Discussion in 'Weapons, Technology & Equipment' started by dbf, Jan 28, 2012.
See attached for details
These small charges, which were first recovered from North AFRICA were probably intended to provide a rapid and easy method of demolishing cylinder blocks and similar components of vehicles.
In both cases the charge was contained in a cup-shaped aluminium case, painted field-grey, with a detonator pocket in the top secured by a circular flange. This pocket was provided with a standard thread for insertion of an igniter. A curved plate was recessed into the base, the centre portion being shaped to form a while surrounding the hollow space in the base of the charge. Hooks were fitted to either side of the charge so enabling it to be attached to the target by cords. The main explosive was penthrite/wax.
Although the diameter at the base of the 400 gm. charge was greater than that of the 300 gm. charge the depth of the hollow space was slightly less.
The general shape and design of this charge was similar to that of the small 300 gm. charge. Its purpose was to blast holes in steel plates of permanent fortifications, and to accomplish this efficiently the charge was required to make good contact with the surface to be perforated and was preferably to be used on horizontal surfaces. If used on vertical or inclined surfaces special supports were necessary to ensure good contact and stability.
The T.N.T. charge was enclosed in a sheet iron cover with a web handle on top, and a centrally situated threaded detonator socket which was closed prior to use by a paper label giving the designation of the charge and the type of the explosive filling. As in the smaller types a concave-shaped plate formed a hemispherical cavity at the bottom of the charge.
The Germans claimed that this charge would perforate armour up to a thickness of 4 3/4 ins., the diameter of the hole so formed on the outside of the plate being 4 ins.
This charge was similar to the 12.5 kg. type in that it was approximately hemispherical in shape, but in addition it had three hinged telescopic legs fitted to the hollowed base and a cylindrical projection closed by a perforated coned cap at the top. These three legs spaced the charge from the target and as a result gave a much better penetration than the 12.5 or 50 kg. charges both of which rested directly on the target.
The charge container consisted of the cavity liner, the base ring (carrying the telescopic legs), the cover and the cap.
The cavity liner was hemispherically shaped and consisted of four superimposed close-fitting mild steel domes, which were welded together at the top and at two other points. This four-ply construction of the liner had advantages over those of single sheet construction both from the point of view of ease of production and theoretical efficiency of performance. Failure of the domes to fit closely together tended however, to affect the direction of the pressure and resulted in a perforation of irregular shape.
The base ring was of sheet steel and was soldered to the base of the cavity liner in the form of a flange. Three telescopic legs of strip steel were attached to the underside of the ring at equally spaced positions. The length of these legs could be extended to 13.2 ins. from the base ring, so enabling the charge to be positioned to give the maximum penetrative effect.
The cover was made from sheet metal and was approximately hemispherical in shape. At the top there was a hole with a short cylindrical rim over which fitted a sheet aluminium cap. There was a hole in the cap to allow for insertion of a detonator. A fabric carrying handle was attached to one side.
The main filling consisted of 21 lbs. 3 ozs. of cyclonite/T.N.T. in the proportion 50/50, whilst round the detonator pocket there was a primer pellet of cyclonite/wax 95/5. The weight of the complete charge was 30.5 lbs.
Performance trials with this charge showed that it was easily capable of perforating a 9 in. face hardened plate, and that it would penetrate reinforced concrete to a depth of 3 1/2 - 4 ft. It was not considered that the four-ply construction of the liner was advantageous except as regards facility of manufacture.
The 50 Kg. demolition charge was carried by parachute demolition parties and like the previous types of this series was designed to blast holes in permanent fortifications, either concrete or steel. As before the charge was best used on horizontal surfaces, and was required to make good contact with the surface to be perforated. If used on vertical or inclined surfaces special supports were necessary to ensure that this contact was made.
The charge was made in two parts for convenience of transport. The lower part contained the hemispherical cavity, and was provided with a web carrying handle, and a screw plug on the circumference for closing a hole through which the explosive filling of T.N.T. was poured. The upper portion was provided with a web carrying handle, and centrally situated detonator pocket, and was dome-shaped to make a close fit over the lower half.
