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Old 17-05-2019, 19:31   #1
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Unique Way of tying off to pilings in slip to keep boat centered during storm surge

I wanted to share something that came to mind at the begining of 2018 Hurricane Season. I wanted to create a way to tie off to pilings and keep the boat centered at all points during surge or extreme tidal swings.

Disclaimer: This is still experimental and could use some engineering calculations. This should only be used with the advice of a professional to be sure that it will keep your boat safe during storms. I will not be held responsible for any damage incurred for reasons of too many variables including boat sizes, dockline strengths, and surface area of structures above the waterline that create forces that challenge the physics of keeping a boat tied safely, which precludes having a one size fits all solution. This is why I recommend seeking a professional's advice before installing this in your boat slip.

The Set Up:

Tie a block using dockline and clove hitch to the top one foot of each piling in your slip.
Repeat the process at the lowest point at water level to the bottom of each piling.
Now, run a dockline from your starboard bow deck cleat to the top block on the piling and run it through, then down through the block on the same piling at water level, then back up to your bow cleat to be tied off. This forms a triangle.

Repeat the formation of triangles on all of the other pilings, beginning at each deck cleat, through the 2 blocks and back to the deck cleat on the boat.

Cool physics:

As long as your deck cleat height is between the upper and lower block on the piling, your boat will travel in a straight line up and down with tides. If it exceeds the top or bottom block, you will have to let out some line on the deck cleats. If a storm is arriving, tie off the boat to allow movement side to side to reach close to but not getting closer than a foot or so from pilings to allow for stretching of docklines during wind gusts or surge. Theoretically, the boat should stay centered even if the tide takes your boat above the tops of the pilings, but not too far above. Again, check with a dock neighbor with an engineering degree to be sure your boat will be safe.

Cost:

3 times as many docklines as you have now on your boat.
2 blocks per dockline that form each triangle. This means 16 blocks for 6 pilings, including 4 spring lines. With at least $30.00 per block, this will cost $480.00. Use the heaviest block that you can. Breaking Load of docklines are 7,000 to 10,000 lbs.
Some blocks range in the 3,300 to 5,000 lb. Range. 2 per triangle.
Adding the cost of docklines, at least $480 at $20.00 per dockline. This is for one dockline top and bottom of the piling to secure the blocks, and one to run from the boat, through the blocks and then return to deck cleat.
Not cheap: $960.00

I used this set up during the 2018 hurricane season. Winds here were up to 55 mph. I have not tested this in winds greater than that at this point. It gave me peace during winds and surge.

I enjoy this set up. It took two sleepless nights to finally come up with this, but now I don't worry about the dinghy on davitts hitting a piling, or rubbing against side pilings with tide changes.

I hope this works for you.

Ron
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Old 17-05-2019, 20:25   #2
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

Just one more safety tip. If you enter your boat from the side, the spring line at that location should be tied very low, or eliminated to prevent it from getting in the way of boarding. It should be well below you feet as you board.
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Old 18-05-2019, 00:19   #3
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

Why wouldn’t the Tideminder system work just as well with much less cost?
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Old 18-05-2019, 03:39   #4
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

Greetings and welcome aboard the CF, Ron.
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Old 18-05-2019, 05:18   #5
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

We use TideSlides and accomplish the same thing much more simply and I suspect much more reliably. They aren't cheap, but well-worth every penny. My Catalina 30, in a slip with TideSlides, has weathered three hurricanes and numerous storms that caused significant surge. In 2011 Irene raised the water level in the marina at Oriental, NC almost 11 feet. Yes, you read that correctly - 11 feet. Many boats, as well as the docks, were damaged primarily by the rising water. The wind was manageable. My boat had no damage and I never had to adjust my lines during the nearly 18 hour event. I helped monitor boats and adjust lines of other boats until the water level made working on the docks unsafe.

Isabel in 2003 brought nearly a 9 foot surge, the TideSlides handled it. During Florence in 2018 there was again nearly a 9 foot surge and again no damage and my lines were never adjusted.

