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Dmitry Yudo aka Overlord, jack of all trades
David Lister aka Listy, Freelancer and Volunteer
Showing posts with label doyle. Show all posts
Showing posts with label doyle. Show all posts

Thursday, January 3, 2013

[WoT] Doyle, Kubinka, and Much More. Part 9: Final Answer Bulletin

This post is the final one from Q&A session with H. L. Doyle, well-known German WWII military exert. See previous issues:

Batch 1
Batch 2
Batch 3
Batch 4
Batch 5


Doyle's replies are bolded (just in case).  


51.    I’d like to add something to the penetration questions.
What about:
I) partial deflection of sloped armour which meant that shells did not follow the initial trajectory even if they penetrated.
http://upload.wikimedia.org/wikipedia/commons/2/2a/Projectil_deflection_effects.jpg
see in c) the 'effective thickness' vs. 'line of sight thickness' and in d) 'inertia' vs. 'resistance force'
II) linearity of the 'penetration quality' -> % of fragments behind the plate (the 50 vs. 75% thing) and to what extent this allows you to make assumptions about a certain shell in a different nation's test

As I explained before I have not researched this field of penetration to any great extent.  There is a lot of material in various archives but I did not collect copies.  I am sorry.

52.    I would like to hear what were the merits and drawbacks of the VK3002DB design compared to the MAN version and why it was not chosen in the end.

In our book “Germany's Panther tank” - the quest for combat supremacy, we reproduced many pages of the history of the development of the VK 30 series and the intense competition between M.A.N and Daimler-Benz.
 I will quote the record of a meeting of the Board of Daimler-Benz on 3 June 1942 which describes the final outcome of the competition.
Our proposal for the new tank was not accepted by the special Commission established by Hitler.  Instead they selected the M.A.N design for a large-scale production after the initial proposal from M.A.N apparently was improved.  During a meeting M.A.N had the opportunity to learn all the advantages of our proposal which they then took into consideration in their own design.
At first the majority of the experts were impressed by our proposal.  Even Hitler had expressed his approval. But then the Commission consisting of Thomale and Eberan decided against us for the following reasons:
1.    the double torsion bar suspension from Porsche was chosen over our leaf springs
2.    the MB 507 motor proposed by us cannot be produced in the numbers required
3.    Our design requires a new turret.  The turret for the M.A.N design was already designed.  The M.A.N vehicle had front drive our vehicle had rear drive.  Because of the rear drive our vehicle required a new turret design.  It was admitted at the rear drive possessed advantages.

We are completing only two experimental vehicles that positively will make a good impression.   The two experimental vehicles are to be completed in June /July of 1943.  The entire tank should be completed since we can finally obtain the turret ourselves.  We still have the contract to build these two prototypes and therefore we will also want to demonstrate these as completed tanks.
A Rheinmetall turret mounting the 7.5cm K.w.K 42 L/70 had been designed as an alternative for the Tiger starting in mid 1941.  This turret was the basis of the turret on the M.A.N Panther.


53.    How much information is there yet to be discovered in old German wartime archives? Has everything pretty much been looked thoroughly, or is new or under-examined material still surfacing?

Probably less that 10% of the documentation generated during Panzer development from 1928 to 1945 has survived.   A most was destroyed at the end of the war and sadly quite a lot since then.  During the seventies and eighties we visited many companies and fortunately we were given access to archive materials but now the material we saw has “vanished”   In other cases when we arrived at companies we got the response “it is a pity you did not visit last year before the man in charge of our old archives retired and as we have no need to keep old paper they have been destroyed”
At the Bundesarchiv the 80/20 rule applies to research – probably 80% of the information has been found as it is the part relatively easy to search.  Definitely there is additional information to be located but it will take a long time to find the materials as they are not filled in the expected locations or have yet to be catalogued. There is even a small chance to find new facts by accident when researching other matters. 
The greatest success for Panzer Tracts has come from researching all of different archives in many countries and developing an understanding of what files are worth investigating.   Private and specialist collectors also add finds from time to time.
New finds are very important as sometimes they throw light on and explain other data from old research that may not make sense.


