Re: Some questions regarding Bismarck's armor scheme
Posted: Sun May 05, 2019 11:21 pm
It is perhaps useful to study, as in Figs 12 and 13 of the paper by Hoyer (which appears elsewhere on this site), the curves showing the critical velocities needed for penetration and that of the projectile terminal velocity with range and inclination. If the critical velocity is below the terminal velocity then penetration is improbable depending on how great the difference is. In Fig. 12 the critical velocity for the Obere Zone (penetration of the decks) is a curve almost at right angles to the terminal velocity curve. With this configuration of curves adding a bit more protection is going to have a limited effect..But for the inner limit the critical velocity curve for 3 dez (upwards of 30 deg off the beam) is a curve that runs a bit above the terminal velocity curve and which below 7500 m is about parallel to it. These curves do not cross so protection is offered over a wide range of distances. With this type of critical velocity curve adding a bit or even redistributing some protection from belt to scarp can move the whole curve from a little below the terminal velocity curve to a little above it. In the Bismarck scheme (using the Gercke multiplate formula and taking into account the energy lost in plug ejection from the belt) the critical velocity curve for penetration lay a little below the terminal velocity curve in the case of the 40.6 cm APC while for the very similar H class scheme the critical velocity lay a little above it.
Many years ago in a piece on Bismarck, Nathan Okun also commented on this feature of the critical velocity curve for the inner limit of the protection scheme of Bismarck,
Neil Robertson
Many years ago in a piece on Bismarck, Nathan Okun also commented on this feature of the critical velocity curve for the inner limit of the protection scheme of Bismarck,
Neil Robertson