Naval History Forums

The British after WWI decided to comply with the Washington Treaty absolutely. Thus, to prevent the ships from getting heavier than the maximums allowed, they specified NO PLUS tolerance in any steel thickness measures was allowed. As such was really impossible to achieve without drastic increases i...

Note: The homogeneous armor penetration formulae/data set of M79APCALC is only partly mine. It is based on the major, long-duration work at the US Naval Proving Ground, Dahlgren, Virginia, during and after WWII by Dr. Allen V. Hershey and associates in the Ballistic Division. It is EXTREMELY accurat...

I looked at the TOSA test results (position and size of holes in the hull, etc.) and the Japanese diagrams of underwater trajectories and, interestingly enough, the hit seems to have been a PERFECT example of a tumbling pointed shell, in that it made a hole in the hull in the form of a slot from a S...

The Japanese bomb used at Pearl Harbor (and nowhere else, to my knowledge) was the 775 kg (1709 lb) 41cm (16.1" from the NAGATO and MUTSU guns) Type 99 (Year = 1939) Number 80 (Class Type, not sure of meaning) Mark 5 Bomb (that is, a bomb based on the British Mark 5 APC gun projectile, also use...

This assumes KC n/A ("Krupp Cemented New Type" -- thick plate first used in SCHARNHORST) armor, with its 41% total face layer (59% unhardened back), straight-line hardness drop from the face behind the thin super-hard Cemented (carburized) layer to the back (most other face-hardened KC-typ...

"Danger space" is the hull that can be hit at and above the waterline (upper hull side from the waterline up and the weather deck), though a downward-moving shell can hit the below-deck area sometimes, particularly at a high angle of fall. This puts reserve buoyancy and engine/boiler rooms...

Hit on HOOD: The shell could penetrate the rather thin layers of spaced armor directly into the aft magazine if the fuze delay was long enough (the German base fuze of the time for its 38cm APC projectile was 0.035-second nominal average delay, giving it a distance of about 53 feet at 1500 ft/sec av...

From the look of it, the shell is based on the outer shape and weight of the standard 1900-lb 16" High Capacity (HC) Projectile Mark 13 (pre-VT) or 14 (VT-capable with the nose fuze adaptor altered to allow the addition of a thin metal cover over the fuze for electromagnetic shielding during st...

No armor. Just thin steel weather shield. Some other parts of these ships may have had kevlar, etc. added for some protection, but other than aircraft carriers, which have some light armor designed as such in specific spots, no current US Navy warship has anything that would be classified as "a...