Guns vs naval armour in ww1

[delcyros]

Doggerbank:

INDOMITABLE took part but was the slowest ship, and hampered by 2crh shells so she did not open fire until 113 minutes after Lion at a range of 16,250 yds. Her target was the already crippled Blucher expending 40 APC 15 CPC and 79 HE, as well as 2 shrapnel at the german airship L5. It is not recorded the number of hits she made on Blucher, but she was hit by 1 8.3in in return with little damage.

PRINCESS ROYAL expended 176 13.5in APC, 95 13.5in HE and also 2 13.5in shrapnel at airship L5. She reported to have made 5 hits, 2 on BLUCHER and 3 on DERFFLINGER, altough only one hit on DERFFLINGER can be linked with PRINCESS ROYAL and she was not hit herself in return.

Other than BLUCHER, the british Battlecruiser and flagship HMS LION suffered most in the action of Doggerbank and was in effect damaged critically enough to leave the line. Later she had to be taken in tow and the loss of the shipwas only prevented by a sea valave not giving way according to Campbell. In the action she expended 243 x 13.5 APC scoring one hit on BLUCHER, 1 on DERFFLINGER and 2 on SEYDLITZ at a range of 16,000 yds or more. Altogether she was hit by 16 11in or 12in shells and 1 x 8.3in.

1) 17-18ft below lwl one compartment flooded

2) As above with similar efect.

3) 8.3in from BLUCHER on 3.5in turret roof of A, roof dented and driven down a little, left gun out of action for 2 hours.

4) 11in from MOLTKE at about 18,000yds, struck water about 15ft from side ricocheted and pierced 5in armour aft 2ft above deep wl, passed through escapes and vent trunks of 4in magazines, through the 0.25in main deck, was deflected upwards and finally dropped unexploded on the main deck. The after low power switchboard compartment was flooded, eventually causing 2 of the ship's 3 dynamos to be shorted.

5) 11in from SEYDLITZ at about 16,000yds, one hit 5in armour forward, just below the main deck, drove in a piece 30ins x 24ins and burst 6ft from impact in a wing compartment abreats the torpedo body room, wrecking it, and flooding it up to the main deck, flooding the torpedo flat, the compartment below it, the port cable locker and the capstan compartment. A splinter hole in the exhaust pipe from the capstan engine filled the auxiliary condenser with salt water and the resultant salting of the boilers made it necessary to stop the starboard engine.

6) 11in from SEYDLITZ at about 16.000yds. This shell shell hit further aft, bursting on the 6in side armour, 3-4ft below full load wl. 2 armour plates were forced in 2ft, the outer and inner bottoms bulged over an area of 40ft x 7ft, the slope of the 1in armour deck forced in and some of the foremost bunkers flooded. Hit together with 5).

7) 11in amidships at 17,000yds. struck 6in side just below the upper deck and burst 8ft inboard, and the other

8 ) 11in amidships at 17.000 yds struck the junction of the 6in and 9in armour at main deck level and bursting 2ft inboard, much damage to light structures. Hit together with 7)

9) 11in went through forecastle skin plating and 1in upper deck bursting against 8in armour of A barbette, little damage done.

10) burst in bakery which was wrecked, part of shell passed through the armour gratings and holed the exhaust bend to the port inner condenser without damaging the tubes.

11) Hit 9in belt armour amidships, failed to penetrate.

12) Through no. 1 funnel and 1.25in forecastle deck, bursting 6ft beyond.

13) Through no. 2 funnel and burst on skylight.

14) Through no. 2 funnel and overboard.

15) Through forecastle deck and burst as it passed through ship's side.

16) Thought to be 12in from DERFFLINGER. Hit lower strake of 9in main belt armour abreast engine room and just below deep load wl and burst on the armour forcing in a 16ft x 5ft 9in plate at least 2ft inward (burst in holing). The outer and inner bottom plating and the 1in armour was much torn and distorted. The port feed tank was opened to the sea, overflowed into the reserve feed tank and thence into the port engine room. The feed tank bulkhead in the port engine room was badly bulged, 2 lower bunkers were flooded and the ship heeling 10 degrees to port and capable of only 15kts, shortly afterwards the remaining engine had to be stopped. The resultant rise in the water level shorted the remaining dynamo and the LION was out of action. This was a very serious hit, crippling Beattys flagship.

