S 622 type XXVIIB SEEHUND submarine

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aukepalmhof
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S 622 type XXVIIB SEEHUND submarine

Post by aukepalmhof » Thu Oct 14, 2010 8:31 pm

S 622 type XXVIIB SEEHUND

Builders: Germaniawerft, Kiel
Operators: Kriegsmarine & French Navy
Built: 1944–1945
In commission: 1944–1945
Planned: 1,000
Completed: 285
Active: 138
Lost: 35

Displacement: 17 long tons (17 t) submerged
Length: 39 ft (12 m)
Beam: 5 ft (1.5 m)
Propulsion: 1 x 60 hp Büssing Diesel engine
25 hp AEG electric motor
Speed: 7 kn (13 km/h; 8.1 mph) surfaced
3 kn (5.6 km/h; 3.5 mph) submerged
Range: 270 nmi (500 km; 310 mi) at 7 kn (13 km/h; 8.1 mph) surfaced
63 nmi (117 km; 72 mi) at 4 kn (7.4 km/h; 4.6 mph) submerged
Complement: 2
Armament: 2 G7e torpedoes

The Seehund (German: "seal"), also known as Type XXVII, was a successful series
of German midget submarines created during World War II. Designed in 1944, and
operated by two man crews, the submarines were used by the Kriegsmarine during
the closing months of the war, sinking 9 merchant vessels and damaging an
additional 3, with 35 losses mostly attributed to bad weather.

As the orders were being placed, Hecht variants were under construction. The
first was the Type XXVIIB, which had a greater range, could carry two G7e
torpedoes, and had diesel/electric propulsion. The design was completed at the
end of June 1944 and resembled Hecht but had a better boat-shaped external
casing for improved seakeeping while surfaced, and saddle tanks. Additional room
had been made inside the pressure hull by moving the batteries to the keel,
while the two torpedoes were slung externally in recesses in the lower hull. A
22 hp diesel engine was fitted for surface use and was estimated to give a
surfaced speed of 5.5 kn (10.2 km/h; 6.3 mph), with a 25 hp electric motor
providing a submerged speed of 6.9 kn (12.8 km/h; 7.9 mph).

The final variant of the Type XXVII was the Type XXVIIB5, better known as the
Seehund ("Seal") or Type 127. Seehund had a small raised platform midships with
the air intake mast, magnetic compass, periscope, and a clear dome which could
survive depths of 45 m (148 ft). The submarine's fixed 10 m (33 ft) periscope
incorporated lenses which let the commander check the sky above for aircraft
before surfacing.

The first contract for Seehund construction was placed on 30 July 1944.
Enthusiasm for the submarine was so high that most of the contracts and hull
numbers were allocated even before the design was completed. A total of 1,000
boats were ordered, Germaniawerft and Schichau-Werke to build 25 and 45 boats
per month respectively. Other centres involved in Seehund production were
CRD-Monfalcone on the Adriatic and Klockner-Humbolt-Deutz at Ulm.

However, Dönitz would not consent to the production of the Type XXVII U-boat
being held up for Seehund construction, while shortages of raw material, labour
and transport problems, and conflicting priorities in Germany's economy all
combined to reduce Seehund production. In the end Seehund production was
undertaken by Germaniawerft at Kiel using a facility which was no longer needed
for Type XXI or Type XXIII production.

A total of 285 Seehunds were constructed and allocated numbers in the range
U-5501 to U-6442.
Construction:
Sept 1944: 3
Oct 1944: 35
Nov 1944: 61
Dec 1944: 70
Jan 1945: 35
Feb 1945: 27
Mar 1945: 46
Apr 1945: 8

From the Allied point of view the Seehund's small size made it almost impossible
for Asdic to get a return from her hull, while her very quiet slow speed running
made her almost immune to detection by hydrophone. As Admiral Sir Charles
Little, Commander-in-Chief Portsmouth put it, "Fortunately for us these damn
things arrived too late in the war to do any damage".

Seehunds operated mainly around the German coast and in the English Channel, and
could attack on the surface in turbulent weather, but had to be almost
stationary for submerged attacks. From January to April 1945 Seehunds performed
142 sorties, during which they sank 8 ships for a total of 17,301 tons and
damaged 3 for a total of 18,384 tons; 35 Seehunds were lost in action.

The last Seehund sorties took place on 28 April and 2 May 1945, when two special
missions were performed to re-supply the cut off German base at Dunkirk with
rations, the boats carrying special food containers (nicknamed "butter
torpedoes") instead of torpedoes, and on the return voyage using the containers
to carry mail from the Dunkirk garrison.

The French navy received four units as war damage, and commissioned them as S
621, S 622, S 623 and S624. They were used until August 1953.

In 1953, at the request of the U.S. Navy to test its harbour defences, the
French Navy prepared two submarines and their crew (S 622 and S 623). They went
to San Diego, California where they made more than 60 sorties and travelled
1,400 miles. They returned to Toulon on 16 April 1954 from Norfolk on the
transport ANTARES. In September 1954 the navy disarmed S 621 and S 623 (Q24 &
Q25 ) due to wear and tear on their hulls. In August 1956 the fleet of mini
submarines were decommissioned. S 622 and S 624 were placed in special reserve
B.

S 622 was left at the naval base in Lorient in three pieces. Between October
1988 and July 1989 she was reassembled and put on display at Brest Naval Museum.
S 622 was the former U 5090.

The U-5075 is on display at the United States Naval Shipbuilding Museum, part of
the Massachusetts Military Research Centre, in Quincy, Massachusetts. Occasional
amateur radio events are conducted by this museum ship, using the call-sign
WW2MAN.

There are a number of SEEHUND submarines on display at European and US museums.

Guinea 2006 she is in the margin of the sheet, above the stamp.
Maldives 2018 SEEHUND type midget submarine MVR22 sg?, Scott
Chad 2017 3300f sgMS?. Scott? (She is depicted in the margin below the stamp.)
Central African Republic 2022 1200 FCFA sg?, Scott?

Source: Wikipedia. http://www.uboat.net/types/seehund.htm.
http://sous-marin.france.pagesperso-orange.fr/E19.htm. Dictionary of French
Naval Vessels (Part2) by Lt de Vaisseau Jean-Michel Roche. Various other
internet sites. Photo from the Internet.

Peter Crichton
Attachments
FS S 622   SEEHUND CLASS   GUINEE    2006a    NC    xx.jpg
Image (67).jpg
2018 seehund.jpg
2017 U-995 German-submarine-U-995.jpg
2017 U-995 German-submarine-U-995.jpg (119.37 KiB) Viewed 274 times
2022 U-Boat-Type-XXVII--Seehund- (2).jpg
2022 U-Boat-Type-XXVII--Seehund- (2).jpg (51.19 KiB) Viewed 127 times

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