Balcongerät Research

[dougie47]

Hi Simon,
Well noticed in the spare containers. My guess is one of them is for a spare 20mm barrel and the other for a spare 37mm barrel. I wouldn't like to say which side was for which barrel.
Cheers,
Dougie

[NZSnowman]

Hi Simon,
Well noticed in the spare containers. My guess is one of them is for a spare 20mm barrel and the other for a spare 37mm barrel. I wouldn't like to say which side was for which barrel.
Cheers,
Dougie

Yes, it could be a space 20mm barrel. I not seen any documentation indicating that the barrel of the 20 mm being changes during combat. If my memory serves me well, I think the German only needed to put constant 100 rounds through the 3.7 cm flaK M42 before it overheated and started to deformed barrel.

The thing that surprises me the most about the double barrel, is the obvious keenness of using the flaK gun because of the double spare barrel. I would had imagine it would be suicidal at that time of the war to fight aircraft on the surface.

[uboatfan]

Hello,

is it possible that the duble replacement barrel container is related to a 20mm four-barrel gun?
U-Boot im Focus Nr. 9 page 47 shows U 596 with these gun and also two containers...


Regards

Uboatfan

[NZSnowman]

Hello,

is it possible that the duble replacement barrel container is related to a 20mm four-barrel gun?
U-Boot im Focus Nr. 9 page 47 shows U 596 with these gun and also two containers...


Regards

Uboatfan

I not seen the photo of U-596, any chance you are able post an image of it?

It seen to me very unlikely that they would mount this flaK gun on U-1305, for several reasons.

The gun was super heavy, and was almost too heavy for the Type VIIC’s. I believe it was only mounted on a very few Type VIIC’s.

As U-1305 as a late war Type VIIC/41 (Commissioned 13 Sep 1944) I would imagine it would follow the trend of other late war Type VIIC’s and be mounted with the new single 3.7cm Flak M42U gun on the LM 43U mount.

At the start the German trend of Flak on U-boat Type VIIC’s was to add bigger guns to there boats. As Allies airpower improved, the German drifted to putting more lead into the sky with smaller calibrated guns like the 20 mm Flak (a much higher firing rate). This was easily counted by Allies airpower by adapting new tactics against U-boat. The Allies began to use two aircrafts to hunt U-boat, one aircraft would fly around in plain view of U-boat but just outside the range of the smaller 20 mm Flak. While the U-boat was distracted by the first aircraft, a second aircraft would come in hard and fast, perhaps with the sun behind it and get the killer blow. So near the end of the war the German’s started replacing the 20 mm Flak with the bigger 37 mm Flak to keep the Allies aircraft further away and at bay.

[Capt Kremin]

Hi NZSnowman,
 
most boats that had 3.7cm zwilling guns, (M42 DLM42U) have 2 spare barrel containers, it is possible that a single 3.7cm gun could have 2 barrel containers, although unlikely. So far I have found only type IXs with M43 DLM42U, but it is not impossible for a type VII to have M43s, single or twin.
 
Regards
Jon

[NZSnowman]

Hi NZSnowman,
 
most boats that had 3.7cm zwilling guns, (M42 DLM42U) have 2 spare barrel containers, it is possible that a single 3.7cm gun could have 2 barrel containers, although unlikely. So far I have found only type IXs with M43 DLM42U, but it is not impossible for a type VII to have M43s, single or twin.
 
Regards
Jon

Jon,

I maybe wrong but I thought that they only made the Flak M43 for surface ship. That is why they never call it the M43U.

Or I am miss-understand and you are taking about LM 43U mount.

