1921 firing trials against Baden
Posted: Fri Mar 11, 2005 10:02 pm
Hello,
The following data is from a report part of ADM 186/251. The original report is a bit extensive, so I am only including a brief summary and the results of the four rounds that were fired against 13 ¾ in. [350mm] thick WWI German KC plates:
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H.M.S. “EXCELLENT’S” REPORT ON “BADEN” FIRING.
On 2 February 1921, firing trials were carried out against the ex-German battleship “Baden”, to the eastward of the Horse Tail Bank. The firing ship was the H.M.S. “Terror” [Monitor of the Erebus class], who was moored 500 yards from the target.
The ship was heeled to 11 deg. towards the firing ship, this angle varying about 2 deg. either way due to the roll; also the ship grounded at low water which reduced the heel about 1 deg. during that period. The amount of heel was produced by removing coal and armour plates on the port side of the ship and by flooding wing compartments on the starboard side. All oil fuel and bilge oil had previously been removed to reduce the chances of fire. This angle of heel kept the top of the 10 in. belt about 3 ft. above water amidships; and the trim of the ship had been previously adjusted by removing the revolving weight of “A” turret.
The gun used for the trial was the 15 in. B.L. Mark I, being the left gun in turret of H.M.S. “Terror.” The charges were adjusted to give a S.V. [striking velocity] of 1,550 fps. [472 mps] corresponding to an angle of descent of 13 ¾ deg. These were:
Charge: 172 lb. 4 oz. M.D. 16
Pressure in tons: 9ּ14
S.V.: 1,550 fps [472 mps]
Range corresponding to S.V.: 15,500 [yards] = 14,173 meters.
Detailed results of selected rounds:
Round 9.
Target: Barbette armour of “X” turret.
Shell: 15 in. A.P.C.
Fuze: 16 D.
Filling: 70/30 Shellite.
S.V.[striking velocity]: 1.550 fps [472 mps].
Delay: 3 ft.
Nature of burst: E.O.
Point of impact: 3 ft. 9 in. from top edge of fixed armour and 25 ft. 9 in. from midship line forward.
Angle of impact from normal: Vertical, 11 deg.; horizontal, 0 deg. Resultant from normal, 11 deg.
The [13 ¾ in.] armour was completely penetrated, a hole 17 in. diameter being made in it.
Apparently the shell burst when it was two-thirds of its way through the armour and the nose of the shell as far as the shoulder was found inside barbette 23 ft. from outer edge of entry hole.
Considerable damage was done to the roller path.
Some damage was caused to machinery in the pocket between girders where the nose of the shell was found.
Round 10.
Target: Barbette armour of “B” turret.
Shell: 15 in. C.P.C.
Fuze: 15 N.D.
Filling: Powder.
S.V.: 1.550 fps [472 mps].
Delay: On impact.
Nature of burst: -
Point of impact: 5 ft. 3 in. above forecastle deck and 23 ft. 4 in. from midship line forward.
Angle of impact from normal: Vertical, 11 deg.; horizontal, 5 deg. 20 min. Resultant, 12 deg. 10 min.
The shell burst on impact [failed to penetrate] with the plate, penetrating 1 ½ in. over a diameter of 9 ½.
The angle connecting the upper deck to the armour was torn away and flattened for 7 ft.
The forecastle deck was bulged downwards for 9 in. and a hole 6 in. by 4 in. was made in this. A large piece of the base was found on the upper deck under the burst.
The thin liners between the plates were loosened and partly squeezed out.
Round 14.
Target: Front plate of “B” turret.
Shell: 15 in. A.P.C.
Fuze: 16 D.
Filling: 70/30 Shellite.
S.V.: 1.550 fps [472 mps].
Delay: Blind.
Nature of burst: Blind.
Point of impact: Front plate of turret midway between the guns.
Angle of impact: Vertical, 12 deg.; horizontal, 11 deg. Resultant, 18 deg. 40 min.
Shell completely perforated armour, making holes of 18 in. in diameter flaked off to 36 in. by 48 in. outside and 24 in. by 36 in. inside.
Shell was found inside turret with nose resting against left girder of right gun-slide.
The center position sight and apparatus in its immediate vicinity was wrecked.
The shell was eventually exploded by a gun-cotton charge with the following result.
The sound of the burst was indistinguishable from that of the gun-cotton detonating, and degree of rapidity of burst was therefore difficult to estimate. Thick black smoke was emitted from all holes in the gun-house.
The left rammer (main cage to transport wagon) was unshipped and damaged.
The nose of the shell and a large part of the body were found lying on a platform 2 ft. below the burst, and two large fragments were lying where the shell had been. Part of the base weighting 30 lb. went through the main cage trunk and was found lying in the gun-house just near of this trunk. Other fragments were found lying about the gun-house and working chamber, but no other serious damage could be found.
Round 14. Shell intact through 13 ¾ in. [350mm] armour at 19 deg. to normal, S.V. 1,550 fps [472 mps].
