Could the Kriegsmarine have assembled a battlefleet for the Atlantic ?

[Belisarius II]

I half-take these points.

Renown was escorted by 9 destroyers IOTL which didn't get into range because of the bad weather. I did start a thread where I suggested that Repulse was sent out with Renown and the consensus was that it wouldn't have made much difference because both sides were lucky to score the hits that they did because of the bad weather.

Re the 15" shell that hit Renown and didn't explode. I can match that with the 11" shell that hit Renown and didn't explode and raise you the 15" shells that hit Prince of Wales and didn't explode in her action with Bismarck.

However, they'd send Bismarck and Tirpitz out on their own in the autumn of 1940 if Schanhorst and Gneisenau weren't available to sail with them.

Interesting. In the Renown vs. Scharnhorst, and Gneisenau battle I think it was Scharnhorst that suffered a failure in her radar, and in fire control. This added to the German desire to disengage. In these what if's we always assume fights to the finish. Duds, or pass throughs are common. The 15" shells of Renown had a good chance of penetrating the armored citadel of the German Ships, and at that range it would the more dangerous plunging fire. The 11" German guns had very flat trajectories, giving them a good chance of penetrating Renown's main belt, or any of it's armor. Ether side could've done major damage to the other, but the Germans have the advantage of 18 guns, vs. 6.

You can debate the German Policy of avoiding battle, if it risked major damage, but the Germans have to deal with having a small number of ships, and bases to go to. However In the heat of battle it's easy to imagine pressing an advantage. The Germans might have sunk Renown, which would have had a shocking effect on the British. It would hurt moral, and the RN doesn't have as many effective capital units as people are thinking. If the Bismarck had sunk the Prince of Wales the shock of losing the Hood would be magnified. PW was the best protected ship in the RN, the fact it really wasn't battle worthy would be obscured by events.

Effectively only the Rodney, and Nelson could take on Bismarck, or Tirpitz on equal terms, the 14" shells were just too light. It was Rodney that destroyed Bismarck. The shortage of RN Battleships that could handle Tirpitz prompted Admiral King to send 2 Fast Battleships to join the Home Fleet. The timidity of the RN in Northern Waters in mid 1942 so disgusted King that he withdrew them, and sent them to the South Pacific, where they might do more good.

So I don't see a German Battlefleet in the Atlantic, and the chances of a Little Jutland in Northern Waters is small. Nether the Germans, or RN want to come in range of enemy aircraft, and the British advantage in FC Radar later in the war gives them too big an advantage in an Arctic Night action for the Germans to risk it. It was just foolish for the Germans to send the Scharnhorst stumbling out into an Arctic Night, in high seas, groping to find a convoy. Not their best thought out operation of the war.

 

[NOMISYRRUC]

The Bismarck and Tirpitz were not worth the money. It would have been much better if Germany built the 3 O-class battlecruisers instead of the Bismarck class.

I think the Hipper class would have been better with a combined low pressure steam and diesel machinery like the light cruisers that preceded them instead of the immature high pressure steam boilers used IOTL. However, as I wrote about the O class it might not be possible to do that in 1935 because suitable diesel engines might not be available.

 

[Belisarius II]

The Deutschland class used all diesel engines.
I don't see how this couldn't be done with the O-class.

They would've needed much larger engines, of far greater power to give a 35,000 ton ship a 35kt speed.

 

[NOMISYRRUC]

But this would be less of a problem if the ship in question had more fuel in the first place.

It would have been less of a problem had Bismarck refuelled in Norway, which could have been done because Prinz Eugen did.

There were also a number of tankers on station in the North Atlantic that Bismarck could have refuelled from. Lutjens might have had good reasons for not doing that and we'll never know what they were.

 

[McPherson]

The Deutschland class used all diesel engines.
I don't see how this couldn't be done with the O-class.

