Habebty
Well-Known Member
Interesting film....
(apologies if posted before)
(apologies if posted before)
ISO Container Loss Film
- Thread starter Habebty
- Start date
Kukri
Well-Known Member
It’s a very good presentation. It shows just how unpleasant our own North Sea can be.
However this excellent bit of work deals with ultra large container ships in beam seas and in (relatively) shoal water.
The losses of containers from similar ships on the North Pacific route must be due to something else; the usual suspects are parametric rolling, where a ship’s period of encounter with a wave train on her bow or her quarter matches her natural roll period and the rollling is thus amplified, like pushing a child on a swing, and errors in stowage and lashing.
However this excellent bit of work deals with ultra large container ships in beam seas and in (relatively) shoal water.
The losses of containers from similar ships on the North Pacific route must be due to something else; the usual suspects are parametric rolling, where a ship’s period of encounter with a wave train on her bow or her quarter matches her natural roll period and the rollling is thus amplified, like pushing a child on a swing, and errors in stowage and lashing.
Tomahawk
Well-Known Member
Looking at that film, some of the waves were leaping all over the boxes.. A few hundred tonnes of water dropping down from a great height probably doesn't help the lashings
dolabriform
Well-Known Member
Really interesting, thanks for posting.
Bilgediver
Well-Known Member
Had to smile at your description of parametric rolling. I was on a 15000 ton cargo ship the Elena ex Cherry Herring sailing across the Pacific fro Japan to Mexico. It was moderately rough but nothing to be concerned about and riding the waves well but wet in a quartering sea. The bridge watch keepers spotted something on deck that needed sorting so altered course to put the ship beam on. We were probably at 16 knots plus. The ship started to roll in the way you describe and I had visions of the sea hitting the bridge front at the extreme angles were were reaching. I tried to extract myself from behind a long fixed table in my cabin to reach the phone on the desk in order to get the engine pulled back. However by the time I got free someone else realised and reduced the revs. Heaven knows to what angle we were rolling through but I doubt if container lashings would have held in an event like that.
The change was dramatic as soon as the speed reduced the mate was able to do what needed to be done on a placid dry gently rolling deck.