Reichsmarine goes nuclear

[J VonAxel]

Basically Otto Hahn as head of the Kaiser Wilhelm Institute, together with Lisa Meitner, in need of funds during the 1920s goes to the Reichsmarine with a tantalizing tale of a new power source for their ships. With the already felt delays until new capital ships can be laid down and the currently rather modest funding request, plus Otto's Iron Cross, they set up a small research fund.

So Otto and Lisa start out with a search for quite why his newly discovered Thorium generates heat and exactly how much. Focusing on heat/power generation. Through the usual ups and downs of research there is a small experimental Thorium reactor around 1925 and the Deutschland Class ends up being powered by heavy water/natural Uranium reactors.

Now said reactors aren't generating all that much power yet but a few knots extra can be squeezed out. Further subtracted is the massive amount of tonnage with normally needed for funnels and thousand of tons of fuel. So much that if you take in account the Treaty clause that excludes the weight of (heavy) water from the standard displacement calculations that the ships are actually almost VT compliant. Also no experimental Diesel engines but instead well known turbines to turn steam into motive power.

So the Deutschland is launched with even more fanfare than OTL. Especially when the news gets out that they have practically unlimited range at cruising speeds only dreamed off. Only excessive wear and tear would halt the RM from sailing around the planet at a constant speed of 30 knots. Though a few trips around the British Isles will be taken at max speed, just to ensure that the RN and the UK as a whole can have the appropriate melt down.

Even better for the RM the patents and intellectual property are in their hands. So when during the early days of the Depression budget cuts start to hit, they start getting profits from the first few civilian power plants. And as a further benefit though unknown to them the sudden influx of cheap electricity and the increase in morale for having the ships of the future actually buffers some of the worst economic effects. An economy soon aided by the additional foreign contracts and trade deals won by having the nuclear powered wonder ships doing plenty of naval diplomacy and port visits.

This gives just enough of a boost in the budget that the remaining three pre-dreads are replaced with a second batch of three Panzerschiffe (as permitted under the VT). Giving von Papen plenty of photo ops onboard the new vessels, ensuring that the mustache boy and companions don't get the numbers needed to filibuster the Reichstag. So von Papen is still Chancellor and gets the credit when the economic recovery starts, the Saar and Rhineland are fully brought back into the Reich, and a lesser version of the AGNA (say only 25%) is signed.




-So one of the biggest hinderances to a nuclear powered navy is the massive investments needed in infrastructure. However after the depravations of the VT the Reichsmarine had almost no infrastructure left, so if they have to start up a new they might as well go in new direction. Much like they did with the Diesels of the OTL Deutschland.

-They would have to use Heavy Water Natural Uranium/Thorium reactors as there is no plausible way for them to enrich the fissionable materials to the needed levels for a continues reaction in less than a decade. Especially when you consider the hellish brew that is Uranium Fluoride.

-Saxony contains plenty of Uranium mostly underneath former silver mines.

-Without Funnels there would be plenty of room in the ships balance for items like extra AA and Radar.

-With better relations between the RM and KWI further research advances could well be possible say in the field of Radar and computing.

-The lesser AGNA isn't actually a real issue as that was the number originally proposed by the RM to get Germany added to the LNT. Nor would the Germany be able to build up to said tonnage anytime soon.

 

[CaptainCalvert]

I could see it being very attractive for milch cows and other large subs, which are large enough to fit a reactor, need long range but not necessarily speed, and for which the ability to stay submerged without recharging batteries is a big bonus.
As for surface ships, the reactor becomes useful if it can power electrical systems provided the system overall isn't heavier or bulkier than the equivalent fuel load.
One feature of electric cars is very rapid smooth power delivery from standing. I don't know whether 2020 car technology provides a useful guide to 1940 naval applications but I could see that a rapid acceleration, even if only in short bursts, could be very useful.

 

[Garrison]

Basically Otto Hahn as head of the Kaiser Wilhelm Institute, together with Lisa Meitner, in need of funds during the 1920s goes to the Reichsmarine with a tantalizing tale of a new power source for their ships. With the already felt delays until new capital ships can be laid down and the currently rather modest funding request, plus Otto's Iron Cross, they set up a small research fund.

In the 1920s? They didn't discover Uranium fission until 1938 and I don't think they even had a clear idea about structure of atomic nuclei until the 1930s. Any suggestions about atomic power in the 1920s would a million miles away from an actual practical system.

