I wasn’t sure what to call it. I started referring to it as a gantry, but that sounded a bit industrial. After some research I found that most people described it as a radar arch or solar arch, so I’ve settled on the latter.
This all started with the decision to move Millie out of a marina onto a mooring. We obviously couldn’t depend on shore power and would need a way of charging batteries, other than the engine. Rather naively I bought a wind generator at Southampton Boatshow last September without really thinking through how it would be mounted. Surely a simple case of a stainless steel pole stuck on the back?
The first quote I got was for £680+vat for a pole, which seemed a bit steep and wasn’t necessarily a good solution. Millie was already booked to spend the winter at Harbour Marine in Southwold. I was talking to John, the owner, and he suggested building an arch to support. It would look cleaner and have the advantage of being able to carry some solar panels as well. The idea grew on me and I agreed to go ahead, despite a much higher price ticket.
Getting the design right wasn’t easy. The shape was important for aesthetic reasons, getting the right sweep aft to look right together with a curve on the top bars. The guys cut into the old pushpit so the arch could be built into it. This avoided too many attachments at deck level and also helped the stiffness of the structure. At this point Millie looked as if she had been attacked by vandals out collecting scrap metal!
The build was delayed for several weeks because of a missing ring roller tool to create a gentle curve in the rails. Their machine was broken and new parts had to be imported from the US. Eventually it all came together and the basic frame was tacked into place while Millie was still in the shed.
Next I had to determine exactly what I wanted to mount on the arch, apart of course from the wind generator. The list was quite extensive:
- Mounting for Silentwind wind generator
- Mounting rail(s) for antennas
- Radar mount. (Raymarine Quantum)
- Mount for solar panels
- Mounting panel central underside for:
- Aft decklight
- Stern nav light
- CCTV camera
- Lifting points for outboard and dinghy
- Cable ducting
- Mount for danbuoy and life sling
At the point the guys from R&P Metalwork took the arch back to their workshop to add most of the fittings. Once Millie had been moved back outside, the arch was fitted and joined up to the original pushpit. The only thing left to fit was the pole for the wind generator. This had to be larger than most of the metal work (48mm od) and needed to carry the substantial weight of the windgen. It also had to be tall enough for the blades of the windgen not to create any risk for anyone on deck – rapidly spinning carbon fibre blades and human flesh is not a good combination.
Finally it was complete, ready for me to install the extensive list of equipment – the only problem now is that it’s the end of May and we want to go sailing! Anyway we’ve put the windgen on and I think it looks great. I’ll work on the rest over the next few weeks and I’ll add some more photos once I can get the boat somewhere I can get a good view.