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WW2 shaped charge bomblets question?

jrwlynch

LE
Book Reviewer
I’m not sure how that could happen.

The SD1 had quite a robust (for the time) safe-to-arm delay mechanism involving the wings (hence ‘butterfly’ bomb) acting as an arming vane. If the bomblet didn’t fall the prescribed distance through the air it wouldn’t spin enough and couldn’t arm.

And like other cluster munitions it was carried in a ‘mother bomb’. If anything was going to get hung up in the bomb bay it would be the mother bomb.

I know it's Wikipedia, but the source is Alfred Price: "The SD 2 saw use in the opening stages of Operation Barbarossa, the German invasion of the Soviet Union, which began on 22 June 1941. Twenty to thirty aircrews had been picked to drop SD 2s and SD10s (10 kg submunitions) on key Soviet airfields, a flight of three aircraft being assigned to each field. The purpose of these early attacks was to cause disruption and confusion as well as to preclude dispersion of Soviet planes until the main attack was launched. It was reported that Kampfgeschwader 51 lost 15 aircraft due to accidents with the SD 2s - nearly half of the total Luftwaffe losses that day."

It may not be correct, but back in the 1980s I remember reading about how while the SD-2 "devil's eggs" were very effective against aircraft parked in the open, they were touchy beasts not loved by aircrew - if it's a myth it's a persistent one.
 
I know it's Wikipedia, but the source is Alfred Price: "The SD 2 saw use in the opening stages of Operation Barbarossa, the German invasion of the Soviet Union, which began on 22 June 1941. Twenty to thirty aircrews had been picked to drop SD 2s and SD10s (10 kg submunitions) on key Soviet airfields, a flight of three aircraft being assigned to each field. The purpose of these early attacks was to cause disruption and confusion as well as to preclude dispersion of Soviet planes until the main attack was launched. It was reported that Kampfgeschwader 51 lost 15 aircraft due to accidents with the SD 2s - nearly half of the total Luftwaffe losses that day."

It may not be correct, but back in the 1980s I remember reading about how while the SD-2 "devil's eggs" were very effective against aircraft parked in the open, they were touchy beasts not loved by aircrew - if it's a myth it's a persistent one.

There’s three levels of safety involved.

ECR fuzes on the mother bombs aren’t armed whilst inside the aircraft.

There is a delay between being dropped from the aircraft and the mother bomb opening.

There is then another delay whilst the SD2 arm.

Whatever the problem might have been, it won’t be from individual SD2 ‘hanging up’ in the aircraft.

What might have happened is this.

In order to complete the arming sequence and get optimum separation between the individual cluster munitions, a minimum height is required. This puts the bomber right in the envelope for AAA.

Pilots soon learn this. Indeed, many of the cluster munition strikes I have wombled over in the past have included mother bombs that have opened on impact or otherwise dropped too low for the arming sequence to complete.
 
Could it have been that shape charges were seen as modern and therefore the sort of thing that the New Soviet man would use everywhere?

No it was seen as no rearward movement into the Rodina. All units defend to the last round. This wasn't some Hollywood nonsense. No falling back and no reinforcement by the STAVKA of strategic failure. They were playing for keeps.
 
No it was seen as no rearward movement into the Rodina. All units defend to the last round. This wasn't some Hollywood nonsense. No falling back and no reinforcement by the STAVKA of strategic failure. They were playing for keeps.

It's not immediately clear to me as to why that might lead to a shape charge being an option on FROG.
 

HE117

LE
Are you getting confused between the SD1 and SD2 bombs...?

The SD1 was basically a modified mortar bomb filled with TNT or Amatol. It used a type 73 impact fuze, details of which I cannot find (yet!)

The SD2 was the "butterfly bomb" which was designed from the start as an air dropped cluster weapon, and was more of a scatter-able mine system than a direct action bomb. Apart from anything else they would have been difficult to lay down with any accuracy..

The SD2 came with a number of fuzes. The 67 fuze was a mechanical delay which could be pre-set for up to 30 min delay. The 70 fuze which was a mechanical anti disturbance fuze which armed on impact and then would initiate when moved. There was also a third, chemical long delay fuze which could delay from 4 to 30 hours and also had an anti disturbance "feature" although there is no record of these being used.