17) On starboard side 17-18ft below lwl.

In addition to these hits, the right gun of Q turret was out of action after 15 rounds from incorrectly diagnosed trouble with the firing mechanism, and 4 minutes before LION was overtaken by TIGER A magazine was erroneosly reported as on fire and flooded 2ft deep.

TIGER expended 355 13,5in rounds ( 249 APC 54 CPC 52 HE ) and scored 2 hits each on SEYDLITZ (one unconfirmed) and DERFFLINGER (one unconfirmed) and an unrecorded number on BLUZCHER. She also fired 268 6in HE at BLUCHER and destroyers and fired 2 x 21in torpedoes at BLUCHER, one of which was claimed as a hit.

HMS TIGER was hit 6 times by heavy shells;

1) 12in from Derfflinger burst on 9in main belt.

2) 11in on Q turret on 3.25in roof of Q turret at junction of 2 plates. Most of the shell deflected overboard but fragments entered the turret jamming the training gear and damaging the left gun breech mechanism.

3) 11in hit signal distributing office below CT bursting 6ft from impact in the intelligence office, all communcications between control top and connign tower destroyed. Above the burst the CT and the main and 6in gunnery control towers had 4in floors with access doors to all except the CT. These doors were open in the main and port 6in towers and all the occupants were casualties.

4) 11in hit 1.5in forecastle deck amidships severe damage to light structures.

5) 11in hit 9in belt below waterline no damage.

6) 11in on side armour forward, no details.

7) 8.3in went through the after funnel.


It was unlikely that MOLTKE was ever fired at, and no hits were made on her. She expended 276 x 11in at between 16,000 and 18,000 yds and 14 x 5.9in at btween 13,000 to 14,000 at destroyers. LION was hit by 16 shells and TIGER 6 and it is likely that MOLTKE scored 8 or 9 of these.

SEYDLITZ expended around 390 11in APC and made at least 8 of the 22 hits obtained. She recieved 3 hits.

1) 13.5in APC from TIGER, forward with little damage

2) 13.5in APC from LION, struck quarterdeck and burst in holing of the 9in barbette armour of sternmost turret. Shell and fragmentation was kept out but plugs of hot armour fragments entered, piercing the ring bulkhead, and ignited 11in main and fore charges in the working chamber. The flash ignited charges in the gunhouse, in the lower hoists and handling room, as well as some in the magazine. The ignition of these charges was comparitively slow until the crew of the handling room opened the bulkhead door to allow fumes to excape, at this moment the charges in the handling room ignited and flash passed into the superfiring turret, setting fire to charges in the gunhouse, magazine and handling room. Altogether some 62 charges were destroyed, Fumes and flames made the after part of the ship untenable, but it was possible to flood the after torpedo flat and magazines. This hit has to be considered as a very serious event and the loss of the ship must have followed had SEYDLITZ used cordite instead of RPC/12.

3) 13.5in APC from LION burst on 12in main belt with no effect.

DERFFLINGER expended 234 x 12in APC and 76 x base fused HE (effictively SAP), and scored 5 or six hits. She was hit 3 times in return:

1) 13.5in from LION, burst near hull and caused some leakage.

2) 13.5in from PRINCESS ROYAL, similar to no. 1 but after outer starboard shaft tunnel bent. A diving hit.

3) 13.5in from TIGER, burst on 12in main belt armour, at junction between two plates, plates forced in by 2-4in and caused some flooding of the adjacent wing compartements.

[delcyros]

From the aforementioned hits we can see that MAIN BELT HITS were by far the most numerous hits of the pre-jutland incidents. This result appears to be contrary to general believe but I might add that the samplesize is rather small and -more importantly- incomplete. Compare the following graphs.


Note: the second graph shows superimposed points, significance is 65% out of N=44 investigated hits.

