Naval History Forums

As I understand the main reason allies went to single deck armor plate was to defeat bombs, not shells. Both. Reason was simple. With increasing power of shells allies goes to conclusion that detonation of shells had to keep out of ship. Multilayer protection was designed in such way to force shell...

In regard to some of the points made in post 1 it can be said that they are wrong. (a) The Bismarck was not intended for operations in the North Sea but for cruiser-type warfare in the North Atlantic. Had it been designed for the North Sea then it would not have had a fuel stowage of about 7450 mt. ...

In Warship 2018 there is a detailed analysis of the Battle of the River Plate by Alan Zimm and a detailed analysis of the damage suffered by Graf Spee by Bill Jurens. Mr Zimm compares the action with US expectations according to the NWCMR and British rules. The main armament of Graf Spee scored more...

The 38 cm SKC/34 was the most accurate German heavy gun: it had the lowest dispersion by some margin. In gkdos100, vol. a, there is a graph at the end showing 50% longitudinal dispersion curves versus gun elevation (less than the angle of fall) for weapons from 15 cm upwards. Over 7 deg the 38 cm SK...

Yes, this does look more plausible in thinking about it further. There was an advantage of 1100 yds, which would have needed about an inch of protection. The Americans in their calculations added 0.7 times the strength of secondary protection to the main protection so here the hull skin in Iowa adds...

A point about Montana's protection scheme which puzzles me. I have a copy of a document listing official IZ values for US battleships (C-BB/S1-1 of 13 July 1942) against 16 in 2240 lb shells with an MV = 2520 fps. The inner limit for BB 61 (Iowa) is given as 17600 yds and that for BB 67 (Montana) as...

Regarding the extrahard Wh splinter armor for, e.g. splinter bulkheads, was this material classified as Wh (UTS 85-95 kg/mm2) or was it Wotanstarrheit as used in AA directors or something else? The finding that base-fused HE had a splinter penetration effect intermediate between nose-fused HE and AP...

According to Nathan's study, British 1920s cemented armor had 85% - 90% of the resistance to perforation of British post 1930 cemented armor, at best ... If this mean the ballistic limit was approximately 10% lower compared to german KCnA, Hoods facehardened armor had about 275mm effective thicknes...

I would be interested to see endurance curves for these ships with a common auxiliary consumption (say 5 t/day) so that their relative propulsion efficiencies would be discernible. Of course, bigger ships would have somewhat higher auxiliary loads than smaller ones but assuming a constant value woul...

Just to say I appreciate people posting original documentation regarding trial speeds, ranges and displacements of various ships in this thread. With regard to Thorsten's last post could it be that the normal operating condition in wartime was different in the KM from that in the USN? Namely, did a ...

If the ship steadied with the bows pointing north west, perhaps it was worth trying going astern. Unfortunately, with turbines reverse power is small. Perhaps if the original plan to have turboelectric drive had been implemented, with full power possible astern, the Bismarck might have managed to mo...

Interesting discussion. Perhaps, I speculate entirely, considerations of an offensive nature, also played a part. If he crossed the Atlantic from Greenland to France he would dislocate British convoys for several days even if he did'nt sink any merchantmen, whereas returning to Norway would seem les...

I just realized that the test results Bagnasco gives make possible a comparison of the performance of the deck armor layouts of US and Italian battleships against AP bombs dropped from a high altitude. Friedman gives US battleships as safe to 1600 AP bombs below heights of: 8750 ft (North Carolina),...

Italian AP shells were pointed, which gave them a good performance against vertical armor (because the shell could dig well into the armor while removing much less armor than for a blunt nosed shell, i.e. early on low energy is required in relation to penetration into the plate) but rather poor hori...

The book does not say a 16 in shell was used but that one was simulated, however that was done. At 18 deg angle of fall, the virtual thickness of a 36 mm deck is about 116 mm. As importantly, for this very oblique impact, the force acting upwards on the cap is all on one side of the cap, which intui...