Hinging my arch

[SKYCHENEY]

My radar arch is off and I'm getting ready to cut it and hinge it. I'd appreciate and ideas(especially photos) of your hinge setup. Thank you.

 

[dottieshusband]

Before buying my boat, I looked at a few that had hinged arches. One had Clivis pins on each end, so it could fold forward or backwards. The hinge was an interlocking finger type much like a residential door type. The boats that had them were Tiwanese built, mid to late 80's models.

 

[SKYCHENEY]

Thank you.


Any others?

 

[Plan B2]

Here is a pic of the hinges on mine. It can be folded in either direction. A local machine shop fabricated from stainless flat bar and tubing. There are two bolts that hold the hinge to the arch on each side and tweo bolts that hold the hinge to the boat. They are 1/2" to 5/8" and counter sunk into the metal bar stock. I'll take additional pics this weekend and post Monday

 

[saltshaker]

Here is a pic of the hinges on mine. It can be folded in either direction. A local machine shop fabricated from stainless flat bar and tubing. There are two bolts that hold the hinge to the arch on each side and tweo bolts that hold the hinge to the boat. They are 1/2" to 5/8" and counter sunk into the metal bar stock. I'll take additional pics this weekend and post Monday
View attachment 16270

That looks like a very nice set up. What did it cost to have the hardware made? Did you do the install or have it done?

 

[Nonchalant1]

Sky,

The hinge plus bolts configuration is how my arch was hinged. The bolts go through the fiberglass of your flybridge and through the base of the arch, with aluminum plates strengthening both. Thereby, the arch is held by both the bolts and the hinges, not just the hinge pins. It takes a little more doing to lower it and access plugs to get at the bolts (as shown in Plan B2's picture), but imagine the forces put on that area when the boat is banging around in heavy seas.

One other consideration is that the arch is rather heavy and you'll need to be able to handle it without letting it crush anything. I had a simple sling and cable pulley system so I could use my dinghy davit cable and winch to hold the arch upright while I put in the bolts, or in any position while I put in the support frame to hold it in the down position. I didn't use the davit cable to actually raise and lower it (although it would), just to hold it in the up position while I installed the 2 bolts on each end. I could do it by myself that way. Otherwise, you need somebody to hold it up while to loosen or tighten the bolts or install the hinge pins. A simple wood brace post might work well too, designed to hold it in the up position when the bolts are removed. For instance, when you are going from Chicago into the Illinois River, you need the arch up for strength due to possible big wave action from Chicago to the Cal Sag entrance, but then you need it down for the river, with no good place to stop and tie up. So Kathy would pilot the boat while I put the arch down by myself after entering the breakwater.

Doug

 

[TopHattandTails]

Sky - I have a hydraulic hing on my arch. When I bought the boat I added a 8" lift to it so I would n't knock the noggin anymore. Here are a few pics of the hydraulic, lift, and finished product (you have to zoom in to see it in the background) in photo #1. The hydraulic pump is in the forward cowling and has a switch on the stbd side panel next to the data marine gauges (which is now redundant depth to the Garmin 5212).

 

[SKYCHENEY]

Brain,
Thanks for the pics. I think I'll have to hinge mine up about 6-8" from where it mounts to the FB in order to clear the railing behind it. It will be kinda like yours.

I have seen hydraulics used before but only internally with a cable or change from inside. Your setup is interesting in that, for me at least, the cylinder would sit behind the seating and wouldn't be visible at all.

So, now for the 20 questions. What did you use for a pump? Where did you get the pump/cylinders? Are the cylinders thru-bolted or just screwed into the deck? Is there some sort of mechanical fastener to keep it in place once its up?

 

[TopHattandTails]

The pump and hydraulics were installed when I took tenure of the boat. I will be at the boat in a few hours and will get some numbers / model for you. The pump sits in the forward cowling (Classic MY), runs braided SS hose to the cylinders. Cylinders are through bolted to the aft salon where the wall separates the main from aft salon. I don't think you would want to simply screw it into the deck - even if you dug out the balsa core and poured epoxy / starboard. I like the through bolt set up on that piece. Once its up or down - your not moving that arch since the hydraulics hold it. The arch weighs - I don't think I could hoist it manually. The bottom plate of the hinge is through bolted through the gunnel, through a plate, and bolted. They are flat head screws that don't interfere with the top plate of the hinge. I also have 6 flush mount screws that bolt the top plate of the hinge to the bottom plate of the hinge to hold them together - so even if the hydraulics failed, its not going anywhere once up (never tried cruising with it down). Before I inserted the aluminum blocks to give it the 8" lift off of the gunnels, the hinges sat flush on the gunnel, the 8" aluminum block was inserted at where the bottom plate hit, through bolted, and then the bottom plate of the hinge now bolts to the top of the alum. block. I used the same connection elbow that wraps the aft corner of the arch (polished chrome that you see) immediately above the painted hinge. I'll get the pump spec's this weekend and post.

 

[TopHattandTails]

Sky - here is a pic of the pump that controls the arch. Sorry - no spec's that I could tell. Looks pretty original and via the gauge of the electrical connections on the right side of pic is 32vDC.

 

[SKYCHENEY]

Thanks Brian. I'm sure if I go this route, I can find a pump and valves. Even 110v would be okay. I have also heard of others that used the stabilizer hydraulics or a Bennett trim tab pump. I guess it all depends on the size of the cylinders as to how much pressure is actually needed.