Anyone Have Experience (or Engineering Advice) on DIY Helix / Screw Anchors ?

[Northeaster]

Hi folks,

I am considering using a couple / few Helix / Screw style anchors to hold my floating dock in place.

For a couple of reasons ( need to do this in next couple of weeks, no local availability of Pre-made, and cost) I am condiering welding up my own out of some heavy duty galvanized pipe, and flat stock cut / welded to form the conical screws.
I would have to grind off the galvanized coating where I weld, but, as this part would be buried several feet in the deep sand and mud, I would think it would be good for several years.

I think I would walk up to about my waist, at low tide, and have a friend help me turn them into the bottom, prehaps using a 10' piece of pipe / rod , horizontally, to turn it in. I could have this go through a slot or hoop at the top of the anchor, to drive it in.

Any thoughts would be appreciated.

[svcattales]

Originally Posted by Northeaster

Hi folks,

I am considering using a couple / few Helix / Screw style anchors to hold my floating dock in place.

For a couple of reasons ( need to do this in next couple of weeks, no local availability of Pre-made, and cost) I am condiering welding up my own out of some heavy duty galvanized pipe, and flat stock cut / welded to form the conical screws.
I would have to grind off the galvanized coating where I weld, but, as this part would be buried several feet in the deep sand and mud, I would think it would be good for several years.

I think I would walk up to about my waist, at low tide, and have a friend help me turn them into the bottom, prehaps using a 10' piece of pipe / rod , horizontally, to turn it in. I could have this go through a slot or hoop at the top of the anchor, to drive it in.

Any thoughts would be appreciated.

I bought 2 helix anchors from this company Helix Mooring Systems to secure my boat for hurricanes in Florida. I set the first one a couple years ago and it wasn't too difficult to do by myself. The anchor shaft is about 5ft long with a 9.5 inch diameter on the helix. I used a heavy steel bar about 5ft long as a lever to twist the anchor into the bottom in 1ft of water at low tide. I put the end of the bar through the loop at the top of the shaft. (The bottom was sand) The company claims the anchor should handle at least 5000 lbs of load before pulling out. I used it for one "hurricane drill" but we didn't get a direct hit and winds were not that strong so I haven't given it the ultimate test... thankfully.