equivalent to a broadside of a cruiser.

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RAGMAN

Airman
78
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Jul 5, 2005
vancouver ,B.C.
:oops: 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?
 
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.
 
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
 
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.
 
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:
105254815253.jpg
 
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.
 
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.
 
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.
 
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
 
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:
105254815253.jpg

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.
 
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.
 
Thanks for the info Kurfürst Tony.
 
More than likely AP with that ME reading.

Apart from the fact that everyone learnt early on that unless you used AP against another warship all you were likely to do was clear the seagulls from the rigging.

in contrast to their rarer direct hits on targets the size of tanks

Try reading the book by Group Captian Desmond Scott RNZAF, it is strangely enough called "Typhoon Pilot".

Read up on the Cab Rank system and how devastating it was for the tiffies in 2nd TAF, especially in the Falaise Gap.

It was not actually necessary to get a direct hit, a few feet away would cause enough blast and over-pressure to render a crew into soup inside their tank, if it didn't flip the damn thing over.

And that was a 2 rocket salvo, meaning 4 sets of 2 for each aircraft from a Squadron of 18 aircraft makes for a really bad day for a convoy in anyones language.

RP3 60 Pound HE/SAP (High Explosive / Semi-Armor Piercing Rocket)
Diameter Length Total Weight Warhead Explosive Velocity Range
125mm 1397 mm 36.8 kg 27.22 kg 6.4 kg 350 m/s 800 m

RP3 60 Pound HE/GP (High Explosive Anti-Tank Rocket)
Diameter Length Total Weight Warhead Explosive Velocity Range
125mm 1397 mm 36.8 kg 27.22 kg 5.8 kg 350 m/s 800 m

The SAP version of the 60 Pound had enough explosive force to destroy any lightly armored vehicle, or disable it with a near miss. It was devastating against exposed targets such as troops, trucks, or artillery. The GP version could penetrate 85mm of armor, although it still suffered from the same angle of impact problems as with all HEAT weapons. It was good enough to destroy a Pz.III or Pz.IV tank from any direction, and the famed "Panther" tank from the back and sides. All 60 Pound rockets had a reported accuracy of 1% against a stationary tank-sized object at 300 meters range.
 
1. Apart from the fact that everyone learnt early on that unless you used AP against another warship all you were likely to do was clear the seagulls from the rigging.
2. Try reading the book by Group Captian Desmond Scott RNZAF, it is strangely enough called "Typhoon Pilot".

Read up on the Cab Rank system and how devastating it was for the tiffies in 2nd TAF, especially in the Falaise Gap.

3. All 60 Pound rockets had a reported accuracy of 1% against a stationary tank-sized object at 300 meters range.
1. Depends on the ship. Rockets in practice were used against unarmored ships, destroyer size or below though big enough to hit at a reasonable rate. Against those type targets, destroyers would use 5" common (the usual term for HE/SAP naval rounds of that caliber, essentially the same as rocket warheads). Just like a tank would fire AP against another tank, but not against say, a truck or AT gun position, where it would fire HE.

2. One of the biggest claim v. actual damage discrepancies in WWII era was fighter bombers claims against tanks v actual destruction of tanks. It ran on the order of 10:1. The Falaise Gap was a prime example, wreck surveys showed relatively few German tanks actually KO'd by fighter bombers, a small % of what was claimed. In contrast it's true that fighter bomber attacks (not limited to rockets; also bombing, .50cal/20mm strafing and napalm) were often quite effective against the soft skinned support vehicles of armor columns; ominpresent fighter bombers did severly impact German mechanized operations overall. They just didn't actually destroy many tanks. The discrepancy in FB claims and tank kill is documented in numerous sources, I think it qualifies as common knowledge at this point.

3. Hard to hit a tank as I said, especially considering such ratings were typically in test conditions and not matched in combat. And see above, near misses by 5" naval shells/5" head rockets were not in fact likely to KO a tank, although it was possible. A photo in "Panzers in Normandy Then and Now" shows a Panther with track cut, and abandoned, after apparent rocket near miss right behind it. A few tanks were at least 'mission killed' even by .50cal strafing, documented. But neither was common, leaving again real tank kills by fighter bombers a small % of what their pilots believed they'd achieved.

In contrast it was not that hard to hit a fair size ship with a rocket, equivalent to a 5" hit, and crippling if several hits in repeated attacks on the relatively small unarmored warship targets, as happened on occasion both in ETO and the Pacific. Claims of warships sunk or seriously damaged by rockets and the actual damage recorded by the other side were much more in line than with tanks targets.

Joe
 
All of the British 6 inch shell(according to Jane's) weighed the same. The ME would not vary with HC or AP as long as the projectile weight was the same.
 
The Swordfish had some success against submarines using very crude 4 inch rockets with solid heads but obviously a sub is alot bigger than a tank how they faired when carrying 60lb rockets against targets I have little info on . In the desert campaign they were deployed as dive bombers using amour piercing bombs and according to The Swordfish Story by Ray Sturtivant managed to be surprisingly effective against amour . I suspect due to their extremely slow air speed.
 

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