8 Mann diesels, each 5,000 kwatts for 38,000 kwatts put-through on two shafts.

Want to see what that looks like in an O-class? That is 16, yes SIXTEEN diesel engines or 75,000 kwatts on four shafts. Deutschlands broke down often as a diesel would suffer a mechanical at the gearboxes. . Guess what a nightmare the O-class would be?

Unless you are an experienced diesel electric or turbo-electric user, diesels are NOT recommended for warships.

 

[NOMISYRRUC]

The Deutschland class used all diesel engines.
I don't see how this couldn't be done with the O-class.

The Deutschland class had considerably less powerful diesel engines than the ones planned for the O class and said more powerful diesel engines didn't exist in 1935-36. To paraphrase Oscar Goldman, "They didn't have the technology."

 

[McPherson]

Postwar for commercial, and even today not WAR-rated.

The Deutschland class had considerably less powerful diesel engines than the ones planned for the O class and said more powerful diesel engines didn't exist in 1935-36. To paraphrase Oscar Goldman, "They didn't have the technology."

I wrote that.

 

[NOMISYRRUC]

The Deutschland class used all diesel engines.
I don't see how this couldn't be done with the O-class.

The Deutschland class had 8 diesels each producing 6,750 bhp.

The H class were to have had 12 diesels each producing 13,500 bhp

The O class was to have had:

8 MAN double-acting 2-stroke 24-cylinder diesels (outer shafts) each producing 14,500bhp for a total of 116,000 bhp​

4 Wanger boilers (central shaft) 60,000 shp​

That produced a total of 176,000hp on all shafts​

​

The maximum speed of 33.4 knots for the O class was the maximum speed at 176,000hp, not when using the steam plant of 60,000 shp alone. It looks like the ship would use its diesel engines for cruising and only use the central shaft when maximum speed was required.

 

[thaddeus]

The O class was to have had:

8 MAN double-acting 2-stroke 24-cylinder diesels (outer shafts) each producing 14,500bhp for a total of 116,000 bhp​

4 Wanger boilers (central shaft) 60,000 shp​

That produced a total of 176,000hp on all shafts​

​

The maximum speed of 33.4 knots for the O class was the maximum speed at 176,000hp, not when using the steam plant of 60,000 shp alone. It looks like the ship would use its diesel engines for cruising and only use the central shaft when maximum speed was required.

the O-class was considered to be lacking in armor and has been criticized for that, any changes on that front and it would start to reduce top speed?

that was the vicious cycle they confronted.

 

[BlackDragon98]

Deutschlands broke down often as a diesel would suffer a mechanical at the gearboxes.

AFAIK they spent much of their time at sea, rather than in a shipyard being repaired.
Unlike those F-class escorts which used high pressure boilers with no diesel engines.

Edit: if they were as problematic as you said, they would have been rebuilt like some the shitty destroyers of the Kriegsmarine, which they weren't.
This means that the diesel engines of the Deutschland class were fine. They weren't particularly problematic or anything.

 

[NOMISYRRUC]

OK so we're re fighting HX106 that's cool, so you destroy one well protected convoy and a WW1 era battleship, so what? Not every convoy has a Ramillies attached to it, so it's massive overkill for many convoys and you still have all the issues stated above.

Lutjens also turned away form SL 67 because it was escorted by Malaya.

According to the convoyweb website it consisted of 55 ships, but doesn't give their tonnage. Thought the average for HX84 was nearly 6,000 GRT and HX106 was 5,000 GRT. On that basis the aggregate tonnage of SL 67 would have been between 275,000 and 330,000 GRT.

 

[NOMISYRRUC]

AFAIK they spent much of their time at sea, rather than in a shipyard being repaired.

And much of the time they did spend in dockyards was to repair battle damage such as the two occasions when Lutzow/Deutschland was torpedoed rather than machinery repairs.

 

[BlackDragon98]

View attachment 565217​

The Deutschland class had 8 diesels each producing 6,750 bhp.

