Listing to one side...

TangoWhiskey

TangoWhiskey

Touchdown! Greaser!
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3Green
This must be why sailors pack extra underwear... :yes:

450_ap_cougar_ace_060725.jpg


http://www.ctv.ca/servlet/ArticleNe...5/alaska_ship_060725/20060725?hub=CTVNewsAt11

Praise to our Coast Guard members!! Say bye-bye to 5000 new automobiles.
 
Frank Browne said:
Wow. That thing looks like it's bobbing like a cork. Not enough ballast?
Click to expand...

Something must have shifted below decks?
 
a couple of weeks ago I read about a pax liner (Princess?) that 'suddenly listed 15 degrees' then returned to normal.
Water and people splashed out of the pool, several pax were hurt.
The article said the same thing happened to this Cruise operator on another ship. They never explained what caused it but they said the cpt was reprimanded, no mention of a mechanical.

Sketchy articles raise more Qs than they answer...what could a capt do to cause a sudden list?? I figured ballast would need a long time to be pumped one side to the other and would result in a slow list as in, 'hey were 5 degrees off, did you leave a pump running?" A sudden list? Having too much fun with the steering wheel?
 
Let'sgoflying! said:
a couple of weeks ago I read about a pax liner (Princess?) that 'suddenly listed 15 degrees' then returned to normal.
Water and people splashed out of the pool, several pax were hurt.
The article said the same thing happened to this Cruise operator on another ship. They never explained what caused it but they said the cpt was reprimanded, no mention of a mechanical.

Sketchy articles raise more Qs than they answer...what could a capt do to cause a sudden list?? I figured ballast would need a long time to be pumped one side to the other and would result in a slow list as in, 'hey were 5 degrees off, did you leave a pump running?" A sudden list? Having too much fun with the steering wheel?
Click to expand...

The one you are referring to happened out of Port Canaveral Florida and was reported to have been caused by a malfunctioning steering thruster.
 
Let'sgoflying! said:
a couple of weeks ago I read about a pax liner (Princess?) that 'suddenly listed 15 degrees' then returned to normal.
Water and people splashed out of the pool, several pax were hurt.
The article said the same thing happened to this Cruise operator on another ship. They never explained what caused it but they said the cpt was reprimanded, no mention of a mechanical.

Sketchy articles raise more Qs than they answer...what could a capt do to cause a sudden list?? I figured ballast would need a long time to be pumped one side to the other and would result in a slow list as in, 'hey were 5 degrees off, did you leave a pump running?" A sudden list? Having too much fun with the steering wheel?
Click to expand...

A sharp turn at speed would probably do that. Also AFaIK most cruise ships carry massive gyros that dampen the ships rolling to keep the pax less green at the gills in rough water. Perhaps there was something wrong with the servos on the gyros.
 
I don't think the ships have big honkin' gyros to counteract the rolls. According to the Captain on a couple of cruises, they have have stabilizers- essentially fins or rudders used to damp the rolls. I was told they are up to 20 feet long. I think you meant the stabilizer servos. I never got a chance to ask if they were activated by gyros or just a pendulum system.
 
Hey I didn't dream that one up
http://www.orlandosentinel.com/news...jul21,0,7158501.story?coll=orl-home-headlines
but they now report 7 instances....included in causes mentioned are autopilot failure, computer glitches.

PS anyone know about this? When we took a ferry from PEI to Nova Scotia last week, an on board infosheet said it was driven by a Voigt-Schneider propellor. The pic of it was wild! It looked like 5-7 long straight blades on a plate, and they were pointing straight down! I could not figure how it could do any more than whip the sea into a frothing frenzy.
Anyway I have been searching google and metacrawler (my fav) for info and came up with zip.
 
Let'sgoflying! said:
Sketchy articles raise more Qs than they answer...what could a capt do to cause a sudden list?? I figured ballast would need a long time to be pumped one side to the other and would result in a slow list as in, 'hey were 5 degrees off, did you leave a pump running?" A sudden list? Having too much fun with the steering wheel?
Click to expand...
You are right that there is not much the crew can do to cause a sudden significant list aside of a high speed turn. The attached photo is the USS Nimitz with the rudder hard over at high speed, probably taken during sea trials. This is an emergency maneuver. Imagine what is happening to everything below!

The stabilizers on a cruise ship are vanes. Think underwater wings with hydraulicly controlled AOA. The AOA goes both positive and negative, and they are controlled to counter the rolling moment of the sea. Because these ships are designed with the vanes, they have a tender stability in the roll axis without the vanes operating. But the vanes let them put on more decks and cram in more cabins. Just looking at them makes me cringe - they do not appear to be stable and I guess that without the vanes in operation they are indeed marginally stable. My pure guess at the problem is that the cruise ship's control mechanism went south. Oops, pull the breaker fast!

-Skip
 

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Let'sgoflying! said:
When we took a ferry from PEI to Nova Scotia last week, an on board infosheet said it was driven by a Voigt-Schneider propellor. The pic of it was wild! It looked like 5-7 long straight blades on a plate, and they were pointing straight down! I could not figure how it could do any more than whip the sea into a frothing frenzy.
Anyway I have been searching google and metacrawler (my fav) for info and came up with zip.
Click to expand...

Dave,

Voight-Schneider is an application of a technology called cycloidal propulsion. It's supposed to provide some pretty good maneuverability. Here's a good description of it:

http://members.surfeu.at/fprossegger/english/vsp-function.html

Here is the PDF from the manufacturer:

http://www.voithturbo.com/media/vtmh_am_specialprint_1930_e.pdf

Some are even trying to apply cycloidal propulsion to aircraft. Would you need a rotarywing certificate to fly one of these?

http://serve.me.nus.edu.sg/cyclocopter/
 
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