How effective were unguided rockets - really?

beitou said:

Wasn't accuracy one of the reasons why ASW Swordfish changed over to AP rockets from HE as with a 3" hole in its pressure hull a U boat couldn't dive any better than with a HE hit.

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All anti-shipping aircraft switched to AP rockets because the 60lb SAP warhead needed a 'dry' hit in order to be effective. The 25lb AP shot remained intact if it struck the water and had a long, upward curving trajectory that was ideal for ranging/accuracy errors when firing against shipping.

Francis marliere said:

Gentlemen,

I am not surprised that there is few records of ships damaged by 5'' rockets during the battle of Samar. While these rockets may (or may not) be a good ground attack weapon, it has IMHO a too small warhead to be really effective against a warship. I have read several times that these rockets have roughly the same hitting power as a 5'' shells, which is a destroyer, ie small caliber weapon in naval warfare. It is not surprising that at Samar US planes used 500 and 1000 lb bombs or torpedoes to attack Japanese cruisers and battleships.

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I'm not surprised that rockets didn't sink Japanese warships outright off Samar, but I am surprised that there aren't references of severe personnel losses being caused by the rockets. Remember, these ships had tons of men actively engaged on deck, manning antiaircraft guns against constant air attack. Also, these ships were carrying hundreds of extra people, survivors of the submarine action in the Palawan Passage and the carrier airstrikes in the Sibuyan Sea. The stories that passed down from the battle off Samar is that the planes strafed until they had no ammunition left, and then they made dummy attacks. With over a thousand sorties against these ships, that's millions of rounds of ammunition and thousands of rockets. You'd think there would be many more accounts of damage and casualties from these small scale attacks.

flight of Tempests armed for ground support would give any ground pounder a wave of relief

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Only if ground pounders are reasonably confident Tempest aircraft can accurately put the ordnance on target.

To use an extreme example, B-17s conducting CAS mission caused more anxiety then relief among ground pounders as friendly casualties are likely to be as great as enemy casualties. Or else heavy bombers are apt to miss target area entirely as was normally that case during Normandy invasion.

Conslaw said:

I'm not surprised that rockets didn't sink Japanese warships outright off Samar, but I am surprised that there aren't references of severe personnel losses being caused by the rockets. Remember, these ships had tons of men actively engaged on deck, manning antiaircraft guns against constant air attack. Also, these ships were carrying hundreds of extra people, survivors of the submarine action in the Palawan Passage and the carrier airstrikes in the Sibuyan Sea. The stories that passed down from the battle off Samar is that the planes strafed until they had no ammunition left, and then they made dummy attacks. With over a thousand sorties against these ships, that's millions of rounds of ammunition and thousands of rockets. You'd think there would be many more accounts of damage and casualties from these small scale attacks.

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Conslaw, I may be mistaken, bur I think that there are few references of ships damaged by rockets because rockets were not effective against warships. Hence planes did use weapons more suited for the task : bombs and torpedoes.

Best,

Francis Marliere

davebender said:

Only if ground pounders are reasonably confident Tempest aircraft can accurately put the ordnance on target.

To use an extreme example, B-17s conducting CAS mission caused more anxiety then relief among ground pounders as friendly casualties are likely to be as great as enemy casualties. Or else heavy bombers are apt to miss target area entirely as was normally that case during Normandy invasion.

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The British actually carried out Operational research on the accuracy of their unguided rockets. Below is "Montgomery's Scientists".
http://lmharchive.ca/wp-content/uploads/2014/02/The-Full-Monty2.pdf

On page 201 you will note that it would take 140 rockets fired at a Panther sized target for a 50% chance of a single hit using an ideal 45 degree dive angle. To put that in perspective it would take 18 aircraft (1.5 complete RAF Tactical Air-force Squadrons), firing all of their 8 rockets each, to have a 50% chance of hitting the rather large Panther.

The Germans were shooting back of course which is why the Allies lost some 2400 of aircraft of the 16000 committed to the Normandy invasion. Chances of a hit on a pillbox or small AT gun emplacement were minimal. There may have been proximity fused RP deployed which in anti personal use may have been deadly. They used an optical trigger, don't know of their use just read of their development in WW2.

