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- - 977 U-boat (https://www.subsim.com/radioroom/showthread.php?t=150776)

Sailor Steve

04-19-09 03:53 PM

Quote:

Originally Posted by bobchase (Post 1086789)

The airdales will tell you that a CV will rock & roll in heavy seas but that is both their bravado talking and their relative world of living inside a giant. For them, their ship really is moving hard in those seas but let a DD or DE come alongside for refueling. If they pay attention, what constitutes rock & roll gets seriously re-written when you watch the smaller ship half-buried in seas that cause a carrier's deck to only pitch or roll +/- 5 degrees.

Been there, done that!:rotfl::rock:

Sensekhmet

04-20-09 12:11 PM

Quote:

Originally Posted by bobchase (Post 1086789)

For them, their ship really is moving hard in those seas but let a DD or DE come alongside for refueling. If they pay attention, what constitutes rock & roll gets seriously re-written when you watch the smaller ship half-buried in seas that cause a carrier's deck to only pitch or roll +/- 5 degrees.

A little DE does move about in almost any sea so one would presume that a surfaced U-Boat would behave much like that. However, there is a sea-state where the swells (waves) are very sharp, almost vertical, and far enough apart where a DE's hull won't rise to meet the swell. The water just simply breaks onto the foredeck and rolls off at the forward the breakwater. Down below you'd think that you were in much calmer seas if it wasn't for the big 'shudder' that goes though the ship every time a wave breaks. On a U-Boat, in that sea state, one would imagine that the sea would simply roll over the whole sub and never even break.

Bob

Speaking of destroyers in bad weather, I've read an account of a Polish destroyer in WW2 in the midst of a monstrous storm. The whole DD group proceeded at top speed with wind from the stern and they all suffered from a peculiar phenomenon. The ships would loose their course, and start to turn by themselves. They would also list badly and it continued until they were at 90 degrees to the wind. At that point the ship would slowly straighten itself and be ready for another uncontrolled turn... the situation was absurd and it made it impossible for the group to stay in any kind of formation.

Sailor Steve

04-20-09 02:17 PM

I missed this part the first time around:

Quote:

The range was 400 yards; we could get no closer, for
300 yards was the danger limit. If we had gone much
nearer, with all the explosive we had on board we should
have been in danger from the shock-wave of our own
torpedo. Many U-boats were in fact lost this way.

How would he, or anyone, know that?

Schroeder

04-20-09 05:10 PM

Maybe survivors told the story.:06:

Sag75

04-20-09 11:16 PM

but is not close to the torpedo arming limit?

Sailor Steve

04-21-09 11:56 AM

I agree. They probably didn't want to get closer because the torpedoes might not arm. My point was that I've never read any report of a u-boat being lost that way, and even if there was one it would hardly translate to 'many'.

bobchase

04-21-09 07:46 PM

Quote:

Originally Posted by Sensekhmet (Post 1087364)

That is a hard one to understand. The only thing that comes to mind is that a ship has to make way through the water to have steerageway. If the current goes faster than the boat, then the boat has negative forward speed and starts handing as if it is in reverse. (Right rudder becomes Left Rudder) I've done this in a sailboat on a strong outbound tide. On a destroyer capable of 30+ knots? I can't imagine that kind of current speed unless you just roared past Three Sisters Island heading for the down hill side of Niagara Falls.

