Ships Nostalgia banner

1 - 14 of 14 Posts

·
Registered
Joined
·
1,201 Posts
Discussion Starter #1

·
Premium Member
Joined
·
1,389 Posts
My understanding of "Twistlocks" from my time in small container ships in Caribbean is:-
At the corners of each container are slotted holes incorporated into the load bearing frames of the container. The Twistlock engages into this slotted hole and is turned through 90 degrees.
When containers are being loaded or unloaded the container crane has a lifting frame with both "twistlocks" and "flippers". The Flippers locate the lifting frame onto the container the twistlocks then enter the slotted holes and when rotated allow the container to be remotely (and safely) lifted.
 

·
Registered
Joined
·
1,201 Posts
Discussion Starter #3
Jim S said:
My understanding of "Twistlocks" from my time in small container ships in Caribbean is:-
At the corners of each container are slotted holes incorporated into the load bearing frames of the container. The Twistlock engages into this slotted hole and is turned through 90 degrees.
When containers are being loaded or unloaded the container crane has a lifting frame with both "twistlocks" and "flippers". The Flippers locate the lifting frame onto the container the twistlocks then enter the slotted holes and when rotated allow the container to be remotely (and safely) lifted.
Oh! I was completly wrong. As I said, because of the cross they make, I thought that the twistlock was what I now blelive to be the lashing bar.

Thank you Jim. ;)

Brgds
 

·
Premium Member
Joined
·
1,389 Posts
Twistlocks under Review

The September 2006 edition of "Marine Engineers Review" gives a worrying account of some recent incidents where large numbers of containers have been lost overboard thereby questioning the reliability of fully automatic twistlocks (FATS) under hostile conditions. In February 2006 P&O "Nedlloyd Mondriaan" (8450TEU) lost nearly 60 containers between Hamburg and Rotterdam and then unbelievably a further 50 containers shortly after en-route to Asia. In the same month CMA CGM "Otello" (8500TEU) lost 50 containers and damaged a further 30 in Bay of Biscay. The same company's "Verdi" (5700 TEU) lost 77 containers off Cape Finisterre.
All the Class Societies are investigating these problems that appear to be linked with ships getting larger, some can stack 8 high. One unusual feature seems to be that these latest losses happened at aft end of ships raising the question was it hull vibration causing the twistlocks to bounce out rather than simply sea conditions. You wonder how many of these containers are still floating around semi submerged.
 

·
Registered
Joined
·
3,021 Posts
Twistlocks , now that's a bone of contention.

Have been involved with container lashings for nearly 30 years
from ch.mate to marine ops manager and container terminal manager.

Have no experience of auto or semi auto twistlocks , but the basic system
is ( where both ends of the bays are acessable ) is twistlocks between
each tier , bridge fittings to connect top of the upper tier then wire lashings
with turnbuckles and moscow hooks - made up depending on the stow
configuration and class requirements.
Have also experienced lost containers but these were mostly caused by
improper stowage i.e. stowing 20'outside of 40' etc.

Have a feeling that with stacks going higher , one problem could be the
increased moment of inertia of the complete stack allowing slackness
to get into the stow.

JC
 

·
Registered
Joined
·
634 Posts
Twistlocks.

Hi all. "Twistlocks". Term generally used for the device that secures containers to HGV trailors for transportation. Ken.
 

·
Registered
Joined
·
954 Posts
Nightmare for the Mate. Trying to keep tabs on thousands of twistlocks and other associated container claptrap is a full time job in itself. You can never find them all when you have a full load! The best lashing system I have seen was on Sealand ships where a large frame was inserted between layers that locked all containers together so no twistlocks, stackers, bridging pieces etc etc etc.

regards
Dave.
 

·
Registered
Joined
·
1,214 Posts
The twistlocks have nothing to do with containers being lost from the 8500Teu ships.
The latest theory is "Newtons Cradle" and poor or damaged corner castings.
The T4 twistlocks were all replaced by semi automatics and still ships had problems.
GL did a detailed study before stating the twistlocks were not to blame.
 

·
Premium Member
Joined
·
1,389 Posts
The article I referred to did state that GL investigated the Bay of Biscayi ncidents and did tests under "laboratory conditions" and found no fault with the twistlocks but ammended their cargo lashing manual for containers "specifying that visual confirmation should be obtained to ensure the positive latching of all containers" - how that is achieved in practice who knows,- seems to defeat the purpose of the automatic twistlock.
Lloyds also don't believe that there is any reason to question the operation of FATs "provided the limitatiions defined in their General Approval Certificates are complied with". Yet say that "FATs have not broken during testing it appears they are jumping out as a result of hull vibration".
Some manufacturers have taken precautionary measures - German Lashing has offered to exchange FATs for semi-automatics and MacGregor has recalled all 70,000 of their FATS and is replacing with semi-automatic models. A new model of FAT - C8A is due to be released by the end of 2006.
Are the problems being experienced due to the scaling up of the size of container ships? Cannot be much comfort for the ship's staff with responsibility for the stowage.
 

·
Registered
Joined
·
1,214 Posts
Just uploaded a couple of pictures of boxes using semi automatic locks.
Damage at 82+84+86 at bay 74.
Rest of boxes perfect.
You can imagine the number of surveyors etc investigating this lot.
 

·
Premium Member
Joined
·
1,389 Posts
Just uploaded a couple of pictures of boxes using semi automatic locks.
Damage at 82+84+86 at bay 74.
Rest of boxes perfect.
You can imagine the number of surveyors etc investigating this lot.
Brian,
Interesting pictures - it looks like the container failed all around the twistlock.
The only container ships I sailed on were two small self loading ships in a Gulf of Mexico service. We only stacked two high on deck and the locking arrangements looked similar to that described by PilotMac on Sealand ships - a substantial frame between layers.
 
1 - 14 of 14 Posts
Top