The Germans claimed that this charge would penetrate armour plate up to a thickness of 10 ins. For greater penetration two charges in succession were laid. Under these conditions a 50 Kg. charge followed by a 12/5 Kg. charge would penetrate 12 ins. of armoured plate, whilst two 50 Kg. charges in succession would pierce 1 ft. 7 ins.
When being dropped from aircraft two 50 Kg. charges were packed in a container, the four half charges being placed in such a way that each could be removed from the container separately. The container could be fitted with wheels on stub axles similar to those used with the standard mobile container, and when on the ground was propelled by means of a hinged handle. A detachable lid kept the contents in place, and an additional fastening was provided by two web straps which passed through slots in the lid. Two runners were fitted to the underside of the container to ensure ease of handling in the aircraft. The parachute was attached to two D-rings at the front of the case, and a corrugated iron shock absorber was fitted to the back. Demolitions accessories were carried in the container comprising two small boxes containing 15 No. 8 detonators and a larger box of six demolition sets (No. 8 detonator, detonator holder, safety fuze, and friction igniter adapter). The total weight of the container and contents was 388 lbs.
This was an assault weapon designed to be placed on enemy tanks and fired by means of a short delay igniter. It operated on the hollow-charge principle, but the shape of the cavity differed from those of the charges previously described, in this case being a simple 60 degrees cone. The charge consisted of an H.E. container mounted on a plastic base-plate, to the underside of which were attached three permanent magnets so enabling it to be attached to the target. Performance trials showed that it would penetrate 6 ins. of armour plate, and 12 ins. of concrete.
The charge liner was a 60 degree cone made from mild steel and was crimped under the inner edge of a mild steel base ring, which was secured in turn to the plastic base plate by six screws (not shown in the photograph). The charge cover was a truncated mild steel cone and fitted over the charge liner. It was slightly lipped at the bottom, and the outer edge of the base ring was crimped over this lip to hold it in position. A cylindrical projection at the top of the charge cover contained a primer pellet, and was closed by a screw cap, which served as the igniter holder. The igniter employed was of the type used in the egg hand-grenade, and had a delay of 4 1/2, 5 or 7 1/2 seconds. The primer pellet was of PETN/Wax, and the main filling of RDX/TNT in the proportion 50/50, the total weight of the two being 3 lbw. 5 ozs.
Three horseshoe magnet assemblies were bolted to the underside of the plastic base-plate. Each assembly consisted of a permanent magnet held between two pole pieces by two brass bolts, the pole pieces being screwed to the base-plate. If used on vertical surfaces the charge was so placed that two of the three magnets were uppermost, so lessening the risk of it dropping off; a static pull of over 30 lbs. was then required to withdrew the charge from the surface.
Nine charges were carried in a wooden box, with which ten igniter assemblies were supplies. During transit the magnets were provided with a keeper.
Catalogue number: B 6015
Part of: WAR OFFICE SECOND WORLD WAR OFFICIAL COLLECTION
Subject period Second World War
Alternative Names: object category: Black and white
Creator: No 5 Army Film & Photographic Unit
Lance Corporal Lodge of 278 Field Company, Royal Engineers, holding a German hollow charge anti-tank magnetic mine during Operation 'Epsom', 26 June 1944.
Both these charges, which were Luftwaffe stores, were intended to be used as anti-tank assault weapons, and were provided with magnets by which they could be attached to the target. The 4 Kg. charge was the earlier model and although much more elaborate construction was no more effective than the lighter charge whose plain bottle-shape showed a distinct improvement in design. Neither, however, was as effective as the corresponding Army store the 3 Kg. magnetic hollow charr. Although the official designation was Panzerhandmine 3 (P.H.M.3) the German Army usually referred to the charge as the Haft Hohlladung Luftwaffe (Haft H(L)).
