Hello Bob,
Datas from wk2ammo (I know a nice 5cm cut by DJH, and a10.5cm shown on bocn) :
Two type of 21 cm shell was serviced for the 21 cm Mrs 18.
1., 21 cm Rö. Gr. 42 Be.
Total weight: 193 kg,
Weight after firing: 165 kg,
Explosive charge weight: 3 kg,
Explosive type: RFp,H10,H5
Diameter: 210,9 mm
Diameter after firing: 116 mm
Explosive cavity biggest diameter: 48.6 mm
Fuze: BdZ 5141
Total lenght: 2580 mm
Maximal muzzle velocity: 370 m/s
Maximal shoting range: 11275 m
Powder charge weight: 12,5 kg
Penetration in concrete: 2-3,5 m
Penetration in homogen stone: 1,3-4 m
Penetration in soil: 40-50 m
2., 21 cm Rö. Gr. 44 Be.
Total weight: 195 kg,
Weight after firing: 168 kg,
Explosive charge weight: 8,03 kg,
Explosive type: G-Satz, H10
Diameter: 210,9 mm
Diameter after firing: 116 mm
Explosive cavity biggest diameter: 75 mm
Fuze: BdZ 5141 and Wgr Z.T.
Total lenght: 2383 mm
Maximal muzzle velocity: 370 m/s
Maximal shoting range: 11275 m
Powder charge weight: 12,5 kg
Penetration in concrete: 2-3,5 m
Penetration in homogen stone: 1,3-4 m
Penetration in soil: 40-50 m
1- 34 cm Rö. Gr. 42 Be. (34 cm Mle 1912 AGLP)
Total weight: 919 kg,
Weight after firing: 812 kg,
Explosive charge weight: 31,3 kg,
Explosive type: G-Satz,H10
Diameter: 340 mm
Diameter after firing: 220 mm
Explosive cavity biggest diameter: 115 mm
Fuze: BdZ 5141
Total lenght: 3727 mm
Maximal muzzle velocity: 540 m/s
Maximal shoting range: 23100 m
Powder charge weight: 75+28 kg
Penetration in concrete: 5-10 m
Penetration in homogen stone: 4-12 m
Penetration in soil: 60-100 m
2- 34 cm Rö. Gr. 44 Be. (35.5 cm H M1)
Total weight: 925 kg,
Weight after firing: 812 kg,
Explosive charge weight: 115 kg,
Explosive type: G-Satz, H10
Diameter: 356 mm
Diameter after firing: 220 mm
Explosive cavity biggest diameter: 115 mm
Fuze: BdZ 5141 and Wgr Z.T.
Total lenght: 4000 mm
Maximal muzzle velocity: 355 m/s
Maximal shoting range: 11050 m
Powder charge weight: 49,5 kg
Penetration in concrete: 3,5-6 m
Penetration in homogen stone: ?
Penetration in soil: 50-70 m
The 35,5 cm H. M1 with Rö. Gr. was used in combat at Sevastopol. Turret Maxim Gorkij II with tripple 30,5 cm barrel was knock-out by two shot. First they try to break it with normar Be. shells but it was too hard for it. So the Germans used the Rö. shells only in this case under the whole war. The first hit was deadly but the second can drop the whole turrret some meters far from the original posiion. Finally the whole fortress was killed by German pioneers not by Rö. shells.
Other places was only for test shooting.
Fortress Aubin-Neufchateau and Battice in Belgium;
Fortress Hurka, Hanicka, Dobrosov and Nachodsko in Czech Republic;
Gössler-Wall at Toplitzsee in Austria;
Hillersleben testplace in Germany;
And one found 34/35 cm shell in Budapest, Hungary.