Towards the end of the war the Germans started deploying "Panzerblitz II" which was the R4M folding fin rocket equipped with the 3.5 inch (88mm) Panzerfaust (German Bazooka) shaped charge warhead.
Since an Me 262 could carry 24 of these and a Fw 190 some 16 and assuming the same accuracy the chances of a hit are trebled over an allied style aircraft with only 8 rockets. It's my expectation that these missiles would actually be slightly more accurate though that wouldn't improve p-K much, they key is the number of rockets. The shaped charge warhead penetration fell to 130mm (somewhat less than the Panzerfaust) likely due to higher impact and rotation speed but this is likely also a penetration at the usual German angle of 30 or 45 degrees.

The main German problem was their think skinned and lightly armored vehicles. Transport might take place at night but lightly armored half tracks were likely vulnerable to 20mm canon and possibly tungsten cored 0.5 inch guns. This means the lightly armored Half tracks which acted as accompanying APC for troops and maintenance crews were likely the vulnerable units, not the medium tanks.

The solution would have been a heavy armored APC, say a 30 ton tank on the basis of Mk IV panzer mechanicals but carrying say 8 troops with enough Armour (say 40mm) to be secure against aircraft canon and perhaps a power driven gun to counter the fighter bombers and make the cost of a rocket attack too 'high'. Ultimately you need trucks but at least you can leave them further back or operating at night.

Zetterling (He's a Swedish Military Historian) analyses the German performance at Normandy highly with a 2:1 advantage to the Germans even when the Germans were on offense. What killed the Germans in Normandy was a major transport problem, they couldn't get enough ordinance in, this was irrespective of disruptive allied air power attacks on the German logistics chain which only worsened matters.

The post war solution was the shaped charge cluster bomb and computing bomb sites both of which the Germans were beginning to use combat trial (though not together that I know of) towards the end of the war.

German progression towards using rockets (apart from the Panzerblitz II) was to develop a standoff weapon to keep the attacking aircraft safe: you can see photographs of German fined rockets but equipped with cluster warheads in Fleischers "German air dropped weapons". The Germans actually seem to have copied Russian rockets rather than allied ones judging by their shape though the warhead was all their own work. They had 15 or 30 shaped charge bomblets. I immagine the idea was to fire a salvo so hypothetically a salvo or 8 rockets could deliver 120 bomblets.

The Ju 87 seems to have been an effective tank buster when simply used as a dive bomber: a 250kg bomb would crack open the Armour of a Char B heavy tank even with a 5m miss.

7,326 x Sd.Kfz.250 light APC.
16,800 x Sd.Kfz.251 medium APC.

Lightly armored APCs are inexpensive enough that they can be produced like hot rolls. Most of these German APCs were produced over a four year period. Build an APC based on Panzer III chassis with Panzer III scale armor and you will have 6,000 vehicles rather then 24,000 vehicles. Maintenance, bridging, transportation etc. support for 22 ton APC would also be more expensive.

WWII era German Sd.Kfz.250 and Sd.Kfz.251 APCs had same level of armor protection as 1960s era M113 APC. Armor scheme designed to protect occupants against 7.92mm AP rounds.

How accurate? Not very.



Notice that only 1 in 10 rockets fired hit a target covering 1000 square yards. Hitting anything smaller was nigh on impossible. 350 rockets had to be fired at a gun pit sized target to have a 50% chance of a hit !

After the invasion of Normandy only 1 in 100 2nd TAF pilot claims to have destroyed a tank could be confirmed by the various ORS working on the ground.

Things don't change. In the NATO campaign against Serbia one NATO officer claimed that aircraft were destroying '50 tanks a day'. In reality, after 78 days of attacks, the real figure was a total (confirmed destroyed from the air) of just 14.

They also shot back and despite having no really modern anti aircraft missiles, with the exception of some SA-13s which forced the NATO aircraft to higher altitudes, they still managed to shoot down a supposedly invisible F-117.
Most of their air defences were antique SA-2,3,6 and 9 missiles designed to operate in combination with the ZSU 23-4s familiar to the US in particular from the Vietnam war.

