December WNS Scenario

That's what I'd do. So you may wish to change your mind...

.............................................

You didn't I did. You agreed with my rediculase solution. /forums/images/graemlins/tongue.gif
 
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Anyone else think lifting the rings that lie on the dory's centreline by 2ft vertically is going to produce 2ft of sideways movement?

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err, yes? if the rings are two feet below the cleat and you lift them level with the cleat, you can then move the boat two feet to the side and the lines will be no more taught than they were to start off with?

Anyway I think the answer is to tell your crew to stop being such a pussy. It's calm, slow current, he/she can put on a lifejacket and harness, you can hold the boat right alongside, and they're in a protected river. The worst that can reasonably happen is they get wet, and your 40 foot flybridge has a hot shower.
 
Houghn

Off the top of my head, I don't agree because each line as it slopes down effectively forms the hypotenuse of a right angle triangle: the other two sides being the 2ft vertical 'base' and the horizontal distance from the dory's cleat to the ring when the ring is lifted to the same level. So I THINK you'll only gain a few inches of line. But I'll do some calcs and get back to you.

Cheers
TJ
 
Gentlemen

I think we now have all the suggestions (excluding those involving social skills, of course /forums/images/graemlins/grin.gif) we are going to get, so I'm calling a wrap on this WNS. Continued discussion may continue, of course, but I need to move on to the next one.

Basically, the printed WNS will say: All those suggestions that involve anchoring or mooring so that you can board the dory and slack of it's lines are valid. Those that involve simply mooring to the N'ly pile and drifting back are not because there's no way of accurately determining the sideways force on the dory caused by your boat trying to assume its rightful position in line with piles. That force might well cause the dory's lines to part. Of course, they might NOT - but trusting to luck is bad seamanship.

No one has suggested doing what seems to me to be the obvious thing, which involves repositioning the dory in a particular way that completely eliminates the risk of parting its lines and leaves it moored with minimal tension on its head and stern ropes. But you will have to wait for the December issue to see what that is. /forums/images/graemlins/grin.gif

As always, thanks to all those that contributed.

Best wishes
TJ
 
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N.B It was stated that the lines were very thin so adding 36% tension would probably part them.

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This feels a bit like kicking a puppy, but here goes..... /forums/images/graemlins/wink.gif

Firstly, the tension that a line can stand before breaking is determined by the material and construction, so there's no reason why a 36% increase should be an issue. "Bar tight" Dyneema could almost certainly stand a 36% increase with almost no extension, since we have no idea of the starting load. "Bar tight" nylon 3 strand could almost certainly stand a 36% increase by being all stretchy.

Secondly, (mostly) irrespective of construction/material, the degree of stretchiness is inversely proportional to diameter. A nice skinny bit of cheapo 3 strand polyester will stretch like a piece of elastic (and not break).
 
I did forget to mention, that on jumping in the dory with the dodgy lines, they of course break or one of them does, leaving you to spend the night in the dory, attached only to the southern pile. Numpty of course is warm and dry and sleeping in your bed on the boat.
 
Nope, sorry, you get the dunces cap. The 17ft dory is in the middle of a 50ft gap, leaving 33ft spare, divided fore and aft. That's 16.5ft between its bow and stern and each pile - measured horizontally as that is the shortest possible distance. If the dory's cleats are 1ft above the water, and the ring to which the line are attached are 2ft below the surface, the vertical distance is 3ft. By simple maths, the distance between the dory's cleats and the rings is therefore 16.77ft. If you raise the ring to the horizontal position you will have gained 0.27ft slack. That's 3.24in.

Best wishes
TJ
 
Many, many years ago I was taught never ever to JUMP into a small boat unless I was prepared to find myself with my legs poking through the bottom, a large splinter in my crutch, and a sizeable bill to pa. But fings aren't wot they used ter be - sadly.
 
Nope, you definitely get to keep it. The 3.24 inches is just the difference in length between the adjacent side and the hypotenuse, but we're interested in the length of the opposite side. Sketch it out on a piece of paper, its the same triangle just laid in a horizontal plane, instead of a vertical one.

The sideways movement is now 3 feet by the way, cos you moved the goalposts, and height of the cleats above water is irrelevant, its only total height above the rings that matters.
 
Oh, goody! Do I get a special 'IPC Customer Care Dunce Cap'?