[Capt Kremin]

Hi NZSnowman,


To clarify
M42 LM42U single 3.7cm fitted to both type VIIs and type IXs
C38 DLM43U twin 2cm fitted both types. DLM43U would not have been able to support the 3.7cm M42 or M43
M43 LM42U single 3.7cm fitted to type VIIs and type IXs, cheaper to manufacture, greater rate of fire, shorter range (and barrel)
M42 DLM42U twin 3.7cm - U boats ]
M43 DLM42U twin 3.7cm - U boats ][size=78%] [/size][/size]same mount, just different gun[size=78%]


Or the short answer the M43 I was previously referring to was the gun not the mount. The M43 was definitely fitted to at least one U Boat, the U 534, so was most probably fitted to other boats that had their single 3.7cm upgraded to a twin during the latter months of the war, no exact date for the U 534s fitment but sometime after October '44. It would not have been necessary to develop a new mount for the M43 as its pivot point and firing linkage are virtually identical to the M42. To be honest it is very difficult to spot the difference between the M42 and M43 in wartime photos.


Regards
Jon

[NZSnowman]

Jon,

Thanks for the information about the M43.

Q. How do I tell the diffent between the M42 and M43 in wartime photos? Do you have any drawing/photo's of the M43

Q. As the LM 43U mount is a upgrade on the LM 42U and is a late war gun mount. Would you say all LM 43U were mounted with the M43?

[Capt Kremin]

Hi NZSnowman,


I have various bits and pieces, I will sort some out and post them during the weekend.


Regards
Jon

[Capt Kremin]

Hi NZSnowman,


As promised some differences between M42 and M43.
The easiest difference if you can see the rear of the breach is the cutout at the bottom of the back plate which is only present on M43s, also note that the fillet plates on the rearmost ammo guide is much longer, compare M42 breach.jpg and M43 fillets.jpg and the guides on the U 534 M43.jpg. As I said before the barrel is shorter, that is very hard to spot in a photo, I've included the ends of a pair of M43 barrels but I think they are too similar to M42 flash hider and breach connection to be able to determine the difference. The real give away is the rear breach cover. I am not convinced that other differences are absolute for each type so I have noted those that I am certain of.


Regards
Jon

[NZSnowman]

Thanks, Jon.
 
Thanks for the pictures and information.
 
You are right, a good photo is essential to tell them apart. I checked all my photo's and the only one I can tell that had a M43 is on U-190.

How much shorter is the M43 barrel? As I want to update my drawings.

[Capt Kremin]

Hi NZSnowman,


I can't confirm these figures, but I have barrel length 2.56m for M42 and 2.11m for M43, only thing is I assume that is for a complete barrel. Unfortunately the 2 spare barrels for the U 534 are suspended from the ceiling out of reach.


Regards
Jon

[Capt Kremin]

Hi NZSnowman


Just to muddy the water I have a few different figures for the M42 barrel length, but all are longer than the figure for the M43 barrel, next time I visit the U 534 I will figure a way of measuring the spare barrels. I'm still trying to figure out how to get under her and maybe on the deck, failing that a laser range finder and some surveyor poles (and a dull day).


BTW I have a picture that claims to be the U 190 after capture with a M42 DLM42U, but the picture definitely shows an M43.
Lets be honest, how many time have you seen a wrongly captioned picture. I've discussed these problems with Dougie several times. I put some of these mistakes down to the pressures of professional authors meeting a deadline.


Regards
Jon

[NZSnowman]

Today I had a I few spare hours between studies so I choose to start modelling the Balcongerät in SketchUp. It was not long before I realise something was not right with my initial drawing.
 
After a little bit of research, I am sure that I got the wrong curve at the front of the Balcongerät in my initial drawing. I will try to fix this over the next few months when I have free time.
 
So if anyone is using my drawing or are planning to, beware that front of the Balcongerät is incorrect

[NZSnowman]

In the past with my drawings, when there are no original German plans it very hard to work out the correct angles or dimensions of U-boat objects. Now with 3-D modelling there a new way to check these.

You can build a basic model and rotate and align the model so it matches a war-time photo, you can now see if the outline matches.

Below I wanted to check the angle and the sizing of the front of the Balcongerät.