Cheers

Steve

davebender said:

WWII era German Sd.Kfz.250 and Sd.Kfz.251 APCs had same level of armor protection as 1960s era M113 APC. Armor scheme designed to protect occupants against 7.92mm AP rounds.

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Not quite: M113A3 Armored Personnel Carrier | Military-Today.com

The armor on the M113A3 remains unchanged from that of previous models, and is the same 5083 aluminum alloy. It is 44 mm thick over the frontal arc, 38 mm thick over the sides, rear, and roof, and 28 mm thick over the belly. 5083 aluminum has 25% more protection over the same area at twice the thickness as RHA steel, the making the M113's protection is thus roughly equal to 28 mm of steel in front, 20 mm underneath, and 22 mm on all other sides - it is thus proofed against 12.7-mm ball rounds, 12.7-mm AP in front, and all anti-personnel mines, small arms fire, shell splinters, and blast overpressure on all sides. This armor has proven highly resilient against shoulder-fired anti-tank weapons and heavy machine gun fire, though it is no match for vehicle-fired anti-tank munitions or continuous heavy machine gun fire.

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The SdKfz 251 had a maximum of 8mm and, on most versions, there was no protection from air attack for the troops because there was no overhead protection.

The RAF rockets were very effective against ships both civilian and military. Clearly they are going to struggle against armoured ships but anything the size of a destroyer or below was at serious risk from rocket attack. I certainly agree that hitting something the size of a gun emplacement would need a lot of luck but ships are much bigger.

I've known several people who rode in M113s during Vietnam war. Consensus was the vehicle was barely proof vs 7.62mm AP rounds.

The US Army didn't start getting the M113A3 till the middle 1980's, it had a armor upgrade for up to .50 cal, and that upgrade was also fitted to earlier models in that time period.

The Vietnam era M113 models were only proof to 7.62X 54, I'm not sure it was proof to all 7.62x54 AP.

davebender said:

7,326 x Sd.Kfz.250 light APC.
16,800 x Sd.Kfz.251 medium APC.

Lightly armored APCs are inexpensive enough that they can be produced like hot rolls. Most of these German APCs were produced over a four year period. Build an APC based on Panzer III chassis with Panzer III scale armor and you will have 6,000 vehicles rather then 24,000 vehicles. Maintenance, bridging, transportation etc. support for 22 ton APC would also be more expensive.

WWII era German Sd.Kfz.250 and Sd.Kfz.251 APCs had same level of armor protection as 1960s era M113 APC. Armor scheme designed to protect occupants against 7.92mm AP rounds.

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I recall one of the German generals in command at Normandy saying it was getting to the point that only fully armored units could be moved in daylight. I took that to mean that to protect accompanying infantry support troops and maintenance crews, fuel supplies and ammunition an APC with almost medium tank Armour was required. The minimum standard being the ability to resist 20mm Armour piercing canon. The 20mm Hispano canon, especially the long barreled versions when shot from an aircraft moving at 150m/s (330mph) must have had considerable penetration. In reality anything up to a 30mm gun can easily be fitted to an aircraft before the aircraft's own performance is degraded to the point it is no longer a self defending fighter bomber. Dives of 45 degrees were standard for Allied fighter bombers attacks in both gun, rocket and dive bomb attacks so the top of the APC would be vulnerable.

I agree, this creates a great problem in that a heavy APC would consume more fuel, required more resources and itself require a larger number of trucks however given the overwhelming allied air superiority thin skinned support vehicles must have been highly vulnerable and restricted to the point that their absence limited heavy Armour movements and operations.

Just ask Rommel how safe it was to drive about...

Koopernic said:

I recall one of the German generals in command at Normandy saying it was getting to the point that only fully armored units could be moved in daylight.

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This is not due to the vulnerability of other vehicles to rockets. Rocket armed fighter bombers simply couldn't hit them without a large slice of luck. These soft skinned or even semi-armoured vehicles were vulnerable to the most accurate weapons the fighter bombers carried BY FAR. This was their 20mm cannons or, in the case of US types, .50 calibre machine guns.