[delcyros]

The following two graphs show how the hits relate to distance, armour thickness angaged and are of impact. Note that some datapoints are superimposed.

Definitions for effect:

A) unknown: No data avaiable

B) no effect: Projectile engaged armour, projectile rejected without serious damage to the plate and without any fractures behind

C) Burst on impact: Projectile burst on impact with all parts of the projectile kept out and no calibre sized hole punched out. Damage to the frames and fastenings my still be considerable and hot plugs of armour may be punched out.

D) Burst in holing: Projectile holed armour with at least a calibre sized hole. Blast & fragmentation partly effective outside and inside with fragments of the projectile body / nose be found inside.

E) Pierced: complete Projectile pierces plate but either fails to fuse or is not in a condition fit to burst

F) pierced & burst inside: complete Projectile pierced the plate and burst behind the plate (including low order bursts).

[delcyros]

The following graph displays how the projectiles behave. The 8.3" and 11" projectile are german, the 9.3" and 14" are turkish, the 13.5" is british while the 12" projectile is either german or british, respectively.

[delcyros]

Discriminance analysis:

This is the graphical display of an investigation of the areas of impact and how they relate to each other in terms of individual ship, weight of projectile, distance, error in distance, effect, result.

The aim of every discriminance analysis is to verify groupings. The groupings analysed are the areas of impact. It is a very interesting statistical approach to display meaningful korrelations...

The dominance of main belt hits as shown in this graph is notable!

rectangles show mathematically centroids for each group.

[delcyros]

Some preliminary critics on the approach may be formulated herewith:

A) The amount of selected informations is considerable. The engagements are not comprehensive: The hits on ACR BLUCHER, GNEISENAU and SCHARNHORST are missed and their numbers are important. Unfortunately no detailed informations exist for these hits.

B) The allowance for target angles and obliquities is not known for all shells in question.

C) The exact mark of shell is usually unknown for all cases

Both limit any conclusioin drawn on the base of the datas. Nevertheless it appears unprobable that deck hits were given a larger percentage at long range than belt hits for Doggerbank, even if the significance is limited owing to A). More complete information, however, is aviable for Jutland. Note that the angle of fall for the ww1 UK 13.5"/45 at ca. 17.500 yards (LION & TIGER at Doggerbank) approximates the angle of fall of the ww2 UK 14"/45 and US 16"/45 with 2.700lbs APC to ca. 20.000 yards, thus attributing Doggerbank as "long range action" (hits on BLUCHER not counted. But probability is against numerous deck hits from point blanc range in this case).

The huge amount of damage absorbed by HMS TIGER and HMS LION in this action point to some interesting questions. Where british BC really that poorly protected / designed as we might read? I think that the degree of protection given to the Splendid Cats was adaequate for such a long distance of engagement. On the other hand the terrible long range shooting of PRINCESS ROYAL, TIGER and LION compared to that of SEYDLITZ, DERFFLINGER and MOLTKE foreshadow the run to the south of Jutland. Campbell is right in stating that it was probably fortunate for the british that Hipper broke contact...

[boater]

This is quite fascinating, especially given the discussions going on about Naval Gunnery for the forthcoming game "Jutland" at Distant Guns! - GameSquad Forums.

Good, solid, attributed data on the effectiveness of big guns in the dreadnought era would be fabulous.

In your available data have you kept track of where each data point was obtained, so it can be verified and not just dismissed as 'someone's opinion?' The data is nice to have, but being able to scrutinise and verify it would make it ever so much more useful.

Regards

Boater

[delcyros]

In your available data have you kept track of where each data point was obtained, so it can be verified and not just dismissed as 'someone's opinion?' The data is nice to have, but being able to scrutinise and verify it would make it ever so much more useful.

Primary and secondary sources for each datapoint exist and can be verified. They are based on british after action reports, the comprehensive 1920" Panzertreffer (source aviable in Bundesarchiv, Koblenz )detailing every hit in ww1 above 20mm armour for the HSF, and of course on scholarly works of brooks, padfield, Campbell & Co.