How can a "better" Kriegsmarine be built?

[ValiantHeart]

I’m not sure if this topic has been discussed before, but I’d like to hear your ideas for building a "better" Kriegsmarine than the one that existed irl.

I am not saying that "if Hitler had ordered the construction of [A, B, C...], Germany could have won the Battle of the Atlantic," but I do expect that a "better" Kriegsmarine would have adopted a more rational strategy and shipbuilding plan (Plan Z was pure fantasy/madness), leading to a better performance than what actually occurred?

From the moment I began to find this topic interesting - something surprising to me, as I am not typically a fan of alternate history - I delved into various forums and gathered a wealth of noteworthy opinions:

• Focusing solely on U-boats would not work, as the Anglo-German Naval Agreement restricted the construction of additional vessels, and any attempt to "spam" U-boats would inevitably draw the attention of the Allies. Although U-boats - as in real life - should be prioritized for resources, the ideal Kriegsmarine remains a balanced fleet across its various branches.
• There is broad agreement that the effort to build a surface fleet capable of competing with Britain was futile... yet the consensus ends there, as opinions differ on how such a fleet should actually be constructed. However, most of the views I have encountered tend to revolve around the concept of scaling back battleship construction in favor of focusing on smaller vessels.
• S-boots and auxiliary cruisers (Hilfskreuzer) were underrated.
• The Germans could have gained more - and reduced their losses - had they invested more in amphibious warfare.
• Perhaps Kriegsmarine should have limited itself to using U-boats and auxiliary cruisers for power projection in the Atlantic and across the globe, while the remaining fleet focused on securing dominance in the Baltic Sea and defending the English Channel?
• Or would the development of naval air power - or at least better coordination with the Luftwaffe - compensate for the lack of naval strength?

I also wonder whether closer and more extensive cooperation with Italy and Japan would have been of any further benefit to Kriegsmarine?

...as you might guess, many of the assumptions involved here would require more than just "abandoning one thing to build another"; they would necessitate a "profound shift" in the power structure and strategic mindset of the Nazi leadership. For instance, unless Göring had died prematurely from illness or an accident, there would have been no better coordination with the Luftwaffe. Hitler himself would have needed a better understanding of naval affairs - or at least the decisiveness to strip Göring of his absolute authority and cede some of it to Raeder. Something like this, something like that, yada yada...

 

[tomo pauk]

What is the starting date?

 

[ValiantHeart]

By 1939, it would be too late to start anything; you would simply have to make do with whatever you already had.

Most people tend to use 1933 - the year the Nazi Party came to power - as the starting point. After all, the most impressive aspects of the Kriegsmarine emerged from that time onwards.

But there is no "Law of Alternate History" preventing me from doing anything, and in any case, Germany's rearmament efforts had already begun in the 1920s under the Weimar Republic.

In that case... I'll pick a point far back in time. How about 1921? The first thing I want to do is find a way to get close to Hitler and become one of his Inner Circle, and then—

 

[tomo pauk]

In that case... I'll pick a point far back in time. How about 1921? The first thing I want to do is find a way to get close to Hitler and become one of his Inner Circle, and then—

Before the early 1930s, the historical development is probably okay. What might be useful for the next 10+ years is to keep the keen eye on foreign developements wrt. the carrier aviation, submarine and anti-submarine warfare, as well as to test different armor schemes (like the British usage of water between the plates to improve underwater protection). The development of low-drag shells, from the high length/diameter ratio, to the shells with aerodynamic caps. Do the work on different radio devices: radars, radio detectors, underwater sensors etc. All of this requires time, and can be done without provoking the Entente.
For the early 1930s, the carrier aviatino needs to take form, 1st in order to learn the tricks of the trade, then to make that aviation a real weapon of the war. After the Panzeshiffe, make the aricraft carriers before the 38cm guns are ready.
Supoport the Lufthansa in buying the diesel-powered 4-engined aircraft for the immense range, later have these outfitted with radio devices of different kinds to act the fleet eyes at far distances.
Have the automatic 37mm AA gun procured - the single-shot 37mm Flak was a bad joke.
Submarines should have the means to breath air without announcing themselves to the enemy miles away.
Wired guide bombs might've been interesting, keeping the lumbering aircraft in the safe altitudes/distances.

 

[builder396]

Well, if I wanted to be a party pooper Id say Germany should start with not losing WWI. But that wouldnt be any fun.

Have the automatic 37mm AA gun procured - the single-shot 37mm Flak was a bad joke.

This is certainly a good point, since the 3.7cm Flak 36 was a decent enough gun, even if it combined the firepower of a 40mm Bofors with less effective range, but the later 3.7cm Flak 43 gave it double the rate of fire at least, and it got adopted by the KM. But in 1943 it was too little too late. Only big downside I can see on those guns is that they are not well suited to multiple mounts, certainly won't ever have a sextuple mount like the Bofors.