The H class were to have had 12 diesels each producing 13,500 bhp

The O class was to have had:

8 MAN double-acting 2-stroke 24-cylinder diesels (outer shafts) each producing 14,500bhp for a total of 116,000 bhp​

4 Wanger boilers (central shaft) 60,000 shp​

That produced a total of 176,000hp on all shafts​

​

The maximum speed of 33.4 knots for the O class was the maximum speed at 176,000hp, not when using the steam plant of 60,000 shp alone. It looks like the ship would use its diesel engines for cruising and only use the central shaft when maximum speed was required.

My solution for the O-class.
This:

MAN Double-Acting Diesel Marine Engines

In the first half of the 20th century, MAN (Maschinenfabrik Augsburg-Nürnberg) developed a number of double-acting, two-stroke, diesel, marine engines, including a V-24 that displaced 224,957 cu in…

oldmachinepress.com

"The six-cylinder engine was first run on 23 February 1914. By September 1914, the engine was producing 10,000 hp (7,457 kW) at 130 rpm. By this time, World War I was underway; priorities shifted, and shortages were encountered. A single cylinder made a five-day run at over 2,000 hp (1,491 kW) in April 1915. On 24 March 1917, the six-cylinder engine produced 12,200 hp (9,098 kW) at 135 rpm for 12 hours. In April 1917, the engine passed its five-day acceptance test, running at 90% power and producing 10,800 hp (8,054 kW) at 130 rpm.

By mid-1917, it was obvious that due to delays and the war, the engine would never be used, and the other five engines would never be built. MAN decided to test the engine to its limits. The engine test stand at MAN could not absorb the maximum anticipated power of the complete six-cylinder engine, so just one cylinder was run. On 16 October 1917, a single cylinder produced 3,570 hp (2,662 kW) at 145 rpm. If all six cylinders could match that performance, the complete engine would produce 21,420 hp (15,973 kW). The engine was later scrapped as a result of the Treaty of Versailles."

21,420 hp from a 1917 design.
21,420 hp x 8 engines = 171,360 hp

add 2 more engines and you have 214,200 hp
on a WW1 era 6 cylinder diesel

That's more than enough to get 35 knots. Top speed would probably be 36 or 37 knots.

As long as the design plans were still there, the engineers at MAN could reproduce it.

Design time goes down to zero.
The only problem is making the damn engines.

 

[BlackDragon98]

And much of the time they did spend in dockyards was to repair battle damage such as the two occasions when Lutzow/Deutschland was torpedoed rather than machinery repairs.

Not to mention the Deutschland getting bombed in Spain.

 

[Gokbay]

the O-class was considered to be lacking in armor and has been criticized for that

Like separate from being a battlecruiser? Because battlecruisers do have less protection than battleships to get speed. That is the entire concept.

 

[NOMISYRRUC]

My solution for the O-class.
This:

MAN Double-Acting Diesel Marine Engines

In the first half of the 20th century, MAN (Maschinenfabrik Augsburg-Nürnberg) developed a number of double-acting, two-stroke, diesel, marine engines, including a V-24 that displaced 224,957 cu in…

oldmachinepress.com

"The six-cylinder engine was first run on 23 February 1914. By September 1914, the engine was producing 10,000 hp (7,457 kW) at 130 rpm. By this time, World War I was underway; priorities shifted, and shortages were encountered. A single cylinder made a five-day run at over 2,000 hp (1,491 kW) in April 1915. On 24 March 1917, the six-cylinder engine produced 12,200 hp (9,098 kW) at 135 rpm for 12 hours. In April 1917, the engine passed its five-day acceptance test, running at 90% power and producing 10,800 hp (8,054 kW) at 130 rpm.

