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2014-10-01 Africa North

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Posted by Skidmark 2014-10-01 00:00|| || Front Page|| [11127 views ] Top

#1 Nothing sez O foo like a rudder jammed hard port during a starboard pass in a canal.

Posted by Shipman 2014-10-01 00:14|| 2014-10-01 00:14|| Front Page Top

#2 Ship handling in a close channel is tricky, nothing like maneuvering in open water. The hull displaces water and, guess what, you're in a canal. The water surface flow speed between two ships in a shallow channel is almost 2X of what the ships themselves are moving, creating a 'suck' between them.
John McPhee's "Uncommon Carriers" has an interesting chapter in it about a lake in Switzerland of all places, where they use 10 meter scale ships to teach senior ship masters handling under controlled conditions.

Posted by ed in texas 2014-10-01 07:51|| 2014-10-01 07:51|| Front Page Top

#3 For a safe proof of concept you can try at home, simply bring your knees up to your chest in the bath. Notice how the boats begin moving towards one another.

Posted by Besoeker 2014-10-01 07:56|| 2014-10-01 07:56|| Front Page Top

#4 creating a 'suck' between them

Known as the Venturi Effect.

Posted by Pappy 2014-10-01 09:56|| 2014-10-01 09:56|| Front Page Top

#5 My Ex-GF used to give great Venturi ;-)

Posted by Herman Thud6100 2014-10-01 11:12|| 2014-10-01 11:12|| Front Page Top

#6 Looks to me like Columbo Express was attempting to overtake and pass the Maersk Tanjong but then got too close to the shore and was forced to either turn or run aground. Maybe his turn was accelerated by the suck but it looks like it could have been avoided if he had just slowed down.

Posted by Ebbang Uluque6305 2014-10-01 12:09|| 2014-10-01 12:09|| Front Page Top

#7 Didn't look like the Columbo Express had a lot of clearance to starboard. Was there perhaps a sandbar or other obstruction?

Posted by Steve White 2014-10-01 12:57|| 2014-10-01 12:57|| Front Page Top

#8 A man will forget many things, but he will never forget a Venturi.
~ Barbara Bush

Posted by Besoeker 2014-10-01 13:00|| 2014-10-01 13:00|| Front Page Top

#9 Didn't look like the Columbo Express had a lot of clearance to starboard. Was there perhaps a sandbar or other obstruction?

Another problem with high speed in shallow waters is that the venturi effect also occurs between the hull and the bottom, or the sides of a canal.

Posted by Pappy 2014-10-01 13:48|| 2014-10-01 13:48|| Front Page Top

23:15 Alpha2c
23:10 SteveS
22:53 USN, Ret.
21:58 Ebbomosh Hupemp2664
21:54 JosephMendiola
21:53 JosephMendiola
21:40 Ebbomosh Hupemp2664
21:08 Barbara
20:53 Frank G
20:52 Pappy
20:50 djk
20:47 rammer
20:41 RandomJD
20:30 SteveS
20:29 rammer
20:28 SteveS
20:25 ed in texas
20:00 BrerRabbit
19:59 AlanC
19:58 Frank G
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19:51 phil_b
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