Round 15.
Target: Thickest part of conning tower (13 ¾ in.) [350mm].
Shell: 15 in. A.P.C.
Fuze: 16 D.
Filling: 70/30 Shellite.
S.V.: 1.550 fps [472 mps].
Delay: On impact.
Nature of burst: P.D.
Point of impact: A 1 in. angle iron round the conning tower 6 ft. from top of tower and 9 ft. 6 in. from center line forward.
Angle of impact from normal: Vertical, 18 deg.; horizontal, 25 deg. 50 min. Resultant from normal, 30 deg. 10 min.
The shell burst on impact [failed to penetrate], making a bulge 4 ft. 6 in. by 2 ft. 6 in. and 4 in. deep, and opening out the plates half an inch at a join.
The inner side of the plate attacked was badly flaked and cracked, two cracks 6 in. deep and 8 ft. 10 in. long being made. No loosening of plates or of securing bolts was made inside the conning tower, but outside the join of the plate attacked was opened from 1/8 in. at bottom to 7/8 in. at top of conning tower. This was 3 ft. from point of impact. The plate attacked was driven in 1 ½ in. from the plate immediately below it, the join being 2 ft. below point of impact.
The starboard door was blown off, the upper hinge bracket being broken.
The deck round the tower under the point of impact was blown away for 6 ft. 6 in. by 3 ft. 6 in. and a storeroom underneath was demolished.
The deck over the Admiral’s cabin was holed and several pieces of shell were recovered from this cabin.
The diameter of the bulge inside the conning tower was 5 ft. and superficial star cracks were made on the bulge.
The damage to fittings inside the conning tower was very slight.
Summary of Rounds. (Barbettes, turret front plate, and conning tower, 13 ¾ in. [350mm] thick.)
This trial shows that A.P.C. will penetrate 13 ¾ in. [350mm] plate where C.P.C. will fail. Round 15 was fired at an angle of 60 deg. which serves to determine by comparison with round 14 the angle of impact at which perforation of 13 ¾ in. armour may be expected.
The performance of A.P.C. shell as regards penetration would appear to be satisfactory.
The insignificant damage caused by round 15 to instruments inside the conning tower, which were mounted on plates built up from the deck and not in contact with the side of the tower, shows that this method of fitting instruments is entirely justified.
Round 9. The German system of connecting the roller path support to the barbette armour was shown to be unsound.
Round 15. An armoured door is a danger unless its hinges are very strong and it is very securely fastened.
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The following data is from a report part of ADM 186/251. The original report is a bit extensive, so I am only including a brief summary and the results of the four rounds that were fired against 13 ¾ in. [350mm] thick WWI German KC plates:
------------------------------------------
H.M.S. “EXCELLENT’S” REPORT ON “BADEN” FIRING.
On 2 February 1921, firing trials were carried out against the ex-German battleship “Baden”, to the eastward of the Horse Tail Bank. The firing ship was the H.M.S. “Terror” [Monitor of the Erebus class], who was moored 500 yards from the target.
The ship was heeled to 11 deg. towards the firing ship, this angle varying about 2 deg. either way due to the roll; also the ship grounded at low water which reduced the heel about 1 deg. during that period. The amount of heel was produced by removing coal and armour plates on the port side of the ship and by flooding wing compartments on the starboard side. All oil fuel and bilge oil had previously been removed to reduce the chances of fire. This angle of heel kept the top of the 10 in. belt about 3 ft. above water amidships; and the trim of the ship had been previously adjusted by removing the revolving weight of “A” turret.
The gun used for the trial was the 15 in. B.L. Mark I, being the left gun in turret of H.M.S. “Terror.” The charges were adjusted to give a S.V. [striking velocity] of 1,550 fps. [472 mps] corresponding to an angle of descent of 13 ¾ deg. These were:
Charge: 172 lb. 4 oz. M.D. 16
Pressure in tons: 9ּ14
S.V.: 1,550 fps [472 mps]
Range corresponding to S.V.: 15,500 [yards] = 14,173 meters.
Detailed results of selected rounds:
Round 9.
Target: Barbette armour of “X” turret.
Shell: 15 in. A.P.C.
Fuze: 16 D.
Filling: 70/30 Shellite.
S.V.[striking velocity]: 1.550 fps [472 mps].
Delay: 3 ft.
Nature of burst: E.O.
Point of impact: 3 ft. 9 in. from top edge of fixed armour and 25 ft. 9 in. from midship line forward.
Angle of impact from normal: Vertical, 11 deg.; horizontal, 0 deg. Resultant from normal, 11 deg.
The [13 ¾ in.] armour was completely penetrated, a hole 17 in. diameter being made in it.
Apparently the shell burst when it was two-thirds of its way through the armour and the nose of the shell as far as the shoulder was found inside barbette 23 ft. from outer edge of entry hole.
Considerable damage was done to the roller path.
