Floating walkon mooring

[rogerthebodger]

The marina we ar in has sections of floating walkon moorings that are fixec to the sea bed with concrete weights and steel chain to connect the floating jetty to the locating weights.

This steel chain allows for the rise and fall of the tid which is max 2.3 m range at springs

The steel chain rusts and any galvanizing soon corrodes away soon.

Does any on used rope like polysteel to connect the floating jetty to the location weights or may be old conveyor belting to connect the jetty to the weights or to connect any plastic floats to the walk on structure.

What is commonly used to connect a trot mooring to the anchor/weight to hold the anchor to the connection buoy

 

[penfold]

The chain isn't there just to connect the anchor and the pontoon, it damps movement and the catenary means lateral location is controlled while allowing keelboat access.

 

[Chiara’s slave]

The marina we ar in has sections of floating walkon moorings that are fixec to the sea bed with concrete weights and steel chain to connect the floating jetty to the locating weights.

This steel chain allows for the rise and fall of the tid which is max 2.3 m range at springs

The steel chain rusts and any galvanizing soon corrodes away soon.

Does any on used rope like polysteel to connect the floating jetty to the location weights or may be old conveyor belting to connect the jetty to the weights or to connect any plastic floats to the walk on structure.

What is commonly used to connect a trot mooring to the anchor/weight to hold the anchor to the connection buoy

By floating walkon moorings, do you mean a pontoon of some description. The usual answer is of course a pile driven into the sea/river bed

 

[RunAgroundHard]

By floating walkon moorings, do you mean a pontoon of some description. The usual answer is of course a pile driven into the sea/river bed

A few marinas the water is too deep and then a combination of weights, chains and maybe anchors are used. Certainly the case in many areas of Scotland's west coast. The Firth of Clyde has piled mooring for marinas.

 

[RunAgroundHard]

The marina we ar in has sections of floating walkon moorings that are fixec to the sea bed with concrete weights and steel chain to connect the floating jetty to the locating weights.

This steel chain allows for the rise and fall of the tid which is max 2.3 m range at springs

The steel chain rusts and any galvanizing soon corrodes away soon.

Does any on used rope like polysteel to connect the floating jetty to the location weights or may be old conveyor belting to connect the jetty to the weights or to connect any plastic floats to the walk on structure.

What is commonly used to connect a trot mooring to the anchor/weight to hold the anchor to the connection buoy

Similar set up at Ardfern, Craobh, Dunstaffnage, Oban, Tobermory, Loch Aline marinas and other West of Scotland marinas. Quite common up our way.

 

[srm]

The chain isn't there just to connect the anchor and the pontoon, it damps movement and the catenary means lateral location is controlled while allowing keelboat access.

I have had discussions with suppliers/installers of such marina systems, and been involved in the management of an anchored marina. The length of chains and geometry of the moorings are critical for the depth of water and keeping the geometry of the installation if more than one pontoon. The pontoons do move relative to fixed points with varying wind loadings.

Yes, the chains do corrode, probably more rapidly than steel piles, so there is an ongoing maintenance cost to be budgeted for covering chain inspections and replacement. However, I would be surprised if ropes would be effective other than for a short single pontoon moored away from the shore and room to move around with different wind/tide loadings.

In the case of the marina I was involved with the sea bed was too soft for too great a depth to make piles economic. I suspect that for smaller installations in remote locations the initial costs are significantly less than bringing in test drilling and pile driving contractors.

 

[vyv_cox]

Galvanising is pretty much a waste of money. Our mooring chain used to come from Manchester Ship Canal lock gates, from which it was retired after a number of years. It was never galvanised, black chain being known to last longer. The only galvanised chain we used was for the pick-up between buoy and boat. That mostly lasted three years but the underwater black chain could easily do ten years.

 

[RunAgroundHard]

… black chain could easily do ten years.

What is black chain?

