Pineapple grenade

[browningautorifle]

they ALWAYS fire the main armament in BROADSIDE mode

That's the only way all guns can be brought to bear. Otherwise there's obstacles at muzzle and all guns can't fire.

HMS Victory passing the stern* at point blank range and firing just a single broadside into the stern

Also quite right. They could do more damage because the ship was narrower that way and there was more likelyhood of destruction. The ball goes in the end and out the other.

[bombdoc]

Ok Chaps... A few misconceptions here...

The whole business of "do the grooves help the fragmentation" is down to the filling.. if it is low explosive, then yes, if the filling is high explosive then no (with an exception!)

What a lot of folk do not understand is that the original US M1 Pineapple grenade was filled with NC rifle powder, not HE! There was no detonation when this grenade went off, simply a pressure build up which caused the case to split along the lines of the grooves.

Latterly, the filling was changed to TNT and a detonator added to the end of the time fuze. TNT detonates at around 6km/sec and cast iron simply shatters at these velocities. They did not make any other changes to the design, but (i think!) the body was painted yellow..

The Mills (36) grenade was always designed to be filled with an HE (usually Baratol which is Barium nitrate and TNT) and the checkers were always just to improve the grip. The fragmentation of the 36M was improved towards the end of its life by using malleable cast iron instead of plain grey cast iron, which gave a more "jaggy" fragment, but the real problem was the base plate! Most of the body fragments only went about 30m however the base plate would go 100m+ which gave the grenade a safety trace with a frying pan/skillet shape.. the problem was that you never knew which way the handle was pointing.. (by the way.. ROF (P) is Patricroft in Manchester not Poole!). The 36 grenade was coated with copal varnish to stop the explosive reacting with impurities in the cast iron. The 36M had a thick coating of lanolin grease to stop moisture entering the body of the grenade, which had to be removed prior to use...!

The combination of HE and cast iron was never that good, hence the adoption of pre formed fragmentation solutions in the latter half of the war.. These were both more predictable to the user and lethal to the prospective target..!

The exception to the "grooves rule" is that you can form fragments with high explosives by putting grooves on the inside of the casing.. what happen is a variation on the shaped charge principle in that the grooves form shock waves in the explosive mass which break up the case along the line of the groove. You get the same effect by stippling the inside of the casing..

The photo shown above of a grenade casing peeled back like a banana skin is the result of an ammunition performance failure.. the explosive has either burned or encountered a low order detonation, possibly as a result of EOD action. If the grenade had performed as designed, the high order detonation would have resulted in a cloud of fine, high velocity fragments, which is what you want!

...hope this clarifies things a bit!

[browningautorifle]

the body was painted yellow..

And then later due to complaints of it standing out in combat in the Pacific, it was changed in color.

The photo shown above of a grenade casing peeled back like a banana skin is the result of an ammunition performance failure.. the explosive has either burned or encountered a low order detonation, possibly as a result of EOD action.

We saw these from time to time on the range. They happened naturally on the range, and were a basic misfire or failure. Most were destroyed as blind ordnance.