A study was carried out in 1945 by the British Army's Operational Research Group to look into this, as they were likely to be on the receiving end of such air launched/dropped ordnance. It compared the number of rounds that could be fired per attack, per aircraft, against ground targets and the probable number of hits secured on a 10' square target, normal to the line of flight of the attacking aircraft.

The 20mm cannon(s) could fire 120 rounds securing 32 hits

The 3" rockets could be launched a salvo of 8 securing 0.045 hits.

I would suggest that 32 hits from 20mm cannon would do for most unarmoured vehicles. You can work out how many salvos of rockets need to be fired to score a hit on a small target!

Cheers

Steve

There was no air-delivered weapon in WWII truly capable of successfully interdicting a tank-sized armoured vehicle target. Both rockets and bombs were ineffective, although bombs delivered by low-level or dive attacks would have greater chance of success. Probably the optimal weapon against all vehicles in 1944-45 was the humble 20mm cannon. It could obliterate soft-skinned vehicles and had a much greater chance of inflicting an M-Kill on an armoured vehicle. Now I'll agree that an M-Kill isn't outright destruction but it made life difficult for the crew, particularly if they were trying to get anywhere in a hurry. The benefit of using aircraft like the Typhoon is that you could either rockets or bombs but still had the 20mm cannon - I'd be surprised if all available weapons weren't used in attacks on German vehicles of any flavour.

Rockets were much more successful against shipping targets. Yes, the dispersion and aim was sometimes off-the-mark - there's famous film footage of Banff Wing Mosquitos attacking German ships and some of the rockets are going nowhere near the targets - but, overall, rockets were a successful anti-shipping weapon, at least in RAF usage.

What did the Soviets use on their Stomoviks? I am familiar with how ineffective rocket firing Typhoons were in the west but I still have the impression that the Soviets had an all conquering airborne tank that terrified and immobilised German armoured formations, well something like that anyway. What weapons did they use and where any after action trials and assessments carried out similiar to the allied ones to show how effective, or not they were?

beitou said:

I still have the impression that the Soviets had an all conquering airborne tank that terrified and immobilised German armoured formations

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Rocket firing Typhoons did that. The psychological effect of the rockets, despite their inaccuracy, can not be over estimated.

A report by ORS 2nd TAF after examination of a sample of 101 tanks and armoured vehicles destroyed in the Ardennes salient noted that only 4 of 66 tanks had been destroyed from the air. 1 by a bomb and 3 'possibly' by other air attack.
The reports conclusion gives the real tactical effect of the fighter bomber. It concluded that the contribution of the air forces in stemming the German attack had been considerable but that this

'was not by the direct destruction of armour, which appears to have been insignificant; but rather by bombing and strafing of supply routes, which prevented essential supplies from reaching the front.'

This, combined with the psychological effect of the attacks, explains why 24 of those 66 tanks were abandoned or demolished by the Germans themselves.

Cheers

Steve

Did the Soviets manage to hurt the German front line vehicles or were they only effective against the logistics tail?

beitou said:

What did the Soviets use on their Stomoviks? I am familiar with how ineffective rocket firing Typhoons were in the west but I still have the impression that the Soviets had an all conquering airborne tank that terrified and immobilised German armoured formations, well something like that anyway. What weapons did they use and where any after action trials and assessments carried out similiar to the allied ones to show how effective, or not they were?

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The Il-2 used, among other stuff, the PTAB bomblets, even some Yak-9 used those (bomb bay was installed behind the pilot). The 20mm cannon was quickly deemed as powerless against the Pz-III and better panzers, and so was the 23 mm cannon. The 37mm cannon was used on later Il-2s, but the cannons were firing in a slight mismatch of timing, hence throwing the aim. Also, with 37mm on board, bomb load was as good as zero, and both speed and climb suffered. The Il-10 used four 23mm cannons, but of new type, that were not as powerful as the older VYa-23 - mostly firing HE shells? Rockets were used, but neither the Soviets never claimed that those were effective against tanks.
The Lagg-3-37 and, later, Yak-9T, were also using the 37 mm cannon, both against ground and aerial targets.