"This report describes the studies undertaken on the four principal german SPGs used in service in the late war. They are the PzJag 35(t), PzJag IV, Jagdpanther and Jagdtiger. The objects of these studies were firstly, to examine the main armament loading arrangement and assess the loading times, and secondly to examine the crew's controls and accomodation."
Seems simple enough. British researchers made several brief conclusions - controls were badly positioned and accomidations were generally unsatisfactory, but ammo stowage was well-positioned.
"
(i) When the gun is traversed left or right, it hems in certain members of the crew, to the detriment of the performance of their duties.
(ii) Crew seating is badly designed and positioned.
(iii) Vision devices are badly mounted and positioned, and in many cases inadequate.
(iv) Gun controls are badly positioned.
(v) Driving controls are badly positioned.
(vi) Basically, the ammunition stowage is well-positioned, but bin fittings and the position of rounds in the bin is unsatisfactory in some of these vehicles.
(vii) Loading times, though reasonably fast, could have been reduced if the disadvantages in (vi) had been eliminated. "
However, its not all as bad as it seems, as researchers leading the study admit that "(ii) to (vii) are minor points of design, since they could easily have been eliminated by more careful attention to the design and positioning of minor items. Item (i) is not as serious as it would seem, since the vehicle could be steered to face the target while keeping the gun on central traverse."
Sounds like slave labor, lacking quality control and/or disconnect between end-users and designers.
Well lets see what the final verdict is:
" Although certain comparatively small disadvantages exist in the S.P.G's studied, these could have been easily overcome. The basic design of all four vehicles is excellent, and the advantages and disadvantages of this type of A.F.V are compared in this report with those of turreted vehicles (tanks. In our opinion, the results show that in many respects, the S.P.G is a better vehicle.")
Information taken from WO 291/1307 - Motion studies of german S.P equipments, pg. 3-4.
My blog is a place where I upload various ww 2 documents, analysis and various reports that found their way into my hands. I hope you will like it.
Thursday, 15 September 2016
Monday, 5 September 2016
The curious case of "ronson", Pt.2
I ended the Pt. 1 of this article with assumption that the prominent sponson racks on early Shermans were an attractive target for enemy gunners. ORO-T-117, Survey into allied tank casualties in WW 2 seems to comfirm this assumption.
Apart from forward side of the turret and driver's position, researchers noted that german gunner also favored the sponson stowage on early M4 Shermans.
And again, this analysis is showing a rather high number of burned-up tanks. However, it is not that simple. as the statistic of "burned because of charge" is ambiguous and does not seem to directly indicate whether it is a hollow charge or demolition charge. Considering that researchers are only counting with the categories of tanks destroyed by gunfire and tanks burned up because of hits in simillar studies involving german tanks, I will apply the same logic here.
Which means that if 42 tanks out of 72 burned, it is 58%.
Compare this to Pz. III and Pz. IV:
20 out of 59 burned, which is 34%.
12 out of 30 tanks destroyed by gunfire burned, or 40%.
Well, let's not hang on one study. Here is another report from 1945 that claims 60% - 90% of
75 mm Shermans are lost by burning. Armoured bins seem to reduce the risk of fire nearly tenfold.
In cocnlusion, it certainly looks like Shermans that were not modified with protected ammunition storage were in a very high risk of fire from penetrations.
Sunday, 4 September 2016
The curious case of "Ronson", Pt. 1
Everybody interested in history of World War 2 heard of the "Ronson myth" about Sherman tank. Ronson was a nickname reportedly give to the Sherman, apparently because it was extremely flamable. It came from the Ronson lighter company advertisement : "Lights first every time".
Origin of the slogan
Many people dispute the "ronson myth" with a claim that the particular slogan of "lights first every time" came only after war. There are various Ronson adverts post-war and during the war, none of which have slogans that are worded in a similar way. There is this one exception, which apparently is from 1927.
From my search on the internet, I was unable to comfirm it indeed is from 1927, past few forum and blog entries. If anyone have any information on this, I would appreciate if you comment.
So was it really that flammable?
First look at Analysis of 75 mm Sherman tank casualties suffered between 6th June and and 10th July 1944 is pretty damning.
More than 80% of given sample caught on fire, 73% of Shermans penetrated by AP shots caught on fire.
However, it is not that simple. It was noted that proportion of brewed-up tanks was not always that high. Reason as to why so many Shermans caught on fire became apparent with further examinations.
" A more recent examination of later battles, which is not yet complete, has shown that the 1st Bn Coldstream Guards (5th Gds Arm. Div.) have suffered fewer brew-ups than other units, e.g., during operation BLUECOAT only 1 in 20 casualties,"
"The unit concerned attributes this to the fact that they carry no extra ammunition outside the armoured bins."
This points to the fact that most tank fires are caused by ammunition, and that proper, and more importantly armoured stowage helps to greatly reduce the probability of fire upon penetration.
But what about the competition?
Lets compare the relative fire safety of Sherman tank to a sample of german tanks, studied in the Analysis of German tank casualties in France 6th June to 31st August 1944:
Compared to a smaller sample of Pz. IV, Sherman proves to be less fire-prone, but it needs less penetrations to be set on fire than Panther. Tiger tank, with a miniscule advatange of 0.01, is the safest vehicle when it comes to fire safety.
However, there are few things that should be taken into consideration:
- Sherman had a rather sizable ready rack positioned inside the turret. While it allowed the crew to reach an amazing rate of fire (as high as 20 rounds per minute), it also added a big fire hazard if the turret was penetrated, compared to German tanks.
- Ammo stowage in sponsons could be located from the outside due to "bumps" in the armor like this,
which would draw the eye of any german gunner trying to position the crosshair, and that would result in ammo being ignited.
More in Part 2.
Saturday, 3 September 2016
Ironman Panther
"IX Exceptional achievements of tank drivers
1. Achievements of a Panther recovery tank driver
NCO Krause of Panther maintenance battalion drove 4200 km with his recovery Panther, chassis number 212 132, until the fifth of May 1944, without engine change or damage to the final drive, gearbox or clutch, 1000 kilometers thereof with another Panther tank in tow.
The recovery vehicle, including its engine, is still in top condition and remains in use. The regiment has recommended NCO Krause for high award for his exceptional performance in the handling and care of vehicles.
Inspector General of tank forces bestowes his special recognition of service on NCO Krause."
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