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Old 07-12-2019, 05:03 AM   #21
Tomsdad
 
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Default Re: Tsunami-1

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Originally Posted by Michele View Post
First thing, I'd like to mention that of course homing acoustic torpedoes were introduced during WWII, and that's exactly the weapon I was thinking about when I said that a submarine might sink a destroyer after having been sunk by the same destroyer.
In particular, the G7es/T11 "Zaunkönig II" was very sensitive, fast enough to reach an evading destroyer, and able to be launched not at periscope depth but at under 50 meters of depth.

That said, WWII submarines did occasionally engage each other, and sink submarines too.
So an accident between two submarines may happen. It's not impossible.
But submarines were not suitable as submarine hunters. It's a matter of recon range against the least noisy engines. If they stumble into each other they can stalk each other, and they can launch torps at each other; but finding each other in the vast oceans is the issue.
So, the British deciding to increase their submarine fleet in order to counter submarines is not plausible with WWII-era tech. They would increase their destroyer flotillas and even more their ASW aircraft squadrons, and build lots of small ASW aircraft carriers. As per our timeline.
Yep, and unless Britain going to use these subs to sink German merchant shipping I'm not sure what use they're for. Destroyers however can be used for a few things as well as sub hunting

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Subs would be useful to lurk at the chokepoints from the Baltic and such. Subs tend to run on the surface at night, it's faster and they need to recharge the batteries. So a sub in wait slightly submerged can spot and ambush them while a destroyer shows up on radar and would be avoided.
Thing is with lurking at choke points it make the subs easier to spot and sink, subs operating in choke points especially shallow busy ones have issues with just not running aground or into things (being submerged makes it really quite difficult to manoeuvre in difficult terrain). Even surfaced they can have tough times because they're so low in the water.

Also subs tend to run on the water except when attacking, or evading attacks at whatever time of the day simply because being submerged it's really hard to see anything (even with WW2 sonar) and you are extremely slow and have very poor range submerged. You also never know when you will need to submerge to escape something so you really want those batteries charged just in case. On top of this basically everything is harder when you are underwater.

German u boats really didn't spend much time submerged (look at the prow of a WW2 u-boat and post war submarine for comparison of where their designers knew they'd spend most of their time).

Someone once described a u-boat as a pretty rubbish normal boat that occasionally goes underwater.
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Old 07-12-2019, 07:34 AM   #22
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Default Re: Tsunami-1

There was, IIRC, precisely one recorded sinking of one submerged submarine by another in WW2 (and, IIRC again, only one since) and it was something of a freak (a British boat detected its opponent due to the noise made by engine problems, estimated the location and fired a spread of torpedoes, one of which hit).
For those that like maritime trivia, the only recorded sinking of a sub by a battleship was carried out by HMS Dreadnaught during WW1 - apparently she found it surface in front of her and simply ran it down before it could dive.
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Old 07-12-2019, 08:23 AM   #23
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Personally I like the OP's idea that actually both just collided and sank with all hands, and both sides assumed* the other had torpedoed or shelled their boat

Some bits of the Irish sea could make that not unlikely





*which is a actually a bit of an assumption since if neither side's boat radios out what happened (even just there had been contact) both sides only have their own boat's last known position and an overdue for contact / lost boat
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Old 07-12-2019, 08:24 AM   #24
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Default Re: Tsunami-1

Actually here's a question does Enigma/Shark etc get broken in this TL?
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Old 07-14-2019, 09:50 AM   #25
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Default Re: Tsunami-1

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Actually here's a question does Enigma/Shark etc get broken in this TL?
Given the timing, probably. The UK-German ceasefire happens at the end of 1942, by which time the Short Signal cribs had been discovered. There will presumably be fewer U-Boats at sea during the cease-fire and thus less material to work on, but there was plenty that had been received and recorded during 1943.
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Old 07-15-2019, 02:52 AM   #26
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Actually here's a question does Enigma/Shark etc get broken in this TL?
I don't see why not.
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Old 07-15-2019, 05:19 AM   #27
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Given the timing, probably. The UK-German ceasefire happens at the end of 1942, by which time the Short Signal cribs had been discovered. There will presumably be fewer U-Boats at sea during the cease-fire and thus less material to work on, but there was plenty that had been received and recorded during 1943.
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I don't see why not.
Cool, in that case I can see British efforts to work on that (and thus crypto-analysis and computers in general) during the ceasefire period.