In both cases the charge liner was hemispherically shaped and was enclosed by a bottle-shaped cover into the neck of which fitted the igniter assembly. This was either the 7 1/2 second friction delay igniter Brennzunder 42 or the Srengkapselzunder assembly used with between 7.5 and 10 cms. of safety fuze. Both charges had two carrying handles, one round the neck of the charr and one on the keeper ring. Two types of charge cover were encountered in the 3.6 Kg. model, one of zinc and one of cardboard construction.
The charges differed from one another in two major respects. The heavier charge had a 3 ins. bottom collar of zinc, which was the principal external identification difference, and had in addition a complicated magnet assembly. This consisted of four composite horseshoe magnets mounted onto short steel brackets which were in turn secured to the bottom collar by steel studs. Quarter inch thick rubber washers kept the magnets spaced away from the brackets. A plain circular keeper ring covered the magnets during transit.
In the 3.6 Kg. charge there were only three pairs of magnets, these too being covered by a keeper ring. On one side of the ring, however, were three equidistant spikes to enable the charge to be fixed on wooden targets. During transit the keeper was reversed so that the spikes were positioned between the magnets. For standard use (i.e. against steel surfaces) the keeper was removed.
Performance trials showed that these charges would penetrate 3 1/2 ins. of armour plate with a hole 1 1/2 ins. in diameter, and would cause a large amount of flaking on the inside. Splinters could be expected up to a radius of 100 ids. The fillings of both types was RDX/TNT, and the weight of explosive in the 3/6 Kg. charge was 2 1/4 lbs.
These charges were used for the destruction of A.Tk. and M.G. barrels and consisted of an explosive in a metal ring which was slipped over the gun barrel and fired by means of a detonator and length of fuze. It was claimed that this was a more efficient method of destroying gun barrels than the insertion of hand-grenades which merely produced bulging of the barrel and did not necessarily put the gun out of action. The fragmentation effect of these charges was negligible so making them especially suitable for raiding or saboteur parties whose safety would not be endangered by flying shrapnel.
The metal charge container was circular in shape, and had a single projecting detonator socket on the external circumference. Inside the container itself was a hollow space, semi-circular in cross-section, designed to increase the force of the explosion. The explosive surrounding this cavity was T.N.T.
The 3.2 kg. charge was similar to the 1.2 Kg. charge but was designed for use against medium guns.
[Please note: There is no illustration]
This weapon was similar to the British type Bangalore torpedo consisting of steel tubes filled with explosive and joined end to end by bayonet type fittings. Its main use was to blow gaps in defensive wire to allow the passage of assaulting troops.
Each section consisted of a steel tube with one male and one female end. At the latter end the explosive was retained by a thin metal plate, which was situated 4 ins. from the bottom of the tube. At the male end there was a recessed metal cap with a standard threaded detonator socket to take either a delay igniter or standard safety fuze firing assembly (Sprengkapselzunder). To form the joint two tapered cleats on the male end engaged with clips on the female end of the succeeding section. When assembled, a distance of approximately half an nice separated the charge in one section from the charge in another, and no provision was made for the insertion of a primer or a length of detonating fuze to close this gap. Presumably, however, a detonator was placed in the socket at every male end when the sections were being joined for operational use. The forward end was closed by a wooden nose plug the joint also being effected by bayonet type fittings.
The explosive filling in the charge was cylindrical pellets of pressed T.N.T. A label attached to the torpedo was marked "Fp.02 Sulfitturi" indicated the explosive filling of T.N.T. and the process by which it was purified.
The German designation for this piece of equipment was Donnerkeil (abbreviation D.K.), which may be translated as "thunder wedge". It was designed for the rapid production of small diameter vertical holes in the ground, into which could be placed the bases of telegraph poles or similar supports. Presumably it could also be used in the same manner as the British camouflet equipment, although there is no evidence to support this theory.