Because the surge in each storm was strictly wind driven, once the flow reverses water leaves my marina almost a quickly as water going down a toilet when flushed. During Irene the water went from 11 feet above normal to nearly 4 1/2 feet below normal in about 2 - 3 hours. There was damage done as boats were left hanging by their lines in slips. The TideSlides allowed my boat to safely settle in, almost completely upright in her slip, even though the keel was deep in the mud.
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Old 18-05-2019, 06:26   #6
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

It looks like Tideminder is much less complicated and cheaper. If your pilings are free of cleats, neighbors lines etc. Tideminder works like the rigging on Schooners masts. I don't have experience with Tideminder. Most of the time, your deck cleats will not exceed the tops of the pilings, so Tideminder should work fine. I did not know of Tideminder at the time that I came up with this. I do like how this works. A lot of the slips in my marina have lines running between pilings, plus lines from neighboring boats that would limit the height that Tideminder could travel. I do like the Tideminder Idea.
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Old 18-05-2019, 07:34   #7
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

That was an innovate scheme you envisioned with the lines and blocks, good on you.

Tideminder like systems are great for fluctuating water levels and for minimizing chafe on the lines from the piling.

Do realize that any obstructions on a piling would limit the ability of vertical travel of the tideminder, such as loops tied by adjacent boats, or cleat or ring.

The tideminder balls scheme is specifically intended for coupling to just one side of piling, whereas there are the types that form a complete sliding ring around the piling can be tied to from many sides simultaneously. An example, there being many types and you could fashion one from the tideminder balls: http://https://www.pilering.com/

Their only inherent limit to safekeeping your vessel is if the water level rises and over tops the pilings. Marinas with REALLY TALL pilings can provide for weathering tremendous storm surges, even 11+ feet [WOW, I suspect the shore based facilities were made a mess]. When the pile drivers are done pounding in the piles just don't ask them to shorten them, ask them to use extra length piles and then keep them long, don't have them cut. They look kind of funky sticking twenty feet above the water line, but look grand when they are only five feet above water level at peak of the surge.

During a storm surge or a tsunami, ya, just don't want to get caught holding onto the short stick when it comes to piling lengths.

Seen the results of boats ending up speared on the top of their pilings. Also seen many floating docks and finger piers rising up and off their too short pilings with tremendously adverse results.
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Old 18-05-2019, 08:12   #8
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

How do you keep Tideminders from floating off the top of a piling (I've seen the tops go under)? A minor point, impossible for most. Obviously, they could be tied down.

Obviously, if a neighboring boat uses the same piling, the range is constrained. More to the point, if you put one EITHER over or under my fixed tie, I would have a problem with that (chafe). You have installed something that will rub and move against my dock line. Not OK and your problem to solve.

I'm sure this must come up. Practical experience?
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Old 18-05-2019, 08:33   #9
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

Quote:
Originally Posted by thinwater View Post
How do you keep Tideminders from floating off the top of a piling (I've seen the tops go under)? A minor point, impossible for most. Obviously, they could be tied down.

Obviously, if a neighboring boat uses the same piling, the range is constrained. More to the point, if you put one EITHER over or under my fixed tie, I would have a problem with that (chafe). You have installed something that will rub and move against my dock line. Not OK and your problem to solve.

I'm sure this must come up. Practical experience?
Good observation. Simple solution, just share a common ring. See image below, albeit this piling is too short to weather a major storm surge, and I don't see any really tall pilings holding the floating docks, so in a high water situation this marina is likely going to fair poorly.

And as to overtopping the pilings if that happens the entire marina is SOL as the floating docks and fingers will also ride over the pilings and so all the infrastructure and adjoining boats will float loose, or if they are fixed tied they boats will be pulled under the water.

Yet another simple solution: USE REALLY TALL PILINGS for supporting the floating docks and for tying off the boats. E.g., take the largest projected potential surge level at highest possible tide, add in a rising global sea level and then multiply by two to determine safe level above water line. Pilings that look like half the height of a mast should suffice,
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Old 18-05-2019, 10:05   #10
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

The slides are expensive but nice. 11 foot surge? You must have tall pilings.

It would be great if all marinas installed 15 foot pilings with floating docks. The insurance companies would be happy.

This is a good discussion. We will most likely have to endure more severe storms and higher storm surges in the near future. Here in Florida, we get pop up thunderstorms during summer. In the past couple of years, we are seeing pop up hurricanes that develop from a small tropical waves to full fledged hurricanes overnight. The warm surface water seems to be maintaining it's warmth further into the depths, as was seen with Katrina. Irma's backwind sucked all of the water out of this marina, collapsing sea walls and leaving boats sitting in mud. Irma and Maria popped up quickly.
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Old 18-05-2019, 10:34   #11
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

One can make such very floating rings inexpensively and there are many versions available at different price levels and ruggedness.


