210mm Krupp Mortar M. 1910

 

 

 

 

Bulgarian designation :

21-см скорострелна мортира Д-12

German designation :

21-cm- Mörser L/12

Calibre :

210mm L/12

Weight of the barrel :

2620 kg

Weight of the breech-block :

229 kg

Weight of the shield :

86 kg

Weight of the carriage :

3713 kg

Weight of the pedrails :

820 kg

Weight in action :

7380 kg (with pedrails) – 6630 kg (without pedrails)

Weight of the limber :

450 kg (empty) – 640 kg (loaded)

Weight in marching order :

8520 kg

Weight of the pedrails wagon :

1328 kg (empty) – 3345 (loaded)

Barrel length :

2530 mm

Land diameter :

211 mm

Groove diameter :

214 mm

Rifling

length :

1763 mm

twist :

from 32 to 18 calibres

Barrel grooves

number :

64

width :

6.85 mm

depth :

1.5 mm

Width of the lands :

3.5 mm

Height of the line of fire :

1600 mm

Battering charges :

9th charge: 5.6 kg R.P. (3x25.5) + 50 g n.Gew.P. 71

8th charge: 5.2 kg R.P. (3x25.5) + 50 g n.Gew.P. 71

7th charge: 4.9 kg R.P. (3x25.5) + 50 g n.Gew.P. 71

6th charge: 4.3 kg R.P. (3x25.5) + 50 g n.Gew.P. 71

5th charge: 3.9 kg R.P. (3x25.5) + 50 g n.Gew.P. 71

4th charge: 3.5 kg R.P. (3x25.5) + 50 g n.Gew.P. 71

3rd charge: 3.2 kg R.P. (3x25.5) + 50 g n.Gew.P. 71

2nd charge: 2.9 kg R.P. (3x25.5) + 50 g n.Gew.P. 71

1st charge: 2.6 kg R.P. (3x25.5) + 50 g n.Gew.P. 71 

4.2 kg Wurfpulver (12x12x2) + 50 g n.Gew.P. 71

(only for seven charges)

3.82 kg Wurfpulver (10x10x1.5) + 20 g n.Gew.P. 71

(only for Gr. 14 and 14 A)

3.95 kg Wurfpulver (10x10x1) + 20 g n.Gew.P. 71

(only for Gr. 14 and 14 A)

Shells

 

21cm-Gr. 96

weight :

120 kg – charge 17.58 kg  of Füllpulver 02 (Trotyl)

length :

839.1 mm

fuze :

Kz. Bod. Z. 10

muzzle velocity :

367 m/s

max. range :

9400 m with the 9th charge

8900 m with the 8th charge

8500 m with the 7th charge

21cm-Gr. 14

weight :

83 kg – charge 7.7 kg of Füllpulver 60/40

length :

502 mm (without the fuze)

fuze :

Gr. Z. 04 or Gr. Z. 04/14

muzzle velocity :

406 m/s

max. range :

8800 m with the 8th charge

21cm-Gr. 14 A

weight :

83 kg – charge 6.3 kg of Füllpulver 60/40

length :

500 mm (without the fuze)

fuze :

Gr. Z. 04 or Gr. Z. 04/14

muzzle velocity :

406 m/s

max. range :

8800 m with the 8th charge

21cm-Gr. 17

weight :

120 kg – charge 13.7 kg of Ammonal

length :

803 mm

fuze :

Kz. Bod. Z. 10

muzzle velocity :

367 m/s

max. range :

9400 m with the 9th charge

8900 m with the 8th charge

8500 m with the 7th charge

Elevation :

+ 70° / + 6°

Traversing angle :

Wheels

weight :

254 kg

height :

1400 mm

track :

1610 mm

Transport :

drawn by horses dismantled in two loads: barrel - 4065 kg, carriage – 4455 kg

Remarks :

Quick firing heavy mortar with hydro-pneumatic recoil system, wedge breech mechanism, box-trail gun carriage, and shield. Even before the beginning of the World War, the standard wooden wheels were replaced by steel wheels with pedrail of Rheinmetall construction. This meant that the mortar could fire without a platform, making easier to move it and faster to put it in firing position. It was adopted in 1910 and called simply Mörser without specifying the calibre. At the beginning of WW1 German Army fielded 216 of these mortars.

The Bulgarian Army received a little number of these mortars: the 1st battery of the 4th heavy artillery was rearmed in 1918 with 2 – 21cm mortars, while the 16th battery of the 3rd heavy artillery regiment could not receive its mortars due to the end of the war.

 

 

 

21cm Mörser

without shield and pedrails

21cm Mörser

with shield and pedrails

 

 

Gun wagon

Pedrails wagon