The principle of the Donnerkeil was to blow a tube into the ground by means of explosive, removed the tube and with a second explosive charge to enlarge the diameter of the hole sufficiently to allow for the insertion of a telegraph pole. The drive rod, which made the hole was constructed from steel and had attached to its upper end a cylindrical hollow pot or firing chamber. Two steel projections near the top of the pot received two tubular steel hand-levers. The propellant charge was cylindrical in shape and fitted into the pot. Two types of charge were encountered, both o the same diameter, but one being longer than the other and containing 2 lbs. 7 ozs. of explosive as against 1 lb. 7 ozs. This charge was initiated by a Sprengkapselzunder 28 with 12 ins. of safety fuze giving a delay of approximately half a minute. The explosive charge, as opposed to the propellant charge, consisted of seven 5 ft. lengths of instantaneous fuze tied together in three places, this too being initiated by a Sprengkapselzunder 28, but with only 6 ins. of safety fuze.
The last item was a thin steel rod with a loop at the top end and the bottom end forked. The total weight of the equipment less the explosive was 75 lbs.
The method of operation was first to set up the drive rod vertically over the spot where the hole was required and to push it in by hand till it was securely held. The propellant charge was then inserted into the pot, the large charge being used for hard and the smaller charge for soft ground. Firing of the charge drove the rod into the ground, and the lever rods were then used to withdraw it. The instantaneous fuze was placed in the hole so formed, being attached to the thin steel rod. A Sprengkapselzunder was fitted to the end of the fuze and was then fired, so enlarging the hole sufficiently for the positioning of a telegraph pole.
Another great job Diane - well done, you really do these files justice. Personaly I don't know how you do it
Ps How apt I reach 20,000 posts with this one-I can't think of a better place to have done it !
Just re-read this whole remarkable thread after dusting off the missus's Glasmine and wondering more on deployment.
Maybe we need a spot specifically for transcribed technical manuals etc. Stuff relating to materiel. There's a tendency for some great reference to get buried.
I had never heard of the glass mine
Museum of Technology, The History of Gadgets and Gizmos
WWII GERMAN GLASS MINE 43
I worked in the food packaging industry for a time in metal detection and weighing. Our chief design engineer told us about the origin of our metal detectors.
Apparently some Polish design engineers escaped the Nazi invaders coming to the UK with secret drawings of metal detectors which were adapted for mine detection .
These were first used at El Alamein to clear the German minefields for Monty's advance.
Polish mine detector - Wikipedia
Post war a few British Companies acquired the technology which is still used today to detect metal contamination in food products.
I wrote this in my draft book "Too Close for Comfort" using research on line years ago regarding Teller mines. I cant recall where. in the light of this thread, any comments regarding the mines would be appreciated.
Peter Mennell when writing the War Diary mentions "at least two Teller mines."
The 67th sent out their usual Recce Party of two Jeeps with CPO’s to find a suitable site within range of the Gordons, who were to advance over the hills north of Florence to the west of the main route 65 to Bologna.
67th knew of a location in La Pietra, used a week previously by the 2nd North Staffs accompanied by the 446 Battery FOO party,
They were lucky to escape when a Recce Regt carrier in front of them was hit by a German anti tank gun killing all the crew when taking the bend on route 65, near the junction with Via di Montughi. The FOO carrier withdrew down the lane to call in fire to destroy the Anti Tank gun.
A week later the 67th Field Regt Recce Jeep went down the same very narrow lane beside the Villa La Pietra towards the valley below, to check a possible location for the guns.
The Survey Jeep was following behind them when it detonated a cluster of Teller Anti Tank Mines laid by the German 4th Parachute Regt. They had been buried deep and modified with a strengthened pressure mechanism so as not to explode under lightweight vehicles but had enough explosive to blow over a Sherman Tank and kill the crew, rather than just break the tracks.
The mines must have been driven over many times by Jeeps, trucks and carriers but the torsion bar on the trigger eventually snapped due to metal fatigue when the Survey Jeep went over it. All the occupants and the Jeep were blown over a 2 metre high wall. three officers and the bombardier driver were killed.
The lane was thought to have been cleared but only one end was marked as clear, the other end to that taken was not.
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