equivalent to a broadside of a cruiser.

[RAGMAN]

i want to know what "the equivalent to the power of a broadside of a cruiser" by the rocket firing typhoons and mosquitos.can someone enlighten me please? is it that much power those rockets?

[syscom3]

I think its rated by the pounds of explosive in the rockets as compared to the pounds of explosive in a gun shell.

[k9kiwi]

That would be the definitive answer.

8 X 60 pound rockets deliver a nasty headache.

Thread over.

[DOUGRD]

I don't think there has ever been any real explosive force comparison. I believe it's more of just a saying. A 15" shell X 3 or 6 or 9 depending on the cruiser can deliver a lot more punch than 8 x 60 but that 8 x 60 coming off an aircraft looks quite impressive.

[syscom3]

Originally Posted by DOUGRD

I don't think there has ever been any real explosive force comparison. I believe it's more of just a saying. A 15" shell X 3 or 6 or 9 depending on the cruiser can deliver a lot more punch than 8 x 60 but that 8 x 60 coming off an aircraft looks quite impressive.

Most of a naval shells weight is in its steel structure, not explosive content

[Tony Williams]

Ermm, cruisers in WW2 typically had guns of 6 inches or 8 inches calibre, and nothing larger than that.

The classic cruiser design to which the Typhoon salvo was being compared was probably the Leander class, the most common RN type at the start of the war. These had eight 6 inch guns, thereby matching the eight-RP salvo. Each HE RP warhead weighed 60 lbs whereas a 6 inch shell weighed 112 lbs but, as has been observed, a gun shell has a much smaller proportion of HE than an RP warhead, so the effect in terms of HE delivery was comparable.

[Soren]

Tony do you have info on the HE content of the German rocket projectiles often used by ground attack a/c, the FW-190 being capable of carrying two IIRC and the Me410 four ?

They look pretty potent:

[Tony Williams]

I don't have any data on the one shown in your pic - I think that was used more for attacking bombers - but there were two rockets which were used in ground attack and carried by the Fw 190.

One was the 28cm Wfk. Spr. which weighed 82 kg total and carried an explosive filling of 36 kg - quite devastating but slow and probably difficult to hit with; the Fw could carry four of these.

The other was the much smaller 8 cm Pb 1, which weighed only 6.9 kg and carried 0.61 kg HE, but was faster; 12 were carried by the Fw 190.

[mhuxt]

Was hoping you'd chime in on this one Tony.

[delcyros]

A 3.5", 54lbs HVAR carries a 20 lbs warhead made of explosive D (equals ~19lbs TNT, other warheads were around, too). The body weight is less than 20 lbs because of the solid rocket fuel. So any comparison only taking this into account will be limited to deal with chemical energy only and neglect kinetic impact energy or splinter production (minimal compared to an 8" or 6" shell), both is contributing to the general power. The striking velocity of the HVAR is about 1190 fps at a typical range of 1500 yards.

The projectile charge of an 112lbs RN 6"/50 HC such as used on Sheffield (12 guns) is only 8 lbs with an body weight of 104lbs, while the striking velocity at 2000 yards is about 2375 fps.
The splinter production can be estimated to be more drastic on the 6" projectile, the blast effects on the other side are superior in the HVAR. There is no comparison in the kinetic energy between both. The HVAR has no hardened projectile body, causing it to breake apart if striking any armour or massively reinforced construction grade structures.

Roughly estimate:
HE factor * body weight * (strkiking velocity*striking velocity) = raw netto value

3.5"HVAR:19 * 20 * (1190*1190) = 538.1 mill (unitless)
6"/50: 7.8 * 104 * (2375 * 2375)= 4575.6 mill (unitless)

for comparison the 5" HVAR:
5"HVAR: 43 * 80 * (1800*1800)= 11145.6 mill. (unitless)

The CL Sheffield carried twelve 6"ers, which gave her more than twelve times the striking power of a 8 x 3.5" HVAR equipped Fighter. Of course, The CL typically projects it´s striking power to larger distances (at which the striking velocity drops) but we still have no equal comparison there.
The 5" HVAR "Holy Moses" looks much better in comparison with unpredecented blast effects and reasonable kinetic energy.

[timshatz]

Weren't there also 10" rockets that the USN used in the Pacific. I believed they were found unsatisfactory.

BTW- Good post Delc. Good info.

[JoeB]

Originally Posted by syscom3

Most of a naval shells weight is in its steel structure, not explosive content

True, but the higher performance WWII medium caliber aerial rockets used modified naval shells as warheads. Both the 60# 3.5" rocket's HE/SAP head (see Campbell "Naval Weapons of WWII" pg. 101) and the US HVAR ('Holy Moses') warheads were modified 5" shells. The latter upped body diameter to 5" too and w/ higher performance rocket got 1375 fps initial velocity, v 886 for the 3.5" but 2600 for a 5"/38 gun (though the plane had forward speed of a few 100fps and would fire at shorter range than a ship would typically). But a salvo of 6 HVAR from say an F6F in 1945 was literally identical as far as just blast/frag effect to the broadside of a Sumner/Gearing class DD, not a cruiser. As was mentioned, 'equal to a cruiser's broadside' was mainly just a saying, and actually seems to me I've seen it more often, and more accurately, put as 'equal to a DD's broadside' even in statements of the period.

In any case, aircraft rockets could readily hit targets the size of ships (in contrast to their rarer direct hits on targets the size of tanks) and be quite effective if they did. 5" gunfire was also very effective against the same types of smaller unarmored ships typically sunk or badly damaged by rockets, again given hits (5" naval fire also claimed tanks, but even more rarely than the case of rockets can actual direct hits be documented from the side operating the tanks). The key was getting hits, in either case.

Joe

[Kurfürst]

Originally Posted by Soren

Tony do you have info on the HE content of the German rocket projectiles often used by ground attack a/c, the FW-190 being capable of carrying two IIRC and the Me410 four ?

They look pretty potent:

It was based on the Army's 21cm Nebelwerfer rocket tubes, and I'd risk the statement it was the very same rocket; in any case, the Army's rocket was filled with 10 kg amatol as I recall. Some sources quote far higher value, I suppose they refer to the warhead as a whole, ie. probably including fragmentation metal body around the explosives.. BTW, the 21cm tubes were jettisonable by explosives by a small explosive charge in emergency.

Judging a rocket's explosive head size is tricky, they vary wildly in size, whereas the conventional arty's H.E. shells are quite typically carry 10% of explosives compared to their total weight.

[renrich]

According to "Janes" a WW2 British Mk XVI 6 inch projectile weighed 100 lbs, had a MV of 3100 fps and a ME of 6665 foot TONS. The explosive charge in a shell was not the only factor to be considered, the kinetic energy was enormous.

[syscom3]

Originally Posted by renrich

According to "Janes" a WW2 British Mk XVI 6 inch projectile weighed 100 lbs, had a MV of 3100 fps and a ME of 6665 foot TONS. The explosive charge in a shell was not the only factor to be considered, the kinetic energy was enormous.

Was that AP or HC?