RN going with 15' or 16' for KGV BB - pros cons?

Not only AGNA but also the five powers delaration bound Germany to the qualitative limits -in principle- which also affected other marine powers, and thus the WNT. However, while other nations had worked out the details Germany and Britain had not yet settled on them and agreed upon principially equal rights. Thus, there can be no doubt that Germany cannot exceed the qualitative limits imposed to Britain. In return, this means that there can be no doubt that BISMARCK was heavily overweight in it´s actual displacement.

So where other vessels, too. D&S may not have violated the qualitative limits but due to their much lower official displacement, France was about to violate the general limits outlined in the Treaty. Britain did that with it´s aircraft carriers, too.

delcyros said:

The non-fuel oil, non-reserve feed water liquid in BISMARCK´s TDS (all liquid) has to be counted as standart displacement. This is entirely correct.

BISMARCK´s designed deep displacement was
50,935 metric t.
now we substract only what the Treaty allows to substract:
- 7814 metr. t ship fuel oil
- 373 metr. t. reserve feed water

= 42,748 metr. t. stand. displacement (= 42,075 tons standart)

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You'd be correct if Bismarck had a propulsion system that didn't actually burn fuel, since she would then never need to replace the used fuel with sea water to maintain the effectiveness of the TDS. By your interpretation of the treaty, replacing oil fuel with seawater would be a treaty violation, since at that point the ship would exceed her treaty displacement, by adding protection not permitted under the treaty.

delcyros said:

Thus, there can be no doubt that Germany cannot exceed the qualitative limits imposed to Britain. In return, this means that there can be no doubt that BISMARCK was heavily overweight in it´s actual displacement.

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No, as I have pointed Germany has not ratified any such tonnage limits and thus those limits did not apply to her. AGNA specificed a % of the British total tonnage, and that this total tonnage shall be used proportionately for the various classes of ships. It merely held a very vague about any specific limitation, namely, that German shall 'favour' such. There's a good reason in diplomacy when such words are used, instead of the very specific agreement about total tonnage. It clearly means that such agreement about naval tonnage limitation per ship class was not agreed upon, but a sense of goodwill exist between the parties.

That's the very point of the concept of sovereignty and international treaties - since there is no supreme power over nations, they are only bound by treaties if they want to be bound by them, and can withdraw at any point. In short, you are clearly reaching. If you really believe you have a point, please point out the article of whatever agreement that would bound Germany (or the USSR for that matter) to any naval limitation.

I think that saying that since the ships were completed after the war broke out means that the countries weren't cheating is a copout.

Ships of the same class (plans or blueprints) could vary by several hundred tons even in cruisers depending on the yard building the ships. Turning paper ships into real ones often meant mistakes were made, especially considering that at times many of the items going into the ships were "paper", the actual weight of the items were not known as they had not been built yet. Quite a few airplanes came out overweight compared to original estimates and there are a lot fewer parts in an airplane than in a 500-700 ft long ship.

However being off by around 20% isn't an innocent mistake or trying to shave a little too close to the limit. It is a blatant cheat and did NOT come from additions in the last year of construction. It is like trying to say you planned a ten story building and added two stories at the last minute. Your structural framing wouldn't be strong enough and your pre-ordered elevators wouldn't reach all floors.
It takes as long or longer to build the engines, main armament and armor plate as it does the hull structure and minor parts. Adding 4-7,000 tons more STUFF to a 35,000 ton ship in the last 25% or less of it's construction time would make for a very, very unsatisfactory ship.

Some countries may have tried to follow the limits (or at least stay close enough to be somewhat believable) while others made announcements of weights that were blatant lies. At least one naval architect is supposed to have said when questioned as to why he could not come up with all the features of a foreign ship on it's legend displacement that he could do it IF he was allowed to lie about the displacement as much as the foreign designers/government were lying.

There are/were rough formulas for figuring what size ship you need for a given weight of armor or armament and unless your machinery was in a totally different league than everybody else they could make a good guess at to what eh machinery weight was.

The treaty was a good idea but there was little or no way to actually verify it let alone enforce it (go to war over an overweight ship?) so a lot of winking and nudging was done over some of the announced weights. The actual enforcement would be to abandon the treaty and go to unrestricted building which few, if any, of the countries wanted to do as none of them could actually afford such an open arms race.

The Germans may not have been bound by the Washington treaties but a public announcement that they were building 40,000-42,000 ton ships would have meet with much disapproval in the international community and a probable response from England to effect of canceling the later KG Vs in favor of something like the Lion class. Germany WAS bound by their agreement to 35% of the British fleet by tonnage and under rating their ships allowed them to build more ships before hitting the total tonnage limit.

