How would you make this fit?

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I was asked to do this job, I am going to pass on it.    This is an old power company knuckle boom.  Model 50 something, so I ASSume it goes 50 feet up.  The truck belongs to an electrical company.  One of the drivers left the jib on the back of the truck and drove away.  This is the replacement.  I was asked to make it fit.   Note the rope in the upper left.Real world weldin.  When I grow up I want to be a tig weldor.
Reply:The old and new one are fiberglass as insulation.I thought the only way is to cut the mount all apart and re configure it to fit the square tubing.Legal stuff will be professionally ignored.  I already said I am not doing the job.How would you go about it?DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:I probably would personally cut out the round tube completely and use the square tubing.
Reply:cut off the round tube get square tube and weld it on were the round was , done now get back to workChuckASME Pressure Vessel welder
Reply:I would think that cutting out the round stock and making the square stock butt straight to a new plate at the base of where the round is would be the best way to go about it.Come try it out and stay a while.
Reply:Well you can't put a square peg in a round hole so an adaptor must be made..OR...Cut the round end off flush and get square tubing that fits around the outside of the new mast and make it at least 12" long..Weld the new square with gussetts to the existing plate.......zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:I would base any modification on a comparison with the missing  original jib's dimensions; with attention to extension length and any swivel capabilities.My first choice would be to fit the new jib, without modifying the original goat head. If first choice wasn't practical, and the goat head must be modified - It almost seems that the round to square fit-up will require so much rework, that you probably would consider cutting the side plates off, between the pivot and receptacle, and starting from scratch.
Reply:Is this the same electrical company you reworked the Ford dump box for?
Reply:Originally Posted by AcemanIs this the same electrical company you reworked the Ford dump box for?
Reply:Did the old jib fit inside the uh "goat head" and get a pin put through it?Maybe you could have a pin turned out of square stock, the square stock being the right size to slide inside the new jib and be welded on the end and rosette welded elsewhere,the other half being the right size to slide inside the goat *** with a hole drilled for the pin to go through. Its gotta be able to come off there right?I dunno.Yup
Reply:Following the original manufactures lead, I would fab a complete new attachment assembly only for square instead of round. Follow the design concept to a "T".  He could keep the original for memories sake or in case he stumbles across a replacement appendage.If for some reason a guy were to take on the job build it as tho it had to pass fed and or state OSHA inspection and certification tomorrow (usually an indipendant company). Even though we all know this thing hasn't been inspected since it sold the first time and ain't going to be either.
Reply:Originally Posted by BurnitDid the old jib fit inside the uh "goat head" and get a pin put through it?Its gotta be able to come off there right?
Reply:Wouldn't it just be easier to modify the jib on the bench, than to work "monkeyman" on the boom?Why not start with a piece of heavy wall round, and attach the sheave mount to it?
Reply:Originally Posted by denrepWouldn't it just be easier to modify the jib on the bench, than to work "monkeyman" on the boom?Why not start with a piece of heavy wall round, and attach the sheave mount to it?
Reply:Sorry - Okay, now I see z parblem; rust stains fooled me..Back to posts 3 and 4, tomorrow we look for large square tube.Pin location must stay were it is on the square tube shoulder, to keep insulation integrity.
Reply:Square peg and round hole = no fit.The replacement mast is all fiberglass (multiple sections, at least two from the pics), and the sheave/pulley mount at the tippity-top is a steel 'peg' that slips into the mast top and is held there with the cross-pin, and the top mast section is also extended out to the desired length and also held there with a cross-pin as well?The replacement mast is the right 'size' (length -AND- cross-sectional thickness/strength) for the unit, just it's square shaped instead of round?It's not a case of the masts are a certain shape for one size range of extension and then for another size range they are a different shape?  Example, booms up to 20 ft are round and 30-50 ft are square (I made up the numbers) or vice-versa???In other words, all the pieces are the right (and compatible) rated strength (the mast/boom, the knuckle/goats-head, etc) but just the wrong shape?Based on the sketchy background info, I say don't modify the original knuckle/goat's-head, but make an adapter with round peg to fit into original knuckle and a square socket for the 'new' mast to fit into.  Overkill would be good, use h-e-a-v-y wall thicknesses.And smooth out and repair (or replace) that area on the hinge-plate where it has that cracked "W" shape  and the other crack(s) as well.  The sharp point of the W is just waiting to cut/scrape those electrical/control cables (the red ones in picture #1 and #2 and #3) and the crack(s) look like they are spreading/propagating.For total over-kill, make the adapter out of 4130 billet, mill it out, and harden it to Rc=28.  Or round peg 4130 TIGged to plate 4130 TIGged to square tube socket for the fiberglass mast to fit into, heat-treat after welding (stress relieve after welding/machining, harden and quench to Rc=28).  Extend new square-tube socket up the mast 2x as deep as the old round socket was.  Coat with appropriate rust-preventative (HD-galv, or paint).Or make all-new goat's head.  Because by the time you cut off the old round socket, there won't be much left any way.  About all that would be left would be some of the side plates.  Keep old goat's-head  just in case and as a model for new head.  Two side plates and section of heavy-wall square tube for mast to fit into, optional top-n-bottom plates if needed to tie tube to side plates, clevis-mount ears on the bottom.  Check to make sure old knuckle is plain steel and not hardened material, if hardened then make new out of appropriate 'matching' material.  If in doubt of knuckle strength/design, up-size wall/plate thickness.  If really in doubt, get a PE to design or stamp-off on the design.All hypothethical, because you said you aren't going to do the job.  Rightly so IMO, because there are too many unknowns and gotchas and you would be 'IT'.