I'm still interested in how Britain gets the bomb though, and perhaps more importantly how quickly it can manufacture them.
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Old 07-15-2019, 09:37 AM   #28
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Default Re: Tsunami-1

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I'm still interested in how Britain gets the bomb though, and perhaps more importantly how quickly it can manufacture them.
Well, as Michele said back in post #13, the trick is affording it. There are plenty of scientists and engineers who can have the necessary insights, but this is an expensive project and the UK has many other things to pay for.
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Old 07-15-2019, 10:14 AM   #29
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Well, as Michele said back in post #13, the trick is affording it. There are plenty of scientists and engineers who can have the necessary insights, but this is an expensive project and the UK has many other things to pay for.
My question over the US bankrolling it is the US is recovering from a massive disaster. Don't get me wrong I'm sure it could if it really wanted to, but would they really want to enough to do it? Especially on something that is as unknown and open ended as what ever this version of the Manhattan project would be.

There's also the question that if the US is bankrolling it one assume they'll also want access to it. (Which shouldn't be a major problem really, but in this TL we don't have the same side by side shared fighting history and close co-operation you do in OTL)

On actually doing it the theory might have been known, but there is still a lot of unknowns and pitfalls between drawing board and deliverable weapon system. Not forgetting you also need a delivering platform a technology that also requires a significant development* and practice, it's just in OTL we were already doing that to drop conventional bombs of course.


*the B-29 bomber project cost more than the Manhattan project! Not that the B-29 was the only 4 prop heavy bomber of course but once you get away from the B-29 other options have disadvantages.
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Old 07-15-2019, 02:17 PM   #30
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Default Re: Tsunami-1

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I'm still interested in how Britain gets the bomb though, and perhaps more importantly how quickly it can manufacture them.
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Well, as Michele said back in post #13, the trick is affording it. There are plenty of scientists and engineers who can have the necessary insights, but this is an expensive project and the UK has many other things to pay for.
Historically, the British did think of it independently. Quite a lot of people did: the paper describing the discovery of fission was openly published in January 1939. Within a year, there had been over a hundred follow-up papers. Germany and Japan were the first to start military projects, in April '39, but they didn't get anywhere. FDR reviewed Einstein's letter on October 11th. Igor Kurchatov informed his government some time the same year, and the British had their first go that year too, but stalled out.

Frisch and Peierls, German emigres in the UK who were technically enemy aliens and thus not allowed to work on military projects had a go on their own initiative early in 1940, found an easy way to calculate an approximate critical mass, and realised the job was doable. The British project was called "Tube Alloys" but most of its people ended up at Los Alamos.

Merging the projects just made sense historically: the US had far more industrial capacity and money, and was not exposed to bombing.

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Not forgetting you also need a delivering platform a technology that also requires a significant development* and practice, it's just in OTL we were already doing that to drop conventional bombs of course.

*the B-29 bomber project cost more than the Manhattan project! Not that the B-29 was the only 4 prop heavy bomber of course but once you get away from the B-29 other options have disadvantages.
The Lancaster was thoroughly capable of dropping a atomic bomb. In fact, that was exploited by the Manhattan Project when the USAAF took against the idea of supplying B-29s. Pointing out that the British would doubtless happy to supply Lancasters changed the USAAF's mind swiftly.

The Lancaster doesn't have the same range capability as the B29, but that just means you have to launch from Okinawa rather than the Mariana Islands. The bomb shackle that was used in the B-29 for the atomic bombings was from the Lancaster, and had been developed for the Tallboy and Grand Slam bombs, the latter of which was far heavier than the WWII nukes.
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