Deadweight anchor for a dinghy morring?

[Kelpie]

I'm looking at setting up a running mooring when I get my Wayfarer soon, and whilst I have a spot marked out I don't have any of the gear yet. The other guys there mostly seem to use an anchor and that seems to work out OK- but I'm getting rather skint having spent more than I wanted on the boat itself!
Since a second hand anchor is going to be hard to find, I was thinking about using some sort of deadweight instead. It's only for a Wayfarer, after all. I've heard of people using railway carriage wheels, for yacht moorings, so with the much smaller dinghy would something like an engine block be suitable?
I also came across an intruiging find on the beahc today- a pair of old manhole covers, each about 2ft square, cast iron, and I would estimate at least 30kg each. Being big and flat, would these do the job?
Thanks for any advice!

Rob

 

[Fascadale]

Depends a bit on the bottom.

Rock and the manhole covers may not be so good, soft sand or mud and the manhole covers may be excellent

 

[Rivers & creeks]

Old car tire (free from car tyre centers). 2 meters of chain and some cement.

Put the tyre on a flat surface with some polythene at the bottom of the tyre. Mix the cement and put it in the tyre, as you do, wind in 1.4 meters of chain. Leaves 2 feet left sticking out the top (tie off to keep it vertical). Attach a swivel if the boat can swing otherwise don't bother. Once set, use! Has the great advantage that it's almost free and can be rolled rather than lifted into position.

 

[LadyInBed]

a pair of old manhole covers linked by a chain with a centre riser would do an excellent job.
When the manhole covers settle into the bottom the suction on them is terrific, so very effective.
The low profile stops the chain wrapping around them.

 

[tangomoon]

Another - go to a place where they repair lorries or scrap - get a (ot two) brake drum chain down the MIDDLE (you need a bar or something to keep chain central - bury in sand - fine - have had 15' boat on this system off the quay wall for two years no trouble. ~

In fact I bolted a smallish chain through one of the wheel-nut holes then buried it -

BOL

 

[tangomoon]

Another - go to a place where they repair lorries or scrap - get a (ot two) brake drum chain down the MIDDLE (you need a bar or something to keep chain central - bury in sand - fine - have had 15' boat on this system off the quay wall for two years no trouble. ~

In fact I bolted a smallish chain through one of the wheel-nut holes then buried it -

Manhole covers - have they a hole through the middle

BOL

 

[Kelpie]

Oh, excellent, I wondered if the weight of the manhole covers might have been out by a factor of ten or something. The bottom is muddy with some boulders, I had a hunch that the suction could help. Thinking of laying them with a chain between, and I'm sure all the other boat owners will appreciate the flatness of the covers.

I do like the idea of the tyre filled with concrete, but if my physics is correct then concrete isn't really much good, is it? You lose half the benefit of it because of the water it displaces.

 

[FWB]

There are a lot of these around /forums/images/graemlins/ooo.gif

 

[Kelpie]

Re: Deadweight anchor for a dinghy mooring?

Surely that can't be heavy enough to hold a dinghy??

 

[AncoraLatina]

Re: Deadweight anchor for a dinghy mooring?

It depends of the size of your dinghy, /forums/images/graemlins/confused.gif

For example, for a 4,50 m boat, you need 410 kg of concrete or about 0,165 cubic meters.

This is only an overall indication, in mud, where the concrete bloc will dig in itself, you can reduce this weight

 

[FWB]

Re: Deadweight anchor for a dinghy mooring?

[ QUOTE ]
Surely that can't be heavy enough to hold a dinghy??

[/ QUOTE ]

If you look closely at the pic you can make out a couple of clamps-----similar to those fitted to outboard motors. I think the idea is to get say an iron bar and clamp the right number of them on. The right number being dependent upon the type of dinghy. /forums/images/graemlins/grin.gif

 

[William_H]

Re: Deadweight anchor for a dinghy mooring?

Basically any weight is OK. The difficulty is in getting the weight to site then out to the place on the bottom. Look out for studs on an engine block if there is any chance the dinghy can hit the block on a low tide.
Anchors and chain between are far more efficient for the weight so more convenient to set up. good luck olewill

 

[Kelpie]

Re: Deadweight anchor for a dinghy mooring?

Bump.
I thought I'd weigh one of the manhole covers today. Turns out I underestimated. Rather than 30kg, they are in fact 77kg!! So a pair of these should presumably do the trick.
I've also acquired 4m of 13mm chain to join them together, and a length of 10mm chain as riser. I bought the riser chain because when I was in the chandlers anything smaller just looked a bit wimpy, but now that I see it in the light of day I'm worried it'll drag my mooring buoy under. Should I swap it for a lighter chain or just get a decent sized buoy?

 

[stevebrassett]

Re: Deadweight anchor for a dinghy mooring?

A thought - is the mooring in an area exclusive for dinghies? If you put a large buoy on it, you may get a large yacht tied to it whilst the wayfarer isn't there.