A 5cm Flak 41 would also be a decent candidate. It's pretty obscure, but imagine the ballistics of a 5cm Pak 38 combined with the clip feed and mount of the 3.7cm Flak 36, except bigger. On land it was considered pretty useless, because it closed a performance gap between the 3.7cm Flak and the 8.8cm Flak, but on land youre either dealing with ground attack aircraft or heavy bombers, but few things in between where the extra range matters. On sea however it's a whole different ballgame, where being able to open fire on approaching planes earlier can be a life-saver. At 180 rpm the fire rate is pretty good, too, so with proper integration into a fire director it would be a pretty amazing if heavy gun.

I got one original point, too, though.

Get rid of these stupid split secondary batteries!

Seriously, splitting the secondary batteries on Battleships and Panzerschiffe and above into 15cm anti-ship guns and 10.5cm (or even 8.8cm) AA guns did neither job any favors. 15cm guns had a time fuze round in theory, but they traversed too slowly and couldnt elevate enough to use them, while the AA guns werent all that great at anti-ship work, but what both batteries have in common is not having enough guns.

I see three solutions to this problem:

Solution 1: Replace all 15cm guns with more 10.5cm twin mounts. Yes, anti-ship firepower takes a nosedive, but youll be firing way more shells at an enemy ship, and if 10.5cm guns are wholly ineffective the target is big enough to involve the main battery, even on a Bismarck.

Solution 2: Develop a unified gun based on the 12.7cm SK C/34 with a high elevation mounting, preferably twin turrets, and good enough traverse speed to track planes. Get the best of both worlds. Z46 turrets are pretty much what Im thinking of.

Solution 3: O-class twin 15cm turrets, a few were used when Germany decided a 15cm-armed destroyer was a good idea, so look at Z32. 60° of elevation isnt all that great, but the turrets rotate and elevate fairly fast, so maybe thatll be good enough if the priority really is on surface firepower. Just dont fumble around with these stupid single 15cm gun mounts.

 

[Rule of cool]

Develop a unified gun based on the 12.7cm SK C/34 with a high elevation mounting, preferably twin turrets, and good enough traverse speed to track planes. Get the best of both worlds. Z46 turrets are pretty much what Im thinking of.

Dual purpose guns was the way the RN and USN were moving, and the Germans cannot afford to waste anything so ruthless efficiency is a must.

 

[ValiantHeart]

Here is an opinion I just came across, quote:

The High Seas Fleet in World War I had one great success - Moon Sound. A perceptive admiralty might have fixed on this and specialized the navy for Baltic operations. Anything that hastens the German advance to Leningrad could have important repercussions.

In my opinion, anything that strengthens the KM for warfare against Britain is missing the point. The Germans cannot defeat the Royal Navy. It's nice to pretend the Germans could become a carrier-based power, but then we have to ignore any British response to that and hope that the fleet is sitting in Scapa at the right time and place to be Pearl-Harbored. And then what?

The Germans need to restrict their westward navy to jeune ecole warfare, scare Britain with subs and raiders, and focus their primary effort to the east where they can be the Big Man on Baltic and reap the benefits of naval superiority. More training ships, more amphibs, more minesweeping sloops.

I don't think changing Scharnhorst's guns will accomplish anything significant except taking the ship out of action long enough to make those extensive changes.

 

[Rule of cool]

Sea Power is a combination of fleet and geography. In WW1 Germany had the fleet but not the geography, in WW2 they had the geography but not the fleet. The ability of Germany to capture superb naval geography really boosts whatever fleet they manage to construct, making capital ship building not a waste of time as has been often asserted.

 

[Ainen]

I am not saying that "if Hitler had ordered the construction of [A, B, C...], Germany could have won the Battle of the Atlantic," but I do expect that a "better" Kriegsmarine would have adopted a more rational strategy and shipbuilding plan (Plan Z was pure fantasy/madness), leading to a better performance than what actually occurred?

There's nothing mad about Plan Z, it began in 1938. Absolutely no decision taken so late will have any impact, Germans failed to complete any heavy vessels from well before that point(since XI.1936).

If you want to get more out of Kriegsmarine - don't begin war in 1939. Navy isn't tanks, the cycles are longer. KM couldn't hold even a single proper summer fleet training cycle before the war, as their first heavy units only arrived in 1939. KM can't be expected to organizationally perform against the UK until 1943, and that they did IRL is already way out of proportion for the size of the force at hand.

Get rid of these stupid split secondary batteries!

All German heavy units until 1940 had a basic belts problem (Encounter with French superdestroyers; they can - and did during the war - reach there in a matter of hours). Sufficient escort force couldn't be expected to arrive in time.
All German battleships other than Tirpitz had to repel multiple determined destroyer torpedo attacks through their career. All 3 same ships had to repel (or at least engage in case of Bismarck) air and surface threats simultaneously.
In most cases they repelled manageable air attacks well enough, and in cases where they did not - more/heavier DP guns would've made matters even worse.
On no German battleship through their career DP gun would've had any additional substantial positive impact. Negative - easily so.
Keep in mind that the basic assumption "bigger=better" doesn't work here.
Before VT fuse and evolved radar GFC, even the great 5"/38 was rather mediocre in its performance; British 5.25" was simply meh, and throughout the war never achieved the level of AA performance SK C/33 had.
Since the active career of German battleships more or less ended in 1942, you'll not just sacrifice ASuV, you'll ironically sacrifice AA performance as well.