Bulgarian designation : | 150-мм нескорострелна гаубица Д-12 |
Schneider designation : | Obusier de 15 cm de campagne, type puissant sur affût à frein hydropneumatique |
Calibre : | 150mm L/12 |
Weight of the barrel : | 777 kg (before the modernization : 760 kg) |
Weight of the breech-block : | 55 kg |
Weight of the carriage : | 1050 kg |
Weight in action : | 1965 kg (before the modernization : 1810 kg) |
Weight of the limber : | 393 kg (empty) – 641 kg (loaded) |
Weight in marching order : | 2600 kg (before the modernization : 2466 kg) |
Barrel length : | 1800 m |
Barrel grooves | number : | 36 |
depth : | 1.5 mm |
angle of twist : | progressive, 3° to 6° |
Height of the line of fire : | 1150 mm |
Battering charges |
Original Schneider charge : | French 4 x 4 x 1 B.M. (pyroxylin flaked powder) 1st charge : 180 g 2nd charge : 3rd charge : 450 g 4th charge : 680 g 5th charge : 825 g |
Charge adopted in 1912 : | 4 x 4 x 1 W.P. (nitroglycerine flaked powder) 1st charge : 260 g 2nd charge : 355 g 3rd charge : 455 g 4th charge : 560 g 5th charge : 680 g + 10 g of black powder Vereinigte Köln-Rottweiler Pulverfabriken AG |
Charge adopted in 1914 : | 123 x 1 W.A.S. (nitroglycerine powder in tiles) 1st charge : = 2nd charge : 360 g 3rd charge : 465 g 4th charge : 580 g 5th charge : 710 g Vereinigte Rheinisch-Westfälische Pulverfabriken AG |
Shell | weight : | 40 kg – charge: 2.8 kg |
max. range : | 6500 m (increased to 7800 m) |
Shrapnel | weight : | 40 kg – 900 bullets x 20 g |
max. range : | 5480 m |
Mine shell weight : | 40 kg – charge : 8.785 kg Schneiderite |
Muzzle velocity : | 260 m/s (5th charge) 230 m/s (4th charge) 200 m/s (3rd charge) 170 m/s (2nd charge) 140 m/s (1st charge) |
Angle of descent : | range | 1st charge | 2nd charge | 3rd charge |
100 m 500 m 1000 m 1500 m 2000 m 2500 m 3000 m 3500 m 4000 m 5500 m | 2° 12’ 12° 19’ 29° 23’ | 0° 32’ 4° 31’ 7° 27’ 12° 05’ 17° 06’ 23° 23’ 31° 18’ | = 2° 11’ 4° 17’ 6° 42’ 9° 41’ 12° 52’ 16° 20’ 20° 20’ 24° 44’ 36° 38’ |
Elevation : | + 45° / - 5° |
Recoil : | 510 mm / 535 mm (before the modernization : 450 mm) |
Height of the wheels : | 1.27 m |
Track : | 1.30 m |
Transport : | drawn by six horses |
Ammunition : | gun limber - 5, wagon limber - 8, wagon body - 16 12 ammunition wagons for every battery |
Remarks : Heavy howitzer à tir accéléré, i.e. howitzer modernized in 1904-05 (see H.BARBY, Brégalnitsa, p. 309 – some sources speak of them as “not quick-firing” and others as “quick-firing” howitzer) with hydro-pneumatic recoil system, swinging block breech mechanism, equipped with panoramic telescope (description). It was fitted for an independent line of sight. In 1897 twenty four howitzers were ordered. To make them more movable, major Kalin Najdenov designed a special field carriage. The innovative heavy howitzer that resulted from this conversion was presented to the Paris International Exhibition in 1900. Unfortunately the howitzers were delivered hastily and without appropriate test and soon showed major faults: after 4-5 shots the compressors broke down. In 1904 they were modernized on the basis of a Bulgarian project : the accessories were built in France, but they were assembled in the Sofia Arsenal. |