Shell transport - opening in the floor

[jopaerya]

For the elevatorshaft idea sounds very logical but the only problem that I have that
there is no exit on the lowest level or it must be below water level ??

Regards Jos

[jazote]

For the elevatorshaft idea sounds very logical but the only problem that I have that
there is no exit on the lowest level or it must be below water level ??
Regards Jos

Sorry Jos, but we saw (Jürgen and me) on the right of the elevator shaft bottom an openig which is under the water level... This exit goes to a room which is just near and its door is under the stairs....

Pictures from Anton
Regards
JLM

[jopaerya]

Thanks J.L.

I trust you

Regards Jos

[jazote]

Jürgen,
Nice pictures, thanks for sharing.

I guess, I can share this photo (Karola/Anton) from me with comments from you Winve:
And thanks JÜrgen.....

Yup that where my question to you some time ago.
Problem I have/had was that there is a track which would have had lorries of some kind on it.
So if you want to unload a shell or cartridge, you also need a crane or at least a (ceiling) hook. Question was/is: are there any remains to could point to a crane or overhead system ?
And there is not much space or better no space left/right of the tracks.
But even then You are at the dead end of that track, so you can only unload the last lorry. Then you must roll it back and the next one rolled in. This seems to me as a very time consuming process.
On your inital picture we see a "window"in the wall to a space without floor: was there a elevator planned bit not build ?

Karola/Dora:

Regards
JLM

[juestr]

Very very strange. Since 2003 I have been more then 10 times inside Dora and never "seen" this hole in the floor ( neither the hook at the ceiling).
The only reason: I didn´t expect a hole at that place
Jürgen

[wimve]

Very very strange. Since 2003 I have been more then 10 times inside Dora and never "seen" this hole in the floor ( neither the hook at the ceiling).
The only reason: I didn´t expect a hole at that place
Jürgen

Well I guess it is dark inside, dangerous because of the holes and there are more holes in and around the floor ?

But maybe an idea for the 11th expedition: use a small boat to take pictures with such a "adventure camera". They are waterthight and with a string attached you can alsways retrieve the boat.
Or tie the camera on a fishingrod and try to gain pictures from next to the staircase.

But I do see traces of high (1m ?) water level changes. Where does the water drain to ?
I mean the object itself is rather watertight and normal evaporation is slow. In fact I would find it more normal that the whole thing fills with rainwater over time.

[jazote]

Very very strange. Since 2003 I have been more then 10 times inside Dora and never "seen" this hole in the floor ( neither the hook at the ceiling).
The only reason: I didn´t expect a hole at that place
Jürgen

.....But maybe an idea for the 11th expedition: use a small boat to take pictures with such a "adventure camera". They are waterthight and with a string attached you can alsways retrieve the boat....

I said that to Jürgen...next time we should try to rent a dinghy....
the waterhight was low that year....
JLM

[juestr]

1. My friend Jean-Luc was quicker than me, - but too quick in this case:



Here the opening of 35-40 cm width on the right side is better to be seen.

2. This is the "normal" view when passing the entrance. The only dangerous place because of ammo explosion after war.



Jean-Luc by knowing about the hole found a very good position from inside powder store to take his photo. Thanks a lot !!!
The hole is in the middle at the end of the rails, not visible here.
The water level in both Bunker was never as low as this time. I calculated a height of about 90cm only, probably evaporation.

As I don´t have very much time at the moment, next week Maginot excursion, the discussion about the questions and remarques above must wait two weeks

Gruß Jürgen

[juestr]

...............
Problem I have/had was that there is a track which would have had lorries of some kind on it.
So if you want to unload a shell or cartridge, you also need a crane or at least a (ceiling) hook. Question was/is: are there any remains to could point to a crane or overhead system ?
And there is not much space or better no space left/right of the tracks.

But even then You are at the dead end of that track, so you can only unload the last lorry. Then you must roll it back and the next one rolled in. This seems to me as a very time consuming process.
....................

ok, no time but more fun for a short answer than for "duty":

1. Inside the Bunker is a track switch with siding. So it was possible to enter several lorries (3-4) inside the protected area. You have only to push the empty lorry about 10m back and take another full one from the siding track.


But let´s go back to the roots:
2. Here we have to do with an original and complete naval gun turret (20,3cm) with high performance and accuracy and highly sophisticated technique. Even installed on shore it was intended to be used only against naval targets at high distance. In comparison to “land-artillery” the consumption of ammunition is much lower, even the shot sequence is much higher. (hit or disappear at sea). So the typical stock of “shots” on board for this heavy cruiser was 960 for 8 tubes (4 turrets). Maximum during the war ca. 1.400. This means 290 shots/turret. In the 4 storage rooms at Karola were stored about 500 shots. 600 shots should be stored there by the french navy after war. As you can see it is nearly the double than on board for an p.ex. Atlantic campaign (Prinz Eugen with Bismarck, Admiral Hipper….).

