Boat Lift Center of Gravity ....
03-19-2005, 03:33 PM
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Re: Boat Lift Center of Gravity ....
Why the wood on top of the beams? Don't worry the bunks aren't going anywhere. I've lifted 60,000# boats with the same system for bunks. They will not move. If the wood is treated then you will eat the galvanizing off the beam very quickly. Also it will take longer to dry increasing the corrosion problems. If it were mine I would take all the wood off the lift except for the bunks. Even them I would but 2 layers of tar paper under the treated bunks to eliminate any corrosion problems.
You can tell by the tension on the cables if you have the cg correct. Doesn't matter where the beams are if the cg is in the center of the lift then both beams carry the same load. However, with the beams farther apart like you have them you will reduce shock load on the cables. My beams, not by my choice, are closer together on my lift. So I have a lot of bow hanging over the front beam, 41' boat. You can feel the cables stretch and load when you walk to the bow of the boat. Your setup should just about eliminate that problem.
CG is CG, doesn't matter where the beams are.
With your setup I would be more concerned about single part cables, they are the going to be the point of failure. This is the first 9000# lift I have seen with a single part. Most are 2 part similar to strip's above.
You can tell by the tension on the cables if you have the cg correct. Doesn't matter where the beams are if the cg is in the center of the lift then both beams carry the same load. However, with the beams farther apart like you have them you will reduce shock load on the cables. My beams, not by my choice, are closer together on my lift. So I have a lot of bow hanging over the front beam, 41' boat. You can feel the cables stretch and load when you walk to the bow of the boat. Your setup should just about eliminate that problem.
CG is CG, doesn't matter where the beams are.
With your setup I would be more concerned about single part cables, they are the going to be the point of failure. This is the first 9000# lift I have seen with a single part. Most are 2 part similar to strip's above.
Last edited by mr_velocity; 03-19-2005 at 03:38 PM.
03-19-2005, 04:54 PM
#12
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Re: Boat Lift Center of Gravity ....
Originally Posted by mr_velocity
Why the wood on top of the beams? Don't worry the bunks aren't going anywhere. I've lifted 60,000# boats with the same system for bunks. They will not move. If the wood is treated then you will eat the galvanizing off the beam very quickly. Also it will take longer to dry increasing the corrosion problems. If it were mine I would take all the wood off the lift except for the bunks. Even them I would but 2 layers of tar paper under the treated bunks to eliminate any corrosion problems.
You can tell by the tension on the cables if you have the cg correct. Doesn't matter where the beams are if the cg is in the center of the lift then both beams carry the same load. However, with the beams farther apart like you have them you will reduce shock load on the cables. My beams, not by my choice, are closer together on my lift. So I have a lot of bow hanging over the front beam, 41' boat. You can feel the cables stretch and load when you walk to the bow of the boat. Your setup should just about eliminate that problem.
CG is CG, doesn't matter where the beams are.
With your setup I would be more concerned about single part cables, they are the going to be the point of failure. This is the first 9000# lift I have seen with a single part. Most are 2 part similar to strip's above.
You can tell by the tension on the cables if you have the cg correct. Doesn't matter where the beams are if the cg is in the center of the lift then both beams carry the same load. However, with the beams farther apart like you have them you will reduce shock load on the cables. My beams, not by my choice, are closer together on my lift. So I have a lot of bow hanging over the front beam, 41' boat. You can feel the cables stretch and load when you walk to the bow of the boat. Your setup should just about eliminate that problem.
CG is CG, doesn't matter where the beams are.
With your setup I would be more concerned about single part cables, they are the going to be the point of failure. This is the first 9000# lift I have seen with a single part. Most are 2 part similar to strip's above.
I was wondering the same thing .I bet with the wood it floats
I added 2x12x16 walkways beside the boat. My slip is 14 foot wide and it was hard to reach the boat to do anything to it .I had to add weight to the lift ti get it to sink.I also cut the bunks to match the steps in the bottom of the boat . Really would like the Myco cradle but. this is close .Rob
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03-19-2005, 05:41 PM
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Re: Boat Lift Center of Gravity ....
Originally Posted by Strip Poker 388
I was wondering the same thing .I bet with the wood it floats I added 2x12x16 walkways beside the boat. My slip is 14 foot wide and it was hard to reach the boat to do anything to it .I had to add weight to the lift ti get it to sink.I also cut the bunks to match the steps in the bottom of the boat . Really would like the Myco cradle but. this is close .
Rob
I added 2x12x16 walkways beside the boat. My slip is 14 foot wide and it was hard to reach the boat to do anything to it .I had to add weight to the lift ti get it to sink.I also cut the bunks to match the steps in the bottom of the boat . Really would like the Myco cradle but. this is close .Rob
03-19-2005, 08:15 PM
#14
Re: Boat Lift Center of Gravity ....
No problem Floating ...beams are Steel ...why we put the wood under the bunks ? I have no Clue ... 
I think maybe to keep the Keel from Banging the steel ..... we are going to move the front beam 12" towards the rear .... see how it does ...I can always move it back ...been yankin and pullin on those cables all day ....cant really tell much difference . Prob a good idea to remove the wood ....
Single part cables ? you refering to the single cable coming down ? There are two ...one wraped around the pipe down thru a pulley and then back up to a deadman ... There is a single SS cable from the Pulley down to the Beam ... I think The lift is rated 14000 lbs ... Mark Lunmar in louisiana designed the Lift .... http://www.lunmar.com/
I think maybe to keep the Keel from Banging the steel ..... we are going to move the front beam 12" towards the rear .... see how it does ...I can always move it back ...been yankin and pullin on those cables all day ....cant really tell much difference . Prob a good idea to remove the wood ....Single part cables ? you refering to the single cable coming down ? There are two ...one wraped around the pipe down thru a pulley and then back up to a deadman ... There is a single SS cable from the Pulley down to the Beam ... I think The lift is rated 14000 lbs ... Mark Lunmar in louisiana designed the Lift .... http://www.lunmar.com/
03-19-2005, 11:44 PM
#15
Re: Boat Lift Center of Gravity ....
Originally Posted by mr_velocity
His lift looks to be galv steel, probably not a problem like our alum lifts. With my massive bunks I have 200# of lead blocks bolted to it, that in addition to the alum catwalk I have. Your catwalks are wood? With the alum I was able to make the walk 20'.
I dont drag my feet across them ..I did pvc with concrete.I might need to ck with ya on some cats.
Rob
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The Only Time You Have To Much Ammo Is When Your Swimming Or On Fire.
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The Only Time You Have To Much Ammo Is When Your Swimming Or On Fire.
I put the concrete in the pvc.