By mid-1917, it was obvious that due to delays and the war, the engine would never be used, and the other five engines would never be built. MAN decided to test the engine to its limits. The engine test stand at MAN could not absorb the maximum anticipated power of the complete six-cylinder engine, so just one cylinder was run. On 16 October 1917, a single cylinder produced 3,570 hp (2,662 kW) at 145 rpm. If all six cylinders could match that performance, the complete engine would produce 21,420 hp (15,973 kW). The engine was later scrapped as a result of the Treaty of Versailles."

21,420 hp from a 1917 design.
21,420 hp x 8 engines = 171,360 hp

add 2 more engines and you have 214,200 hp
on a WW1 era 6 cylinder diesel

That's more than enough to get 35 knots. Top speed would probably be 36 or 37 knots.

As long as the design plans were still there, the engineers at MAN could reproduce it.

Design time goes down to zero.
The only problem is making the damn engines.

If that's correct then the Germans build Scharnhorst, Gneisenau, Bismarck and Tirptiz will all diesel machinery rather than O class with mixed steam and diesel production.

That would give them more range, but not necessarily higher availability rates because AIUI both classes had reliable machinery and that's in spite of Bismarck and Tirpitz having high pressure boilers.

The diesels might be easier to make than the steam turbine machinery that the OTL ships had and it would mean more production capacity would be available to make turbine machinery for the cruisers and destroyers.

 

[thaddeus]

Like separate from being a battlecruiser? Because battlecruisers do have less protection than battleships to get speed. That is the entire concept.

from within the KM itself, my reading of it yes partly as reaction against the concept of a battlecruiser, as you point out, and also for "opportunity cost" that they are only going to have finite number of ships.

the O-P-Q known as Ohne Panzer Quatsch "without armor nonsense"

 

[NOMISYRRUC]

My solution for the O-class.
This:

MAN Double-Acting Diesel Marine Engines

In the first half of the 20th century, MAN (Maschinenfabrik Augsburg-Nürnberg) developed a number of double-acting, two-stroke, diesel, marine engines, including a V-24 that displaced 224,957 cu in…

oldmachinepress.com

"The six-cylinder engine was first run on 23 February 1914. By September 1914, the engine was producing 10,000 hp (7,457 kW) at 130 rpm. By this time, World War I was underway; priorities shifted, and shortages were encountered. A single cylinder made a five-day run at over 2,000 hp (1,491 kW) in April 1915. On 24 March 1917, the six-cylinder engine produced 12,200 hp (9,098 kW) at 135 rpm for 12 hours. In April 1917, the engine passed its five-day acceptance test, running at 90% power and producing 10,800 hp (8,054 kW) at 130 rpm.

By mid-1917, it was obvious that due to delays and the war, the engine would never be used, and the other five engines would never be built. MAN decided to test the engine to its limits. The engine test stand at MAN could not absorb the maximum anticipated power of the complete six-cylinder engine, so just one cylinder was run. On 16 October 1917, a single cylinder produced 3,570 hp (2,662 kW) at 145 rpm. If all six cylinders could match that performance, the complete engine would produce 21,420 hp (15,973 kW). The engine was later scrapped as a result of the Treaty of Versailles."

21,420 hp from a 1917 design.
21,420 hp x 8 engines = 171,360 hp

add 2 more engines and you have 214,200 hp
on a WW1 era 6 cylinder diesel

That's more than enough to get 35 knots. Top speed would probably be 36 or 37 knots.

As long as the design plans were still there, the engineers at MAN could reproduce it.

Design time goes down to zero.
The only problem is making the damn engines.

If that's correct it makes an all-diesel Hipper or one with mixed low-pressure steam and diesel production feasible too.

That would increase their endurance and it would be hard for it to be less reliable than their OTL machinery. AIUI Hipper had to be sent to Trondheim to refuel in Operation Juno. ITTL she might have been with the twins when they met Glorious, Acasta and Ardent. That increases the chances of the British force being wiped out before it can hit back.

 

[BlackDragon98]

If that's correct then the Germans build Scharnhorst, Gneisenau, Bismarck and Tirptiz will all diesel machinery rather than O class with mixed steam and diesel production.

