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Posted: Wed Apr 06, 2005 11:02 pm
by marty1
Tiornu wrote:"Perhaps you can elaborate on why you are so sure MkIII was used in the Baden trials and not Mk1."
the jutland-type shell was replaced fairly quickly after the battle. the shell that replaced the jutland shell appeared soon after; this is the greenboy, and it was standard until c1923. the only ap shell which is identified specifically in the report is a non-standard one. there would be no need to identify a standard type.
i can't imagine the rn would go to the trouble of conducting trials and then use shells that had been obsolescent five years earlier. i can imagine a comparitive trial of old and new shells, but then the report would be focusing on that aspect; here we have no mention at all. so the question should be, why would we think the shells were not greenboys?
I found the following in Admiralty Record 186/251, “Progress in Gunnery Material”, dated 1921. The report was written post Baden Firing Trials, and actually encompasses the results of the Baden Firing Trials in one of its Sections. Of interest is a bit in Section X of the report dealing with ballistic proof testing of armor plate:

Existing Specification Tests for Armour. –At present our plates are tested with pre-war standard A.P.C. shells at normal impact (Pre-War obviously refers to pre-World War One). These specifications will remain in force until the correct tests with new shells at oblique impact enables us to lay down more modern conditions of proof of amour plates.”

So as of 1921 the Admiralty proof testing of Armor plate was still employing pre-WWI APC shells.

A table than follows indicating that 15inch A.P.C. IA will penetrate approximately 15-inches of KC armor @ 0-degrees @ 1500-fps.

Posted: Mon Jun 20, 2005 7:22 am
by Serg
Hi guys,
I examine russian armor penetration formulae (modified form of De Marre formula, accepted in Russia in 20th years), and I don't have good descriptions of shots against the thick horizontal armor at high obliquity. It is possible to post rounds against Baden's roofs, I have in view rounds 1,2,5,6,13.

Re: 1921 firing trials against Baden

Posted: Tue Oct 27, 2009 5:58 am
by José M. Rico
I found this piece of information about the Baden trials and remembered this old thread.

This is from:
Armor Penetration Trials with Baden

In 1921 the British conducted a series of gunnery trials using the last battleship completed by the Germans during World War I, the surrendered Baden. These trials were conducted as a part of the design process for the next generation of capital ships, which were later cancelled as a result of the Washington Naval Limitation Treaty. During these gunnery trials, the monitors Erebus and Terror fired a total of 31 shells using reduced charges in order to obtain striking velocities equivalent to the expected battle ranges. Two primary striking velocities were used, 1,550 fps (472 mps) simulating a range of 15,500 yards (14,170 m) and 1,380 fps (421 mps) simulating a range of 21,800 yards (19,930 m).

Tests at 1,550 fps (472 mps) with 4crh "Greenboy" APC showed that these projectiles could penetrate turret face armor of 35 cm (13.8 in) when struck at an angle of 18.5 degrees and penetrate barbette armor of 35 cm (13.8 in) when struck at an angle of 11 degrees, but that this same armor thickness on the conning tower successfully defeated an APC striking at an angle of 30 degrees. Another test at this velocity saw an APC striking at an angle of 14.5 degrees penetrating the upper armor belt of 25 cm (10 in) and this shell then traveling some 38 feet (11.6 m) before bursting on the funnel casing and damaging two boilers, having first penetrated a 3 cm (1.2 in) splinter bulkhead and the 1.2 cm (0.5 in) main deck.

Five rounds of APC were fired at 1,550 fps (472 mps) at the 10 cm (3.9 in) turret roof armor, with four of these failing to penetrate.

Tests at 1,380 fps (421 mps) with CPC projectiles showed that armor of 17 cm (6.75 in) could be penetrated, but that these shells could neither penetrate nor significantly damage the 35 cm (13.8 in) barbette armor when striking at a 12 degree angle.

There is a cautionary note in ADM 186/251 that may apply to these trials:

Unsteadiness of shells at plate proof - When firing shells with reduced charges to obtain the required S.V. [striking velocity] for the proof or trial of shells or armour, particularly with the larger natures, there is a tendency for shells to be unsteady in flight, as shown by the shape of the hole made in a jump card erected in front of the armour plate. This unsteadiness tends to vitiate the result of the trial. As each round at thick armour may cost as much as £2,000 or more, it is a serious matter to reject the evidence of a round and to repeat it on the score of unsteadiness, although this has sometimes to be done.

