Mooring Ideas

[Scra99tch]

I am looking to put a mooring in place for some fresh water aperatii. My father had used concrete awhile back and that has since degraded away along with the chain some 35 odd years ago.

The house sits on the NE side of a pond just beyond the foot hills of the White Mountains in Maine and sees some fairly high wind gusts. I'd like to at some point put in a swim raft and possibly tie off a 14-18' boat in the future.

So I am looking at ideas materials that would be needed that you may have had experience with. I like the idea of 5-6 semi truck brake drums chained up in a way that would embed and scoop through the mud. Using galvanized HD chain with a cross piece to hold each drum away from the mouth of the next.

What makes this nice is they are somewhat portable and can be fed onto the end of the chain one by one. Instead of trying to maneuver a heavy block.

I am not sure but I think those drums weigh close to 120lb's each. And would lose maybe 15% with buoyancy as opposed to concrete which loses upwards of 40% of its weight holding capabilities.

Thanks

 

[matthewsx]

Sounds like a reasonable idea.

At my old club the mooring field had all the individual moorings linked together and that made it more resilient. Single moorings would drag way before individuals.

John

 

[projectnut]

We made a mooring anchor for an 8" x 8" aluminum swim raft (350 lbs.) by pouring two bags (50 lbs. each) of premixed concrete in a tub like this.

Rubbermaid FG335192GRAY 21" x 17" x 7" Gray High Density Polyethylene Bus Tub

Looking for a sturdy bus tub for clearing away dirty plates, flatware, and cups at your restaurant? This Rubbermaid 3351-92 Gray Bus Tub features reinforced handles, bottoms, and ribs for long life, and rounded corners for easy cleaning and superior strength. Constructed of high density...

www.webstaurantstore.com

Before pouring in the concrete, we bent a piece of 1/2" reinforcing rod into an arc. The arc was tall enough to rest on the bottom of the tub and extend about 6" above the top of the tub. We left about 8" of rod on either end of the arc so that it could be bent at a 90* angle. We centered the arc in the tub and poured in the concrete. The end result was a 100 lb. block with a loop for attaching a quick connect chain link. We added enough 3/16" diameter chain to reach about 4' above the surface of the water. We added another quick link on the free end to attach it to the raft.

In our case the raft had to be removed for the winter. When taking in the raft we used a 1-gallon plastic milk bottle as a buoy so we could find the chain in the spring. We filled the milk bottle about 2/3 full of water so it would be below the level of the ice. In the spring we would go out in a boat or canoe and use a garden rake to raise the milk bottle. We would empty the bottle and let it float with the chain attached until we reconnected the raft.

The hardest part of the whole project was to get the block into the water. In our case we tried transporting it to the chosen location in a rowboat first. That didn't work out in that by the time we got the anchor to the top of the gunnels the boat was ready to tip over. We went back to shore and loaded it on the raft. It was much easier to position and drop in from the flat surface.

The picture of the square block below are similar to what the finished product looked like. It's been in the water about 25 years with no problems.

https://aquaglidesupport.zendesk.com/hc/en-us/articles/1500000245702-Where-do-I-source-anchors-How-do-I-make-my-own-anchors

 

[Nutfarmer]

Is there anyone in the area that can drive some pilings. That will work better than anything else.

 

[RaisedByWolves]

We used a 55gal drum full of concrete with a 6’ piece of railroad track run through the center and set in the concrete.

The chain was looped and bolted around the track and set in the concrete also.

This kept a 22’ Chris Craft cabin cruiser in place through several tropical storms over 15yrs with little movement.

We built the whole thing on the dock and just shoved it off letting it roll down hill to the flat bottom.

It’s still in there to this day 50yrs later.

 

[mickri]

The yacht club I belong to is reviewing everything about our mooring field. I am on the committee. In the last 5 months I have learned more about moorings then you can shake a stick at. First question is does the water level change over time? What is the bottom like. Mud, silt, sand, hard pan, rock. How deep is the water? How far from shore? Do you want to remove everything ever winter? Or just the raft and skiff. Answer these questions and I can give you some ideas on what might work for you.

 

[Scra99tch]

Mickri,

To answer your questions the water does change over time. Could rise several feet with a good rain storm. The bottom is silt/sand combination probably if I were to guess 1 foot I can still see some cinder blocks from an old moring that was put in around 1990.

I am looking to have it 25 ft from shore. Maybe farther to get a nice long line on it so its not pulling with so much upward force in high winds. I'll end up sinking the float then diving the 12 ft in the spring to bring it to the surface.

Turns out a bulldozer idler wheel came up on my facebook marketplace feed which looks to be very heavy. This in turn with a swivel may be a better option that the semi trailer brake drums. Although a V pattern with brake drum could work well as long as the hitch to each drum allowed it to tilt downwards to scoop the silt and sand.

 

[Scra99tch]

I was never that keen on the concrete block knowing just how much downward force it loses with buoyancy. That brings back memories of a project a previous engineering class had made at Colorado State, a kayak made from concrete.

 

[projectnut]

I don't think I would be too concerned about the buoyancy of the concrete. Almost every bridge, dock, and pier is anchored in a concrete base. I've never seen one float away or even rise to the surface. As mentioned in my earlier post the mooring block we made has been holding the raft in place for many years.

I should have looked through the wife's photo albums before I mentioned how long it had been in the water. There are pictures of the raft anchored to it dating back to 1985. That makes it at least 39 years in the water.

 

[mickri]

Once the mooring block sinks even a little bit into the mud/silt on the bottom it takes a lot of force to move it. A concave bottom on the block increases the holding power of the block. Think of it like the perimeter foundation on a concrete slab. If you need to keep the raft in a certain location you will need two mooring blocks to keep it in place. If it can move around some then one block is all you need. By calling it a block I am only using that term for convenience. The block can be concrete, brake drums, steel wheels, etc. Based on the info you have provided I would think that a semi brake drum attached to a wheel should be sufficient. You want the wheel/drum sitting with drum side down and the lug side up if that makes sense. 2 to 1 scope should be enough. In 12' water that would be 24' of chain with swivels on each end of the chain.

Another option is a semi tire filed with concrete. I saw this being used as a mooring block when I was cruising on my sailboat in Mexico.

There are lots of ways to skin this cat.