In my case it will eventually support antennas, radar, solar panels, the mainsheet traveller, safety gear, stern light, a small jib boom, an outboard motor, fishing rod holder and hand hold for several occasions. And for others it may work for a davit, as well.
I ordered the arch as I was starting the hull/deck joint. I needed it before I could complete the caprail because the out-coves needed to be built for it to set on. I'm not going to give credit to the guy who built it because he didn't want to build it the way I wanted it, a reverse arch, and some of the work wasn't done as I asked and wasn't found until it was already mounted.
A lot of measurements were taken for mounting and positioning.
After it was built and set up on the boat it ended up being 6" farther back then where planned, which turned out better as far as I was concerned.
I had to straddle the backstay and cut a section out of the center antenna mount.
Here it's up on caprail remnants to get the proper position. The X's are where it was originally supposed to go.
Moving it back caused a mismatch between the pads and deck, which I'll deal with later.
Getting it in position to drill holes.
Made some shims to go under pads for the arch bases to sit flat.
Checking the shims and transferring the holes.
The shims epoxied on and faired in with filler and FG/epoxied over.
Painted and mounted...........
The builder supplied a jib for hanging over the stbd side for lifting an OB or whatever. I plan to build a roller car that will ride along the tube.
I made a hinge for it so it could be swung forward or back but the builder put the support in the wrong place on the arch. So I'll have to build an adaptor to support the jib end on it's center line.
Then came the mounting of the traveller track. Drilling SS by hand, it would have been impossible to get the holes lined up. As it was it took all day even with the mag drill. It was nice to have the boom to hold the mag drill while moving it around and to get it on/off the boat.