The Admiralty's overall conclusion from these trials was that the new "Greenboy" APC projectiles had satisfactory penetration characteristics, although their fuzing was not considered successful. Neither the experimental SAPC nor the older CPC used in these trials was considered to be effective. The penetration of the SAPC was disappointing and showed no advantage over APC. The CPC projectiles had considerable blast effect, but the fragments created by their thin walls were too small to cause significant damage.

Data in this section is primarily from "Washington's Cherrytrees: The Evolution of the British 1921-22 Capital Ships" articles by John Campbell, from excerpts of ADM 186/251 provided to me and from "The Baden Trials" article in "Warship 2007" by William Schleihauf.

Re: 1921 firing trials against Baden

Posted: Tue Oct 27, 2009 6:10 am
by José M. Rico
"The Baden Trials" article in "Warship 2007" by William Schleihauf. ... ls&f=false

Re: 1921 firing trials against Baden

Posted: Tue Oct 27, 2009 3:09 pm
by Bgile

Re: 1921 firing trials against Baden

Posted: Thu Oct 29, 2009 1:10 am
by Karl Heidenreich
This has been here all this time? Wow!

Re: 1921 firing trials against Baden

Posted: Thu Oct 29, 2009 1:57 am
by José M. Rico
Karl Heidenreich wrote:This has been here all this time? Wow!
Yes, this is the thread with more views of the whole forum: 45,222!! :shock:

Re: 1921 firing trials against Baden

Posted: Thu Dec 03, 2009 10:03 pm
by marty1
José M. Rico wrote:
Karl Heidenreich wrote:This has been here all this time? Wow!
Yes, this is the thread with more views of the whole forum: 45,222!! :shock:

I Havent been here in awhile. Thanks for posting the additional information on the Baden Trials. I dug up sveral of the references cited on the NavWeapons forum and it seems pretty definative.

Re: 1921 firing trials against Baden

Posted: Fri Dec 04, 2009 12:18 am
by José M. Rico
You're welcome.
Nice to see you around Marty.

Re: 1921 firing trials against Baden

Posted: Sat Jun 04, 2011 12:20 pm
by delcyros
The Baden Firing trials represent British 15” APC & CPC Shells vs. German circa-WWI KC armor. Specifically, I am referring to the limit case of 15” APC vs 13.75” of KC -- the limit case is about 1550-fps at about 25-30-degree obliquity.
The Bayern and Baden were sister ships.

My point is that the armor on the Baden and how it performed during the British firing trials is basically identical to the German's KDOS estimate of how circa WWI German KC armor will perform vs. 15” APC. All I'm saying is that I don't think there is evidence within the Baden trials of substandard performance of this ships KC armor.
The BADEN trial´s do not show substandart KC performance. At all, the armour didn´t fail a lot with spalling and plugging except when hit close to the plate edges as was the case with the 15in APC striking the turret face. Note that the view angle of the picture omitts the fact that this penetration is subject to plate edge effects:


To further complicate things, the author of ADM either made a typo or a miscalculation for the netto impact obliquity. This is stated to be 18.4 deg but the involved horizontal and vertical angles are referenced there to be 11 and 12 deg, respectively. That makes for a netto impact obliquity of 16.22 deg, only.
The projectile penetrated completely with very low remaining velocity and received sufficiant projectile damage to render it blind (eventually it was blown up after many attempts with help of a guncotton charge to assess damage of a possible high order burst inside the turret). The same happened to the other 15in AP striking the 350mm barbette, which didn´t blinded but burst in holing the 350mm barbette armour. Nose & shoulder were found inside the barbette, striking it at correct 11 deg obliquity.
Without fuse action it must be assumed that this projectile would have completely penetrated in this condition.
Two more 15in APC tests were conducted at 30 deg (one at the CT and another on a barbette from the 2nd series of trials) and neither was able to penetrate or to hole 350mm KC at this obliquity, the round 15 from 1st series of trials hit the CT and APC round No.6 from 2nd series of trials hit the very joint of two 350mm plates of barbette A at 32 deg and made a dent 3in deep).
No 15in trial APC penetrated 350mm KC in a condition fit to burst.
One projectile hit the curved 350mm barbette at 11 deg and burst in holing (probably penetrated with a blind fuse)
One projectile hit and barely penetrated the 350mm turret face of B in blind condition close to the plate edge at 16.2 deg
At 30.1 & 32 deg these projectile couldn´t hole nor significantly damage 350mm (dented in by 3in on the plate joints).
The limit obliquity is probably in between 15 and 20 deg for the projectiles of these trials to defeat 350mm ww1 vintage KC at 1550 fps.
Striking in within 11 and 16.2 deg netto obliquity, it is highly unlikely that they could penetrate 0.918 cal ww1 vintage german KC in a condition fit to burst (Round 14). If the fuse remains intact, the delay would blow up these projectiles anyway before they completely pass the plate (Round 9). If they happen to strike at larger oliquities, they will fail to penetrate or significantly damage 350mm KC plates (Round 15 from series 1 and Round 6 from Series 2)

