AHC/WI: Faster Nelson class?

Riain

Banned
Given the Nelsons were 1500 tons under the treaty limits as built, I think there's some scope to increase horsepower while keeping the gun and armor characteristics and without undue structural modification to the design. Something like an 80,000 shp plant is probably doable; anything more, though, requires more shafts and a corresponding deep redesign.

Sadly, this only gets us to about 26 knots or so. So this really does need either legal shenanigans or a major redesign and reduction of either guns or armor.

Something I came across looking at CVA01 which might also appy to the Nelsons is the 'packaging' of propulsion machinery. The 53,000t CVA01 had 3 shafts, but to go to 4 shafts required 58,000t but provided no tactical advantage for the cost and complexity.

Would something similar apply to the Nelsons? To harness a significant increase in power would require a 3rd shaft which can't be accommodated in 1500t?
 

marathag

Banned
emember that this is the early 1920s and true high-pressure steam plants were not first used until the mid-1930s. The Admiralty Three-Drum boilers on the NelRods were state of the art at the time, and a major step up from Hood’s power plant.
The USN rapidly upped their game with Steam, going from Mahan's 400PSI in 1934 to Somers 650PSI in 1937. Lexington and her sister were still at 300PSI
 
I had a muck about on Ultimate Admiral Dreadnought and built this - behold!

28 knots, 3 x 3 x 15", 5 x 2 x 6" and 6 x 3 x 3" to represent the Pom Poms - 38,000+ full load (which Nelson was roughly - 38,390)

Nelson 28 knot.jpg
 
Something I came across looking at CVA01 which might also appy to the Nelsons is the 'packaging' of propulsion machinery. The 53,000t CVA01 had 3 shafts, but to go to 4 shafts required 58,000t but provided no tactical advantage for the cost and complexity.

Would something similar apply to the Nelsons? To harness a significant increase in power would require a 3rd shaft which can't be accommodated in 1500t?
There’s scope to increase horsepower on two shafts. The Brits were prepared to go as high as 45,000 hp per shaft with the G3s. But above that, you need three or four shafts, at which point you add a ton of weight and have to redesign the whole vessel.

Sadly, to hit 28 knots you’ll need the three or four-shaft arrangement.
 
Apparently the Nelson hull was one of the most hydrodynamically efficient hull designs that Haslar ever tested, so I suspect that it would have been able to absorb the extra power without too much issue.
 
Remember that this is the early 1920s and true high-pressure steam plants were not first used until the mid-1930s. The Admiralty Three-Drum boilers on the NelRods were state of the art at the time, and a major step up from Hood’s power plant.

The Royal navy was one the first to experiment with high pressure boilers, see HMS Swift.

True, that specific 1905 experiment was an abject failure, but later Yarrow development in the early 1920's could have been used (but the Royal Navy would have to pay royalties, and so refused)
 
I wonder what a pair of F3s would have done to other countries interwar planning.

I don't think Japan would have been willing to make the 4th Kongo their training ship in the London Naval treaty. I suspect that they would instead have demilitarised a Fuso.

I wonder about the Italian modernisations. The idea that they could modernise ships and be able to either out run or outfight any British ships (an idea which was questionable when it came to Renown and Repulse but especially when it came to Hood) was appealing to the Italians. I believe that they discounted Hood as there was a lack of Dry Docks (other than AFD8 at Malta and two dry docks at Gibraltar extended in 1937) in the Mediterranean which could handle her.

If the Royal Navy fast squadron was 5 capital as fast or faster than the modernisations may not be considered a viable investment.

Good questions! It might make a case for the 1928 battlecruiser concepts for the RM
I've wondered as well about the panzarschiffe. I realize Germany wasn't looking at Britain when they were conceived, and the ships were very much a political statement as well. But basically the three RN battlecruisers were only 'problem' ships for the concept at the time (we could count the Kongos as well, but Germany wasn't concerned about Japan) What if the RN had five fast ships instead of three? Do the panzarschiffe come out the same? Or do they try for something faster, perhaps without diesels or mixed steam and diesel?

Regards,
 
Do the panzarschiffe come out the same? Or do they try for something faster, perhaps without diesels or mixed steam and diesel?
The Germans don't have many options for replacing their Pre Dreadnoughts and the Panzerschiffe were about the best they could do within (sort of) the restrictions placed upon them. There other options are more conventional Heavy Cruisers or full blown Coast Defence Battleships. Neither of those two options can really do what the Germans want.
 

Driftless

Donor
Do the panzarschiffe come out the same? Or do they try for something faster, perhaps without diesels or mixed steam and diesel?

The Germans don't have many options for replacing their Pre Dreadnoughts and the Panzerschiffe were about the best they could do within (sort of) the restrictions placed upon them. There other options are more conventional Heavy Cruisers or full blown Coast Defence Battleships. Neither of those two options can really do what the Germans want.

