In-Garage Boat Lift Design

[Lakegeezer]

I'd like to build a boat lift in my garage. My wooden rafter beams are strong enough (boat is 2000#, each of two beams are engineered to hold 3500#) but there are several outstanding questions. First, how to attach a strap to the beams? Second, do I need winches on both ends of the strap (to keep movement of the strap to a minimum while I lift) or can I get away with one fixed point and another point for a single winch? Hopefully there is someone on the forum that has done this and can shed some light.

[Dave M]

My wife's relative has one similar to what your looking for. The belt are attached to a drive shaft along the rafters. As I remember it has a motor connected to a gear which turns the drive shaft lifting the boat. Also I think it has a remote cable. I'll check it on this weekend and email him on who installed it.

Dave M

[VitaBene]

I'd like to build a boat lift in my garage. My wooden rafter beams are strong enough (boat is 2000#, each of two beams are engineered to hold 3500#) but there are several outstanding questions. First, how to attach a strap to the beams? Second, do I need winches on both ends of the strap (to keep movement of the strap to a minimum while I lift) or can I get away with one fixed point and another point for a single winch? Hopefully there is someone on the forum that has done this and can shed some light.

LG,

Does the rating include the weight of the roof/snowload? Or are you saying you have 3500 pounds of headroom above those factors?

Great idea though!

[Lakegeezer]

LG,

Does the rating include the weight of the roof/snowload? Or are you saying you have 3500 pounds of headroom above those factors?

Great idea though!I doubt I'll be using it during high snowload days - because the boat will be outside, under its tarp and plowed in. But - the rest of the rafters were designed to code for snowload and two (fore and aft) lift beams were added specifically for the boat lift.

Dave M - Thanks!

I'm trying to not break the bank - but when dealing with a ton of boat hanging in the air - I don't want to skimp either.

[Seeker]

OK I'll ask. Why do you want to hang the boat? Bottom painting? Repairs?
I used to hang mine briefly (using straps and a chainfall) and then lower it onto homemade stands. I didn't have a trailer for that 16' tri-hull. I was hanging it from 12x12 wood beams in a early 1900s barn.

[Lakegeezer]

OK I'll ask. Why do you want to hang the boat? Bottom painting? Repairs?
I used to hang mine briefly (using straps and a chainfall) and then lower it onto homemade stands. I didn't have a trailer for that 16' tri-hull. I was hanging it from 12x12 wood beams in a early 1900s barn.All of the above. I want to be able to clean the bottoms without leaving the trailer pads. My sailboat needs its centerboard pulled, checked and possibly repaired. Did you use a single point for hoisting or did you have two points?

[Dave M]

Lakegeezer, this is the reply I got. I checked the web and Watermark comes up. Looks like a fancy rig though.

Hope its helpful

Dave M

The boat lift we have consists of two slings that are connected to two cross beams in the boat house, by pullys. The cables to the pulleys are connected to an electic motor and gears that are operated by a simple up/down switch. You place the slings under the boat in the appropriate places and turn the switch to the up position. It is a fairly simple arrangement, but is designed to work where you have something to hang the pullys and slings onto. My recollection was that it cost about $1500 installed about 15 years ago. I called various marinas to see if any one did that kind of work and found a guy at the Goodhue Hawkins navy yard in Wolfboro who i think did it as a side job. I think he was the service manager at the time but i tried to reach him a few years later about adjusting the lift for the new boat, but he was long gone. I then talked to someone at channel marine at the weirs who referred me to a guy that worked on their boat lifts and he came over and modified mine. Unfortunatly i had some problems after the modification and could not ge him to come back to fix it. Found another person to make the adjustment.

Unfortunatly all my paperwork is in New Hampshire so i can not be more specific. I think you might call around to the various marinas to see if they can recommend someone or look up boat lift dealers distibutors or manufactures on the internet who might have someone in the area who installs them.

[Seeker]

All of the above. I want to be able to clean the bottoms without leaving the trailer pads. My sailboat needs its centerboard pulled, checked and possibly repaired. Did you use a single point for hoisting or did you have two points?

@ 2 points, 1 forward and 1 aft. I would recommend a couple homemade stands a couple inches below the bottom JUST IN CASE. After you paint just lower and move the boat a few inches then relift to paint those areas you missed.

[John A. Birdsall]

I lift my boat out of the water in the boathouse and it has worked for me, I take a chain yoke to the waterski eyelets in the stern and another yoke with cchain on the bow ilet letting the chain with canvas around it go on each side of the bow. I use two chainfalls and pick the boat up. In the winter if I leave it in the boathouse I put four 2x8 under it and release the pressure from the roof structure.

[Winnipesaukee]

I'm no expert, but I would definitely use two hoisting points, and do NOT use any hull fittings. Lift from straps under the hull.

I say take a couple of 3 strand nylon ropes and send them through a pulley system to lift the boat. Simple and safe. Just make sure to get a rope with a maximum load of at least 6000 pounds.

[ApS]

When using straps, be sure to connect the two straps underneath the keel. That kind of oversight resulted in this "lift failure" seen at PhotoPost.

:eek2:

http://www.winnipesaukee.com/photopost/data/512/1126067745_7445fcffbc_o.jpg

[upthesaukee]

....WOO HOO, what a ride!!!!!:D

back to the topic on hand.

[brk-lnt]

In every case I've ever seen, you have two straps, connected to two shafts, which are geared to move in unison (typically through a chain mechanism).

You are going to have a lot of weight on a relatively wide strap. This results in high friction, so if you lift the strap from one side only the boat is going to tilt, until gravity takes over at an unpredictable time when it shifts suddenly.

[cowisl]

What kind of boat and how long? Trailer is the best since the weight is evenly distributed and supported.