From evidence of the discussion of these results, it appears that MkIII GREENBOY were used for these APC impacts mentioned as the RN was statisfied with the armour piercing performance of their "new" APC. Alternatively, also MK1-mod may have been used in these trials (these were old Mk1 APC given a new armour piercing cap, copied from Krupp and remodeled nose with 1.6D headradius instead of the usual 2.0D of original Mk 1 to fit the new cap).

Re: 1921 firing trials against Baden

Posted: Sat Jun 04, 2011 6:23 pm
by delcyros
While there have been big difficulties in the BADEN trials to penetrate relatively thick armour (near calibre thick as in our cases with 15in APC striking 13.8in KC), there were relatively few difficulties to penetrate medium armour in these trials:

170mm /6.7in /0.45 cal plates for the 15in:
[+] No.16 penetrated 6.7in battery belt at 18 deg and burst after 53ft delay
[+] No. 4 was striking the 6.7in fwd at 22deg and penetrated in condition fit to burst (38ft delay)
[+] No.12 (light APC) striking the 6.7in belt fwd at 27 deg and penetrated (30ft delay)

250mm / 9.8in / 0.66 cal plates for the 15in:
[+] No. 8 was striking the 9.8in upper side belt at 18 deg and just penetrated with a low order detonation, indicating damage to the projectile (7ft delay)
[+] No. 17 penetrated 9.8in upper side belt at 14.6deg and burst after 38ft delay

Fuse delay was very inconsistent and outlined by the authors to be unreliable. Indeed, when the japanese copied the GREENBOY design and used them in their TOSA-trials, they pretty much experienced the same unreliability with delay pattern ranging from ultra-short, nearly non-delay action to longer than desired fuse action. The penetration performance pretty nicely mirrors the performance of german L3.1 & 3.2 APC in Jutland, which were unable to penetrate near calibre thick armour in the conditions of impact but had little problems defeating half calibre sized plates at a wider range of obliquities.

The aforementioned hit on the turret face of SMS SEYDLITZ is noteworthy for two reasons.

1) this was an old pattern, type 1 APC with 2.0D headradius and Firth soft armour piercing cap. These projectiles, similar to Krupp L2.8 APC (there was a tehnology sharing agreement between Krupp and Firth) introduced ca. 1902 and replaced by more improved Krupp L3.1 APC about 1911-13 had more penetration capability when striking right angles than later mk-III GREENBOY or Krupp L3.2 APC. At the specific condition of impact and generally in between 0 and 15 deg obliquity soft caps work. Normal penetration for this projectile striking at 1640 fps would be 22in KC (ca. 18in at the reduced impact velocity).

2) the inability of the projectile to penetrate just 250mm of KC at 0 to 5 deg obliquity is therefore only explainable in case the soft armour piercing cap shattered on impact (almost cutting penetration performance of this projectile in half at right angles impact). This is indeed true, as I believe. Krupp changed the details of manufacture of it´s KC slightly initiating 1906, mainly triggered by an attempt to delete the "plugging" problem experienced with thick KC plates and in order to adress the increased level of competition for armour manufacturers in europe. It is not known how long it took in the procurement process but Tirpitz mentions in a letter that Krupp and Dillinger required 32months for prodution, proofing, transportation and installation of their KC armour plates. From Jutland we know that a very similar 225mm upper side belt plate of SMS VON DER TANN didn´t stopped or shattered a similar 15in APC mkIa striking at at about the same range with the projectile in one of only two cases known penetrating and bursting behind armour high order. VON DER TANN was a 1907 programm cruiser and seems to have not received these plates. MOLTKE on the other hand repelled two 15in MkIa APC striking it´s belt armour 16.23 and 16.23 and SEYDLITZ, a 1910 programm ship repelled a 15in at this range with almost no obliquity involved. This allows us to put the change time to ca. 1909/10 -when You have similar improvements made in manufacturing KC in the US, Britain and Austro-Hungary and (I suppose) in Italy and France, too.
The other impact which penetrated and burst behind armour was that often repeated hit on the 260mm barbette of SMS DERFFLINGER. But this was at to low obliquity and to short of the range so that the projectile could have penetrated in nose or full shattered condition anyway, independent of successful cap action.