How does ice damage docks?

[Toller]

I bought a house with a permanent dock in Upstate NY 2 years ago and have spoken to many people and read much about ice damage. Everyone seems to have a different opinion on it. Can anyone lead me to some definitive information on the subject? I am trying to decide if I need to get a bubbler. About half of my neighbors have them, and they seem quite effective.

As I understand it, there are three ways ice can damage docks.
1) Ice forms under the dock when the water is low. If the water goes up, the ice takes the dock with it. Our winter water level is well below my dock, so that is not a problem.
1b) A variation on 1 is that ice forms around the piling. When the water level goes up, the ice pulls the pilings out. Some people tell me that is a serious problem, others think it is silly that ice could grip a piling that securely.
2) The lake freezes solid, and expands. The only place it can go is out on the shores, taking the docks with them. That is not an issue for me, as the lake is much too deep to freeze anywhere near solid.
3) During Spring thaw 100 ton chunks of ice can be blown by the wind and smash into docks, destroying them. (that actually happened this year while I was standing on the dock. It drove about 12' past the pilings at about 5mph before stopping. The ice was 5" thick, but was apparently too soft to matter. The dock vibrated alarmingly, but there was no damage)

So, 1) and 2) are not issues for me. 1b) is an unknown that I would dearly like more information on.
3) Would not be prevented by a bubbler and it couldn't possibly melt the ice fast enough to matter. In fact, having ice around the dock might actually protect it from the wind blown ice chunks.

As I see it, it pretty much comes down to 1b).
Any help would be appreciated

 

[Bifflefan]

All I can add is, I have a bubbler and the circuit breaker tripped one year when we were out of state. The ice pushed the dock about 1/2 a foot towards the shore as it froze over.
My dock is 8x8 wood piling driven into the soil and the dock is solidly attached to them.
FYI the boat lift is built the same way and it did not move.
I still run the bubbler on a timer from first ice.

 

[JimS123]

All of your scenarios are good reasons, depending on the circumstances of the water. I'm in upstate NY as well, and there is only 1 way to solve the problem around here. First of all, never use wooden pilings. We use 8" or 9" steel pilings are they are pounded down until they hit bedrock. Then they are filled with concrete to bond them to the bottom.Above water level then they are cut off at the appropriate length and then steel I-beams are welded across the pilings in both directions. Twenty years ago a 3-finger dock to moor two 25' boats (or 4 if you use the outsides) was worth about 20 grand. I know of 30 year old docks that have had the pressure treated decking replaced already, but the steel structure is still straight and level.

 

[kjsAZ]

there's one more scenario which is actually the worst. When water freezes the ice expands in volume which means the ice sheet has to go somewhere. Imagine your pilings solidly frozen into an ice sheet which then expands and pushes them apart..... It doesn't have to be the entire body of water freezing to cause this, just a sufficiently thick layer of ice.

 

[Frank Acampora]

I had a summer place on a lake near Albany--not really upstate, to an old school New Yorker, anything below Albany is downstate. At any rate, during the winter the ice would freeze about 2-4 feet thick and heave about 10 feet up the beaches. There is where your dock will end up too

 

[rbh]

Ice is a pretty destructive force, when in sheet form it moves mountains just look at a glacier, and as was said its force while expanding can rip apart concrete (see ice jacking) this happened at a ski resort when water got into a lifts foundation froze and blew apart the concrete footing.

 

[Toller]

OP here...
Dock is 9" steel piers filled with concrete; presumably my neighbors are also. I have kayaked 5 miles each way, and no docks suffered any damage. As I said, about half had bubblers. (I mean half of the permanent docks; about 60% are removed in the winter)
This was the worst winter a neighbor who has lived here 30 years has seen. I chopped a hole in the ice when it froze over 25' from shore and it was 3"; 50' from shore was 2". It may well have gotten rather thicker, but I doubt it tripled.
Last year it didn't form any ice by me at all; I was able to go kayaking all winter.

 

[shaw520]

Build your dock on wheels,... tow it out in the winter,.. back er' back in come spring.

 

[Ned L]

"1b" is real and is probably the major cause of ice damage to piers in tidal areas. (Ice freeezes around the pilings, tide goes up and takes the piling with it, as the tide goes down the piling stays there (and is not pushed back down), the cycle repeats itself with each tide cycle and little by little pops the pilings out like toothicks. Bubblers do work to prevent this.
The principle way that bubblers work is that the bubbles actually bring up the warm water from down below, which keeps the ice from forming (not just the action of the bubbles).

 

[gtochris]

Where I am in NJ, we have some community docks with steel pilings and they get twisted every once in a while, ice can move slow and overnight completely warp something. One of the steel pilings on our row is still bent in quite a bit from last winter- I think just a big slab blew into it since we in a very large section of open water. They use to do the bubblier thing but I think liability with all these crazy ice fishermen trying to get on the ice kicked in and the org found it was safer to just let the docks get mangled a bit and fix in the spring.

 

[Outsider]

Ice is a pretty destructive force, when in sheet form it moves mountains just look at a glacier,

Not the same forces at work at all. The best way to eliminate damage is to remove it, sooner or later Mother Winter will win ...

 

[Scott Danforth]

I have a good friend who lives on a lake. ice shove this past spring not only took out his dock and boat lift (they were on land for winter), however pushed its way across his lot the 75' to his lake house and took out his deck and patio doors filing the place with ice which damaged all the drywall. and that was just the wind pushing the ice. (scenario 3). all he could do was video tape it as it destroyed everything in its path

Another friend of mine runs a company that does dredging, sea walls, and installs permanent docks. Based on his comments over the years, I would go with 4...All of the above

 

[moosehead]

Toller, seems as though you're about to find out firsthand how ice can do damage to docks. Given you already have 9" steel pillars filled with concrete, it's you vs. mother nature. Let us know, but seems like Scott Danforth may be right in the long run, all of the above.

Good luck and let us know how she fares in upstate. I currently live in a really cold area of the U.S., but learned how to drink coffee and to wear insulated coats in upstate NY.

 

[NYBo]

Sounds like Seneca Lake, which hasn't frozen over since 1912. Check with your neighbors. Localized ice conditions can make a difference.

 

[rallyart]

My floating aluminium dock is not bothered by the ice at all. When it is at breakup the ice can push the dock around if there is a wind but that is remedied by either pulling it in some in the winter so it does not stick into the lake as far or by making sure the attaching cables have enough slack at the time of breakup. I can't give you good advice about pilings.

 

[rbh]

Ice is a pretty destructive force, when in sheet form it moves mountains just look at a glacier,
freaken another double post

 

[rbh]

Ice is a pretty destructive force, when in sheet form it moves mountains just look at a glacier,

Not the same forces at work at all. The best way to eliminate damage is to remove it, sooner or later Mother Winter will win ...

This statement was a generalization of the power of ice, and it can kick your butt or wharfs however you look at it!