Backstay mounted radar

[willroberts]

We are considering a backstay mount for a small (JRC1000/1500 type) radar. to be added as part of a refit. Has anyone any experience with both problems and advantages. We have a variable tension single backstay and good clearance between the backstay and the main above the boom hieght.

 

[BAtoo]

I suspect it will oscillate far too much & you wont get a reliable reading; never seen one there before which suggests its not a good idea...
Mounted on mast or pole at the stern seems favourite.

 

[Dyflin]

Funny you should mention this, saw a boat just this morning with this exact set up. No idea what make & model she was only that she is American built, relatively new, called Tara and lying at the Royal Irish YC in Dun Laoghaire (she's a big enough boat, probably 40-50ft). I know this isn't much help but goes to show it can be done.

 

[pvb]

If a backstay mount is to work successfully, it needs to be very well engineered, and will therefore cost quite a lot. I looked at some backstay systems about a year ago, but chose a Scanstrut pole in the end. Take a look at the Waltz and Questus websites for more info.

 

[kengill]

Just a thought but I would sugest you consider how you will access it at sea if something goes wrngo.

1 You have virtually no way of stabilising yourself hanging half way up the backstay. Personally I prefer the mast mounted route up by the spreaders so you can sit on one and conveniently brace yourself
2 you have no effective way of stabilising the radar against a torsional oscillation with a single backstay unless you place a fin on the assembly to damp such activities.

3 you run the risk of a flailing reef line or topping lift bashing the hell out of it or snagging as you go about and straining the mounting

4 you would have to have an additional safety line to the unit from higher up the backstay in case the mounting failed to prevent it landing on the head of the helmsman.
Still it could be fun

Fair winds

 

[Blue Fox]

I have seen a system where the backstay is split about 5m above deck, and the radar is mounted between the two lower stays. Looked sturdy enough, and it was a leveling mount.

 

[malcp]

Well, we do have a backstay mounted Radar; and very good it is too. It's a Questus one which I sourced directly from the US. Our backstay tension is also adjustable. The latter point does not adversely impact the mount.

The gimbal is oil damped (which makes it expensive) but this improves performance when heeled. It is also very robust, as the swivel is an alloy casting. It is however, not particularly light.

The point about snagging reefing pennants is a valid one. With the Questus mount it is possible to configure it so that the radar is actually aft of the back stay. If your boat has a roller reefed main then mounting the radar forward of the backstay may be ok, and looks better (check boom clearance).

To maintain the radar at sea it only requires the extraction of 1 allen headed bolt to remove the radar mounting platform from the gimballed unit, and although in a seaway I wouldn't do this out of choice it is not as bad as servicing the radar whilst it is up there. The pole height is about 8 feet from the deck mount, which is not so far up.

I have no hesitation in recommending the Questus gimballed mount. It does have advantages of ease of radar removal if you want the mast down; it helps the problem when heeled of the radar beam on either side pointing up at the sky and the sea; it is also easy to install and involves the minimum of hole drilling, and certainly none in the mast. If you look at what Halberg Rassy do, they have a neat arrangement for attaching the bottom of the pole to the backstay chain plates. I use this method, and it's fine.

The main drawback, as I see it, is cost. Mine was roughly £1000 including freight, import duty etc, but that was when we had about $1.8 to the £1.

I have no links with Questus, other than as a satisfied customer.

 

[willroberts]

Thanks for your answers. We have reefing lines and so will be considering rear mounting where the radar is behind the backstay. The idear of sticking a £899 radar on a £1000 bracket is a bit hard to swollow. I am hopping for more informed opinions like yours, refit is in April.

 

[npf1]

Seems like an easy thing to get a stainless fabricator to make if you can source the damping mechansim. mmm ... where else are rotary dampers used? Anyone any ideas?