Mechanical construction principles
The components we use are the classic 3 mm LEDs, the most proven and most efficient type.
These LEDs are made to Lopolight specifications with regards to intensity and colour, each LED is
graded and tested at the factory, one of the important differences from a standard LED is that the
Lopolight LED is encapsulated in a silicon-epoxy package, this ensures a much longer lifetime.
Each LED is then inserted in to a specially made acrylic lens that ensures the light is guided in the
right direction; acrylic (PMMA) is the only 100% UV-stable transparent plastic in existence.
The lens sits inside seawater resistant anodised aluminium housing.
The housings are CNC machined to exact dimensions.
Inside this housing we hide the electronics – more on this later.
The whole unit is then potted out with epoxy, leaving absolutely no air inside the light. This has enabled
several submarines to be satisfied with standard Lopolight lights. Actually a Lopolight can stand being
submerged to 350 meters!
The above construction process also ensures that a Lopolight is absolutely vibration proof, there
are no moving parts and the LEDs are in themselves fully vibration proofed. Lopolight has been
tested to withstand acceleration forces up to 50G.
During the production process the lights are thoroughly tested in 6 different stages.
Stage 1: Testing of individual LEDs after these have been subjected to minus 20°C and plus 60°C
in several cycles.
Stage 2: Testing of individual lens
Stage 3: Testing of complete electronic assembly
Stage 4: 12 hour test for the complete light before potting
Stage 5: 12 hour test for the complete light after potting
Stage 6: Final test; where the light is tested against preset norms at 12, 24 and 32 Volts and if
within 5% of norm a serial number is issued.
So at any given time of day there are several hundred lights testing at the factory – quite a nice lightshow.
Inside every Lopolight there resides an advanced
electronic circuitry that ensures a long lifetime of
the
light.
The electronics performs many tasks, it ensures:
- that the light works in the Voltage range of 10 to 32 Volts
- that spikes are absorbed and the LEDs are protected against “dirty” current
- the light is protected against reverse polarity (ie. faulty installation)
- the light is monitored by a microprocessor that counts and remembers the hours is has been used.
- when the light is getting close to its 50.000 hours rated lifetime it will communicate this by a blackout
period of 2 seconds shortly after being turned on, this will trigger an the Navigation Light Controller
to show an alarm on the bridge.
- when the light is over its 50.000 hour lifetime this black-out period will be 5 seconds, clearly
signalling that it has expired.
- during the very long life of the navigation light the LED will become less bright due to degradation of
the epoxy surrounding the individual LED, even the high quality silicon expoxy we use will degrade.
To compensate for this we adjust the current over time, in the beginning the current each LED sees
is very low and during the 50.000 hours we increase the current 25% to ensure that a Lopolight has
the same high brightness over the full 50000 hours.
Benefits of changing to Lopolight
There are several things to be taken into consideration when evaluating the financial aspects of changing to
LED navigation lights:
Design of the vessel:
With the frequent need for servicing incandescent navigation lights requires access ways and ladders; these
have to be designed, built and used. This has resulted is some large and sometimes unsightly structures for
especially the sidelights and the all-round lights on the mast.
Lopolight can incur significant savings in the design and build phase by negating the need for access to the
sidelights, so access doors and hinged contraptions for swinging the lights in for service can be avoided.
In some cases even the black sidescreens can be avoided (class and flag dependant).
Similarly the N.U.C. and anchor lights can now be placed on smaller mast structures and the need for ladders
are also negated. Lopolight actually in addition to classical 360 degree lights also offers 180 degree lights to
be placed directly on the mast (1 light on each side – giving a full 360 degree visibility) again reducing the
need for arm and platforms for all-round lights.
The savings realised in the design/build phase will often be larger than the higher price tag of the Lopolight
Navigation lights.
The emergency power supply on the vessel has to be dimensioned to run the very basic communications
and the navigation lights. Using Lopolight the size of the emergency power supply in many cases can be
reduced from a complicated genset solution to a small battery solution.
Finally the wires run to the navigation lights can be significantly reduced in size, all the Lopolight navigation
lights consume less than 1A (in 24VDC mode) and in conjunction with our navigation light controller that limits
the current to 0,95A we can use instrumentation size wiring for the nav lights – typically we would recommend
0,5 mm
2 wires replacing the normal 1,5mm2 wires.
Running the vessel:
The attempt of establishing a Total Cost of Ownership is difficult and can only be assessed individually and
of course includes possible savings made in the design/build phase.
Having said that if we take a 5 year perspective and assume that the vessel is at sea 200 nights per year and
that the vessel is above 50 meters in length and runs her navigation lights 24 hours, then we could get the
following savings:
a. Energy: A reduction from 6kWh to 1kWh: (6-1x24x200x5) that is 120.000 kWh saved. And as the price of
energy is both higher and less clean onboard than on grid this is significant.
b. Maintenance: An incandescent light bulb works 500-1000 hours and the vessel has 5 bulbs lit whilst
running: (((24x200x5)/1000)x5) that is the hassle and cost of 120 to 240 bulb changes avoided.
For all superyachts and commercial vessels it is required to
have a system for monitoring the navigation lights.
Until recently there has been no system tailored to the
specific advantages of LED navigation lights.
The Lopolight Monitoring Relay (LMR) is able
to monitor Lopolight Navigation lights very accurately
and will detect whether the light is operational, has a
partial fault or a complete fault – whatever the reason.
The LMR will learn the profile of the navigation light is shall monitor and will follow it through its life, also showing
when the light is getting too old.
The LMR offers both a manual panel connection which has priority and a communication channel for control
from an integrated bridge system via RS485.
(For special Navy applications the LMR also has an optional RS232 communication towards the navigation light).
