managed to escape - its low of battery charge and the crew are exhausted and any convoy they might have been targeting is 100-200 miles away!
Ultimately winning the BotA wasn't about sinking U-boats - it was stopping U-boats sinking Merchants
I continue to think breaking contact is easier than you do, & I don't think either of us is likely to be persuaded on it.One FIDO vs. 1 sub, maybe. US trials boats were capable of 5 m/s submerged and were battery sustainable at that speed for about 15 minutes. They could not outrun a pair. Type 21s are 1 m/s faster in theory. but if caught shallow are no faster than a US boat. The FIDO is still a success if the sub cannot execute a contact and sink.
True enough. However, the Type IX worked, & adding an identical section is a minimal change, so I'm not seeing the hazard spiking. Also Germany in wartime, so... Is there a chance of it? Maybe. Will it be uncovered in pre-operational trials? Maybe. Will BdU accept a (somewhat) higher loss rate for a higher performance? I would (tho it wouldn't be my default position).Good point. The Germans went to a sliced sausage assembled welded together hull sections method which was different from their usual keel, frame plates method for their previous U-boats' manufacture. Guess why I would not be a happy U-boater in that sausage? Would you trust some schmuck hastily retrained shoe salesman Walter from Stuttgart to know how to weld together an 8 meter in diameter barrel seam?
It will not result in more U-boats sunk. Without the informational advantage, the Allies won't be routing evasively, but they also won't be routing dedicated ASW task forces offensively against the U-boats. U-boat losses will massively decrease as the U-boats are engaging less defended convoys when they are ready (or at least when the Allied convoys are as surprised as the U-boats are), and not engaging strong ASW task forces when they are caught by surprise.Without the informational advantage, the allies wont be able to route evasively as OTL. This will result in more convoy battles and more merchant ships sunk. But it will also result in more U-boats sunk.
That is still a massive increase in time on station over OTL, as each ship whose station time is cut short by having to dive would have either been completely surprised and sunk OTL, or have had to make an emergency dive after being attacked anyway. Either one reduces time on station more than diving with warning from the radar warning receiver.Radar was most efficient in Biscay, against subs entering and leaving port. With radar warning kit, those losses will be reduced (not eliminated, luck and errors also play a part). But it does mean a lot more time submerged, so shorter time on station for the U-boats.
That would work against the usual weapons used, but navies developed homing torpedoes like Cutie (US), Zaunkönig (Germany), and Zaunkönig II (Germany) to deal with those at around the same time. Germany screwed up its design and didn't get a torpedo that was immune to countermeasures like FIDO and Cutie, but a navy that doesn't won't have problems with Loch/Squid or any other WWII-era ASW technologies.Regarding the efficiency of allied efforts against a better U-boat. Well, the Loch/Squid combination was coming in 44, it would be feasible to speed up the squid/sonar part and put it into River class escorts as a priority. That combo was an effective sub killer until the mid-50's, against boats which are better and quieter than a Type XXI. So the allies aren't as helpless as you may think.
But a submarine (of any kind) going fast is still quieter than surface ships going that fast. Outside of minehunters they have very little consideration given to underwater noise. It doesn't help much if the escort can hear a submarine but has to become an even bigger and noisier target than the submarine in order to catch up with and attack it.Remember that a Type XXI still has to get quite close to launch a torpedo, and the escorts are there listening for you. And the faster you go underwater, the noisier you are.
And we know that with the benefit of hindsight. What happens when the Brits are faced with very much faster U-boats that are, by all appearances, immune to any existing ASW? If they appear around May or June '43 (around the time of SC-229, IIRC), they're liable to be just enough to prod the Brits to actually do what they contemplated, but didn't: abandon convoy altogether. So are even less-effective, & less-numerous, *Type XXIs enough to do that?IOW the type 21 becomes just another slow German U-boat now operating in the brown water zone with no useful blue water capability at all to affect the Battle of the Atlantic.
And we know that with the benefit of hindsight. What happens when the Brits are faced with very much faster U-boats that are, by all appearances, immune to any existing ASW? If they appear around May or June '43 (around the time of SC-229, IIRC), they're liable to be just enough to prod the Brits to actually do what they contemplated, but didn't: abandon convoy altogether. So are even less-effective, & less-numerous, *Type XXIs enough to do that?
OTOH, as I think I said, if *Type XXIs lead to no Italian invasion, better in the long run...
You & I know that, but at the time, without even the shock of the higher-performance boats to face, the Brits were seriously considering abandoning it. So don't give me "op art & ops research", because the Brits used it, & still figured convoy might not be working--without facing the greater threat (real or not).Convoy is still the correct solution as log versus cube rule proves.
That's just it. With FIDO only capable of 12 kn for 10 min, you're looking at a Type XXI able to evade for over 8h: it only has to maintain 12kt to keep distance, & only do it for 10-12 min at a time...
Am I being dense? Because I don't see anything "radical" about the idea of the Type XXI. Take a Type IX pressure hull, put in a 5m plug for more battery, sheathe it in a new casing (which sholdn't take too long to design), tank test a bit, & deploy. Knowing the Germans, the first batches probably have a lot of complicated & buggy gewgaws the crews will hate, & those will get deleted in the later batches, but maybe not, if you keep the internal gear to OEM Type IX.