sandy wrote in news:6ccacdb1-2ec8-4076-b2c8- snipped-for-privacy@z72g2000hsb.googlegroups.com:
Your problem is that these pipes could have been installed in any number of ways and there is really no easy way to find out. Bent pipes are useless and shouldn't be straightened because they will kink and those will be weak spots which will bend very easily and could even break. Don't try to strighten and re-use bent pipes.
Some possibilities are;
- pipes just pushed in by hand and hammered a bit. Only a small amount of penetration and thus the pipes would be leaning and may not be bent. Try pulling them out with an old fashioned car jack or a long lever to a chain around the pipe. This is frustrating and dangerous work because it is on a floating unstable platform. Put jack base or fulcrum on a post on the lake bottom and becareful.
- pipes hammered in deep using machinery. In such a case they are bent, not leaning and getting them out would require machinery. Depending on how far they are from shore maybe you can get a medium to large backhoe to reach out pull them out. You could get the backhoe to push in new pipes but they wouldn't last much longer than the old ones. If the pipes can't be pulled out then cut them off and build a fixed dock around them. Don't just cut them off if you want to keep the floating dock because they will wreck boats. Maybe a fixed dock base with a removable top part that can be easily removed for the winters?
- a likely scenario is that the pipes just have a pad welded onto the bottom and they just sit on the lake bottom. In this case they would be leaning and not bent. Should be able to lean them straight by pushing on long poles from shore or pulling with a boat or drop a large anchor off shore and use a pulley arrangement to pull them straight. If the pad is buried into mud then it may be a real pain to straighten out. Probably won't stay straight any longer than original installation if you leave it in for the winters. Floating docks with pipes on pads are intended to be removed every winter - the pipes should be adjustable vertically so you raise them, float the dock out and lower them to sit on the bottom and keep dock from moving away; reverse process for removal. Some docks are lifted up on the pipes so they don't rock around all summer and the weight holds them in place better. Other types are loose on the pipes so they can move up and down when lake levels change. Depends on many site specific factors.
Ice on a lake can exert from zero force to a huge force on docks depending on many factors. Sometimes changing temperatures cause ice sheets to shrink or expand during the winter - these forces are huge and will bend any normal sized dock parts. In spring when ice is breaking up and lake levels rise the ice attached to the dock can exert vertical lift forces and pull the pipes up. Ice sheets also can get blown around by the wind and depending on the distance across the lake could have large sideways pushing forces. Some years none of this happens and some years it is severe. When these forces occur they are irresistable by normal docks so it is good practice to pull the docks out in the fall and replace them in the spring. That is probably why they used floating docks. If they didn't intend to remove them why not simply used a fixed dock which would have been cheaper?
Many folks use a fixed dock with wheels on the outward end so they can roll them in and out. Needs a lake with no currents, a suitable shoreline slope and very little rise or fall of lake levels. I've seen floating docks with wheels to aid in installation and removal. The inward end has pipes on pads that are adjusted up and down to level the dock.
Most floating docks are inadequate from the point of view that they rock way too much when hit by waves or boat wakes. This is dangerous if people get thrown off balance and fall down or fall in the water. A floating dock that won't rock requires careful design and is expensive so is not often done right.
Big question is what are other people on this lake doing with their docks and how succesful are they? Copy what the successful and safe ones are doing - but only if they have been there for a long time, many years. Any old plan can work for a year or two with a bit of luck. Only the good plans last a lot of years and are safe.