Thursday, 28 April 2016

Navigation Lights

During 2013 I fitted navigation lights to Tra Bhui. These consisted of a simple 12 volt tri colour masthead light controlled from a switch in the cockpit. This system was simple and worked OK but suffered from frequent bulb failures which were probably due to the raising and lowering of the mast between rallies.

While the tri colour gave us navigation lights, we had no anchor light, something that I wanted to add in the future

At the end of the 2014 season I altered Tra Bhui’s mast by incorporating a tabernacle to ease raising and lowering it. The tabernacle also meant that masthead wiring could run without a break from the mast head to the instruments and switches in the cockpit i.e. there would no longer be a need to disconnect al the wires from the foot of the mast when I took it down or put it up and therefor the connecting plugs and sockets (a weak part of any electrical system)would no longer be required.

As part of the winters maintenance works I added masthead wind instrumentation and decided that this would be an opportune time to upgrade our masthead lighting.

Given the reliability issues with a fragile 12 volt bulb, wanting to add an anchor light and wanting to minimise the draw down on Tra Bhui’s single battery (Tra Bhui is not a yacht and as such does not have a battery bank) I was attracted to LED lights. After looking at available products I chose NASA’s Supernova Combi Tricolour Light and Anchor Light.

While this was not the cheapest combination light it was the one that suited my requirements best and it was still affordable.

“The Supernova lights use high efficiency LEDs ensuring long life and low power consumption. A tough polycarbonate shell protects Supernova from the elements while a Gore-Tex membrane vent ensures equalization of pressure on the seals”.
The wiring required for the light was really simple as a two wire connection powers the Combi light. Connecting the red wire to positive and the black wire to negative will illuminate the tricolour light. Reversing the connections will illuminate the anchor light. Needing only the existing single two core cable reduced the need for many additional cables within the mast.

Light mounted on masthead

Technical Specifications
Supply voltage - 10 to 20 volts (For full brightness)
Supply current - 200 mA @ 12 volts (Typically 90% less than equivalent incandescent lamp)s
Night time visibility - 2 nautical miles minimum
(25 degrees above and below the centerline)
Waterproofness - IP67 (Submersion)

Dimensions - 91 mm diameter x 133 mm Height (including mounting)

Configuration - Anchor light version - 360 degrees white, tri-colour version - 112.5 degrees red, 112.5 degrees green, 135 degrees white.