From a bang-for-the-Reichsmark, wouldn't a few more merchant cruisers had equal utility? But part of the deal with the Panzerschiffes was also to stick a PR thumb-in-the-eye of the Anglo-French leaders and a homefront PR win.

Had the Germans pushed more of the merchant cruiser building scheme, then would the Anglo-French navies probably push more for construction of light cruisers, within treaty limits?

The Panzerschiffes called for something bigger, heavier, and faster, at least from a preference standpoint by the Admiralties (Even with the OTL end result of the Graf Spee - that was a bit too close for comfort).
 
Postponing final design and construction by a few years and throwing money at an improved steam plant/double reduction gearing would seem to be the best way to achieve 28+ knot service speed.
 
As folks said with the Nelsons, they were 1500 tons underweight, but a lot of that was due to them doing everything they could to shave weight off, which resulted in the turrets being problematic.

And whilst the RN didn't get the gun they wanted and were never really happy with the 16-inch rifles on the Nelrods, when push came to shove, the Rodney still scored possibly one of the most devastating hits that wasn't a magazine explosion in terms of naval gunnery when she basically crippled the Bismarck with that huge haymaker forwards.
 
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The Nelsons were fine. The only one to have a genuine beef about the guns is Bismarck.

The Nelsons were to replace the N3's while the Counties replaced the G3's. Sub optimal in both cases but the Nelsons were required to underpin British position as a great power, premier naval power, global financial hub, global reserve currency etc.
A fast battleship wont really cut that.

Scharnhorst 38,100 tons full load 32 knots
Nelson 37,780 tons full load 23 knots

Which one do you bet on winning a fight?

They were the last and best of the Super-Dreadnoughts. The Washington Treaty delayed by 13 years the advent of the fast battleship and even then a fast battleship needs to be 25% bigger than a slow one to be considered an even match.

Improvements to Nelson could be ditch the conning tower, skip the torpedoes, three shafts and fill out the tonnage a bit closer to the limit with a deeper belt and more secondary armament.
 
The Germans don't have many options for replacing their Pre Dreadnoughts and the Panzerschiffe were about the best they could do within (sort of) the restrictions placed upon them. There other options are more conventional Heavy Cruisers or full blown Coast Defence Battleships. Neither of those two options can really do what the Germans want.
Whitley mentions in German Capital ships one the Weimar Navy's considerations was the MN using the surviving Dantons to force entry into the Baltic. They felt the French would not risk their dreadnoughts in such an effort, and the Dantons would be the likely capital ships.
We explored a similar scenario when Warship Projects 3.0 was around and when Bob Henneman had is board on phpbbplanet. A repost is here:


From a bang-for-the-Reichsmark, wouldn't a few more merchant cruisers had equal utility? But part of the deal with the Panzerschiffes was also to stick a PR thumb-in-the-eye of the Anglo-French leaders and a homefront PR win.

Had the Germans pushed more of the merchant cruiser building scheme, then would the Anglo-French navies probably push more for construction of light cruisers, within treaty limits?

The Panzerschiffes called for something bigger, heavier, and faster, at least from a preference standpoint by the Admiralties (Even with the OTL end result of the Graf Spee - that was a bit too close for comfort).

In a guerre de course, armed merchant raiders can do real damage for a small navy on the strategic offensive, but surface warship raiders can relieve the pressure the larger navy on the strategic defensive can bring to bear. A merchant hull by nature is large, roomy, able to store provisions and supplies necessary for long raiding cruises. Usually too far out to sea to be concerned about destroyers, cruisers are their natural predators. Those same cruisers will always hunt a warship raider first. By its very nature, a warship is more dangerous to commerce, better armed, armored, faster, etc.

A program of merchants that could be converted to raiders, with appearances similar to the merchants of other nations' trading fleets, would be beneficial at least early in the war. But I still think surface warship raiders are a necessity. But they need not be panzarschiffe....

Regards all,
 

marathag

Banned
The UK can't bend the rules. The UK really need to follow the rules to keep costs down.
Steel is cheap, and extra displacement the same.
If you aren't cheating, you aren't trying to win, as goes the saying in the Sports World.
 
The UK can't bend the rules. The UK really need to follow the rules to keep costs down.
I think it's more a case that as the only new Battleships built from scratch following the Washington Treaty their construction was under intense international scrutiny. Any cheating would have been caught.
 
Steel is cheap, and extra displacement the same.
If you aren't cheating, you aren't trying to win, as goes the saying in the Sports World.
Steel maybe cheap, but the extra propulsion you’re adding to boost speed and the extra armor to cover the larger hull are not.
 

marathag

Banned
I think it's more a case that as the only new Battleships built from scratch following the Washington Treaty their construction was under intense international scrutiny. Any cheating would have been caught.
USN had little idea what the IJN was doing, and that was before the real secrecy on the Yamato.
 
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