The Ship Model Forum

This is a rather late reply, but I stumbled across this German wartime film which shows the process of moving the ammunition on a Type IX:

https://catalog.archives.gov/id/78205

Jacob

Gcj,

Further to Vepr157's last reply and re: ammunition stowages in the Type VII U-boat.

If you now have access to the Invenio search engine and the BaMa has digitised the relevant plan, try searching with the term "Munitions Stauung." There may be more than one plan but one of them should show the stowage arrangements for the 88mm ready use ammunition below the forward casing deck, while another might show the stowage inside the pressure hull.

However, if these have not "survived" there are a number of drawings of the said stowages for WW 1 German U-boats, which should give you a "steer" in the "Folded" collection of German warship plans held by the National Maritime Museum in Greenwich.

That is an interesting project that you have going.

Thanks, that drawing is perfect and shows the location of the shute on the conning tower floor was slightly different port and starboard.

Fortunately the Bundesarchiv makes available a large number of digitized drawings. One that may help is RM 25/10315, which details the bridge fairwater construction:

https://invenio.bundesarchiv.de/invenio ... c598d232a/

The ammunition was sent from the bridge to the deck via two chutes port and starboard to either side of the UZO base.

Jacob

I am in the process of building Trumpeter’s 1/48 u-boat. I have a mind to depict the crew replenishing the 8.8cm ready use ammunition. I have photos (on kindle books so I cant post) which show the hatch and chute down which ammo has delivered from the coning tower to the deck. I have one photo showing the ready use ammo locker under the deck where it seems the ready use shells were kept in individual pressure resistant metal containers. What I am struggling with is
Where/how did the ammunition chute go at the top of the coning tower? I have a photo of a crewman crouched down at the front of the coning tower but I cant tell how the shell got from there to the bottom of the chute. Was there a hatch or did they lift up or hinge back a grating?
The ammo store within the boat was, I believe, under the Captains cabin, I have seen a photo which suggested these shells were also stored in individual pressure resistant metal containers, but this doesn’t make sense to me, they were stored within the pressure hull so this seems unnecessary. All the photos of the conning tower ammunition chute in use shows bare shells going down to the deck. It seems to me that it makes sense these shells would be stored in wooden crates for faster handling than in individual sealed containers each of which would need to be opened before the shell could be passed to the deck gun crew. Anyone have definitive info this?
Also any info on the ready use locker in the deck would be helpful, particularly how it was accessed.
Thanks

1st of all, I did not ask a question. I presented a piece of information.

I know many source mention and illustrate the small rod antenna. And revell depicts the rod antenna as so mentioned and illustrated. The small antenna always seem to me to be quite disproportionate to the large bulge on the side of the mid-war VIIC conning tower that accommodates it. The bulge is actually larger than the bulge on the side of thr IXC conning tower that is definitely there to accommodates a periscope shaft sized extendable antenna mast.

So here is the photo of U203 with the periscope shaft sized antenna mast extending from the bulge:




To assess its size you can compare it to the cylindrical portion of the attack periscope shaft visible above CO Mutzelburg’s left shoulder, behind the garlands.

I'm not sure where you're looking, but many sources mention the rod aerial (stabantenne). It was a slim (maybe 1-2" diameter; definitely not the same diameter as a periscope) antenna for radio communications while at periscope depth. The antenna provided with the Revell kit appears to be reasonably accurate. It appears that the aerial for the Type IX was in some cases a much thicker mast, which I assume is what you're referring to.

When you're asking a question, please post photos/drawings so that we know what you're talking about. It's hard to tell you what you're seeing in the photo of the U-203 if we cannot also see that photo.

it appears the prominent bulge on the port side of the conning tower that mid-war type VIIC usually have from around 1941 actually houses a massive extendable antenna mast whose shaft is the same diameter as the main shaft of one of the parascopes. It seems similar to the extendable antenna mast carried by early type IXC on the port side of their conning tower in the same position.

i found a clear photo of U-203 retuning to Lorient with this antenna mast extended.

yet i’ve found no references that mention this nor any drawings, including reproductions of original german plans, that show this on the VIIC, although many drawings of IXC shows this mast extended. revell missed it on their VIIC kit, giving only the option to extend a small jackstaff whip antenna out if this housing, although they too correctly showed the thick antenna mast option for their IXC kit.

