Is it an arch or a tower?

Looks like we have a basic shape in mind for the structure over the stern of the boat, even if we don’t know exactly what to call it. The tasks for this tower are 1. Place the wind vane self steering gear well up in to the airflow behind the mainsail, 2. Mount the radar dome, 3.mount the GPS antenna, 4. Provide the rearmost anchor point for the cockpit shade Bimini, 5. Hold a backup VHF antenna in a pinch. It has to be wide enough for the tiller to swing a proper arc, but can also be a limiter for keeping the rudder from slamming broadside out of control. We also want it to be a sturdy handhold for climbing those steps to/from the stern.

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So this is a cardboard mockup with legs of about four feet tall, raked back for looks but also to center the top platform where it best suits the wind vane. The width has been determined by the (arbitrary) placement of the previously made stairs, and the general idea for this thing has been in mind since first watching the Volvo Ocean Race boats a few years ago, with the little towers on their sterns to mount all the comms gear.

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And no, the real tiller won’t look anything like this ugly grey PVC pipe – that just did the tiller angle measuring role.
One wrinkle in the construction is that this tower will have to be remove able for the road trucking. So I think we’ll build 18-24 inch permanent stubs up from the deck, then sleeve the rest of the legs down over the stubs, with threaded rod inside to bolt the tower in from the aft cabin. Also need to figure out an internal conduit to easily hide all the wires from tower-mounted gear.

If anyone has any warnings, words of advice on stern towers, or info on the minimum suitable height above deck we can run the radar dome, please comment.

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7 thoughts on “Is it an arch or a tower?

  1. Greg;

    Is your rudder going to be swing up, or pull-up cassette? Sorry, I cannot recall. If it is pull-up out of a cassette, the radar archtower can be used for lifting and holding the rudder blade up. My blade probably weighs 25 lbs.

    Also, are you going to have a Sat Phone with external antenna? Sat phone antennas should be mounted well away from the mainsail, and on the opposite side of the archtower from the radar scanner. I struggled with this for over a year, before I hired a professional to fine tune the cable and placement of my sat phone antenna.

    One of the reasons Scanmar would not give me a quote for a self-steering set was that I had too much stuff in the stern area to fit their system. Good that you are integrating things now.

    Rick

    • Rick, GREAT advice as I didn’t know about that radar / sat phone issue. I will put “ears” on each side of the tower to keep those two apart. And add a gantry off the back for the rudder – I had forgotten about that one :)

    • I bought a used Portabote – folded it ends up like a surfboard which can easily be strapped to the side nets. If left open it can ride upside down on a net. Don’t want davits out back because of externally mounted rudder and wind vane gear.

  2. hey Carter! So great to see you in Dville! I’m thinking about the height and shape of your bimini. I know for me, I’ve loved cruising . . . in the shade! ; ) Shade has almost always been welcome and of course water catchment from the bimini is always good. That’s about 2cents worth . . . : )
    Rock on!!

  3. If I were doing this ( which I have thought about )I would make it wider so you could also fit a solar pannel or two.
    Sleves on the outside of the boat with bolts which go into nuts placed on the inside.
    Ihis is for only what its worth, You have been doing a sterling job which I have been followling with great interesy…. Keep having fun.
    All the best.
    Ian Jones .. F82R in OZ

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