aluminum base for davit

[fdcmiami]

i was asked to mount a davit, a very expensive davit, to a dock. i told the owner that i could not do anything that would alter the dock structure. this meant i had to come up with something that would mount to the ten by ten concrete column. easier said than done. the heaviest pick was going to be around 1200 pounds. scary. i also wanted something that could be disassembled and used elsewhere. (the owner has a number of homes) so this is what i ended up with. the aluminum is 6061 architectural, it is a different animal than standard 6 inch structural. there is no welding, other than on the piece of pipe that the davit slips into. hardware is all 7/16ths SS and 3/8ths ss. i used 6, 5/8ths by 4 inch SS expansion bolts to tie the unit into the concrete post. it's not going anywhere, unless they want to disassemble it, starting with the front 1/2 by 10 by 12 inch plate with the four bolts in it.

the box on the side contains the hydraulics, the unit will only swing 115 degrees before hitting post. probably will remove the box and put it on the deck. the davit was an 18k dollar item. i believe it was fabricated for a yacht, that would explain the 12 bolt pattern in the circular plate but when he bought it it was inserted in cement. in both cases the davit would have had 360 degree clearance. i guess it was just to good a deal to turn down.

i just thought of something; when i am setting expansion bolts and i have probably set tens of thousands, i will , if possible, drill a couple of exploratory holes to see if i'm going to hit any iron; since just because it is supposed to be or not be somewhere does not hold up in real life. also, i try to drill deep if i can so that if whatever is being held by the bolt is removed the bolt can be driven into the hole and not have to be cut or burned. a headache when you are using large SS exp bolts.

today i was asked to bid a shipping cradle for a 66 sport fish going to egypt on the deck of a freighter. i will build it out of structural steel, send it to the wharf knock down and reassemble. two tow boats will pull the SF up the river and then two cranes will lift the shipping cradle (app size 40 feet by 10 or 12 feet) onto the deck and weld it in place. then they (riggers) slip straps under the boat, pick it up and lower it onto the cradle. it is secured and delivered to its destination. i have done a number of these and enjoy the work though that 12 inch channel is starting to get heavy. for my helper that is. lol