54.    How long did it take for the Germans to build their tanks in WWII? Again, according to Osprey's _Panther vs. T-34_ the panther took eighteen times more man-hours to build than a T-34-76. Do you have any idea where these figures came from, and whether they are accurate? If German tanks did take longer to build than allied tanks, was it because their designs were complicated or because German industrial techniques were inefficient?

I have not seen any “original” document with such a direct and wild comparison as claimed by the author of this Osprey book.  Clearly, the Panther was a complex machine with a very high level of detailed finish as could be expected from a product of German Industry.  I have often wondered about the need to bevel every armour plate and machine so many surfaces, but I doubt the time 18 difference.  The Germans did not put their industry on to a full war footing until 1943.  The highest production of all types of Panzers was achieved in November 1944.  Component production was highly dispersed but delivery depended upon reliable rail transport.  Increasing shortages of raw materials, manpower, and especially energy caused by bombing caused many problems.
Below us a drawings I made showing the M.N.H. factory in Hannover that was assembling Panther and Jagdpanther.  Certainly they were not using “Henry Ford” mass production methods where each worker did the one job all the time.  Groups of workers were responsible completing the entire task associated with each stage.



55.    Are there any data on German tests of captured Allied weapons?

The German test establishment at Kummersdorf tested many Allied Tanks but as Allied Tanks are not my field of research I have never ordered copies of these documents.


The above photo which was sold on eBay shows a parade of the Kummersdorf detachment with some of their Allied test vehicles in the back ground.  The Kummersdorf reports were like those produced by the British and Russians and gave a commentary on the performance and capability. 

As can be seen on this photo of an IS152 the armour thickness and angle was painted on all test vehicles by Kummersdorf.



The German usually tested their guns against their own vehicles.  Periodically hulls were provided by the armour manufacturers to be used as targets.  Here is a photo Porsche Tiger hull manufactured by Krupp that was set aside and used as a gunnery test on 30 April 1942.


Bonus facts
 
Additional fact pertaining to Questions 33 and 48 on turret traverse speeds

Panther
I located my copy of a British technical examination dated 9 May 1945 on Panther turret traverse speeds.  The performance is quite spectacular when compared to the Tiger Ausf.E. and combined with the accurate 7.5cm K.w.K 42 L/70 made the Panther a tank to be feared if the crew was experienced and motivated and the unit well led.

Like the Tiger the Panther had a two speed hydraulic power traverse. The gunner could selected the desired speed with a gear lever and then using a pivoting foot pedal he could push on the forward end to traverse right and push on the back to traverse left. 

The speed depended upon the main engine speed so at 2500 rpm and in the high gear a full 360 degree traverse would take only 17 or 18 seconds depending on the direction of traverse.  At 1000 rpm the same 360 degrees took 46 seconds. 

When the lower rear was selected and the Maybach HL 230 was running at 1000 rpm 360 degrees took 92 or 93 seconds depending on direction.

KVI
I found a similar report on the KV I.   A three speed electrical power traverse was provided.  At the highest speed the turret took 71 seconds to traverse 360 degrees at the lowest speed it could take 122 seconds for 360 degrees. 

T34/76
The test on the T 34/76 using a similar electrical power traverse to the KVI in high gear could achieve 360 degrees in 14 seconds.
And extra a few tit-bits

The Germans captured and translated Russian document on Tank Tactics published in August 1944
...tank-versus-tank battles are unavoidable but whenever possible German tanks are to be destroyed by the air force, artillery and antitank weapons so that our (Russian) tanks remain free to attack the infantry...
From a German Report of the same period
 .... Russian troops are commended for striving to prevent IS tanks from falling into tour hands and it would be desirable that our Tiger crews would observe the same principles.


PS: Next time we are going to continue with Soviet tanks expert - Yuri Pasholok.

Friday, December 7, 2012

[WoT] Doyle, Kubinka, and Much More. Part 8: Fifth Answer Bulletin

This post is the continuation of Q&A session with H. L. Doyle, well-known German WWII military exert. See previous post. Doyle's replies are bolded (just in case). 

