U-125 has too many mines?

[Rysyonok]

U-125 (ship #425) carries 142 type I mines: 2 facings of 71 each.

I believe it's a typo.

The sub in fact carried only 42.

http://uboat.net/wwi/types/index.html?type=UE+2

Thanks

[DuckofTindalos]

Looks like you're probably right... Sigh, I liked having all those mines...[8D]

[Rysyonok]

And I hated clearing them

[jwilkerson]

Conway's indicates 42 internal and 30 additional external stowage.

Jentschura indicates internal stowage was 42 .. but mine tubes could be replaced by torpedo tubes and then mine stowage was 30.

Just a guess that these two data points are actually aligned and that the actual total is 72 ... though the exact process to launch the 30 externally stowed mines is not revealed by these sources ? Since the 30 mines could still be carried after the internal minelaying tubes were removed, it seems clear that the externally stowed mines were not transferred below for the laying process, but instead must have somehow been launched from outside the vessel ( another guess would be that this needed to be done while surfaced ). Then final question would be ( if the proceeding guess is true ), could external mines be transfered below if the mine tubes were carried, to enable sumerged laying of the final 30 mines.

Externally carried torpedoes ( and same being transferred below ) I've heard of .. but not familar with externally carried mines ...

[DuckofTindalos]

Well, they had external torpedoes, so why not external mines... In fact, I *think* I read somewhere about German submarine minelaying in WWII where mention was made of external mine containers.

[Tankerace]

Yeah, I think its Janes typo. Don't have it with me, but I'll bet it indicate 142 instead of 42. Will fix with the next update (which may well be, well, not anytime soon.

[jwilkerson]

ORIGINAL: Terminus

Well, they had external torpedoes, so why not external mines... In fact, I *think* I read somewhere about German submarine minelaying in WWII where mention was made of external mine containers.

So were these external mines laid directly from the external mine containers or did they have to transfer the mines below to the regular mine launching tubes !?

I guess I'll check some WWII subs .. and see if I can find it there ... odds are the same technique applied ...

Thanks for the "hint" !

[DuckofTindalos]

ORIGINAL: Tankerace

Yeah, I think its Janes typo. Don't have it with me, but I'll bet it indicate 142 instead of 42. Will fix with the next update (which may well be, well, not anytime soon.

Erm, my copy of Jane's Fighting Ships of World War I says 42 mines...

[jwilkerson]

ORIGINAL: jwilkerson

Conway's indicates 42 internal and 30 additional external stowage.

Jentschura indicates internal stowage was 42 .. but mine tubes could be replaced by torpedo tubes and then mine stowage was 30.

Just a guess that these two data points are actually aligned and that the actual total is 72 ... though the exact process to launch the 30 externally stowed mines is not revealed by these sources ? Since the 30 mines could still be carried after the internal minelaying tubes were removed, it seems clear that the externally stowed mines were not transferred below for the laying process, but instead must have somehow been launched from outside the vessel ( another guess would be that this needed to be done while surfaced ). Then final question would be ( if the proceeding guess is true ), could external mines be transfered below if the mine tubes were carried, to enable sumerged laying of the final 30 mines.

Externally carried torpedoes ( and same being transferred below ) I've heard of .. but not familar with externally carried mines ...

Well the last paragraph below indicates that one technique for launching externally stowed mines was to use verticle launch tubes. So this becomes working theory for how U-125 ( U-117 ) class deployed the 30 mines they seem to have carried externally ( in addition to the 42 carried internally ). Still looking ...




http://www.chinfo.navy.mil/navpalib/cno ... andos.html

USS Argonaut (SS-166) was designed originally as a minelayer and launched at the Portsmouth (New Hampshire) Navy Yard in November 1927. On an overall length of 381 feet and displacing 2,710 tons surfaced and 4,080 submerged, she carried four 21" torpedo tubes forward and two 40" mine-laying tubes aft, with an elaborate mechanical handling system for moving the mines from stowage to the launching tracks. Considerable engine room volume was sacrificed to gain additional mine payload, which resulted in limiting the main propulsion diesels to a total of 2,800 horsepower, yielding only 15 knots on the surface. An over-large, under-powered boat, Argonaut was never entirely successful, but early in the war, she was re-engined at the Mare Island Navy Yard to increase her main propulsion horsepower to 3,600 and additionally received two external, aft-firing torpedo tubes. Then, on the way back to the theater, her mine-laying gear was stripped out at Pearl Harbor to make room for Carlson's Marines.
USS Nautilus (SS-168) was the second of the V-class "cruisers" and was launched at Mare Island in March 1930. Although virtually the same size as Argonaut, her main engines developed a total of 4,700 horsepower, and she could reach 17 knots surfaced. Instead of minelaying gear, she had two 21" torpedo tubes aft, and like Argonaut, carried two 6"/53 deck guns. Nautilus was also modernized and re-engined at Mare Island in 1941/42, receiving four external torpedo tubes, two forward and two aft. Soon thereafter, she was also converted to a submarine transport.


http://www.ibiblio.org/hyperwar/USN/ref/AxisSubs/

WHEN AND HOW DO MINE-LAYING SUBMARINES LAY THEIR MINES?
The mines are usually laid either at high or low water. In moderate depths high water is generally preferred, as giving greater depth for diving. In waters too shallow for diving, mines would be laid from the surface at night.

While laying their mines, these submarines can proceed either on the surface or submerged, as the mines are usually released from inside the boat.

The mines may be laid at close intervals, i.e., about 50 yards, and in groups, or they may be laid singly at very wide intervals, say, 800 yards.

The majority of mines laid by U-boats are ,magnetic and are ejected from torpedo tubes. it is known that one type is short enough to allow 3 mines to be carried in 1 tube. Thus a 740-ton U-boat could carry 18 mines in her tubes and probably another 20 or more as spare.

It is probable that the new 1,000 tonners will lay moored mines; the number carried is 48. They method of laying is not known.

Cases are known of submarines having followed up minesweepers and laid their mines in the channel which had just been swept.



IN WHAT SOUNDINGS ARE THE MINES LAID?
In the North Sea and the Atlantic moored mines are usually laid in waters where the depth is between 7 and 80 fathoms. In tideless waters they could be laid at a considerably greater depth.

Magnetic mines would probably not be effective at a depth of more than 20 fathoms. they are usually laid in about 10 or 12 fathoms.


WHAT COLORS ARE THE MINES PAINTED?
German moored mines have, up to date, been painted black, but some have shown patches of red where the black paint has washed away. Magnetic mines rest on the sea-bed and cannot be seen.


http://www.subnetitalia.it/ubootVII.htm

(Ocean-going submarine) In this varying of the "type VII C" was added, behind the conning tower, a central section of around 10 meters. In this space were inserted five vertical mine tubes. With this change these boats "type VII D" transported 54 mines. The six operational boats have been all sunk : four in the Atlantic (1942 - 1943) and two in the North Sea (1944-1945).

[Rysyonok]

Even 72 is still more realistic than 142 =)