Drying out on a scrubbing grid

Ruffles

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Boat: Portsmouth, Us: Stewkley
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I'm considering using the scrubbing grid at the yard we're in this w/e. Never done it before. (Last year I got a good deal on a haul out and scrub - unlikely this year 'cos of Cowes week).

The yard tell me that HW on Monday morning will give me around 14" under my keel on the pad. HW in the afternoon gives me 18".

Is that enough? Or am I likely to spend my Summer holiday on the boat neaped with 2 small children aboard!!

I am of course assuming there will me more water than that leading up to the pad - I think I might check this out first with a lead line in the dinghy.

Bearing in mind that tidal heights are just estimates - anyone know what the effect of atmospheric pressure is in mb/m?
 
If you saw what happened to Gilken (Sigma 38 about 2m draft) on Wicor's scruubing berth a couple of weeks ago I can understand your concern. He struggled to get on the pad for some emergency work and ended up neaped there for a week. You won't have that trouble next week. Monday's tides are 4.2m in the morning and 4.3m in the evening. After that they keep on getting bigger until they reach 4.8m at springs on Saturday. Scott and the boys in the yard know the height of the pad and the draft of the boats so I would believe them; but there is a depth gauge on the pile next to the pad which might save you some work with the lead line. The mud is generally the same height as the pad and a lot softer. If you are afloat over the pad the mud won't be a problem.
 
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If you saw what happened to Gilken (Sigma 38 about 2m draft) on Wicor's scruubing berth a couple of weeks ago I can understand your concern. He struggled to get on the pad for some emergency work and ended up neaped there for a week. You won't have that trouble next week. Monday's tides are 4.2m in the morning and 4.3m in the evening. After that they keep on getting bigger until they reach 4.8m at springs on Saturday. Scott and the boys in the yard know the height of the pad and the draft of the boats so I would believe them; but there is a depth gauge on the pile next to the pad which might save you some work with the lead line. The mud is generally the same height as the pad and a lot softer. If you are afloat over the pad the mud won't be a problem.

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Thanks for your input. I'm minded to go for it if the depth guage confirms there's enough water. I believe you about the mud judging by the plough lines visible at LW.

It seems to be a well equiped facility. There are hooks on posts to attach a halyard. I'm planning on tying extra fenders to the post to hold her off a bit. Is that what you'd recommend?
 
What you really, really, don't want to do is what I did three years ago at Felixstowe - arrive late, try to get on after the ebb has set in and dry out on your side, just short of the posts!

It almost was not funny at all. Luckily the mast cleared the posts. We scrubbed one side nicely!

The moral of this story is - arrive early!

Barometric pressure effects are variable - which is why there are no published tables for them, but basically you want a depression to raise the tide.

Oh, yes, shove a couple of fenders in by all means.

As one who uses posts a lot, I usually range some anchor chain down the deck on the "down" side and take a halyard ashore once she has settled, and about a foot of tide has gone - not before, for fear of heeling her too far, and not later because you really don't want her going the other way after that.

It is unwise to leave the boat unattended over a high water on posts - obvious point, but I once went ashore, thinking I would be back in good time, got distracted by shopping for wallpaper with my wife and came back to find the boat hanging from a halyard over the void...
 
The depth gauge at the scrubbing berth reads depth over the pad. There's another one out on the edge of the main channel that is marked "Depth at Jetty" but I don't know how the two relate. If the gauge at the scrubbing pad reads more than your draft you will get on, there are no other obstructions. But I would always do it on a rising tide. There are usually a couple of fender boards on the jetty at the scrubbing berth so put 2 or 3 fenders out next to each pile and hang a board from your guardrails outside the fenders. A halyard to the jetty or a horizontal rope from the mast step to the piles should stop her leaning out. Last time I used it there were bow and stern lines fixed to the jetty and lead back to the scrubbing berth ready to use. Good luck. If you're going on on Monday I might pop down and say hello.
 
Get some nice big fenders and yes, tie them on the post so that as the boat moves the fenders stay put. Try and get the boat ballasted so that you lean slightly in to the piles as you touch bottom....but not too much. Have in mind some counter to the idiot who steams past you just as you're keel is settling and may hop the keel inwards ie you may need to put buckets of water/anchor cable/boom with a weight on the end/teenagers/ small elephants on the inboard side to give yourself some heel....but not too much! You don't want to be at a monster angle just enough not to lean outwards. I'm simply stating the obvious really. The halliard led outwards to high up on a pile is the right plan and perhaps a rope round the mast highish up, taken to a post.
It's high stress for the first time but it's all common sense...good luck!
John
 
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The depth gauge at the scrubbing berth reads depth over the pad. There's another one out on the edge of the main channel that is marked "Depth at Jetty" but I don't know how the two relate. If the gauge at the scrubbing pad reads more than your draft you will get on, there are no other obstructions. But I would always do it on a rising tide. There are usually a couple of fender boards on the jetty at the scrubbing berth so put 2 or 3 fenders out next to each pile and hang a board from your guardrails outside the fenders. A halyard to the jetty or a horizontal rope from the mast step to the piles should stop her leaning out. Last time I used it there were bow and stern lines fixed to the jetty and lead back to the scrubbing berth ready to use. Good luck. If you're going on on Monday I might pop down and say hello.

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I'd forgotten about fender boards. Thanks for the reminder.
I'm not too worried once on - a Moody 31 has quite a long keel looks like it should balance well.

I'm more worried about my 2yr old son. He will insist on helping and he likes mud!
 
As soon as the tide's gone hose off the pad. You'll get less muddy and be able to see the edges better. Keep two year old on a short lead if he goes down on to the pad. If he, or you for that matter, step off the edge you are likely to sink a long way down.
 
The usual mistake is to lean inwards too much.The fenders will squash a bit making you lean more than you intended .Even bolt upright is OK provided you have a stout rope around the mast plus a halyard.
 
Agree with the other comments. Did this last week (for the first time) against a harbour wall.

Despite apparently having done everything right (checking bottom, mast halyard, weighting with chain etc) - as she settled she still decied shw wanted to lean out.

Quick bit of heaving on line around the mast (much more effective than mast head if its starts to go wrong) and attaching to shore rectified situation.

In future Ithink I'll always try and rig 2 lines off the mast at wall height at 45 degrees for and aft - should allow quick tug inwards if she does settle the worng way - and prevent the possibility of her settling out - or down at the bow or stern to drastically.
 
I have never been a fan of using a halyard when drying out to prevent toppling. I much prefer a bowline tied loosly around the mast so it can slip up and down with the tide, led to ashore or otherwise made fast roughly horizontally.
 
Since you asked and for your info and others, these are the figures I use:


TIDAL HEIGHT CORRECTIONS RELATED TO PRESSURE
963 mb +0.5m
973 mb +0.4m
983 mb +0.3m
993 mb +0.2m
1003 mb +0.1m
1013 mb 0
1023 mb -0.1m
1033 mb -0.2m
1043 mb -0.3m

Good luck with it all
 
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