3. Another remarque: The needed accuracy to hit a small moving target at 25 km (best distance) with a shell flight time of about 1 minute is extremely dependent on the wear of tube. I have read that under these circumstances the inner tube has to be changed after ca. 100 (?)shots, - but at the moment I don´t refind this source.

Conclusion:
The ammunition store rooms had only rarely (here once and never after ?) to be filled up. So there were much time and a lot of people who had “nothing” to do otherwise.

Since knowing about the ammunition transport at Austratt/Oerlandet (28cm and 3x heavier) and the installed transport at Karola, in addition looking to size and position of the openings I am less and less convinced about a planned elevator system using the shaft on the left side of the track >>> to be followed…………..

Gruß
Jürgen

[wimve]

Hello Jürgen,

Thanks for the information.
Somewhere in the back of my mind I also considered this option. But then more as a "refill" in less hectic days after a battle shooting has taken place.

So up to the next question: what about the tunnel that supposed to be going from ?? to the center of the gun pit ?
Is there any evidence for that ?
I know or assume that there where electrical and other cables going into the pit but a tunnel ?

Other question remains: There are pictures online of a dry pit. So someone must have been inside the bunker an taken pictures (?) without the water issue.

For fun and study, here is my last cross section of the whole thing.
Credits to all of you who helped with information.

Karola Ro 01-02 langsdoorsnede

[Janef]

...

3. Another remarque: The needed accuracy to hit a small moving target at 25 km (best distance) with a shell flight time of about 1 minute is extremely dependent on the wear of tube. I have read that under these circumstances the inner tube has to be changed after ca. 100 (?)shots, - but at the moment I don´t refind this source.

Conclusion:
The ammunition store rooms had only rarely (here once and never after ?) to be filled up. So there were much time and a lot of people who had “nothing” to do otherwise.

Since knowing about the ammunition transport at Austratt/Oerlandet (28cm and 3x heavier) and the installed transport at Karola, in addition looking to size and position of the openings I am less and less convinced about a planned elevator system using the shaft on the left side of the track >>> to be followed…………..

Gruß
Jürgen

Some comments to this posting.
Re. 3: This is not correct. A thumb rule is that a tactical range equals one kilometer per centimetre calibre (for 28 cm that is a range of appr. 28000 meters). Then the L/50 and B/50 figures are such that a (p)hit (probability of hit) is favourable. The L/50 and B/50 (ie the error in fall of 50% of the shots in range and bearing) is not very much influenced by the barrel wear.
The barrel wear is occuring at the starting of the rifled part of the barrel, resulting in a erotion of the rifling and a longer ramming distance of the shell. This increases the chamber volume which in turn reduces the muzzle velocity (mv). German standard limit was a 10% reduction of mv, and then a relining of the barrel had to be done (reserve liners were stored at MAZA Kiel and MAZA Wilhemshafen)
The pre-war 10% mv-reduction limit was reached as follows (factory and construction data):
40,6 cm SKC/34 at 200 rounds
38 cm SKC/34 at 242 rounds
28 cm SKC/34 at 300 rounds
20,3 cm SKC/34 at 600 rounds

At Austraatt the remaining tube life after dismantling from Gneisenau was approx. 120 rounds per barrel. For this reason the Germans "conserved" the barrels and only fired calibre munition on two occations during the final mounting of the gun in July and Octobre 1943. For the remainder of the war they only used the 88 mm sub-calibre guns. However, the reserve liners were stored at the fort, giving the battery a total of 120+300 shots capacity per barrel - in total 1260 rounds. In the amunition magazines close to the gun there were room for 400 rounds, the rest were stored at a nearby ammunition tunnel. Total number of rounds in 1945 was 1245 rounds.
As to the idea that filling up the magazines were a one off operation - this is wrong. Ammunition had to undergo inspection routines, and some of these meant that the ammunition had to ble removed and sent to a ammunition maintenance facility.

