36 ft trifly cradle

rooferdave · Post by **rooferdave** » Tue Sep 07, 2010 8:39 am

anyone have drawings for one of these? I have a similar boat in my club but it is sooo buried with all the other cradles I will need towmotor to dig it out, any help wood be appreciated.

Dave

ready123 · Post by **ready123** » Wed Sep 08, 2010 6:54 pm

why build a cradle... why not block the keel and use stands to prevent tipping like this?
http://www.yachtworld.com/core/listing/ ... e=Photo+38

rooferdave · Post by **rooferdave** » Wed Sep 08, 2010 8:51 pm

1 or two reasons...rules of the club I am in require that you have a cradle for your boat, also as the property we are on is in constant motion, if not on a cradle, the land can shift and boats have fallen off stands in the past

Big D · Post by **Big D** » Wed Sep 08, 2010 9:17 pm

If those are the rules then you're stuck. But if it's because the ground moves off season, it's a poor reason for forcing members to use cradles. When done properly and maintained off season, shifting grounds or high winds shouldn't make a difference. Is the place shut down completely in the winter with no staff around?

ready123 · Post by **ready123** » Wed Sep 08, 2010 10:32 pm

rooferdave wrote:1 or two reasons...rules of the club I am in require that you have a cradle for your boat, also as the property we are on is in constant motion, if not on a cradle, the land can shift and boats have fallen off stands in the past

That sounds like the cradle will need to be quite substantial then to absorb shifting ground better than correctly placed stands.
In my view adjustable stands placed around the edges of a boat for support, not weight bearing are likely to be more adjustable for ground shifts than a cradle.
But rules are rules.... can you not just measure your hull and design one? My guess is the cradle would have side ribs that align with the sling points on your hull and the main support is on the keel.

13footbeam · Post by **13footbeam** » Thu Sep 09, 2010 8:27 am

You can easily, well with effort make a heavy duty cradle that will support your keel with adjustable stands built in to keep your boat upright. About 10 years or so ago I was one of the proud owners of the Indian River Marina in Michigan and we pretty much built and rented to our customers this very type of cradle. They were pretty cool, could be used for many boat hull designes.

Pat

rooferdave · Post by **rooferdave** » Thu Sep 09, 2010 9:38 pm

during haulout approx 200 boats are hauled out in one day with 2 640 tonne cranes, there is 1 expierienced swamper and a bunch of designated haulout crew from the club. They do not have the skills to set up stands and so must have premade cradles to drop the boats on.

ready... in reply to your question, this is my first year boating and design of a cradle is something I would like guidance in...

13 ft beam... if I knew where to start I have the equipment to build but not sure how to do it...

I can get the cradle out from the other boat from my club, I just need to float a forklift down there and 3 hours to unbury it, just thought if some one here had a plan for me it would save me the trouble and trucking to figure it out

rooferdave · Post by **rooferdave** » Fri Sep 10, 2010 3:54 am

rooferdave wrote:during haulout approx 200 boats are hauled out in one day with 2 640 tonne cranes, there is 1 expierienced swamper and a bunch of designated haulout crew from the club. They do not have the skills to set up stands and so must have premade cradles to drop the boats on.

ready... in reply to your question, this is my first year boating and design of a cradle is something I would like guidance in...

13 ft beam... if I knew where to start I have the equipment to build but not sure how to do it...

I can get the cradle out from the other boat from my club, I just need to float a forklift down there and 3 hours to unbury it, just thought if some one here had a plan for me it would save me the trouble and trucking to figure it out

As I reread this it does not sound how I meant it...let me rephrase

Michael thank you and I will look at the other trifly in the club for its sling points and this is a great start as to where to put the uprights

as I was doing the math on how many boats in the club it is probably closer to 150 boats and it seems to be a long day for all involved, I guess as the chance of error is pretty good with all the boats on one day and also they are about 1-2 feet apart and layout is done 2 weeks early I guess cradles are their way, some of the long time members (not many) are grandfathered in with stands from before the rule

Pat... the adjustable part sounds appealing how was this accomplished? do you have a picture? As my boat is in the water the width of the supports at the sling points as Michael suggested will be tough.

A clever guy would have thought of this in the 12-14 weeks it was at my shop on stands! I guess I was wrapped up in trying to get it running and launched

also for what it is worth our parking lot that we store the boats on is gravel and to boot it is landfill that sinks 1-2 inches per year... and yes dock repairs are ongoing due to movement

thanks again for the input guys!... guess I can go back to bed now and fret some more....goodnight all

Dave

seems I slept alot better before the boat

rooferdave · Post by **rooferdave** » Fri Sep 10, 2010 4:03 am

Big D wrote:If those are the rules then you're stuck. But if it's because the ground moves off season, it's a poor reason for forcing members to use cradles. When done properly and maintained off season, shifting grounds or high winds shouldn't make a difference. Is the place shut down completely in the winter with no staff around?

no we have bubbler crews to ensure the docks are not destroyed and our 2-5 live aboards do not sink, the clubhouse/pub restaurant is open 3 -4 days a week in the winter, however with all the snow and drifting it is near inpossible to get near some of the boats to even check

13footbeam · Post by **13footbeam** » Fri Sep 10, 2010 9:34 am

RooferDave

I will see if I can get some photos for you

Pat

13footbeam · Post by **13footbeam** » Tue Sep 14, 2010 8:28 am

rooferdave,

Here is a photo of the finished product I spoke of. The adjustable stands with what ever size pads you decide upon slip into the 2" square tubes. and the keel is blocked at the cross member according to the desired slope you desire from bow to stern. As you can see, the sides are triple 2`` x 12`s. The bunks are 6`` I beams, the angle iron is 1/4`` x 4`` The square stock is 2`` od. I hope this helps

IMG]http://i395.photobucket.com/albums/pp33 ... cradle.jpg[/IMG]

13footbeam · Post by **13footbeam** » Tue Sep 14, 2010 8:56 am

I think the image should show this time.

Pat

rooferdave · Post by **rooferdave** » Tue Sep 14, 2010 10:05 am

thank you! this is the one for the boat in your picture? On square tubing for the side supports does it not have to get closer on center as you get near the bow or is support not needed? Also what is the distance between the square tubing o/c and distance between the cross mebers, the picture helps a ton!

Dave

13footbeam · Post by **13footbeam** » Tue Sep 14, 2010 10:14 am

Dave,

you will want to measure where the slings are supposed to be set when lifting the boat and place the jacks at this location when building the cradle. Also you will place jacks at the stern on both sides. Basically, you will custom build the cradle to fit your boat, if you need some more beef, add it.

13footbeam · Post by **13footbeam** » Tue Sep 14, 2010 10:17 am

One more thing, your keel does a lot of the support work, your jacks are mainly to level and stabalize the boat on the cradle.