Moving the crew to the bow.

[Lt.Fillipidis]

This was the standard tactic when crash dive was issued.
But was it helpful? I mean, you have a 1200ton uboat with aprox 50men inside. Those 50men would weight a total of 400kg. Aproximatelly 35of them
would move forward. Then you have about 280-300kg extra weight in the bow section. Would that be enough to reduce the diving time even for a second?

[Mittelwaechter]

Greek men seem to be quite small I guess...

;))

[Torplexed]

When you consider that the weight of items like food and supplies consumed had to be mathematically factored in everyday just to keep the proper trim for a sub I would say the weight of 50 men shifting suddenly would have a discernible effect on a dive.

[Schroeder]

50 men should weight a bit more than 400kg. I guess you forgot a zero.;)
Even if it only speeds up your dive by a single second it might be the difference between life and death.

[Thomen]

This was the standard tactic when crash dive was issued.
But was it helpful? I mean, you have a 1200ton uboat with aprox 50men inside. Those 50men would weight a total of 400kg. Aproximatelly 35of them
would move forward. Then you have about 280-300kg extra weight in the bow section. Would that be enough to reduce the diving time even for a second?

Schroeder is right...
If you take an average weight of 75kg per man, that's 3750kg or 3.7 metric tons.

[TorpedoMo]

I'm sure the weight shift had an significant effect and benefit for the crash dive.
For example when firing at torpedo at PD it could happen that the bow breaks through the surface for a second because of the sudden weight loss.
If a single Torp like the G7e which has about 1600kg has an lighten effect so 40 men running to the bow will have also have a ballast effect on the diving angle.

[TheDudTorpedo]

This was the standard tactic when crash dive was issued.
But was it helpful? I mean, you have a 1200ton uboat with aprox 50men inside. Those 50men would weight a total of 400kg. Aproximatelly 35of them
would move forward. Then you have about 280-300kg extra weight in the bow section. Would that be enough to reduce the diving time even for a second?

Hi,

I speak under correction here, and I hope some submariner will correct me if I am wrong, but because the boat is trimmed to have a neutral bouyancy, any movement of mass from one end of the boat to the other has a significant impact on the boat. Thus, movement to the bow causes the boat to become bow-heavy, and vice-versa.

Regards,
Dud

[irish1958]

There are reports of pleasure boats capsizing because all the patrons rush to one side to see something. Passengers in an aircraft have to be seated correctly to have the plane balanced.
I suspect suddenly rushing a couple of tons to the front of a sub might make a difference.

[Lt.Fillipidis]

Actually yes... Even in my mind, i forgot that extra zero
so it seemed quite a small number! :haha:
I got it all now, there's no question about it.
I only wish that someone had scripted it in the game...:-?

[Pisces]

There are reports of pleasure boats capsizing because all the patrons rush to one side to see something. Passengers in an aircraft have to be seated correctly to have the plane balanced.
I suspect suddenly rushing a couple of tons to the front of a sub might make a difference.Seating arrangements in aircrafts are more important for identification incase things go wrong. That being said, a moved center of mass does distort the balance. But the plane automatically finds a new balance at a slightly different speed, or the (auto)pilot adjusts the elevators a bit. But it is also very important that the center-of-mass (COM) be in a certain position range to the wings and tail. (therefore they want to know the weights of passengers, cargo and fuel) If the COM is too far to the rear the tail doesn't have enough leverage to stabilise the plane and an increase in angle of attack leads to ever growing pitching torque increasing the angle of attack further. Result: bits and pieces.

With subs it's similar. But I am not familar with submarine stability behaviour. Just that the center of mass in relation to the center of buoyancy (center of mass of displaced water) can make big difference in how quickly it tilts downwards. A downward tilt increases the downward force of the water, just like an inverted wing of an airplane. Shortening the dive process.

[nikbear]

There are plenty of reports of Subs being recovered from the bottom after getting they're bow stuck in mud on the sea floor after a bad crash dive by the crew rushing from the bow to the stern and vice versa until they can break the suction of the mud,quite a common accident during training exercises apparently :arrgh!: