Some General notes:The development of electrical bomb fuzes in Germany can be traced back to 1926. Under direction of Dr. H. Rhulemann it was carried out at the Rheinmetal Borsig factory. The original goal was to develop an electrical time fuze for artillery shells that could be set at the moment of firing. Somewhere down the path of development work started on Electrical bomb fuzes. This to such satisfaction that the Luftwaffe adopted the Electrical bomb fuze in 1937.
The design of most Electrical fuzes is generally the same; an aluminium outer housing, to be devided in an upper and lower housing. The upper housing has a shoulder with a locating pin, enshuring that the fuze is placed in the right direction. On top is the fuze head with the electrical plugs. The upper part normally contains the horizontal - and vertical trembler switches, resistances and the depressable pistons of the electrical plug. The lower part normally contains the condensers, the delay devices (either pyrotechnic, either mechanical) and the anti disturbance devices. The gaine is screwed in the base of the fuze. The advantages of electrical fuzes are: Easy manufacturing (low number of different components for many different functions), great flexebility, instant action, low number of duds, arming only after the pilot connects the master switch, very safe. Extensive test with electrical fields around the fuze,up to 2.000.000 volts (ligtning), showed that an electric fuze, when propperly designed, is absolutely safe.
Cutaway model of an El.A.Z 38Electrische Anschlag Zünder 38 / Electrical impact fuze 38 ). This fuze was designed for use in 250kg to 1800 kg Sc (Spreng Cylindrische/ H.E General purpose) aircraftbombs. It could also be found in a variety of other bombs. It is made of an upper housing (1), containing a transperant perspex switchblock (4). This switchblock contains four trembler switches (5); three vertical, one horizontal, perpendicular on the bomb centerline. The trembler switch is made of steel ring, -forming the upper edge of a hole- glued in the switchblock and a conical wound spring, placed in the hole. At impact, the spring is bend by inertia. When the spring makes contact with the ring, the electrical circuit is closed and the bomb explodes or a fuze is lit. The fuze can be set in three different delay modes; 0,05 sec; 0,20 sec; 5,0 sec. In the aircraft , the bombs are placed in racks, the depressable pistons pushed in by the charging arm. The charging of either,or both depressable pistons determinnes the time setting. The condensater (7) is made of rolled up foil with paper inbetween, and four different condensators have been wound one over another, forming four seperate condensaters that look like one big one. The condensater is charged just prior to bomb release. The voltage used to charge the condenser determines the arming time if the fuze, normally 150 volts was used in level filght , 240 volts in diving flight. When the bomb is released , the condensater charging proces(with depressed pistons) stops, the pistons rise and the electric trembler switch circuit is activated. At impact the trembler switches close, and one of the fuzes is lit (part No.8; 0,2 sec ,Part No.9; 5,0 sec). The flame tavels through the holes into the lower black powder pellet (10). This pellet ignites the Kz Zdlg.(Kurze Zundladung / short booster) C/98 (12) The Booster is made of an aluminium can , containing 17 grams of Np (Nitropenta)10 (pink). In top of the fuze a sprengkapsel (detonator) 38 (11) is placed. A leather washer with a celluloid disc is placed above the detonator, the aluminium can is rimmed over the leather washer to close the booster. The booster is placed in the gaine (13), which is screwed in the base (6) of the fuze. The colour of the fuze is dark grey. In the older type El.A.Z 38 fuze, only two vertical trembler switches were placed instead of three in the later types. It is presumed to be intended for greater certainty of action in low level attack, for which the fuze would be set to operate at relatively long delay. The 250 Kg SC bomb with an El.A.Z 38 could be used as a depth charge.
Excellent cutaways,drawings and information.
Thank you very much.
Last edited by waffenamt; 3rd February 2010 at 04:51 PM.
Collector of German ww2 Bomb fuzes and Ordnance.
'The early bird catches the worm!...'