Bubblers. do's and don'ts
 

Dammed if i do and dammed if I Don't. As a recent permanent dock owner on Meredith Bay I read that having a bubbler will help protect my dock from the ice, however I also read that it is the spring Ice out that causes all the damage. My sense is that if i let the ice form around my Crib dock. it will be protected from the ice flow . Whats a new homeowner with a crib dock to do? looking for your years of experience to give me some advice.

Aguatherm Protection
 

These units are used to protect dock posts and pilings from ice pushing against them, as well as changing elevations of the ice. There is no protection against the pack ice floes that move around as the wind pushes them at ice-out.

The problem is that ice expands when it freezes. Sometimes the ice will move two feet up onto the shore moving everything in its path. If the pilings are frozen into the ice they will move with the ice and certainly twist or push the dock until something gives, which is usually the dock.

Crib Dock
 

I have had a crib dock for 20+ years and it was there 20 years before me. I do not and never will run a bubbler. The ONLY time my dock is at risk is during ice out and depending on the wind, direction and how thick the ice is when it break ups will decide if you have damage or not. My dock we damaged 2 years ago (?) when we had very high winds the caused the ice to break up sooner and therefore in bigger chunks than usual. In the case I had huge rocks pushed up onto my dock as they were dislodged by the ice pack. Only thing a bubbler would have done would have done was to invite more ice flow in.

If you have a crib dock you do not need a bubbler and it will not help you...I am sure you will get many opinions as I did 20 years ago.

A few years back we went south for the winter and left the bubbler on a temperature sensitive timer as usual but because it was a mild year it was causing an opening along the shore that was interfering with my neighbors access. He asked me if he could turn it off for the weekend and I agreed. A week later I had two snapped posts due to ice movement. We live on a fairly active area of the lake but it is also behind a breakwater so I didn't think it would be an issue. I was wrong.

post hoc ergo propter hoc
 

2 years ago many, many docks were damaged by the ice out...if that is the year Gatto is referring to then I wonder how anything could have helped other than having a navy ice breaker in front of your dock.

There is more than one force at work and it is diffiult to beat them all.

If you allow ice to form all around your dock posts then the ice will have a secure grip on your dock.

If the ice shifts, you lose. If it pulls away in the spring as the lake is melting, you lose. As the ice melts it breaks up into many individual pieces and when the wind blows there is very little you can do to protect yourself if you are in an open area and an iceberg blows in.

People will have different opinions but it really depends on where you are located. It is almost like asking: What is the best boat? Everyone has a different opinion.

I have two aluminum docks that get raised in the winter. No damage. I have a wood dock that seems to get damaged most years despite the use of a circulator. There is no ideal way to protect your docks from damage but again, it depends upon where you are located.

I bought this house in july, was in a family trust, nobody to talk to to see what was done in past, house was not used in last bunch of years, My guess is they never had a bubbler, house is 100 years old, dock looks like it maybe 50 +. It has had a little damage, not much. Maybe I should leave well enough alone.

Try talking to your neighbors. They should have a good perspective of the typical movement of the ice during ice out, and the propensity of ice damage in your specific part of the lake.

That "List to Port"...
 

Even though there are vertical steel "pins" connecting the corners, most of the damaged crib docks I see have the outermost corners knocked out. Most of the steel gets twisted out, and left hanging—a hazard to swimming. The owners don't usually fix them, and deal with "a list to port". ;)

This U-shaped crib dock below, had a bubbler running into June until about ten years ago.

http://i70.photobucket.com/albums/i1...pszvf95ndp.jpg

If I had a crib dock, I'd reinforce the corners, add galvanized steel sign posts as supports and, if needed, use 5/16ths-inch lag bolts to level the dock each spring.

http://tse4.mm.bing.net/th?id=OIP.M0...715o0&pid=15.1

Temporarily hammering one into the lake's bottom and nailing it to the end of the dock would provide a "witness" to the direction of ice stress—and could "fend-off" icebergs. (If torn away, they'd still be recoverable in Spring.).

Galvanized steel sign posts are expensive from the manufacturer, but they are bountiful and cheap at metal recyclers.

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Dock jacking from ice fluctuations.
 

The principle of a keeping a dock or marina clear of ice is to ensure that the natural crushing pressure of ice is not able to squeeze the structure. Ice is so powerful that it can literally lift lake bed pilings out of their footings and toss them about like sticks.
My bubbler works mostly to prevent heaving of our posts during Winnipesaukees spring thaw.
When the lake is cold enough to start freezing I notice ice collars around my posts. These collars are created when ice freezes around posts but the water level drops. I see these collars form lower and lower as the water level drops and the ice settles. This water level drop begins pretty rapidly around January and by mid to late March we are at 'low tide'. The water level drop is not as big a problem as the ice pushes the posts down and will usually break away from the posts not causing damage due to downward forces. Once the ice is at its lowest we enter the danger zone. At this time the ice forms solid around posts. In late March, early April, the ice starts to melt. Rising temps and longer sun light causes snow melt and rain run-off into the lake. Now the water level quickly rises taking with it the ice. If your posts have ice around them the docks will usually heave. It will rip the posts right out of the footings and docks will be damaged, probably not destroyed, but damaged enough to require costly repair.
Your location on the lake will have an effect on how the ice forms and if your docks are in danger. History is a good indicator.
This very short video shows what happens when dock posts have solid ice form around them. Up down, side to side, expansion, contraction...heaved docks.
Bottom line, running a bubbler correctly is a relatively cheap way to protect your docks. It still does nothing when the spring wind sends ice floes your way. Those floes can and will easily destroy your docks. Even the docks that are lifted out are in danger as the ice can crawl right up the banks and damage the lifts.

https://youtu.be/eYN5yfEko6M

Like above the power behind frozen water is incredible. Not running a bubbler at a permanent dock is dicey. The electricity you will pay for is a fraction of the cost you will pay to repair the dock and by the time you make the call to a marine company to repair the dock you likely will be so far down on the list it can takes months to get them there. Been there done that.

Dock Insurance
 

I don't know if my homeowner's insurance policy is typical, but my dock is insured if a boat hits and damages it, but it is not insured if it is damaged by ice.