[pcmc]

CanisLupusArctos, Thankyou for the very thorough explanation, I appreciate it.

Originally Posted by CanisLupusArctos

Ice isn't always terrible to docks. Sometimes it's even better to have your dock frozen in solidly. Our dock has been in there for 40 years with no bubbler. The ice occasionally takes a couple of posts out but "straightening out the dock" has been an annual rite of passage in spring, makes a great excuse to get the swim season started as soon as the water's warm enough.

The worst damage occurs when the ice is not solid, such as in spring. It breaks apart and moves around. Springtime often brings free-floating ice that slams into docks. There is nothing a bubbler can do about that. If the incoming ice is sizeable enough, you can't even divert it with a metal pipe. I've tried that, and found myself sliding backwards in standing position on the dock, pushed by the momentum of the ice against the pipe I was using to try to fend off the ice.

In April 2007 we had decent ice cover on the lake when along came the Patriots Day storm with sustained 45 mph winds and gusts to 64 mph. The ice broke apart and slammed many docks, taking out large pilings.

An interesting thing to note about that event is that docks with bubblers suffered the most damage. Docks that were solidly iced-in got much less damage. The ice around those docks acted as a wall of equal substance that fended off the "incoming battering" ice. Bubbler areas became open water very early in the storm. At the height of the storm, those open-water areas allowed for waves filled with chunks of drifting ice that took a huge toll on whatever docks were in the clear area.

There are also many location factors to consider when you decide how much you want to worry about a dock in winter.

South-facing shores need very little protection because the sun hits them with increasing amounts of light all winter long (the least sunlight of the year occurs on the first day of winter in December, after which the days start getting longer and the sun gets higher in the sky.) Sun heats shoreline and shallow-submerged rocks. The rocks then heat the water & ice around them.

Many parts of the lake are exposed to the weather, which gives the ice a shorter life span than it gets in sheltered areas like coves and bays.

Ice behavior varies from location to location on this lake, just like the weather does. There are some shores that routinely take a beating from the ice. In others, the ice behaves itself most of the time. In exposed areas, the time to worry about dock damage is spring when the ice starts floating around. In sheltered coves and on north-facing shores that get no sunlight even on sunny days, ice may grow even during the daylight hours, which will make it behave altogether differently.

On the south-facing shores, it takes near-record cold weather to get ice to grow in the daytime, and it's not uncommon to see it melting back from rocks as early as February.