At my marina they are changing out pontoons but not chain. I have been there for 7 years now. The stuff you can see doesn’t appear to be rusty.

 

[vyv_cox]

What is black chain?

At my marina they are changing out pontoons but not chain. I have been there for 7 years now. The stuff you can see doesn’t appear to be rusty.

Black means ungalvanised. The MSC stuff seemed to have been greased but this may only have been in service.

 

[srm]

Just a thought:
If your floating pontoon or mooring is in an area where there used to be a coaling barge or pier chain will probably corrode faster than usual, due to the coal spilt on the sea bed setting up a chemical reaction.

 

[Refueler]

Black Iron chain can last longer than galvanised ...

 

[rogerthebodger]

Just a thought:
If your floating pontoon or mooring is in an area where there used to be a coaling barge or pier chain will probably corrode faster than usual, due to the coal spilt on the sea bed setting up a chemical reaction.

There is a very big coal terminal in the harbour of Richards Bay with coal ship coming in and out

What I would like to do i find a way to reduce maintenance costs

I know Refueler has been to the coat terminal

Zululand Yacht Club · 1 Commodore Cl, Meer En See, Richards Bay, Südafrika

Would zinc anodes on the chain help to extend the like of the chain ?

Coal terminal

Zululand Yacht Club · 1 Commodore Cl, Meer En See, Richards Bay, Südafrika

 

[vyv_cox]

Would zinc anodes on the chain help to extend the like of the chain ?

Zinc anodes can help in theory but chain does not have great electrical link-to-link contact. Our mooring had zinc cast onto the bottom joint but I am not really sure how effective this was. Could be worth carrying out a controlled check.

 

[Refueler]

There is a very big coal terminal in the harbour of Richards Bay with coal ship coming in and out

What I would like to do i find a way to reduce maintenance costs

I know Refueler has been to the coat terminal

Zululand Yacht Club · 1 Commodore Cl, Meer En See, Richards Bay, Südafrika

Would zinc anodes on the chain help to extend the like of the chain ?

Coal terminal

Zululand Yacht Club · 1 Commodore Cl, Meer En See, Richards Bay, Südafrika

WOW what a memory you have ....

Must be ages since I ever mentioned that ??

 

[rogerthebodger]

Yes but my wife says my memory is selective

 

[William_H]

I would think the catenary of the chain is important to get the chain away straight down to get away from boat keels as well as work like a anchor chain to get the pull of the anchor horizontal and provide that spring buffer. I would think rope would work really well long term life compared to chain however you would need like an anchor angel weight to pull the rope into the catenary. ol'will

 

[rogerthebodger]

I would think the catenary of the chain is important to get the chain away straight down to get away from boat keels as well as work like a anchor chain to get the pull of the anchor horizontal and provide that spring buffer. I would think rope would work really well long term life compared to chain however you would need like an anchor angel weight to pull the rope into the catenary. ol'will

That can be achieved with a weight on the line down to the anchor block at about the depth at low water springs so any line would lie straight down and only be a a straight line at high water springs which is the same as a chain.

The weight could be any heavy material like a concreate lead of cast iron block

 

[srm]

Looking at your satellite pics each pontoon is a straight run with its own land bridge that takes east-west movement so a simple set up.

Perhaps the club could try using rope plus heavy weights on the short pontoon and see how it works. I suspect he weight will need to be similar to that of the chain each rope replaces. But, at HWS the weight will be applying a much greater load at the ends, pontoon and anchor, as it will be acting on a span of about 120 degrees or more. If I remember correctly a 60 degree angle puts the full weight on each end of a span. As the span angle increases so the end load increases. Have you any civil engineers or mathematicians among your members who can work out the weights/loadings to avoid dragging the existing anchors?

 

[PabloPicasso]

Sime pontoons/marinas are held by stretchy cords now.

 

[rogerthebodger]

Sime pontoons/marinas are held by stretchy cords now.

Do you have any details or suppliers