 

[CV12Hornet]

Now said reactors aren't generating all that much power yet but a few knots extra can be squeezed out. Further subtracted is the massive amount of tonnage with normally needed for funnels and thousand of tons of fuel. So much that if you take in account the Treaty clause that excludes the weight of (heavy) water from the standard displacement calculations that the ships are actually almost VT compliant. Also no experimental Diesel engines but instead well known turbines to turn steam into motive power.

I hate to say it, but this is all a fantasy. Nuclear power is consistently heavier and more voluminous than conventional steam; it'll do better compared to the Deutschland class' diesels, but overall the removal of the fuel in no way compensates for the heavy reactors.

And that's with proper enriched-uranium reactors, let alone these.

 

[Jürgen]

I’m not an engineer or physicist, but I was thinking; couldn’t we have a submarine which used a the waste heat from uranium or thorium to run a Stirling engine, rather than using it to drive a steam engine? I expect it to be less efficient, but it should also take up less room and have the added bonus of the submarine being far more silent.

 

[Dorknought]

Given the jug-fuck that was interwar German marine engineering, this mercifully would not get off the ground. The necessary development time means you have major ships without power units or go through the development of trials ships that will/should take a decade. As it was, diesels were supposed to be in major German capital ships from the SMS Prinz Regent Luitpold but was delayed and delayed till the Panzerschiffes in the late 20's while the development of high pressure plants for destroyers still took a decade from the 1920's liners through to the troublesome plants in TB and DD in the late 30's.

 

[Gudestein]

Earlier Discovery, focused development. Keep in mind that a nuclear reactor comes before the bomb. Not actually impossible in principle, but probably require turning the Weimar republic upside down as well. Wouldnt survive in post-1900.
Also far better for submarines.

 

[Post]

Earlier Discovery, focused development. Keep in mind that a nuclear reactor comes before the bomb.

But nuclear powered ships came after the bomb.

You're going to need a nuclear reactor first before you start designing a nuclear powered ship.

 

[Gudestein]

But nuclear powered ships came after the bomb.

You're going to need a nuclear reactor first before you start designing a nuclear powered ship.

Nuclear power was considered the easier of the two, clearly as the bomb depended on the power plant. I am not saying this is realistic. Everything would have to align to make it happen. Its not ASB per se, but probably the best place to write it in a TL.
You would need a POD that combines physics understanding with decision making, ressource allocation AND an earlier discovery of nuclear fission….,
I may know just the thing😉

 

[Nell_Lucifer]

-They would have to use Heavy Water Natural Uranium/Thorium reactors as there is no plausible way for them to enrich the fissionable materials to the needed levels for a continues reaction in less than a decade. Especially when you consider the hellish brew that is Uranium Fluoride.

There are other methods of Uranium enrichment that doesn't require UF6, namely Uranium chloride for magnetic separation and probably more complex compounds for photochemical separation. (This was achieved on Mercury I believe in the 30s)

 

[CaptainCalvert]

There are other methods of Uranium enrichment that doesn't require UF6, namely Uranium chloride for magnetic separation and probably more complex compounds for photochemical separation. (This was achieved on Mercury I believe in the 30s)

But the advantage of a thorium reactor is that it doesn't need uranium to operate. It could also be argued that not producing (much) plutonium byprducts is good, unless of course you want to create plutonium bombs.
But overall, the possibility of creating a working nuclear reacto early is better than the likelihood of producing a bomb early because it mostly needs an awareness that the process produces heat, and that the reaction can be controlled by graphite or whatever.
A bomb needs lots of power time and space for uranium refinement, or a working reactor, advanced metallurgical skills to stabilise the plutonium for fabrication, and the engineering skills to generate a suitable implosion for a plutionium bomb. Plus a workable delivery system for either. In comparison, a reactor is relatively easy.

Edit. That should be doesn't neceassarily need uranium, but it is (according to world-nuclear.org, who should know) pretty much essential to have a working reactor to get the thorium reactor started. Wish I'd found that site before I posted!

 

[Garrison]

Nuclear power was considered the easier of the two, clearly as the bomb depended on the power plant. I am not saying this is realistic. Everything would have to align to make it happen. Its not ASB per se, but probably the best place to write it in a TL.
You would need a POD that combines physics understanding with decision making, ressource allocation AND an earlier discovery of nuclear fission….,
I may know just the thing😉

I'm pretty sure what you mean is you have some far-fetched idea that belongs in ASB, an opinion I ma basing on your previous ideas of what constitutes a plausible POD.

