Cutaway model of a 12,8cm Sprengranatpatrone (Sprgr.Patr. / HE shell) L/4,5 as used in the 12,8cm Flak 40 gun. This was the heaviest Flak gun in use with the Luftwaffe. As the gun was too heavy (18.000 kg) to be mobile, it was used either on a train carriage, either in a fixed position. Only a few of these guns were made road-mobile by means of the “sonderanhanger 220”. In fixed position, it was mostly used in a dual mount (Flakzwilling) on flaktowers which protected the larger German city’s like Berlin, Hamburg and Vienna.
As loading these projectiles was a very heavy work it was automated. The loader placed the shell in the tray beside the gun’s breech. On top of this tray the fuze setting machine sets the running time of the fuze after which the shell is automaticly loaded into the gun.
Length of complete cartridge : 1487 mm
Length of shellcase : 962 mm
Weight of complete cartridge : 48 kg
Weight of projectile : 26 kg
Weight of explosive charge : 3,7 kg of cast FP02 (pure TNT), either 3,7 kg cast FP 60/40 (60% TNT, 40% ammonium nitrate)
Weight of powdercharge : A main charge of 10, 0 kg Digl. R.P. –K2- (850x ø5,1 x ø1,7) either 9,50 kg of Digl. R.p. –KN- (850x ø5,6 x ø2,0), with a booster charge of 200 grams Diglicol Blade powder (3x3 mm square x0,8mm thick) and an ignition charge of 20 grams Nz.Man.N.P. rifle powder (1,5x1,5mm square x0,5 mm thick )
Ceiling of projectile : 14.800 mtrs
Range of projectile : 20.900 mtrs
Vo: 880 mtrs/second
Suitable fuzes : ZtZ.S30, Zt.Z.S30 Fg, AZ.23/28
Firing rate : 12rpm
Number of guns produced : 1125
Regards , DJH