Mooring lines, tight or slack?

Nostrodamus

Nostrodamus

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The wind outside is blowing strongly and the mooring lines are groaning.
The question is do I loosen them all off and let the boat roll round a bit more but making it quieter or do I tighten them all up still getting the noise but moving very little.
Should some mooring lines be tight others slack, all tight or all slack.
Does it make any difference?
 
Nostrodamus said:
The wind outside is blowing strongly and the mooring lines are groaning.
The question is do I loosen them all off and let the boat roll round a bit more but making it quieter or do I tighten them all up still getting the noise but moving very little.
Should some mooring lines be tight others slack, all tight or all slack.
Does it make any difference?
Click to expand...

As long as they hold the boat where you want it to be without harming it then they're doing their job fine.

In fact, this question is "How long is a bit of string". :-)
 
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If you are referring to a marina berth, I prefer to let the boat move with any swell/wavelets whilst making sure it is prevented from going forwards onto the main pontoon, assuming bows in. I would have bow lines with rubber mooring compensators wound in to allow some stretch and aft movement, whilst the spring line holding it off the pontoon has no compensators and is tight enough to keep the boat from riding forwards. The stern line should also have no compensator but be slack enough to allow a little movement. All IMHO, but tight lines means snatch jerk and creak and nearly all of the movement if you allow it is cyclical, ie the boat moves around the same base but just needs keeping from riding forwards.
 
Being new to marinas, I thought I'd tighten mine up before I left her, as I thought minimising snatch loads would be good (no movement= no snatch). Should I worry?
 
As they should have some stretch in the warps, if they start tight they will become slack. So I would start with some slack but good control of the boat so it doesn't get near anything solid.
 
sighmoon said:
Being new to marinas, I thought I'd tighten mine up before I left her, as I thought minimising snatch loads would be good (no movement= no snatch). Should I worry?
Click to expand...

As long as you are using mooring warps, not old genoa sheets, then they should have enough stretch in them and you'll be fine.

No matter how I tie our boat up, usually when I return she's a foot off the dock looking after herself perfectly well:)
 
Most of the noise in fore or aft cabins, that is so annoying when trying to sleep, comes from the slight stretch movement of warps over fairleads. Running the warps through a length of plastic hose will usually eliminate it.
 
I don't use marinas, but if I did, I think I would use "Tight, but round a snubber" or slack.

I am moored to a big quay wall at the moment with a 15' rise & fall. We use heavy chain & sash weights to hold the boats close to the quay & ropes fromthe chain to the boat. It worls well until there is a strong wind off the quay when it can be a big step to reach the boat at HW.
 
Personally I try to keep the pressure on the springs and leave the bow and stern lines less tight. Boat will yaw slightly but sits well and blows nicely off the pontoon in the prevailing wind...
 
If you have the lines slack then the cleats will be subject to a much higher peak loading when the boat snubs.

For heavy weather I bought 50m of 10mm Nylon for £28. I tie up as normal with 14mm & 16mm warps (43' boat) with a bit of slack then use the 10mm to hold the boat tight. It will stretch a lot so will act as a good shock absorber and if it gives there's always the thicker line to hold the boat.

Not had any of the 10mm stuff snap or chaff through yet, although there have been obvious signs of chaff which would have become a problem if I'd left the boat unattended for a couple of months. Also a nice way of seeing how my splicing stands up under excessive load.
 
Just allow the boat to make it's regular movement whilst restraining it firmly from going forwards onto the main pontoon. There will be no snatch on the slack lines from the cyclical fore and aft movement in a swell if the lines are adjusted right, but this is made much easier by using rubber mooring compensators wound into the bow lines which will be kept just taut but allow easy movement.
 
We do use the rubber compensators when we can but in a good blow it is suprising just how far they will stretch. Sometimes we have to wait for the wind to drop before hopping on. They do work though and cut down on the snatch loads.
 
I was tied up alongside in a port last weekend. I had the springs fore and aft tied up tight to a the quay side near the bow and near the stern. The bow and stern lines were a little slack.

I got woken up in the night. The boat was charging backwards and forwards by a good 4m. It seems the oscillation frequency of the springs coincided with the wave frequency. The waves were only a few centimeters big!

I moved the boat back a bit so the springs were of unequal length. This seemed to dampen the motion a lot. But I was now well clear of the nasty big black tyre hanging off the wall for the fishing boats and it was raining, so I really could not be bothered after that.....
 
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