View Single Post
Old 12-08-08, 05:14 PM   #32
Bubblehead Nuke
XO
 
Join Date: Feb 2006
Posts: 435
Downloads: 5
Uploads: 0
Default

Quote:
Originally Posted by smack
Bubblehead Nuke thanks for the input, but how can a stopped propeller make you noisier? I have been on a submarine
Have you SERVED on a sub or just toured one?

Quote:
, the propeller stops because moving though the water creates sound that can be picked up by nearby vessels. It is called moving parts, when you have things moving in the water they emit sound.
See my post about the Kilo class submarine. Just because you are not turning the screw does not mean you are not making noise. In most cases, you can turn the screw quite a bit before the screw generated noise level exceeds ownships noise level.

Quote:
And its simple physics, how can the propeller spin and the sub not go forward? Its designed to propel the sub and when the sub stops, the screw should stop as well. Thats why submarines stop their engines when somebody is coming in their wash or behind the subamarine and then perform a Crazy Ivan just to be sure.
See above post.

What you THINK you know may be FAR different from what things are.

Boats do NOT stop turning the screw to listen in the baffles. You have to be making headway in order to turn to DO the Crazy Ivan

Quote:
The screws have to stop. Watch any movie with subs in it and you will see the propeler stops everytime the sub stops.
Where did I say that the screw does not stop spinning to stop? You can also turn ONE RPM and move BACKWARDS if you are against the current

Quote:
A stop device for application to an outboard marine engine to retain the propeller against rotation while the prop nut is being tightened or loosened. The device is T-shaped and includes side wings and a vertical leg. The wings have slots which permit the device to be slipped onto a tail plate located above the propeller. The leg extends downwardly between the blades of the propeller and engages the blades to prevent propeller rotation.
Yeah, we call it the shaft locking device. With the shaft stopped it takes about 20 seconds to engage it. Btw, the boat can be moving at 20+ knots and you can Stop and Lock the shaft if you need to.

Quote:
Thurst is made by faster and faster rotations, so how can a rotating propeller stop the submarine? Its like a bycicle, can you be at one place while turning the peddals? No.
Backing bell. greatest e-ticket ride on the boat from an engineering standpoint. All ahead flank and they order a emergency crashback. You slam the ahead throttles shut and open the astern throttles. The blade REVERSES and you come to a stop REAL DANG fast.

Or you can be slow and lazy. They ring up all stop. you close the ahead throttle and the propellor 'windmills' in the water stream. The drag of the screw will slow the ship and stop it eventually.

Quote:
And I dont expect them to be fixed, I expect a patch that fixes them since it is the only way, unless the developers start thinking outside of the box and use different code for some of these things, for a good code writer its not exactly a head scratcher.
You don't expect them to be fixed yet you want a patch? This is confusing to me.
Bubblehead Nuke is offline   Reply With Quote