All the SD2 fuzes had reliable drop safe arming mechanisms which worked off the rotation of the drag wings..

The tooling for the SD2 went to the US after the war where they continued manufacture..!

The Luftwaffe did not go much for mechanical fuzing.. most of their bombs used a range of electrical fuzes designed by Rheinmetall Borsig. These were electrically linked to the bomb release and arming systems in the aircraft. Cluster munitions such as the SD1 and 2 were dropped in cluster containers which were fitted with Rheinmetall fuzing system that would integrate with the aircraft systems...
 
I read one account which said that aircraft like the 109 and HS 123 and other types carried them on racks, not in bomb containers and that some of them would hang up on the rack and then be knocked off upon landing. There is at least one story of them exploding under an aircraft as the mechs tried to take them off.
 
I read one account which said that aircraft like the 109 and HS 123 and other types carried them on racks, not in bomb containers and that some of them would hang up on the rack and then be knocked off upon landing. There is at least one story of them exploding under an aircraft as the mechs tried to take them off.

Even if there was a rack that dispensed SD2 it would still have to complete the safe-to-arm process. Any hung up SD2 would not be able to do that.
 
Are you getting confused between the SD1 and SD2 bombs...?

The SD1 was basically a modified mortar bomb filled with TNT or Amatol. It used a type 73 impact fuze, details of which I cannot find (yet!)

The SD2 was the "butterfly bomb" which was designed from the start as an air dropped cluster weapon, and was more of a scatter-able mine system than a direct action bomb. Apart from anything else they would have been difficult to lay down with any accuracy..

The SD2 came with a number of fuzes. The 67 fuze was a mechanical delay which could be pre-set for up to 30 min delay. The 70 fuze which was a mechanical anti disturbance fuze which armed on impact and then would initiate when moved. There was also a third, chemical long delay fuze which could delay from 4 to 30 hours and also had an anti disturbance "feature" although there is no record of these being used.

All the SD2 fuzes had reliable drop safe arming mechanisms which worked off the rotation of the drag wings..

The tooling for the SD2 went to the US after the war where they continued manufacture..!

The Luftwaffe did not go much for mechanical fuzing.. most of their bombs used a range of electrical fuzes designed by Rheinmetall Borsig. These were electrically linked to the bomb release and arming systems in the aircraft. Cluster munitions such as the SD1 and 2 were dropped in cluster containers which were fitted with Rheinmetall fuzing system that would integrate with the aircraft systems...

There are US-produced SD2 in the ‘American War’ museum in Saigon.
 
It's not immediately clear to me as to why that might lead to a shape charge being an option on FROG.
Sorry I edited my own post and deleted the bit where I said that it was trialled and never deployed. Not unusual given that we trialled a shaped charge warhead for SPEARFISH but never deployed that either. Or indeed the multi-faceted shaped charge warheads for the UK heavier air defence missiles. It was rumoured to me by a Soviet Officer that they could have been used to target hardened emplacement being fire en masse. But as I said, never deployed.
 
Here's an article from Grimsby's local paper from 2003 about the SD2

WEAPON WAS A FAVOURITE AGAINST AIRFIELDS

Butterfly bomb myths dispelled

Gordon Taylor, of Thoresby Place, Cleethorpes, clears up what he believes are a few myths about the Butterfly Bomb raids in this imformative article.

I read the June issue of Bygones with especial interest, since I recall the night of June 13/14, 1943 very well.

Would you please, in the interest of historical accuracy, allow me to make a few points in order to dispel some of the myths related to the use of the SD2 (Butterfly Bomb) and which are being perpetuated in several quarters?

The author of the article describes the SD2 as a “new terror weapon’ and goes on to state that this raid of June 13/14 was “the first use of the Butterfly Bomb on the United Kingdom."

On March 21, 1987, the Telegraph article entitled “The Day after the Blitz" proclaimed that “The Butterfly Bomb was never used by the Nazis again.” These three statements are just not true.

The SD2 was a two kilogramme, anti-personnel fragmentation bomb which exploded into about 300 small splinters.