 

[Nell_Lucifer]

But the advantage of a thorium reactor is that it doesn't need uranium to operate. It could also be argued that not producing (much) plutonium byprducts is good, unless of course you want to create plutonium bombs.
But overall, the possibility of creating a working nuclear reacto early is better than the likelihood of producing a bomb early because it mostly needs an awareness that the process produces heat, and that the reaction can be controlled by graphite or whatever.
A bomb needs lots of power time and space for uranium refinement, or a working reactor, advanced metallurgical skills to stabilise the plutonium for fabrication, and the engineering skills to generate a suitable implosion for a plutionium bomb. Plus a workable delivery system for either. In comparison, a reactor is relatively easy.

Thorium reactors do in fact need Uranium, or, more precisely, a source of neutrons as thorium is not fissible but fertile. You either kickstart the reactor by using uranium to start the production of U-233 from thorium or a neutron generator (particle accelerators, betatron, cyclotron, et cetera)

 

[Cryhavoc101]

When ever I see an idea for an earlier introduction of a given technology I do like to look at when and how it was introduced OTL - i.e. when it matured and came into practical use.

Which for surface combatants was the USS Long Beach - laid down in 1957 and entering service in 1961

Given the disparity in $ and brains between Germany and the USA during this time period I cannot see them delivering such technology earlier than the USA did - let alone 30 odd years earlier.

 

[gatordad699]

Couple of things.
Reactor comes before bomb. Chicago pile to prove fission. Hanford Reactor B to produce Plutonium 239. Uranium 235 enriched to bomb levels takes too much effort for mass production.

Reactor plants on ships/submarines are more compact than a comparable boiler steam plant. The electric and main engine turbines are exactly the same in both. S3G/S5W submarine reactor plants are tiny. Boilers take up large amounts of space. Plus they have ventilation requirements that nuclear reactors do not have.

There is so much more to going from controlled fission to a ship/submarine reactor plant. You would have to invent how to measure reactor power in the start up, intermediate, and power range. They all use different types of detectors. Instruments and electronics for core protection. Core design, even flux distribution across the core over core life. Types of control rods. Cladding on fuel and control rods. You need make up water (Heavy water was first produced in 1932). Will be a challenge to make enough heavy water at sea. Metallurgy for the core and primary piping. Advanced welding techniques. Type of primary and secondary chemical and oxygen control. And the list goes on and on.

Not really sure what CaptainCalvert is talking about. You would be surprised at how fast a nuclear boat can accelerate from a 1/3 bell to Ahead Flank.

The possibility of this TL happening is probably not technically ASB. It has about the same odds as myself starting at QB in this years Super Bowl though.

 

[Gudestein]

When ever I see an idea for an earlier introduction of a given technology I do like to look at when and how it was introduced OTL - i.e. when it matured and came into practical use.

Which for surface combatants was the USS Long Beach - laid down in 1957 and entering service in 1961

Given the disparity in $ and brains between Germany and the USA during this time period I cannot see them delivering such technology earlier than the USA did - let alone 30 odd years earlier.

Ironically you got the last part wrong. This predates the Nazi induced brain drain and Germany was the leading country in theoretical and experimental physics. Its moving up the discovery of fission and finding the ressources in combination which really stretches belief.

 

[CaptainCalvert]

Thorium reactors do in fact need Uranium, or, more precisely, a source of neutrons as thorium is not fissible but fertile. You either kickstart the reactor by using uranium to start the production of U-233 from thorium or a neutron generator (particle accelerators, betatron, cyclotron, et cetera)

Yes. I'd intended to say it didn't need much, but forgot the 'much' and had overlooked that the form of uranium (or plutonium) could only come from a reactor. Sometimes really good sites hide when I'm checking things and reappear only after I've got it wrong.
I added an edit to my previous post.

 

[Cryhavoc101]

Ironically you got the last part wrong. This predates the Nazi induced brain drain and Germany was the leading country in theoretical and experimental physics. Its moving up the discovery of fission and finding the ressources in combination which really stretches belief.

Well it doesn't because it took until the late 50s before this became a practical application - and they never had the $ during that entire period to fund such a project.

 

[Gudestein]

Well it doesn't because it took until the late 50s before this became a practical application - and they never had the $ during that entire period to fund such a project.

Well, 1920’s Germany is not behind the US in physics. Thats the part you got wrong.

 

[Garrison]

Well, 1920’s Germany is not behind the US in physics. Thats the part you got wrong.

But the rest was entirely accurate. Weimar has neither the money nor the resources to build a nuclear program, even if you were to rewrite the entire history of physics in the previous 50 years to make even the theoretical concept of a fission chain reaction available. Of course in terms of Physics talent and the wherewithal to fund a program the country most likely to be able to build a nuclear program in the 1920s would be Britain and as it would be impossible for Weimar to keep such a project secret I imagine the response from the Entente will be decisive to say the least.