 41.    Aside from the obvious advantage of not requiring rubber, what advantages did the German use of interleaved road wheels have over allied suspension types, such as the Christie or E8 suspension?
 

Steel tired road wheels were adopted for heavy tanks by both the Russians and the Germans.  In this design the rubber tyre still existed but was imbedded internally in the steel  wheel where it was protected from abnormal wear and tear.  The drawing below show a very good comparison of conventional Panther wheels and the steel tired wheels that were in the process of introduction at the end of the war.  
 



42.    I have heard that in early model panther tanks there was a design fault in the turret ring which meant that if the gun was fired with the turret facing 90 degrees to either the left or right from the front plate, the turret would come off the tank under the force of recoil. Is this true?

I have never seen any evidence of such a design fault and would doubt that it ever happened.  The Panther turret was simply an up-scaled version of the tried and tested designs already used on the Pz.Kpfw.III and IV. 

German turrets were constructed with the turret race built as part of the turret.  The complete assembly was then mounted on the tank hull making the levelling and alignment easy.   At least for British tanks the turret race was usually built into the hull before the turret was mounted.  This complicated the subsequent alignment.  I do not know the practice for US or Russian Tank turrets.  However, in Allied reports after the war, the German practice of integrating of the turret race with the turret was noted as worth adopting.


43.    Was the Sturmpanzer 1 ever used for indirect artillery support? or was it mainly an interim assault gun?

Sturmpanzer 1 is a name invented in recent years by modellers to make this expedient self-propelled gun more “exciting”.  The correct and only designation was  “15cm S.I.G. (Mot S) auf Pz.Kpfw.I ohne Aufbau Ausf.B”

Thirty eight of these self-propelled guns were completed in February 1940.  Six Panzer Divisions each received a company to provide mobile artillery support.  The gun, Schwereinfantriegeschuetz 33 (S.I.G. 33), was developed to provide infantry with large calibre high explosive artillery support.  The complete S.I.G. 33 with wheels was loaded onto the chassis of a Pz.Kpfw.I Ausf.B and the result was very effective as it allowed quick deployment.  In fact a few were still in service in mid 1943. 

Obviously, the Pz.Kpfw.I only had thin armour but the shield surrounding the gun was even weaker as it was only designed to protect the crew from lead bullets.  As such it was not intended to be used as an Assault gun.


44.    Do you think any of the Second World War German tanks (production and prototype) such as the Panther, King tiger, E-75 and Panther II would be able to reliably compete with any of the allied post war designs as they do in world of tanks? (such as the US M46, M103 or Russian T-54 and IS-7)

If one discounts the collapse of German industry in 1945 it is possible to extrapolate German Panzer developments for about two years. 

In the final weeks of 1945 the new Panther Ausf.F had entered production.  The hull was deemed very satisfactory and only had minor improvements compared to the Panther Ausf.G.  As I mentioned before Maybach had already been testing more powerful versions of the motor. 

The big innovation was a brand new Schmalturm (narrow turret) which eliminated frontal weakness of the older turret and even reduced the weight.  A full width rangefinder was mounted in the turret which combined with the existing highly accurate and successful 7.5cm K.w.K 42 L/70 would have increased the possibility of  the all important first round hits.  

The Panther Ausf.F had the capability to be an excellent all round work horse for a number of years even without other innovations that were planned. The design of the Schmalturm allowed for mounting of larger weapons such as the 8.8cm K.w.K 43 L/71.  The Germans were also experimenting with autoloaders and gyro stabilisation to further improve gunnery performance.

Similar improvements were underway for the Tiger Ausf.B.  A turret capable of taking an even wider rangefinder was already in production at the end of the War and the more powerful motor was expected.

As mentioned in my answer for Question 30 the E series was envisaged by Kniepkamp (Civilian Head of Automotive design) only to explore future components especially engines, transmissions and suspensions.  Production contracts were not yet envisaged so we do not know that then next steps might have been.

In answer to question 4 I pointed out that the Panther II was an very early project that was dropped after the invention of Schuerzen plates on the Panther Ausf.D  in 1943.


