Schnorchel types - folding, telescopic, enclosing periscope

[kfbr392]

i am looking for precise info on the german snorkel types on uboats 1943-45.

i have identified 3 main types:
- Klapp (first designs, folding forward into deck, most common on VII + XI)
- Teleskop (as in XXI and XXIII, but maybe even on a few VII?????)
- Sehrohrschnorchel nach Dr. Ing. Oelfken (beginning of 1945, this snorkel mast was folded backwards from conning tower - so no flak possible - and when deployed the uboats periscope could be extended through it, thereby decreasing its vibrations and permitting snorkel speeds of 11kn)


in allied interrogation reports of captured VII and IX late war uboats their snorkels were referred to as
- "Standard type",
- "Deschimag Bremen, Type I" or
- "Deschimag Type 2"
so there were 3 types of Klappschnorchel (folding forward)???


who knows more, also on rubber coating, snorkel heads, snorkel valves and snorkel passive radar detectors (fumb)?


A+
Matt

[SES]

Hi please see http://www.gyges.dk/Further%20German%20 ... es%203.htm which has a little info related to your problem and some references.
bregds
SES

[Ome_Joop]

Why did the Kriegsmarine use the snorkel so late in war?
They captured these devices after the defeat of Holland in may 1940!

[Kirill]

A bit on Schnorchel:

http://www.ibiblio.org/hyperwar/ETO/Ult ... 025-3.html

http://uboat.net/technical/schnorchel.htm

[TigersharkNL]

Why did the Kriegsmarine use the snorkel so late in war?
They captured these devices after the defeat of Holland in may 1940!

Probally the same reason why the British wanted to have the Schnorkels removed from the escaped Dutch submarines.

They didn't believe in the invention and thought it was dangerous.

Only at the later stage of the war Germany was losing to many u-boot's wich were recharching their batteries and needed a way to recharge the batteries without being at great risk to be bombed by planes. So I guess they remembered the just invention.

At least that's what I think.

[kfbr392]

i read that the dutch invented the snorkel because of the atrocious heat in the waters of the the indean ocean. snorkeling allowed the boat to cool down to water temperature. i read that in 1943 the german monsun u-boats moving surfaced in the indean had temeratures of 55 degrees celsius in the boat, rising to 70 degrees in the engine room!!!

the mass use of (very) long range radar eqipped patron aircraft prompted the germans to use the snorkel to reduce surface time and exposure. snorkel develloppement was initiated at the same meeting in november 1942 at which decision to devellop type xxi boats was taken.

[gabriel pagliarani]

...i read that the dutch invented the snorkel because of the atrocious heat in the waters of the the indean ocean. snorkeling allowed the boat to cool down to water temperature. i read that in 1943 the german monsun u-boats moving surfaced in the indean had temeratures of 55 degrees celsius in the boat, rising to 70 degrees in the engine room!!!...

An hoax. Temp of open ocean water is the same at any latitude, with an excursion +/-5°C only depending if you are in/out large streams as Gulf, Humboldt, Nino/Nina. Diesels were cut off when submerged, but with the snorkel working the heat exchanger between primary sealed circuit and secondary dispersive did't worked because it was not pressurized. So the primary circuit coolant was fully sent in the internal heating circuit. Only type XXI had a new intercooler having a secondary (dispersive) circuit able to withstand 3-4 Atm. (20-30 mt. depth)

[Karwats]

Hi Gabriel!!!

Dunno about that.

i've operated in both Tropics and down South.
Water temp 30C and 6C

Big difference inside the boat-OK the AC wasn't working in the tropics but still. Biggest problem in the tropics was "rain" condensation inside the boat
everthing was wet-inclusing the electronics. ANd it was hot-way hot 50C sounds about right and that was at PD and 50-100m

[gabriel pagliarani]

99%-100% relative humidity are a standard condition inside submarines. I was affected by a disgusting fungus for a long time just after service.

[tigre]

Hello to all ; a little complement
The Italian snorkel.

During the 20s (twentieth century) Major (Corps of the Navy Engineers) Pericle FERRETTI proceeded to design and to built a real snorkel device through a tube properly positioned in the conning tower of the submarine. This device was equipped with dynamic valves, which rotated when opening, thus preventing the flooding by centrifugal action. The prototype was built in the shipyard of Taranto and installed on the submersible H3 by the local shipyard in Naples. The device was tested in November 1925 and on April 13, 1926, during maneuvers off the coast of Tripoli was shown to the Duce.

In the early 30s Ferretti improved his design and in 1934 the Royal Italian Navy decided to install it in the new submersible "Sirena" Class. However suddenly the Submarine Command decided to remove the snorkel system in 1937.

