Boat-hook thready mooring-buoy thingies

[lw395]

wise words.

perhaps the reason why the ranty types on here can't get their point accross is this:

when you lassoo a buoy, the friction of the chain, and the fact that the buoy will move up and away from the lassoo rope, means you will not put anything like the full force on the buoy.

But lets say you do put the full force on. For a 12 m yacht in a force 4, the rope will have a tension of about 130 kg.

But hey we cause all this carnage. Lets go out in a force 9. The load goes up to 1000 kg.

Do I want my wife pulling even 130 kg on a boathook? No.

But what does the buoy think - this is 3000kg. The equivilant of the full force of a 50 ft yacht in a hurricane.

Oh look it hasn't split or burst.......

Unfortunately it's not like that.
The load is not spread out by a handy plank.
It's not 3000 kg anyway is it, on one wheel? And half of the weight is going straight to the ground via the plank.

But squashing a fender the way it is designed to be squashed is very different to tearing the attachment off of one end.
The force to stop a 7 ton yacht going backwards in the tide at 1 knot, in the space of a couple of inches works out at

a=v^2/2s = 3.9 ms^-2
F=ma =27kN

I have had both Polyform and Norfloat buoys destroyed by this, where the tube goes through the middle of the buoy, you get left with a roughly round bit 4 to 6 inches across.
The PVC, or whatever it is, is about 7 or 8mm thick in this area. That's pretty tough, but not indestructible if mis-used.



To return to the point of this thread, I don't have a snazzy automatic boat hook, if a swinging mooring is hard to pick up, I tend to run a line back from the bow to the cockpit, where the freeboard is less on most sailing boats, and run the end through the buoy or pickup line. You then just walk forward taking in the slack as the boat drops back.
This works for me singlehanded in a lot of wind.

 

[Elessar]

If you expect to get 130kg of force during mooring operations I really think you need to consider your boat handling!

My SWMBO would go ape if she had to pull more than 20kg, in fact she would just drop it and tell me to do it again properly . Or more to the point come back and show me how to do it properly!

Now try threading a rope through it, then Pulling on that rope. No damage to fender?
If you put a knot in the end of the rope and lasso the fender are you feeling so confident?

Confident of what?

130 kg is the approx tension in the rope in a force 4 once the engine is off/sails down and the boat has settled with the wind.

So 130 kg is about what is on the lassoo when I go forward to tie up properly. My wife has no interest in doing this. It's not that easy anyway with a high freeboard. Why do it the hard way when there is an easier way?

The irony is, if it's a buoy with a ring, I use one of the thread through devices that this thread is all about.

If its a pick up buoy I use a boat hook.

Either way, my wife lassos first, then I go forward to tie up properly once the boat had settled. No stress, no hassle, no rushing and no danger. And I am confident that there I no damage despite the rants here.

None of which have gone any way to make me change my ways. But some have made me laugh

 

[Elessar]

Unfortunately it's not like that.
The load is not spread out by a handy plank.
It's not 3000 kg anyway is it, on one wheel? And half of the weight is going straight to the ground via the plank.

But squashing a fender the way it is designed to be squashed is very different to tearing the attachment off of one end.
The force to stop a 7 ton yacht going backwards in the tide at 1 knot, in the space of a couple of inches works out at

a=v^2/2s = 3.9 ms^-2
F=ma =27kN

I have had both Polyform and Norfloat buoys destroyed by this, where the tube goes through the middle of the buoy, you get left with a roughly round bit 4 to 6 inches across.
The PVC, or whatever it is, is about 7 or 8mm thick in this area. That's pretty tough, but not indestructible if mis-used.



To return to the point of this thread, I don't have a snazzy automatic boat hook, if a swinging mooring is hard to pick up, I tend to run a line back from the bow to the cockpit, where the freeboard is less on most sailing boats, and run the end through the buoy or pickup line. You then just walk forward taking in the slack as the boat drops back.
This works for me singlehanded in a lot of wind.

Nice numbers. But you would never get that force dragging up the chain. The force is a squashing force. The same force btw as a pick up line puts on a buoy.

Btw freeboard in my cockpit is a tad under 2m. From the helm it's over 3 m.

 

[johnalison]

Confident of what?

130 kg is the approx tension in the rope in a force 4 once the engine is off/sails down and the boat has settled with the wind.

So 130 kg is about what is on the lassoo when I go forward to tie up properly. My wife has no interest in doing this. It's not that easy anyway with a high freeboard. Why do it the hard way when there is an easier way?

QUOTE]

That is about as helpful as those calculations that a bee can't fly. We have seen statements from people caring for moorings to the effect that moorings are sometimes damaged by lassooing. Either they are misguided, or they are lying, or there is a significant problem which needs to be addressed.

 

[lw395]

Nice numbers. But you would never get that force dragging up the chain. The force is a squashing force. The same force btw as a pick up line puts on a buoy.

Btw freeboard in my cockpit is a tad under 2m. From the helm it's over 3 m.

I appreciate my method won't work for a high-sided powerboat.

I think one of the ripped bits of buoy is at the back of the sheds somewhere, I will post some photos sometime.

But if you ever lasso a private buoy and find your line is covered in tar, or cut by Kev's patent anti-sailing school device, don't say you weren't warned.