Thank you. I already ordered it used through Amazon.

I'd suggest getting a copy of Vom Original zum Modell: Uboottyp VIIC by Fritz Köhl and Axel Niestle.

Jacob

The midship ballast saddle tank venting pipes on either side of the conning tower are almost as prominent as the diesel air trunk and pressure hull air circulation trunks under the casing, but every other reference for details under the casing seems to have missed them.

Thanks. The skitzenbuch is very informative. Far far better than the Anatomy of the Ship volume on the VII and highlight numerous serious omissions in the latter reference,

Ah thanks. That's an interesting book. Good drawings and photos, but somewhat questionable text.

I found this on p. 451 of the Skizzenbuch by Donald M. Prince:



Jacob

Unfortunately I don’t have the rest of the drawing. The image of the drawing is taken from this book: https://www.amazon.com/Hitlers-Attack-U-Boats-Kriegsmarines-Submarine-ebook/dp/B08N1HKNWV?ref_=ast_author_mpb

That drawing probably shows the full range of motion of the mast. The inboard components appear just to be training gear to turn the antenna in azimuth. Where is this drawing from? It would help to know what the numbers correspond to.

Jacob

Could you post the drawing you referenced? I am pretty sure the DF mast could not raise as high as the periscopes and there wasn't any hull penetration as far as I can tell.

Jacob

VII and IX boats have a ring antenna for radio direction finding that retracts into a slot at the side of the open bridge when not in use. Photos of the ring antenna extended seems to be rare, and all the ones I’ve seen the ring rises onto a short distance above the edge of the open bridge. The same with illustrations in anatomy of the ship. However a photo of a original KM diagram of the ring antenna mechansim suggest the mast on which the ring is mounted is telescoping and there is a well inside the pressure hull for the mast, similar to periscope well that lets the long periscope shaft to retract. This would imply the antenna can be raised much higher than the rim of the open bridge, and can probably be raised as high as the attack telescope.

I like to confirm that before building a model with a ring antenna at attack periscope head level.

Has anyone seen any photos of a Uboat with ring antenna raised all the way up?

Thank you!

Ah "limber hole" means a hole in the free-flooding superstructure allowing it to flood and drain quickly. What you are referencing are "flood holes."

In the early 20th Century, nearly all submarines had flood valves (Kingstons) that sealed the bottom of the main ballast tanks. To dive a submarine would have to open both the vents at the top of the MBTs and the Kingstons at the bottom. During WWI the Germans realized that the Kingstons were unnecessary and omitted them, relying solely on the vents to keep water in the MBTs. Air could only leave the MBTs through the flood holes under exceptional circumstances, probably well over 45 degrees of roll and/or nearly 90 degrees in pitch, in which case the submarine was probably in dire straits for other reasons. The small amount of water remaining within the envelope of the MBTs was accounted for in the design. The vents were reliable enough to rely on them alone to hold air in the MBTs, a practice called "riding the vents." After WWI, the U.S. Navy eliminated most of the flood valves on its submarines and all current U.S. nuclear submarines have simple flood holes (albeit covered with gratings to reduce noise).

The Type II and VII had Kingstons for their amidships, internal MBT, probably for safety in the unlikely event that the vents failed. However, they were normally left open. The Type IX apparently had Kingstons on one of its amidships MBTs as well.

One additional thing to consider is that other types of tanks do require Kingstons. Fuel-ballast tanks, which can be used as MBTs after the fuel in them is used up, require Kingstons when acting as fuel tanks. Negative and safety tanks also require Kingstons. Kingstons also are occasionally used when flow-induced noise and vibration is problematic, although these days it is more common to use vortex-dissipating gratings.

Jacob