It must be capable of handling harsh loads in the event of a major storm, the power of the wind is exponential.

Another less expensive example:

http://www.mooringring.com/

I saw a redneck sailor version made from a used tire which had foam sprayed on the inner side to cause if to float and then a dockline just looped over the tire running end passed through the eye splice. Not the prettiest thing but sure worked well, not unlike using inflated inner tubes stacked on top of each other to make a bumper on a piling. Could be one of those use in a storm rig up occasions when appearance be damned and survival of the boat becomes primary. And such configuration is recommended in the State of California's Official Guidelines for Marina Facilities.

"Pile Anchors

Piles can be used as mooring anchors through the use of full length piles extending up above high water, or as stub-piles driven below the mud line.
Full length piles can be driven and fitted with mooring rings at various elevations on the pile to meet mooring needs at various water levels. However, this tends to corrode the hardware, is not always suitable to the boaters, and the rings and connecting hardware constitute somewhat of a protruding hazard to boats and boaters. Also, in applications where water levels change rapidly, a fixed pile mooring ring might be convenient and easy to use at low tide in the evening, but cause the bow of a moored boat to be pulled under water at high tide during the night. Conversely, a boat tied up at high tide could result in a situation where the boat is hanging from the mooring line at low tide, or the boater cannot reasonably reach the mooring ring at low tide. These kinds of situations can occur in tidal areas as well as rivers and rapidly fluctuating water storage reservoirs. As seen below, the extreme tide ranges along the California coastline increase from south to north. At certain times of the year, a tide change of several feet can occur within a few hours.

An alternative is to provide a floating ring around the pile that rises and falls with the water level, and to which a boat mooring line can be attached. Foam-filled rubber tires have been successfully used in this way. They are tough, provide a good long service life, can be fitted with galvanized eye bolts and rings for mooring boats, and can be size selected for fitting over various types of piles of specific diameters. However, they may not be suitable in certain locations because of appearance and environmental permits may not allow their placement in a waterway.

http://dbw.ca.gov/pages/28702/files/guide05.pdf
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Old 18-05-2019, 11:30   #12
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

Too Funny!!

Whatever works!

You can save some money on this system by using bulk line cut in shorter pieces to attach the blocks to the pilings with clove hitches. Blocks are still expensive. The system looks like a web with double lines attached to each piling. It was fun to think it through. The cost caught me by surprise. Figure, a few blocks and some dockline, how much could that cost? Oops!

I liked your suggestions. Funny that California recommended it. My boat was in Southern California for the Chilean Earthquake Tsunami. The water rose and fell every 10 minutes or so about 4 to 5 feet. This went on for a long time. There were still tsunami waves of much smaller magnitude 24 hours after the quake gurgling around the rocks in the harbor.
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Old 18-05-2019, 12:01   #13
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

During Hurricane Alicia in Houston. I put heavy chain around pilings, which were 16 ft tall. I tied my dock lines to the chains shackle and placed a heavy railroad spike at the top of the pilings. Boat was tied securely and simply rode the tide up and back down with the chain sliding up and down piles.
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Old 19-05-2019, 18:46   #14
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

Good idea. You must not share your pilings with other boats. I googled ways to tie off boats form storm surge. There were a couple of suggestions. This discussion has provided 3 to 4 times as many suggestions, all good.

One of the weak links in these systems are the knots that we use to tie to the pilings or shackles. I used blocks that had a loop instead of a shackle on some of the lines. I would have liked all blocks to have a smooth loop at the top. That way there is less wear on lines from a shackle. The line runs through a wider smooth surface.

I liked your idea. Might be a little rough on the piling.
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Old 19-05-2019, 19:59   #15
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Re: Unique Way of tying off to pilings in slip to keep boat centered during storm sur

I've never been to a marina in the hurricane zones of the US but dont the docks rise and fall with the tides? here in southern California, marina del rey they float and rise/fall 7-8 feet with our tide. we have pilings but they go through the docks and the dock rolls up and down the piling. is it not this way everywhere?
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