Bob

Sensekhmet

04-22-09 01:56 AM

bobchase, I found more info.The event took place in heavy seas in the last night of the Bismarck chase, 26th/27th of may. The destroyer group was the 4th flotilla of commodore (?) Phillip Vian, consisting of: HMS Cossack, HMS Maori, HMS Sikh, HMS Zulu and ORP Piorun. Piorun was an N class destroyer but according to the account, all ships suffered from the same phenomenon.
Here is what Piorun's commander had to say (my translation):
When we have reached the ordered speed of 26 knots all five destroyers lost all manouverability, which was by the way forseen by admirality's 'ships' manouverability description' (?). With strong wave from the stern and speeds above 25 knots the ship went totally out of control. With the stern rising high and the bow ploughing deep in the water, the ship listed to either side, until the list of 60 degrees (!) and in this position it turned either way taking in water through superstructures and ventilation. When the stern was pushed around by the waves 120-150 degrees off course and the ship was bow to the waves again, the ship slowly righted itself and begun to respond again to rudder and engines. It's worth noting that at that moment, Piorun had less than 40% of fuel on board, and although in theory it was a ship that was immune to capsizing, trying to navigate in horizontal position and being completely helpless must be considered a difficult experiment indeed.
Taken from Jerzy Pertek's 'Wielkie dni malej floty' (Small fleet's great days), 1972 edition (on a side note I'm surprised you could buy a book like this in Poland at the time...).

PhantomLord

04-23-09 09:02 AM

Interesting read so far... what bothers me is to calculate the described depth from fathoms to meters every time... :shifty:

Oneshot/Onekill

04-23-09 09:38 AM

I am just a thick skulled jarhead, but I have spent time on smaller naval vessels. We called them gator freightors. They were really amphibious warships. The smallest one in service at the time was an LST(Landing Ship Tank) It was the USS San Bernadino, no longer in service. These ships had no keel, they were flat bottom boats, so they could navigate very close to shore.

I was on this ship on my way to the Philipines when we got caught in the edge of a typhoon. I can tell you that we were at the mercy of the Pacific. I was literally walking on the bulkheads from the pitch and roll we were experiencing. I don't know how high the winds or waves were as we were confined to below decks untill we escaped the storm.

bobchase

04-23-09 08:35 PM

Quote:

Originally Posted by Sensekhmet (Post 1088422)

... With strong wave from the stern and speeds above 25 knots the ship went totally out of control. With the stern rising high and the bow ploughing deep in the water, the ship listed to either side, until the list of 60 degrees (!) ...

It sounds like at 25 knots and above that they would just 'flop' over the top of a swell so suddenly that the rudder (and probably the screws) were right out of water for a period of time. During that time, the ship was basically surfing down the wave and then suddenly 'broached' due to lack of steerage. The swell or at least the next swell just knocked her down and rode over her. Not a good thing have to happen...I saw some East German Missile Torpedo Boats (MTB's) broach-too in high winds and seas. (25 foot swells.) They lost half of the boats that came out to
'greet' us. Not a pretty thought, even after 35 years.

A 60 degree roll seems extreme but when the sea is your mistress, anything is possible when you make her mad. Our ships' roll-meter stopped at 45 degrees but that doesn't mean that theirs had too. Anyway, they were pretty lucky that they didn't have water go down the funnel and put their lights out too.

Bob

bobchase

04-23-09 08:53 PM

Quote:

Originally Posted by Oneshot/Onekill (Post 1089264)

...I was literally walking on the bulkheads from the pitch and roll we were experiencing. I don't know how high the winds or waves were as we were confined to below decks untill we escaped the storm.

I think that if you asked Sailor Steve, he would tell you his ship had black colored traction grit glued to the lower 36" of the port & starboard bulkheads on the fore-aft passageway. The DE's that I used to ride to get back out to my 717' inboard sure did. On the other hand, the USS Newport News didn't because she was a Heavy Cruiser and, at 21000 tons, just a tad more stable than a Gearing class DD. Rock & Roll is a relative term. A ships size and shape are just two of the many factors in how much rock & roll that you get to enjoy.

I'm glad that, as a ground pounder, that you got to enjoy some rock, some roll, and some good 'ol Navy cook'in.

Chief Chase, USN

mookiemookie

04-23-09 09:08 PM

Sorry to veer off track, but I just read the intro...

What a bunch of hypocritical horse sh*t. I read and loved The Cruel Sea, but Monsarrat is dead wrong.

Oneshot/Onekill

04-24-09 01:25 AM

Quote:

Originally Posted by bobchase (Post 1089658)

Oooraah Chief. I do belive there was some kind of adhesive now that you mentioned it. I didn't really notice too much though as I was too busy trying like hell to hold down my dinner!:timeout:

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