That would give them more range, but not necessarily higher availability rates because AIUI both classes had reliable machinery and that's in spite of Bismarck and Tirpitz having high pressure boilers.

The diesels might be easier to make than the steam turbine machinery that the OTL ships had and it would mean more production capacity would be available to make turbine machinery for the cruisers and destroyers.

I'm guessing the design plans were destroyed after WW1.
Otherwise it's just the Kriegsmarine being stupid and wanting new tech.
On the website there's just one image of the WW1 design.
The WW1 engine could be heavier than the OTL Deutschland diesels though.
Who knows?
I'm guessing though its probably just the Nazis being stupid.

 

[McPherson]

My solution for the O-class.
This:

MAN Double-Acting Diesel Marine Engines

In the first half of the 20th century, MAN (Maschinenfabrik Augsburg-Nürnberg) developed a number of double-acting, two-stroke, diesel, marine engines, including a V-24 that displaced 224,957 cu in…

oldmachinepress.com

"The six-cylinder engine was first run on 23 February 1914. By September 1914, the engine was producing 10,000 hp (7,457 kW) at 130 rpm. By this time, World War I was underway; priorities shifted, and shortages were encountered. A single cylinder made a five-day run at over 2,000 hp (1,491 kW) in April 1915. On 24 March 1917, the six-cylinder engine produced 12,200 hp (9,098 kW) at 135 rpm for 12 hours. In April 1917, the engine passed its five-day acceptance test, running at 90% power and producing 10,800 hp (8,054 kW) at 130 rpm.

By mid-1917, it was obvious that due to delays and the war, the engine would never be used, and the other five engines would never be built. MAN decided to test the engine to its limits. The engine test stand at MAN could not absorb the maximum anticipated power of the complete six-cylinder engine, so just one cylinder was run. On 16 October 1917, a single cylinder produced 3,570 hp (2,662 kW) at 145 rpm. If all six cylinders could match that performance, the complete engine would produce 21,420 hp (15,973 kW). The engine was later scrapped as a result of the Treaty of Versailles."

21,420 hp from a 1917 design.
21,420 hp x 8 engines = 171,360 hp

add 2 more engines and you have 214,200 hp
on a WW1 era 6 cylinder diesel

That's more than enough to get 35 knots. Top speed would probably be 36 or 37 knots.

As long as the design plans were still there, the engineers at MAN could reproduce it.

Design time goes down to zero.
The only problem is making the damn engines.

i'll keep it very simple.
a. Vibration issues. The same exact kind of issues with reciprocating steam engines.
b. Noise issues. Ever been in a sub diesel engine room?
c. Lubrication issues. Oil leaks everywhere especially along the piston barrels, the crank arms, and the crankshaft collars.
d. PTO issues. WARPING.
e. VOLUME issues. Those engines scale up HUGE as the volume of hull consumed by the cube, not the square.

All which are warship killers. MANN never solved those in 1917, 1937, or until 1947. Those pieces of JUNK were maintenance nightmares, recurring casualties, it did cause mechanicals on the Deutschlands (and the U-boats).

f. and they were SLOW... about 100 to 150 revolutions per minute on the crankshaft using the MANN 2 stroke. You would need French or American 4 stroke diesels to get the
rpm range for high speed transfer and minimum vibration.
g. Last but not least is something few people consider... HEAT and ASPIRATION. Ever see how tall a MACK is on the modern diesel powered freighter? How about the intake and exhaust circuit? HUGE, because not only do the gasses have to be sucked in and exhausted, but so does the heat in carried off largely in that circuit.
h. You are not going to get 15 m/s on a 35,000 tonne ship with those engines using geared drive. You need an electrical power transfer to put watts through the prop shaft.

256 meters long.

Compare her to an IOWA.

262 meters long, just as fast, just as long ranged and with infinitely better armor and GUNS.

Engine and boiler compartments and turbines half the volume.