PEL-6 Sector Light Condenser System
The standard PEL-6 condenser system has been in service for almost 20 years. This uses a 250 Watt halogen lamp with a filament configuration to provide maximum pickup angle with the smallest diameter of optic.
New 600 mm diameter Projection Optic
Prior to this project the narowest beam for a PEL-6 light was 3.5° subtense, giving a range of almost 6 Nm by day. Reducing this subtense to 1.6° allowed the intensity to increase 4.8 times to 3,500,000 candela in the white sector. But this required an optic 600mm diameter. To reduce projector length a doublefolded optical system was deployed, with two Mangin mirrors.
Stainless Steel Tower
To achieve the required resolution the tower was required to be torsionally stiff, with less than 0.01° deflection allowable at the top. The tower was designed using marine-grade Avesta stainless steel to achieve the high stiffness and long life in the marine environment without painting or other maintenance. No security fencing was required because site access is controlled.
Solar Power Supply
There was no option but to use solar power. With only 1 transit per day a significant saving was made by using a radio controlled switch with a 2-hour timeout. The solar power system was installed entirely on the top platform to minimise voltage losses in cables and susceptibility to lightning that would be a problem with long vertical cable runs.
Remote Monitoring and Control
Since a radio link was to be in place, for a small additional cost a complete remote monitoring system could be supplied. This monitors parameters such as the state of battery charge, and number of lamps remaining in the lampchanger. An emergency over-ride switch is provided on the tower in the event of complete radio failure.