calling all "hatch grogs"

[Jagdratt]

One of the very distinctive features of the Pzkw III and IV are the lovely little side hatches - when they're open they look just like the shutters of a little cabin the schwartz wald. A bit of bright paint on the inside and some gingham curtains - Martha Stewart would be so proud.

It seems to me that these hatches would be significant weak point in the turret structure. Is that why they were discontinued in later designs? And if they were a weak point, why weren't later models of the IV changed? Did any of the IV models have the hatches in the side hull area, like the III?

The Pzkw V and IV both have escape hatches in their turrets, but they look much smaller and are placed on the rear face. They also look much sturdier than those on the earlier designs. Were there different design philosophies on escape hatches among the combatants? My uncle, who was a Sherman commander with the Alberta Tank Regiment, mentioned a floor hatch he used to escape from his tank on one occasion. Were there floor hatches in the German AFVs?

[ASL Veteran]

Originally posted by Jagdratt:

One of the very distinctive features of the Pzkw III and IV are the lovely little side hatches - when they're open they look just like the shutters of a little cabin the schwartz wald. A bit of bright paint on the inside and some gingham curtains - Martha Stewart would be so proud.

It seems to me that these hatches would be significant weak point in the turret structure. Is that why they were discontinued in later designs? And if they were a weak point, why weren't later models of the IV changed? Did any of the IV models have the hatches in the side hull area, like the III?

The Pzkw V and IV both have escape hatches in their turrets, but they look much smaller and are placed on the rear face. They also look much sturdier than those on the earlier designs. Were there different design philosophies on escape hatches among the combatants? My uncle, who was a Sherman commander with the Alberta Tank Regiment, mentioned a floor hatch he used to escape from his tank on one occasion. Were there floor hatches in the German AFVs?

Ya know, the primary purpose of those turret hatches might not be escape ... I'm thinking that maybe they were designed in so the loader could toss the spent shell casings out of the turret. Just a WAG though as I'm certainly not a "hatch grog."

[Doug Beman]

From George Forty's German Tanks of WW2

PzIV had escape doors on either turret side, which (unless I missed a sentence) were present in all versions of PzIV.

Panther Ausf D had an ammo-loading hatch on the turret left side, which was dropped for the AusfA and G, anbd a larger circular replenishment hatch at turret rear. Ausf G eliminated the pistol ports in all faces of the turret.

Pre and early-production Tiger had pistol ports, whereas mid and late versions had a single loading/escape hatch at right-rear of the turret.

DjB

[ April 25, 2002, 05:55 PM: Message edited by: Doug Beman ]

[M Hofbauer]

it is less of a problem (aka "weak spot") as you may think.

those hatches basically had the same thickness as the plate into which they were installed.

so theonly issue that remains is that of edge effects on the free edges of these hatches or on the opening of the surrounding plate edge. However, those edge effects are probably more than compensdated for by the considerable overlap that such hatches usually have.

I'm not saying that they weren't a problem for ArmorPenetration considerations at all but my assumption is that the removal of these hatches in later models was simply due to simplification / easier production (a la the single-piece undivided TC top hatch as opposed to the split hatch of earlier models).

[Brian]

Originally posted by Jagdratt:

One of the very distinctive features of the Pzkw III and IV are the lovely little side hatches - when they're open they look just like the shutters of a little cabin the schwartz wald. A bit of bright paint on the inside and some gingham curtains - Martha Stewart would be so proud.

It seems to me that these hatches would be significant weak point in the turret structure. Is that why they were discontinued in later designs?

No, they were discontinued primarily 'cause they took too much time and effort to cut from the turret. As their value was considered neglible, they were eliminated usually on the basis of efficiency for the Germans.

For the Americans, on the otherhand, they were eliminated because they were felt to provide a weak spot on the hulls of M3 Lee/Grant tanks. In the case of the rivetted versions, I suspect it was the case. However, with the cast hulls it was more than likely felt that providing them wasn't worth the effort.

And if they were a weak point, why weren't later models of the IV changed? Did any of the IV models have the hatches in the side hull area, like the III?

No, because of ammunition and other equipment inside the vehicle whose stowage interfered with the concept.

The Pzkw V and IV both have escape hatches in their turrets, but they look much smaller and are placed on the rear face. They also look much sturdier than those on the earlier designs. Were there different design philosophies on escape hatches among the combatants? My uncle, who was a Sherman commander with the Alberta Tank Regiment, mentioned a floor hatch he used to escape from his tank on one occasion. Were there floor hatches in the German AFVs?[/QB]

Well, to answer the first question, those hatches were not intended as "escape hatches" but rather were designed primarily for ammunition replenishment. The one on the back of the Jadgpanther and Jagdtiger were also intended for gun insertion/removal.

As to why the Germans did not utilise floor escape hatches, well, there wasn't room in most of their vehicles becuase of their use of torsion bar suspension. American vehicles which utilised either VVS or HVS units had an unobstructed floor in which to place the hatches. When the Americans adopted torsion bar suspension, floor hatches disappeared as well.

[Michael Dorosh]

The Annoying Nomenclature Grog will point out you mean the South Alberta Regiment, which was an infantry (rifle) unit that converted to armour during WW II, not to be confused with the Calgary Regiment (Tank) that was an infantry (tank) unit that was a tank regiment that converted to armour....

Early Canadian Ram tanks also had side doors, similar to the M3 Lee/Grant used by the British, Americans and Russians.

[Jagdratt]

Originally posted by Michael Dorosh:

The Annoying Nomenclature Grog will point out you mean the South Alberta Regiment....

Early Canadian Ram tanks also had side doors, similar to the M3 Lee/Grant used by the British, Americans and Russians.

Ah hah, I knew I had it wrong, I just didn't know how wrong.

Clearly there was a movement to eliminate these side hatches on tanks designed after each nation gained experience in armoured warfare. Why? Was it a matter of simplifying the manufacturing process, or were they a hazard?

I would suspect the latter - although I'm no metalurgist or even a welder I can't see how the hatch - particularly the dual barn door variety - could match the strength of an unperforated belt of steel.

I would expect the side hatches were of considerable benefit to a crew bailing out of a toasting tank. In situations like that, time is important, and having a choice of hatches may mean you can exit on the leeward - rather than firing - side of the tank.

They probably should have retained side hatches in the SAR - to be utilized for prairie turn signals

[Aunty Jack]

My question has always been, why did the US Army design their jerricans to require so much more manufacturing than either the German original or the British copy of it?

All nations entered the war with certain common ideas on armour design which as the war progressed experience proved them both wrong and inefficient (to manufacture). Of all the tanks used during the war, only the Churchill retained its side escape hatches, purely because they were so useful, although its interesting that the shape of them changed, from square, to round, once it was found that the corners of the opennings for the square hatches were found to crack when struck by enemy shells.