Steel vs cast iron mushroom mooring.

Hi,

I need a new mooring for my new boat. My old boat had a 300lb steel mushroom, but that boat weighted 5 tons. The new boat comes in at 26,000 lbs. or 13 tons.

So a 800lb mooring is line for my boat. They claim that the bell on steel is bigger so you have 20% more holding power than cast iron and a thinner bell so it digs in better too. Steel will wear better so it will last longer. But its twice the price! Since it will last longer, more time between replacements and that too is a cost savings.

But will it last twice as long than cast iron or close to it?

Would anyone know more on the steel moorings?

Give these folks a call.

Anchors and Moorings by Dor-Mor

Is concrete not an option? Probably would be cheaper.

A steel mushroom is fabricated so the bell/disk is thinner and can be a larger diameter. A cast iron mushroom is, well cast iron and it is heavy.

So do you want light, thin and larger diameter or heavy and thick. I vote for heavy.

Also bare cast iron will last much longer in salt water than bare steel. Are any salt water contact parts made of steel on boats? Well yes steel hulls are but they have corrosion resistant coatings. Can such coatings hold up on an anchor?

David

KnotYet said:

Is concrete not an option? Probably would be cheaper.

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A popular alternative in these parts is concrete hog slat. Slats enable the panel to sink deep into the local ooze.

https://www.hogslat.com/concrete-slats-pig-floor-lintels-piers

For what it's worth, our town no longer allows mushroom anchors. Only concrete block moorings now, or a helix screw.

Though they are now hard to find railroad engine wheels moore a lot of boats across the country.

pete

Attach a zinc to the anchor. If you dive, replace as needed. Anchor will last nearly forever.

Cast iron thin sections are easy to crack, cooling after casting and later.

KnotYet said:

Is concrete not an option? Probably would be cheaper.

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Here, all are concrete. Mine is a highway block. Cost under $100. Weighs 4500#
The block is the cheap part, followed by the chain, the bouy, the installation.

A fully dressed marine gasser V8 works pretty well. Oil pan off, wrap chain around crankshaft.

KnotYet said:

Is concrete not an option? Probably would be cheaper.

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No concrete.

DavidM said:

A steel mushroom is fabricated so the bell/disk is thinner and can be a larger diameter. A cast iron mushroom is, well cast iron and it is heavy.

So do you want light, thin and larger diameter or heavy and thick. I vote for heavy.

Also bare cast iron will last much longer in salt water than bare steel. Are any salt water contact parts made of steel on boats? Well yes steel hulls are but they have corrosion resistant coatings. Can such coatings hold up on an anchor?

David

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Both are the same wight. 800lbs is just that for both. My last mooring in 300lbs steel and still in good shape. Never had a cast iron one. So I am not sure how long one would last.

The cast iron mushrooms work well, but the chain needs to be examined every few years , so you still need a pro to pull and service it.

If you are going cruising it is common to have it pulled refreshed and then sold.

IF you will be cruising soon a 3 point set , H60 or H90 Danforths can be pulled by using the tides and one kept aboard for hurricane use the others , and heavy chain stored or easily sold.

sidetrack newby question....

Where are you putting these moorings? off the beach of land you own, or just out in some public waters?
I'm just trying to learn how this works....

I've seen the huge mooring fields...for example in the bays or rivers when I've traveled around MA, but I suppose I figured those were mooring balls owned and operated by the marina or town like they are in places around here.....

Can you just drop your own mooring anchor and ball out wherever you want?

skyhawk said:

sidetrack newby question....

Where are you putting these moorings? off the beach of land you own, or just out in some public waters?
I'm just trying to learn how this works....

I've seen the huge mooring fields...for example in the bays or rivers when I've traveled around MA, but I suppose I figured those were mooring balls owned and operated by the marina or town like they are in places around here.....

Can you just drop your own mooring anchor and ball out wherever you want?

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It varies from place to place. We are in mass and the towns regulate moorings. You apply for a permit, agree on or get assigned a location, etc. Wait lists are typical.

twistedtree said:

It varies from place to place. We are in mass and the towns regulate moorings. You apply for a permit, agree on or get assigned a location, etc. Wait lists are typical.

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Yes, every town is different! Some mooring are town owned. Some like where I am, I own the mooring and I get a permit every year. Than the Harbor Master will tell me where to drop it where it stays provided I renew the permit after the first year.

And yes, there could be a waiting list for a town mooring or just to get a permit.

You must check with the town where you want to drop it. Just to add, non-residents of that town may pay a higher fee.

If your traveling and need a mooring, use Dockwa.

So when I researched this 40 years ago (wow, time flies) the best thing out there was the 2 ton cement block. Oak Bluffs used them as rental moorings. They would have up to 4 boats rafted together and they would not have a problem. And that was with 1:1.5 scope.
That harbor is open to the north and would experience pretty nasty Nor’easters every few years or so during the season.

The idea on the mooring size (there was no science there) was that if it worked for USCG buoys in Woods Hole, it would work for a boat.

But that was 40 years ago. Now the thinking is that helix moorings outperform all others.

twistedtree said:

For what it's worth, our town no longer allows mushroom anchors. Only concrete block moorings now, or a helix screw.

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Gloucester? Very surprising since blocks are know to "roll" and they lose a bit of weight due to buoyancy. I can certainly see the Helix anchor as being a good option. A friend of mine used to own Boston Waterboat Marina (downtown Boston) and hated mooring blocks of concrete or Granite.... He had many moorings in the waterfront district. Not sure if he still owns it or not, I moved away 20 years ago