JEF

[juestr]

Thanks a lot of your post ! I´m very pleased to find somebody coming from Norway and knowing much (all ?) about Austratt/Oerlandet. That´s what I´m looking for since a long time. And as you I am very interested to (naval) fire control systems - without being really expert. I didn´t know about the thread here on axis. In German Foren (e.g. Kriegsmarine) there was really not very much to find.
The principal doc I have for these topics are:
- Leitfaden für den Artillerieunterricht in der Kriegsmarine, Teil I Ballistik (here chapters about wear and all other influences), Teil II Geschützmechanik
- Unterrichtstafeln für Geschützkunde Band I Seeziel
- Geschichte der deutschen Schiffsartillerie, Schmalenbach (I.A.O. heavy cruiser Prinz Eugen, Hipper class like Seydlitz)
- Naval Firepower, Friedmann (difficult for me to read)
- detailed information (Dienstvorschriften) about Flak-Kommandogeräte...........
- two books dealing the "Hipper-class" heavy cruisers with 20,3 cm guns. Here I found the info of 25 km best distance for this gun

A question for understanding: rounds = shots (Schuss, coup) ?
How to understand for two barrels: "120+300 shots capacity per barrel - in total 1260 rounds." (>> 840 ??)

Exists at Oerlandet a more effective elevator system for transport of shells and powder to the magazines around the turret) ?
I only know pictures and the video showing the "manual piece by piece" system (I don´t know the english terms)

Jürgen

[juestr]

.......................
So up to the next question: what about the tunnel that supposed to be going from ?? to the center of the gun pit ?
Is there any evidence for that ?
I know or assume that there where electrical and other cables going into the pit but a tunnel ?

Other question remains: There are pictures online of a dry pit. So someone must have been inside the bunker an taken pictures (?) without the water issue.
.

1. The tunnel as designed in some plans seems for me to be a pure invention (fake). In the machinery room I can´t find any trace, but instead there starts an important cable channel along the walls which goes down to the shell magazine - and (not visible because under water) probably to the center of the turret

2. I have a photo with dry pit from Dora showing the door and opening which can be visited today from inside.
I was told that Anton has "always" been under water (since ???).
My first look to Dora was in the early 80ies, with water in. Because of the explosion a visit of the basement (shell rooms) was difficult (no stairs). You have to keep on mind that at that time no information, no internet was available. I approached the "terrain militaire actif"
from the seaside through the dunes ramping like a "red indian" always aware of being kept by the guardian and his dog or even by soldiers. When I saw the big hole at the top of the dune I had no idea at the monent what it could have been. Being very interested to all Navy issues (I was in the Bundesmarine a long long time ago) soon I had the assumption of a naval gun turret. My interest was awaken till today. Never at that time I had the idea or courage to find the entrance and to penetrate inside . And don´t forget, taking photos under these circumstances was much more complicate as today.

Gruß
Jürgen

[Janef]

...

A question for understanding: rounds = shots (Schuss, coup) ?
How to understand for two barrels: "120+300 shots capacity per barrel - in total 1260 rounds." (>> 840 ??)

Exists at Oerlandet a more effective elevator system for transport of shells and powder to the magazines around the turret) ?
I only know pictures and the video showing the "manual piece by piece" system (I don´t know the english terms)

Jürgen

Round = Chargierungen (shots with full charge - combat charge)
Remember there are tree barrels in the 28 cm turret.

If you have seen the video of us hoisting the shells high in the staircase openings, this is really slow-motion using a makeshift hoist. The original hoist is powered by 220 V DC, and is permanently out of use as is the other 220 V DC generated systems in the turret. The operating speed was much quicker when everything was working. But this was the only way of doing it. This system was also used onboard in a little different configuration.

JEF

[juestr]

Round = Chargierungen (shots with full charge - combat charge)
Remember there are tree barrels in the 28 cm turret.

>>> of course, so silly, must be my age....

If you have seen the video of us hoisting the shells high in the staircase openings, this is really slow-motion using a makeshift hoist. The original hoist is powered by 220 V DC, and is permanently out of use as is the other 220 V DC generated systems in the turret. The operating speed was much quicker when everything was working. But this was the only way of doing it. This system was also used onboard in a little different configuration.

>>>> it´s for clear that higher operating speed of the hoist and young trained people under the former circumstances are much quicker especially for the transfer from hoist to the shell store.....
May be our (mine) thinking about more powerfull hoist systems is due to the fact that we can see everywhere in Maginot artillery forts elevators (monte-charges) with high capacity - without taken into account that a caliber of 20,3 , 28cm and more has really nothing to do with the 7,5 cm gun turrets.

I suppose when talking about the similar onboard hoist systems, you think about the transport from land to the store rooms in the bottom of the ship?

I totally agree to your figures. I could now find the same in the books from Knoop/Schmolke about Seydlitz (Hipper-class) and Gneisenau/Scharnhorst. It seems that you agree with me that the influence of wear is so important that the barrels for "normal" operation had to be relined after 10% wear = predefined rounds/cal.. Ships had to go back to the shipyard. What about the turrets on land? Is the relining possible without the crane and in relative short time?
The aim of this discussion was to know if there was a lot of time possible for the refilling of magazines - at the contrary to e.g. the situation of Maginot turrets


JEF

Jürgen