At that time (early 30s) the Dutch began working on a similar project and patented an extensible mast for air intake for the diesel engines while the boat was submerged (I do not know if they knew the work of Ferretti or developed it by its own). This system fell into German hands after the conquest of Holland in 1940 when they seized the Dutch u boats. But before they could draw conclusions about it, the system was dismantled.

Finally, in a letter dated May 19, 1943 Dr. Walter wrote to Dönitz on the progress of his work and intervention on the Director of Naval Construction, Dr Fischer and the High Office for Ship Building (Hauptamt für Kriegschiffbau). There Walter proposed attach a ventilation system to the periscope of a submersible type II and after obtaining experiences standardize the system to all operating submersible. As a result of the work of Gabler and Hoper of June 8, 1943, was ready a project for a prototype which would be attached to the U 57 and U 58. The construction was alloted to the firm Deutsche Werke AG in Kiel. The Directors Middendorf and Immich built and assembled the prototype in just three weeks on the U 57, which carried out sea trials in August 1943. The tests showed that under normal sailing conditions no damage was suffered by the crew.

In September 1943 a system of retractable snorkel was mounted attached to the conning tower of the U 235 and U 237. The concern of the technicians was that a small variation in depth by steering errors, cause the closure of the intake pipe, causing such shortness of air that the entire crew would be poisoned by gas.

Sources: http://www.sommergibili.com/snorkele.htm
What Italian Schnorchel. Ufficio Storico della Marina Militare.

Does anyone have any idea if there was any connection / contact between the works of Ferretti, Walter and the Dutch? TIA. Cheers. Raul M .

[tigre]

Hello to all ; a little more...................................

The use of snorkel in combat ready U Boats.

It must be emphasized moreover that the greatest opposition to adopt the snorkel came particularly submersibles used in war patrols, whose commanders considered the sailing at periscope level with diesel engines running very difficult and dangerous.

The Snorkel's head left a large trail of foam on the surface that facilitated the daytime detection by the aircrafts, plus the column of smoke from running diesel engines. So the tactical situation caused the system to be used mainly at night. Moreover due to the vibrations of the extended periscopes and snorkel, the maximum sailing speed was reduced to about five or six knots. Due to the vibrations the periscopes became useless.

Following the experimental application of the device in the submersibles already mentioned, in the winter of 1943-1944 the started the assembly of the "snorkels" in other combat submersibles, though not without some apprehension about the outcome.

Sources: The Italian Schnorchel. Ufficio Storico della Marina Militare.
http://www.ebay.de/sch/sis.html?_nkw=Ra ... c=50&rt=nc

This situation would explain the delayed use of this device by the Ubootwaffe, although the Germans had already taken it as early as 1940. Cheers. Raul M .

[tigre]

Hello to all ; a little more...................................

The use of snorkel in combat ready U Boats.

After completion of the ninth patrol of the U 155 (Type IXC), in the period from June 26 to September 1, 1944, it was installed in the U Boat a snorkel system in the shipyards of the Navy in Lorient.............................

Sources: http://www.ebay.de/itm/Orig-Foto-U-boot ... SwZQxW6vgX
http://www.ubootarchiv.de/ubootwiki/index.php/U_155

Cheers. Raul M .

[tigre]

Hello to all ; a little more...................................

The use of snorkel in combat ready U Boats.

In the photos a German U Boat Type IXC (snorkel to starboard) with victory pennants and probably a radar device in Norway after returning from an operational patrol ...............

Sources: http://www.ebay.de/itm/232111451081?clk ... rmvSB=true
http://www.ebay.de/itm/232111459802?clk ... rmvSB=true

Any idea about the U Boat? port? TIA. Cheers. Raul M .

[tigre]

Hello to all ; from previous post...................................

The use of snorkel in combat ready U Boats.

In the photos a German U Boat Type IXC (snorkel to starboard) with victory pennants and probably a radar device in Norway after returning from an operational patrol ...............

The U boat was U 870 (Type IXC/40) coming back to Kristiansand from her First and only operational patrol (Nov 10, 1944 - Feb 02, 1945 - 101 days at sea); the boat operated in the North Atlantic and west of Gibraltar. It was able to sink on this enterprise 1 merchant ship with 4,637 GRT and 2 warships with 1,825 ts and damage 1 merchant ship with 7.207 GRT and 1 war ship with 1,400 ts............................

After attacking a small group of landing ships on 20 December 1944, the U-boat was then attacked by a British aircraft from No. 220 Squadron RAF but got away, and also evading two hunter-killer groups of vessels. For that reason the extensive damages seen in the previous photos ................

Sources: http://www.ubootarchiv.de/ubootwiki/index.php/U_870
http://uboat.net/boats/u870.htm
http://forum.axishistory.com/viewtopic. ... y#p2046639

Cheers. Raul M .