Hello Delcyros
thanks for the WNT text, Brown was clearly wrong. IIRC there is some explanation to British behavior in R&R but I should check the book before commenting more. I'll climb to my attic and take a look into the book when I'll have spare time.

Juha

Some interesting technical information on BB guns and armour can be found here, plus there's a comparison here. Bound to be some debates...

Hello
I took a look in R R Brtish BBs
All weights are English ton (1016kg)
After being inclined on 19th March 1927 Nelson's displacement was estimed at 33,313 tons. Allowing for the addition of 4 multiple pom-poms in place of the singles, and 2 a/c and their equipment, increased this figure to 33,413 tons. The standard displacements of the two ships were published, therefore, as 33,500 tons for Nelson and 33,900 tons for Rodney. The water in TDS, when buoyancy spaces were flooded, weighted 2,870 tons so with it the Nelson's standard displ. was 36,283 English tons/ 36,864 metric tons.

Juha

ADDUM Except for exercises and compartment testing, the buoyancy spaces were to be flooded in wartime only.

Juha said:

Hello
I took a look in R R Brtish BBs
All weights are English ton (1016kg)
After being inclined on 19th March 1927 Nelson's displacement was estimed at 33,313 tons. Allowing for the addition of 4 multiple pom-poms in place of the singles, and 2 a/c and their equipment, increased this figure to 33,413 tons. The standard displacements of the two ships were published, therefore, as 33,500 tons for Nelson and 33,900 tons for Rodney. The water in TDS, when buoyancy spaces were flooded, weighted 2,870 tons so with it the Nelson's standard displ. was 36,283 English tons/ 35,712 metric tons.

Juha

ADDUM Except for exercises and compartment testing, the buoyancy spaces were to be flooded in wartime only.

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36283 long tons are not 35712 metric tons... just have you inverted the conversion?

Vincenzo is right Juha your pencil must be broken 36283 long tons is 36863 tonnes

RCAFson said:

You'd be correct if Bismarck had a propulsion system that didn't actually burn fuel, since she would then never need to replace the used fuel with sea water to maintain the effectiveness of the TDS. By your interpretation of the treaty, replacing oil fuel with seawater would be a treaty violation, since at that point the ship would exceed her treaty displacement, by adding protection not permitted under the treaty.

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no the replace not violate the treaty, in the ready for sea condition the ship has fuel in the TDS

I am pretty sure that a Wiki article said that during tests, the 16 inch shells performance was disappointing compared to the higher velocity 14 inch.

Found the article -
Background
The choice of calibre was limited by the Second London Naval Treaty, an extension of the Washington Naval Treaty which set limits on the size armament and number of battleships constructed by the major powers. After disappointing experiences with the combination of high velocity but relatively light shell in the BL 16 inch /45 naval gun of the Nelson class battleships, the British reverted to the combination of lower velocities and (relatively) heavier shells in this weapon.

Design
These built-up guns were constructed using a non wire wound radial expansion design which was an advance on previous British practice with a longer barrel life and better accuracy. Unfortunately, the choice of mountings was for quadruple turrets, and in practice these developed a reputation as being unreliable with the turrets jamming during battle. However, it has been argued that these jams were typically caused by errors in drill, either due to lack of gun crew training, as was the case when the newly commissioned Prince of Wales engaged the Bismarck in the Battle of the Denmark Strait (1941), or due to crew fatigue resulting from the prolonged nature of the engagement, as was the case when King George V engaged Bismarck in 1941, and Duke of York engaged Scharnhorst in the Battle of North Cape (1943).

vinnye said:

I am pretty sure that a Wiki article said that during tests, the 16 inch shells performance was disappointing compared to the higher velocity 14 inch.

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There were designs for a heavier 16" shell for the NelRods but it never got manufactured. It was planned to weigh 2,250 pounds and have a muzzle velocity of 2,575 fps but the work needed to get the 16" mounts reliable and then work on the newer 14" gun plus a lack of spare money meant it was never a priority.

Vincenzo said:

no the replace not violate the treaty, in the ready for sea condition the ship has fuel in the TDS

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It doesn't violate the treaty because water protection wasn't included in treaty weight calculations.

In the ready for sea condition Nelson has no water in the water protection compartments.

The treaty include all the weight in the ready to sea condition except feed water and fuel.
If Nelson sail w/o water in the compartments is right this water is not weight for the treaty