45.    I want to know why the Germans numbered Panther as Pz 5 and Tiger as Pz 6. If Panther was newer, and better in battlefield, and even wasn't in parallel development with tiger Pz 6.

Why German designations were so complicated and diverse is one of the great unanswered questions.  Firstly, the design firms had their own designations, secondly, the different procurement and Army agencies used different designations for the same vehicle and all of these changed over time.   In our Panzer Tracts Books we set out a table of the various designation and their time line.

In the primary source records for the Tiger the original title used by the firms was VK.45.01 (Volkettenfahrzeuge 45 ton class, first design) this was in July 1941.  Wa.Pruef 6 used the designation “Pz.Kpfw.VI Ausf.H1 (VK.45.01)” for the first time three months later in October 1941 and Pz.Kpfw.VI was used on some documents until December 1942.  The name Tiger only appeared in February 1942.

With the Panther it was different with the name Panther appearing already in March 1942.  The designation Pz.Kpfw .V came in for a period starting in July 1942.


46.    Could you maybe explain what the advantages and knowledge was around that time of having front or rear transmission?

In 1928 the Germans began to experiment with tank designs using the latest technology of the time.  Three companies – Daimler-Benz, Krupp and Rheinmetall were responsible for the Grosstraktor and Leichttraktor designs all of which feature rear drive.  After extensive testing of these tanks in Russia at Kama, near Kasan, from 1929 to 1933 the Neubaufahrzeuge was ordered.  The Neubaufahrzeuge again featured rear drive.

The development of the Pz.Kpfw.I tank was shortened by purchasing three Carden-Loyd Light Tractors from England and basing the new tank on that design.  Thereafter, the Germans favoured front wheel drive.  I have never seen an explanation for this change from rear to front. 


47.    How effective HE rounds were in tank-tank combat, and I’d also like to hear more about the accuracy of tank-mounted guns at that time?

The normal German Panzergranate (armour piercing round) had a high explosive charge which detonated on penetration.  The Sprengranate (high explosive round) was not intended to be used to penetrate armour but for general purpose attacks on light armoured and soft skinned vehicles or infantry targets.  However, a detonation of a Sprengrenaten on or near an enemy tank could cause damage and disorient the crew leaving the tank vulnerable to further attack.

As mentioned before I do not have documents on accuracy although the do exist in the archives.  Anectdotally the 7,5cm K.w.K 42 L/70 of the Panther and the 7,5cm PaK 40 L/46 were regarded as the most accurate of the German guns.  However, records of 1943 to 1945 tank battles indicate that engagements were often ended after on or other side expended all of their ammunition.  The German troops were always asking for greater ammunition storage in their Panzers.


48.    How fast did the Henschel tiger's turret rotate?

Question 33 can be answered with this information also. 


The British technical examination found that The Tiger Ausf.E had a two speed hydraulic power traverse. The gunner could selected the desired speed with a gear lever and then using a pivoting foot pedal he could push on the forward end to traverse right and push on the back to traverse left.  The speed also depended upon the main engine speed so in high gear 360 degree traverse would take only 60 seconds.  At idle speed the same 360 degrees took 360 seconds.  If for any reason main engine was not running then gunner and the commander were equipped with manually operated hand wheels to traverse the turret.  2 rotations of a hand wheel gave a 1 degree traverse. The final fine adjustment was always done with the gunners hand wheel.  The British examiners found these arrangements very satisfactory.


49.    What materials were used to make the armour of the Panther and King Tiger?

Materials have not been a focus in my AFV research so I have not made copies of the many reports on armour I have seen in various archives.  The British had a very thorough technical examination system for captured vehicles and issued a number of reports on armour.

Following the collapse of Germany Allied Intelligence teams were specifically tasked with gaining immediate access to the German steel firms in order to collect specific information on the composition and production techniques for German armour plate as it was recognised that this was of very high quality.


50.    If you could please tell us, what is your estimation as to the thickness of the lower glacis / nose plate of the E-100 design?

The drawings of E-100 Versuchsfahrzeuge (Test vehicle) show that glacis plate was 200mm and the lower nose plate 150mm.

And the bonus photo