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Old 11-07-2012, 15:06   #1
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Securing Radar Tower

I finished the install of my Garhauer Radar Tower yesterday and am a little concerned about how much whip there will be in the pole when sailing.

The stanchion bases are secure, but the whole rail system slops around with a lot of play. I'm concerned that once I get out on the water, the top heavy radar pole will tear my whole rail system and outboard off the boat and into the water. How much play is acceptable? I've seen other towers that look rigged the same and I wonder how secure their tower is...

I also have the engine davit to put on but that's even more weight. I'm scared.

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Old 11-07-2012, 17:28   #2
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Re: Securing Radar Tower

Why is your rail system flopping around. Are all the mounting base bolts tight?

However, even if the rails were solidly mounted I would still want a fore/aft and athwart-ships brace on that pole. It is really quite a long pole.
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Old 11-07-2012, 17:50   #3
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Re: Securing Radar Tower

I will check the bases again, but the play seems to be all above the bases. The pole is 8' but sits on top of the deck so it's pretty long. So you are suggesting two supports correct? There is no real way I can think of to mount a third.

There's a lot of weight on those rails. Propane tank, outboard and BBQ and now the radar tower and potentially the outboard davit. Since the rail is a half circle I think it's overloaded.
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Old 11-07-2012, 17:57   #4
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Re: Securing Radar Tower

The single pole radar mounts I have seen have wider diameter material which prevents the pole from flexing too much. Many of them are aluminum and are through-bolted to the deck or transom, not mounted on the stern pulpit or a railing.

The only suggestion I have if you want to keep the same pole it to add stays....like you see on large AM radio towers.

I think though that the first design would be better for your situation.

The radar also does not need to be that tall. A foot or two above your head is good enough. The taller the mount, the more of a moment arm it becomes requiring beefier engineering.
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Old 11-07-2012, 18:06   #5
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Re: Securing Radar Tower

Quote:
Originally Posted by David M View Post
The single pole radar mounts I have seen have wider diameter material which prevents the pole from flexing too much. Many of them are aluminum and are through-bolted to the deck or transom, not mounted on the stern pulpit or a railing.

The only suggestion I have if you want to keep the same pole it to add stays....like you see on large AM radio towers.

I think though that the first design would be better for your situation.

The radar also does not need to be that tall. A foot or two above your head is good enough. The taller the mount, the more of a moment arm it becomes requiring beefier engineering.
The pole is 2.5" which is the large diameter. The base is bolted to the deck with a backing plate, the pole bolted to the base and also secured to the pulpit. It is stainless steel. Some boats mount this pole on the transom outside the rails, then the support is attached to the rail, but because I have a steep reverse transom, I needed to install the pole inside the rail and on top of the deck.

When I ordered the pole, I ordered the stock 8' but the 2.5" instead of 2" diameter because I was concerned about whip. I had no idea what to expect though. It would suck to have to remove it to cut ti down now. Maybe I should. I think I will need supports either way. Maybe I'll try supports first.

It might have been better to mount it on the starboard side since the outboard is heavy and right beside it. I just thought that since I had a davit going on the pole I should keep it beside the outboard bracket. I might take off the motor when I go back to the boat and see if that helps. I can always move the motor to the starboard side. I'll try it tomorrow when back at the boat.
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Old 11-07-2012, 20:27   #6
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Re: Securing Radar Tower

Yes, I was thinking two braces, one down to the port side deck and one across the stern.

Also, many stern rails have diagonal bracing built into them, which make them much stronger. I can't see well enough to tell if yours does or not.

Edit: Apparently when the US navy sailing Acadamy did a study of lifeline collapse they found that it was the stern and bow rails that were giving way, not the lifelines themselves.
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