Boat Lifts

[Ron]

I've gotten several emails and private messages concerning the boat lift that I'm using down in Florida. I may as well put some of this stuff onto the forum so everyone can see it.

I put in the 4 post lift the year before I bought the Telstar, but I had the Telstar in mind when I designed and ordered it. It's a 14,000 pound sailboat lift sitting on 4 pilings which are boxed at about 14.5 wide x 14 feet long and with a 14 foot wide sailboat cradle. This means that it has dropped down crossmembers to hold the keel and has adjustable jack stands to keep the boat from falling over. I had a wing keel Catalina 250 sitting on in it the first year and it should hold anything up to around 36 feet long with a 13 foot or less beam. The two dropdown crossbeams (fore and aft) are spaced 12 feet apart - which is approx the distance between the two trailer beams holding the big curved main hull bunks. You can do this without the drop down beams but I wanted the option of lifting almost anything within this size and weight range.

I got a set of the two curved trailer bunks from PCI (just the bunks, not the galvainzed beams) which I mounted to the lifts beams using heavy duty treated wood, including a 4x4 vertical post to take the load. I had to build the support in the middle of each because of the dropped down beams. I did not use the trailer's ama pads. For a monuhull keelboat, virtually all of the weight is on the center longitudinal beam, and the stands or pads mounted out side of the center beam just keep it erect - like you see at most boat yards when they are hauled. I'm using these 4 pads to just support the two ama's, noting that there is very little weight (if any) on the ama pads. The trailer is rigged the exact same way - the weight is on the two big fiberglass/steel bunks and the ama side pads are keeping the boat from tilting.

PCI sort of recommends using a wider lift and folding one ama in, but I really think this works a lot better. The lifts at PCI are putting a lot of force onto a much smaller area on the main hull (a wooden beam is run across each end of the lift with a much smaller contact patch on each hull). The trailer bunks must be a foot wide and actually follow the shape of the hull. They designed the trailer to permanently hold the boat, and as far as the boat is concerned - my lift is the trailer. A few photo's follow, including one with the C250 on it.

[rorr1203]

Ron, McCarter’s is starting to fabricate the bunks for my lift and asked if it was necessary that the bunks be mounted using the same rocker mounts as are used on the bunks for the trailer.

I see in the pictures of your lift that the bunks are on the rocker mounts.

I’m thinking that it’s not necessary as the boat will be lifted straight up instead of pulling up onto a trailer that’s at an angle on a ramp.

McCarter’s is asking because they can reduce cost with fewer weld points and less material and cutting. And they think the bunks would be more durable in that they will weld the bunk directly onto a plate that will sit on the I-beam on the lift which would mean fewer weld points and no friction points.

Any thoughts?

Thanks,

[Ron]

Bob -

I think the two main bunks and the ama supports (or what were swivel type sailboat jacks in my case) have to be able to swivel a drop. On the boat , none of these surfaces are exactly parallel to the ground (or the water). They've got to have a little give to provide equal support over their entire surface. You don't really want to introduce a point load on only one edge of any of these 6 suports. You're right about the trailer bunks having to have more of a swivel than the lift, but the lift still needs some. You could mount them rigidly if you can get the angle exactly right, but if it's wrong by even 1 degree then you'll have a smaller load point.

Not sure why your lift builder is having problems. Start out with the two PCI main hull trailer bunks. They'd be happy to sell you the pair, and you don't want or need the galvanized steel trailer cross beams (although your guy could weld or bolt them to the lifts main beams instead). These bunks are made to fit the hull at the recommended two load points. I'm assuming that you're starting out with a power boat style of lift (no drop down cradle). All he has to do is weld or bolt 4 tabs to the top of each flat cradle - two for each single tab on the PCI bunks, to allow these bunks to swivel a drop when a bolt is passed through the set of tabs (like the trailer). I'd use heavy "L" shaped brackets to get more area for the weld. The ama supports should be the same jacks that he would use for any sailboat on a lift, just mount them so the top plates are almost horizontal. They have a little swivel built into them - like jack stands at any marina. Just make sure that the fore-aft spacing of the two cradle beams is approximately the same as that of the trailer. Mine are maybe 6 inches shorter - no problem. Two feet and the bunks may not fit the hull exactly or you'll be lifting at a load point that is not backed up by a bulkhead.