Some damage was caused to machinery in the pocket between girders where the nose of the shell was found.
Round 10.
Target: Barbette armour of “B” turret.
Shell: 15 in. C.P.C.
Fuze: 15 N.D.
Filling: Powder.
S.V.: 1.550 fps [472 mps].
Delay: On impact.
Nature of burst: -
Point of impact: 5 ft. 3 in. above forecastle deck and 23 ft. 4 in. from midship line forward.
Angle of impact from normal: Vertical, 11 deg.; horizontal, 5 deg. 20 min. Resultant, 12 deg. 10 min.
The shell burst on impact [failed to penetrate] with the plate, penetrating 1 ½ in. over a diameter of 9 ½.
The angle connecting the upper deck to the armour was torn away and flattened for 7 ft.
The forecastle deck was bulged downwards for 9 in. and a hole 6 in. by 4 in. was made in this. A large piece of the base was found on the upper deck under the burst.
The thin liners between the plates were loosened and partly squeezed out.
Round 14.
Target: Front plate of “B” turret.
Shell: 15 in. A.P.C.
Fuze: 16 D.
Filling: 70/30 Shellite.
S.V.: 1.550 fps [472 mps].
Delay: Blind.
Nature of burst: Blind.
Point of impact: Front plate of turret midway between the guns.
Angle of impact: Vertical, 12 deg.; horizontal, 11 deg. Resultant, 18 deg. 40 min.
Shell completely perforated armour, making holes of 18 in. in diameter flaked off to 36 in. by 48 in. outside and 24 in. by 36 in. inside.
Shell was found inside turret with nose resting against left girder of right gun-slide.
The center position sight and apparatus in its immediate vicinity was wrecked.
The shell was eventually exploded by a gun-cotton charge with the following result.
The sound of the burst was indistinguishable from that of the gun-cotton detonating, and degree of rapidity of burst was therefore difficult to estimate. Thick black smoke was emitted from all holes in the gun-house.
The left rammer (main cage to transport wagon) was unshipped and damaged.
The nose of the shell and a large part of the body were found lying on a platform 2 ft. below the burst, and two large fragments were lying where the shell had been. Part of the base weighting 30 lb. went through the main cage trunk and was found lying in the gun-house just near of this trunk. Other fragments were found lying about the gun-house and working chamber, but no other serious damage could be found.
Round 14. Shell intact through 13 ¾ in. [350mm] armour at 19 deg. to normal, S.V. 1,550 fps [472 mps].
Round 15.
Target: Thickest part of conning tower (13 ¾ in.) [350mm].
Shell: 15 in. A.P.C.
Fuze: 16 D.
Filling: 70/30 Shellite.
S.V.: 1.550 fps [472 mps].
Delay: On impact.
Nature of burst: P.D.
Point of impact: A 1 in. angle iron round the conning tower 6 ft. from top of tower and 9 ft. 6 in. from center line forward.
Angle of impact from normal: Vertical, 18 deg.; horizontal, 25 deg. 50 min. Resultant from normal, 30 deg. 10 min.
The shell burst on impact [failed to penetrate], making a bulge 4 ft. 6 in. by 2 ft. 6 in. and 4 in. deep, and opening out the plates half an inch at a join.
The inner side of the plate attacked was badly flaked and cracked, two cracks 6 in. deep and 8 ft. 10 in. long being made. No loosening of plates or of securing bolts was made inside the conning tower, but outside the join of the plate attacked was opened from 1/8 in. at bottom to 7/8 in. at top of conning tower. This was 3 ft. from point of impact. The plate attacked was driven in 1 ½ in. from the plate immediately below it, the join being 2 ft. below point of impact.
The starboard door was blown off, the upper hinge bracket being broken.
The deck round the tower under the point of impact was blown away for 6 ft. 6 in. by 3 ft. 6 in. and a storeroom underneath was demolished.
The deck over the Admiral’s cabin was holed and several pieces of shell were recovered from this cabin.
The diameter of the bulge inside the conning tower was 5 ft. and superficial star cracks were made on the bulge.
The damage to fittings inside the conning tower was very slight.
Summary of Rounds. (Barbettes, turret front plate, and conning tower, 13 ¾ in. [350mm] thick.)
This trial shows that A.P.C. will penetrate 13 ¾ in. [350mm] plate where C.P.C. will fail. Round 15 was fired at an angle of 60 deg. which serves to determine by comparison with round 14 the angle of impact at which perforation of 13 ¾ in. armour may be expected.
The performance of A.P.C. shell as regards penetration would appear to be satisfactory.
The insignificant damage caused by round 15 to instruments inside the conning tower, which were mounted on plates built up from the deck and not in contact with the side of the tower, shows that this method of fitting instruments is entirely justified.
Round 9. The German system of connecting the roller path support to the barbette armour was shown to be unsound.
Round 15. An armoured door is a danger unless its hinges are very strong and it is very securely fastened.
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