Polyester Rode

[RunAgroundHard]

Maybe ... I don't Superintend Cruise Ships - but I can soon ask my Brother if I was really that interested .. who conducts Classification Society Inspections of them in Florida.

New drill ship from Korea, owner changed out supplied mooring lines for dyneema, this was start of year. The difference in weight and volume is significant. Classification Society is DNV, UK flagged, inspected by MCA.

ABS is common class society for many vessels as they are lower cost. Depends on who the owner has engaged rather than country. The drill ship changed from ABS to DNV as DNV offered certain notations that ABS did not, good for marketing.

 

[Neeves]

who conducts Classification Society Inspections of them in Florida.

Does not matter. All Classification Societies work to exactly the same standards and rules.

RINA is as good, or bad, as DNV, ABS or Lloyds.

Jonathan

 

[dunedin]

New drill ship from Korea, owner changed out supplied mooring lines for dyneema, this was start of year. The difference in weight and volume is significant. Classification Society is DNV, UK flagged, inspected by MCA.

ABS is common class society for many vessels as they are lower cost. Depends on who the owner has engaged rather than country. The drill ship changed from ABS to DNV as DNV offered certain notations that ABS did not, good for marketing.

When yachts changed to dyneema older boats tended to break the deck gear which could not cope with the shock loads.

Do ships with dyneema mooring ropes only berth in places with brand new bollards - or do the shock loads remove the dock bollards?

 

[RunAgroundHard]

When yachts changed to dyneema older boats tended to break the deck gear which could not cope with the shock loads.

Do ships with dyneema mooring ropes only berth in places with brand new bollards - or do the shock loads remove the dock bollards?

Dock side bollards have failed with any mooring rope material. Bits, or Bollards on the dock and on the vessel have SWL noted.

I can only talk about drill ships, but we are given the loading limits by the harbour and then have to stay within that. If the forecast is that the wind force is too high, we use our DP thrusters to reduce load. There are tables in the marine manual for the vessel that state loads for various wind speeds and directions. Also in a computer programme which gives a mooring plan. A drill ship has this tech because its primary function is to remain on location when drilling at sea, I assume that the same software is available to modern vessels eg cruise ships. All the control systems are fairly standard these days from a few suppliers and my employer has hired cruise liner DP operators. In Korea we were towed out to the anchorage and anchored before a typhoon arrived, as the thrusters were not installed. Big tugs remained on standby.

The main point is it is a known quantity and can be managed. As for shock loads, vessels moor to be stationary, not surge around, although that happens to a small degree.

I am not marine crew, so this is information is just from being there and taking an interest.

 

[Neeves]

When yachts changed to dyneema older boats tended to break the deck gear which could not cope with the shock loads.

Do ships with dyneema mooring ropes only berth in places with brand new bollards - or do the shock loads remove the dock bollards?

They don't have shock loads on commercial vessels using dyneema because they do not move there is, effectively, no elasticity.

You would not use dyneema to secure a yacht in a dock.

It has been found that mooring lines for large vessels that have elasticity can fail and when they do so... men have been killed. I understand for this very reason nylon is banned by the US Navy.

I suspect, no idea really, that the dock bollards have been replaced with bigger kit - because cruise ships have increased in size.

Jonathan

 

[noelex]

I came across this line in a boatyard in the Netherlands (the home of Dyneema and UHMWPE).
I doubt it was used by a recreational yacht

 

[dunedin]

Deleted crossed threads.