Mine was a little different. I've got two lifts behind the house in Florida. One is for a powerboat (flat cradles - yes, I am a stink-potter occasionally) and the other for a sailboat. It has drop down cradles to support a keel. I wound up tabbing some heavy duty pressure treated wood supports to the drop down portion of each cradle. Since the weight is virtually straight down, the load is just passed thru to the drop down cradle.

[Ron]

Bob -

Woops. Made a slight mistake above. After taking a look at the photo's I realized that the PCI bunks have 4 tabs (1 pair per side) and the lift has one per side. Did this almost 2 years ago and forgot. I also used plates that have a single tab already welded to it. Got it from Dolphin Boat Lifts in Fort Myers, FL. They make my lift and these plates are available as mounting options. The plates were bolted to the heavy duty wooden framework (6x6, 4x4, 6x2) which is clamped to the crossbeams with backing plates. Better way of doing it - as opposed to drilling thru hot-galvanized steel, exposing the base metal to salt water immersion.

I did this about 1 year after the lift was installed. The guys who installed the lift helped. It originally held a monohull with keel, and may hold another one at some time in the future. It will hold 14,000 pounds with a 14 foot beam.

One other note - someone will probably have to go into the water to set the ama jack stands. You want them to support the ama's with not that much actual weight on them.

[rorr1203]

Ron, thanks for the additional detail. I had a chance to catch up with Tony and he agreed with your assessment - the bunks need to be on rockers. McCarters is going to go ahead and fabricate the bunks with the 2 tabs on the bunks and 1 on the plates same as yours. They’ll make matching plates for the bottom so I can bolt the bunks onto the I-beams without drilling holes in the beams. I’m still working on the outrigger supports.

[Ron]

Bob -

If you're guy is fabricating the bunks, you've got to make sure that they match the shape of the hull exactly. That's why they work as well as they do. It's like a pair of huge hands wrapped arouond the hull while holding it up. The load must be distributed over 6 to 8 square feet of hull, at the bulkheads. You'd be better off buying them from PCI and letting your people build the eyes on the cross beams. The bunks themselves were not that expensive. You don't need the heavy galvalized cross beams - just the two carpeted bunks with their tabs on the bottom.

Every lift manufacturer in the world makes some sort of jack stand that bolts or clamps to the beams. They need them to hold trawlers, sailboats - anything with a curved hull or a keel. You can see mine in the last photo above. Note that I've since rotated them 90 degrees so that they swivel in the other direction to support the ama's. A long 2x6 or 2x8 will not work on each side of the lift for these kinds of boats. You put the weight on the keel, center of the hull, or bulkheads in our case - and use the stands to keep it from tilting over. Just point the stand upwards and adjust the height to stabilize the boat on the lift - as you're freezing in the water. The bay is probably on the cold side still.

[rorr1203]

Ron, McCarter’s, the company fabricating the bunks, is the company that makes the bunks for Performance.

My problem with the outrigger support is that I need some that are much shorter than yours. My dock is on shallow water. There are times when the tide is out that I’ll need the lift almost on the bottom in order to get the boat on / off. My thought was to make the outrigger supports out of wooden blocks that I can clamp on top of the I-beam. It should be easy and inexpensive to make. If it doesn’t work I can try something else without much lost.

[Ron]

Bob -

Wood blocks could work, but they should swivel a drop because the ama's are curved on the bottom. My setup would work if the shaft holding the jack was a lot shorter. If the company makes anything like them, just cut them down to size. I left them long because I have some water at the dock and the sailboat drop down cradles are even lower.

[rorr1203]

Could you give me the a guide or sight line for where the boat rests on the back cradle / bunk on the trailer? After all the measurements I took I failed to note the exact position of the boat on the trailer in relation to the cradles. When I pull my boat on to the lift I want to make sure the cradles lines up with the bulkheads.

Thanks

[Ron]

Bob -

Assuming you were directing the question at me, I can't really help you. Boat's in the water and I'd need to look at it on the trailer to judge exactly where the hull is in relation to the aft trailer bunk. My ultimate guide is the two stainless supports hanging down from the deck mold in back - they have to fall in the forward third of the matching raised stands, on the marks left there from previous stays on the trailer. Maybe someone has a good photo of the side of the trailer/boat or you can give Will a call. I'll check my photo's but I don't think I have anything taken squarely from the side.