Lethality of various types of ammo

[critical mass]

Notice that the soviet HE-filler for the BR-350 sharedby Miles contains an aluminized RDX variant, desensified with wax.
If 1944 is taken as base for the filling (filling and manufacture of the projectile do not need to match, due to refillings), than this indicates an earlier date for RDX than I had come across previously for RDX as filler in soviet AP projectiles. The use of aluminium is a booster but more effective in underwater blast than air blast, it radiates more heat but at the expanse of blast force.

RDX is a very powerful high explosive, developed independently, by the germans pre-ww2 and by the british during ww2 (then adopted from them by the US). It replaced TNT as filler in german projectiles by midwar (Füllung 92 contained 95% RDX and 5% wax). In small quantities, RDX is sufficiently stable to be put in small filler AP projectiles (large cal projectiles would require various mixtures to increase shock stability, there were experiments with 50% tetryl, 45% TNX and 5% TNT for them instead).

The high stability filler does not explode by itselfe. While shock impact could detonate many of the higher powered explosives like Grf.88 (lyddite) or Tetryl it failed to do so in desensified RDX or TNT, the latter of which was extremely shock resistent and required a functioning, very powerful base fuze with gain and booster which detonates the shell body after it performed penetration in an intact condition. There is a balance to be found between base fuse power, size of cavity, type of filler and projectile solidity. If the base fuze was too powerful, it could damage the thinner (and sometimes damaged) projectile side walls and crack may even reach the cavity, thus resulting in a low order detonation (only 1/3 as powerful). If the base fuze was too weak, it would often cause a deflagration (blow out event), directed backwards (found to be frequently a problem with TNT fills). Base fuzes were not perfected in ww2 (the british rejected base fuses at all for their mass produced anti tank AP) and optimized for a specific plate-velocity-obliquity combination, typically perpendicular impact in the SU and 30° (later increased to 45°) in Germany.

If the projectile stayed intact, base fuzes could work out to 70° before blinding. Krupp developed for major naval APC a special grace function which permitted the fuzes working out to 75° in most - and 80° in few cases. The thicknesses of plate which can be readily defeated at such extreme angles by the projectile in an intact condition (no damage or crack reaching the cavity or deformation of the base) is limited to lower velocities (500m/s and down) because higher velocities exponentially increased the risk of base damage at such high obliquities (remember, at much over 45° the penetration attempt will turn into a base first penetration event).
This, of course, is a problem for higher velocity impact, typically encountered in anti tank work, where the projectile regularely would undergo break up at lower velocities and thus, thinner plate thicknesses. There were many problems with fuzes not working under those conditions against moderately thick plate and high velocities.

For ww2 soviet BR350B type projectiles, the missing base temper conitutes a considerable problem, rendering the projectiles ineffective when striking obliquily. But this in turn -I speculate here- might have been the stimulation necessary to adopt highly sloped armor plating all around for tanks, which increased the resistence against their own projectiles much beyond what would be imagined with thicker plates.

[Ulater]

Well, this thread is a joy to read.

Post your source and on what evidence was it based.

It is from the Technical Memorandum ORO-T-117 Survey of Allied Tank Casualties in World War Two.

I have to find the exact page to tell you what it was based on.

[Christian Ankerstjerne]

Two posts contributing nothing to the discussion have been removed.

[Richard Anderson]

It is from the Technical Memorandum ORO-T-117 Survey of Allied Tank Casualties in World War Two.

I have to find the exact page to tell you what it was based on.

The summary of findings WRT personnel is on page 4: "Limited data on Allied tank crew casualties indicated that an average of 2.0 to 2.5 crewmen per tank became casualties, including killed, wounded, and missing-in-action, to attack by gunfire, hollow charge, or mines."

The detailed report on personnel casualties is pp. 33-43.

[Yoozername]

http://cdm16635.contentdm.oclc.org/cdm/ ... pftype/pdf

[Ulater]

The summary of findings WRT personnel is on page 4: "Limited data on Allied tank crew casualties indicated that an average of 2.0 to 2.5 crewmen per tank became casualties, including killed, wounded, and missing-in-action, to attack by gunfire, hollow charge, or mines."

The detailed report on personnel casualties is pp. 33-43.

Yes, and this is from page. 36.



And I know, It is just a smaller report, but I think the broader sample is dilluted by knocked-out tanks that were not penetrated through the crew compartment, or were not penetrated at all, and that was not what I was looking for.

[Yoozername]

And I know, It is just a smaller report, but I think the broader sample is dilluted by knocked-out tanks that were not penetrated through the crew compartment, or were not penetrated at all, and that was not what I was looking for.

That is my take also. The sub-topic of how many tanks were KO'd is actually off-topic IMO. Even the location of hits is not important. 'Side-hits' can be impacts at very oblique angles when in actuality, the target is presenting its frontal armor predominately. Its a moot point unless you can relate it to the OP topic. Clearly attacking forces in close terrain will have tanks hit almost all around.

In the case of HEAT vs. AP (AP and all it's capped types), they have similar statistics as far as having a destructive effect on penetration. It would be interesting to have data regarding shot vs shell (APHE) as far as destructive effects. Other cases like tungsten carbide penetrators also.

[Ulater]

Still not close enough, but I have found something surprising.







This seems to conflict quite a bit with the high degree of allied tanks burning according to ORO-T-117, and reports contained in Jentz's books for example on how destructive the ammo was.

[critical mass]

The fuze effect requires the fuze to be able to work properly. Esspecially against harder grades of armor (either high hardness homogenious or surface hardned) and at high obliquity, satisfactory fuze action is very variable.

[Ulater]

The fuze effect requires the fuze to be able to work properly. Esspecially against harder grades of armor (either high hardness homogenious or surface hardned) and at high obliquity, satisfactory fuze action is very variable.

Is there any literature or documents discussing this subject?

[Kawinksy]

The German Army manual H. Dv. 469 / 3a "Panzerabwehr aller Waffen", dated 2.2. 1942 (link) makes some notes how to test armor-piercing rounds:

1. In case of new emerging tank designs, which are [currently] not covered in the "Panzerbeschuss-Tafel" [anti-tank pamphlet], are - when the situation permits - to be tested against all available armor-piercing weapons and ammuntions.The same applies to tanks, which armor has hitherto been unknowingly reinforced.

2. The distances of the firing test are to be commenced from 100 m, then progressively increased by one hundred metres until the limit of the resistance is established. If it is not possible to penetrate the target at 100 m, the firing can be carried out at 50 m. Any ammunition used for trial have to be secured against splinter and ricochets.

3. To verify the destructive effect [of armor-piercing rounds] in the fighting compartment, it is advisable to use lively small animals (e.g. dogs, cats, etc.) on various positions.

The firing trial must always be carried out at 60 degrees obliuity, (vgl. Ziff. 17). If no penetration can be achieved, then the firing has to be done at 90 degrees vertically.