Now, here's a simple picture. We just raise the rings to the same level as the cleats and the distance AB remains the same - 3 feet - but the boat has now moved sideways...

geometry.jpg


I'd suggest you get the geometry dunce cap, but I can't work out how you'd wear that and your 'Interpersonal Skills' one at the same time.

Oh, BTW, the piles are 45' apart not 50' (unless the rules just changed again). and you don't need to use any maths, just common sense.
 
Blimey Tony. You most definitely get the dunce's cap. You just have no idea about the physics of this. If this were an O Level maths/physics/geometry exam, you would get 1 mark for writing your name and no more. Just put the spade down and stop digging (I know I've suggested that before...). Your 3.24 inches reply to Houghn's and Wiggo's completely correct analysis of the geometry is just ludicrous. If you go and study what houghn, wiggo and I have said on this instead of handing out dunce caps you'll learn something.

And, btw, I never mentioned 36%. That was your number. I said 12% for a 5m sideways movement of the dory.
 
1. If they were bar taut, the rings would have risen up the piles as the tension was put on. If they didn't they're stuck and you can pull them up by their adjusting lines, creating a few inches slack fore and aft, which will allow the dory to move several feet sideways.

2. Whilst you're getting remedial geometry lessons, please also note the correct spelling of taut. It's nothing to do with learning!

3. I don't see how you remoor the dory without undoing its lines. And that's difficult because (I'm assuming) both ends of each line are firmly attached and inaccessible except from on board the dory.

4. Some pile moorings have a rope stretched between them tied to the rings, sometimes with a pick up buoy in the middle. You could lie to that without putting any pressure on the dory's own lines. Or you could set up one or two of your own mooring warps, with a fender to pick them up in the middle, to achieve the same effect (too much bother I suspect).

5. Of course there's the chequebook approach. Cut the downstream/downwind line to the dory - which can then swing freely to the other pile. Moor up to the piles. Replace old tatty bit of line with a nice new one. Who could possibly complain about that?
 
James

1. As I see it, when they moored up (we dont' know when this was) the fishermen pulled the rings up the poles, looped their lines through them, pulled the lines tight, and let the rings go. The rings then slid down the poles until the tension on the lines exerted sufficient friction between the rings and the poles to prevent them sinking further. As the tide went down so did the dory and the rings until we get to the current stated position when the rings are resting on the bottom of the poles where they attach to the piles but the lines are still taut.

2. Please excuse previous mispelling of taut.

3. Agreed.

5. Fair enough. Yet another possible solution. /forums/images/graemlins/grin.gif

Best wishes
Tony
 
Re 5, I think that would be entirely justifiable in a more stressful situation. But as a raggie of course I'd rejoin the line with a double sheetbend, or a carrick bend if I didn't have the time/inclination to longsplice it! Or donate something from the depths of my still-too-good-to-throw-away rope locker.
 
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2. Please excuse previous mispelling of taut.

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OK, but the misspelling of 'mispelling' is unacceptable for someone who makes his living by writing... /forums/images/graemlins/wink.gif

You have to admit, wherever they found him, this TonyJones bloke is good value for money.
 
Jfm

Sir, you are absolutely correct and I have been talking bollox. Had to draw it out to scale to prove it to myself, doh, which shouldn't have been necessary.

Will now go and stand in the corner feeling really, really, silly.

Mea Culpa
TJ
 
Wiggo

Sir, you are absolutely correct and I have been talking bollox. Had to draw it out to scale to prove it to myself, doh, which shouldn't have been necessary.

Will now go and stand in the corner feeling really, really, silly. /forums/images/graemlins/frown.gif

Best wishes
TJ
 
Well his imagination is much better than Enid Blyton's for a start, so that should be worth a bob or two, but I really think he should concentrate more on the Boaty adventures of Noddy And Big Ears, he'd make a bloody fortune. /forums/images/graemlins/grin.gif
 
[ QUOTE ]

err, yes? if the rings are two feet below the cleat and you lift them level with the cleat, you can then move the boat two feet to the side and the lines will be no more taught than they were to start off with?[ QUOTE ]


Sir, you are absolutely correct and I have been talking bollox. Had to draw it out to scale to prove it to myself, doh, which shouldn't have been necessary.

Will now go and stand in the corner feeling really, really, silly. /forums/images/graemlins/frown.gif

Best wishes
TJ
 
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