Its preferred use, in low-level flight, was against marching columns of enemy troops. However, when operation Barbarossa began with massive air-raids on Soviet airfields on the morning of June 22, 1941 it was soon perceived that often the heavier bombs exploded too deep in the soft ground, creating imposing craters due to upward blasts, but hardly any splinter effect that would make enemy aircraft inoperable.

So the SD2 was then put into very effective use against the airfields and in great numbers during the early part of the campaign.

This same year, an SD2 raid closed RAF Wattisham, Norfolk for several days. This seems to suggest that these bombs were equipped with a “disturbance” fuse rather than the “instantaneous” type - if so, then there was nothing new at all about those dropped on the towns of Grimsby and Cleethorpes.

Jumping ahead to after the Grimsby raid, they were still being used in the same mode on September 19, 1943 during the German counter-attack on the Dodecanese Islands.

Dropped on the airfield at Antrimachia, Kos, they showed how effective they could be by not only making the airfield temporarily unserviceable, but they also damaged all of the RAF transport Dakotas.

Long before the Grimsby raid, on August 12/ 13, 1941, they were dropped inside the Lincoln city boundary, killing one person and injuring another.

In the same year, on August 17/18, 50 SD2s fell on Grantham, with no casualties.

Again, long before the Grimsby raid, more were dropped on Lincolnshire but they did no harm. This was at Stenigot and I imagine that the target was the HC radar station there. This was on October 30/November 1, 1941.

Our turn came on June 13/14, 1943, when about 1,000 fell on Grimsby, 1,000 on Cleethorpes and another 1,000 on the Great Coates area.

In Grimsby at War, Clive Hardy asserted in 1989: "Grimsby and Plymouth jointly held the unique distinction of being the only places in Great Britain where anti-personnel Butterfly Bombs were dropped." However, Bygones of June 1993 did put the record straight.

“The Germans did use these deadly little weapons again. Some were dropped on Plymouth only a week later. Others fell in Essex and Dorset while a number aimed at Hull on August 18, 1943 fell on open ground.

That same year, they were being used against guerrilla hideouts in Yugoslavia.

About 750 of these bombs were dropped in the rural district of Lincolnshire on 17/18 August, 1943.

The chief concentration was in the area of Tumby Wood, Halham Wood, Dalderby and Scrivelsby.

S. Finn in Lincolnshire Air War 1939-45 wrote:" Over a period of three weeks the police had to search more than 1,500 acres. Many of the bombs were unaccounted for for quite some time afterwards. They have been known to explode after two years.” The locations suggest a near miss on Coningsby and Woodhall Spa airfields.

The sources, which are listed below, show that the Butterfly Bomb was not a new weapon or a secret one in 1943, but had been in use since 1941 and its existence was well known.

It was used by the Nazis again after Grimsby and on several targets in differing combat areas.

Sources: The Luftwaffe 1933-1945, Vol. 1. Alfred Price, Arms and Armour Press 1981;

The Luftwaffe 1919-1945. Karl Ries, Motorbuch Verlag, Stuttgart;

Grimsby Telegraph Bygones, March 6, 2001;

Royal Air Force 1939-45, Vol II. Richards & Saunders, HMSO, London 1953

Lincolnshire Air War 1939-45. S Finn, Aero-Litho Company (Lincoln) Ltd 1973

Grimsby Telegraph Bygones, June 12, 1993

SOURCE:

Taylor, Gordon. "Butterfly bomb myths dispelled." in Bygones (Grimsby Telegraph Special Publication) 29 July 2003, page 3
 

Wordsmith

LE
Book Reviewer
I thought one of the first wartime uses of shaped charges was against the Belgian fort at Eben Emael in 1940.

On top of Coupole Nord, two German glidermen had detonated one of the new 26-pound shaped charges, making an impressive explosion that shook the ground around the cupola. The blast twisted the guns, damaged the ammunition mechanism, and cut the cables to the control system. Coupole Nord was put out of action
The charge may not have actually penetrated the copula, but it looks as if it didn't do the guns any favours, nor the Belgians manning the turret. (The damage from the shaped change can be seen above the gun).

1602705208665.png



I would imagine it was easier to get a shaped charge to function if you could place it on a target,, rather then fire it at it.

Wordsmith
 
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