Designing Boom & Mast For Boat

[MOBY95322]

I want to add a boom and mast to my trawler. I have been searching for help and have come up empty handed every where I go. Can anyone send me into the right direction or come up with some ideas for a boom to pick-up dingy off board and new location for radar. I also want to add an electric winch system.

[TeddyDiver]

Some pictures could help

[peter radclyffe]

Originally Posted by MOBY95322

I want to add a boom and mast to my trawler. I have been searching for help and have come up empty handed every where I go. Can anyone send me into the right direction or come up with some ideas for a boom to pick-up dingy off board and new location for radar. I also want to add an electric winch system.

make the boom length half the beam of the trawler at that point on deck, plus half the beam of the dingy plus about 2 feet, if tumblehome add that,this is minimum, mock up with sticks & string or scale rule to clear the gunnel, determine your gooseneck height & put your peak lifting block on the mast on the hounds above the booms length, the diameter of the mast is about 7/8ths of an inch per foot, to an inch per foot of trawlers beam,beef up all your fittings, stays, vangs, work out your block purchase with various blocks, to a winch, build ultimately for the worst case scenario, i.e, the weakest member of the crew when tired has to get the boat on board when it's heaviest when wet, & the power is down so pulley blocks by hand, dont worry if it looks too strong it may save your life

[peter radclyffe]

Originally Posted by peter radclyffe

make the boom length half the beam of the trawler at that point on deck, plus half the beam of the dingy plus about 2 feet, if tumblehome add that,this is minimum, mock up with sticks & string or scale rule to clear the gunnel, determine your gooseneck height & put your peak lifting block on the mast on the hounds above the booms length, the diameter of the mast is about 7/8ths of an inch per foot, to an inch per foot of trawlers beam,beef up all your fittings, stays, vangs, work out your block purchase with various blocks, to a winch, build ultimately for the worst case scenario, i.e, the weakest member of the crew when tired has to get the boat on board when it's heaviest when wet, & the power is down so pulley blocks by hand, dont worry if it looks too strong it may save your life

mast dia at hounds is about 7/10ths of mast at deck, if you have lifelines above the gunnel, you can have an opening section with quick release wires, you can mock up a body section of the dingy in ply ,full size & trial run it over the rail on a mock boom till your happy with all sizes, build 2 chocks on deck or coachroof for stowage, shaped to hull, with 4 strong eyebolts one on each quarter, cover with leather or rubber seating, ask a rigger for sizes or buy , the riggers handbook by brion toss or gaff rig by john leather, or any good rigging book, in the dingy have 2,3 or 4 lift points to a central bridle, to one lift point, use your painters for control, one purchase at houns, one purchase on boom end , pull in line with boom