EXPLOSION IN TURRET TWO
Investigation Continued

            each shot.  After it is reloaded and ready, when plot wishes to fire they sound the standard two salvo warning buzzers, followed by a salvo buzzer simultaneously with closure of the firing key.  For the last (casualty) shot, gun elevation was 4120 (35 deg) gun train 067 deg relative.  The shot was fired by the procedure described, and the shock of firing was felt in plot in normal relationship to plot’s firing actions.  Come observers thought they felt a second, more muffled, shock; this could have been from the additional cartridges which went off as described later.

CASUALTY

23.       All men in the turret and the upper and lower shell decks apparently died instantly at their stations.  One lower shell deck man, apparently transiting the lower handling room at the moment of the casualty, escaped the turret but died outside, of chemical pneumonitis from fume inhalation, as did two others from the lower handling room.  One man not part of the turret crew died from the same cause, bringing total deaths to 20.  Many others, including officers and men from various below-deck stations outside the turret, were given medical treatment for various degrees of exposure to fume inhalation.

24.       Principal material effects of the explosion included the following:

    a.     The gun liner bulged and ruptured longitudinally for a length of 6 to 7 feet, but was not severed.   The principal rupture was on top (location of the liner keyway).  The bulge, which opened a gap in this rupture to a maximum width of about 6”, was centered over the seated position of the projectile, about 10” forward of its base.  Several additional longitudinal cracks and ruptures were found when the liner was sectioned at Dahlgren.  Gases venting through the top rupture blew partly outside but primarily inside the turret face plate.

    b.     The tube was shattered throughout its circumference, with radial cracks both transverse and longitudinal, such that for a length of perhaps three feet the tube was blown away in large chunks.   This area was approximately centered over the area of the liner bulge and rupture.  The forward portion of the tube was blown some unknown distance up the liner (elevated to 35 deg.), then fell back, trapping some tube fragments below it; two large tube fragments were caught in the empty case net on the front on the turret.  Ten large tube fragments were eventually recovered.  Initially, the tube fracture surfaces did not show the “hoop spall” failures considered characteristic of high-order detonations.  After damage clearance had progressed somewhat, parts of the tube were recovered which appeared to show hoop spall, and this was confirmed when the parts were sectioned at Dahlgren.

(page 7)