I am currently doing some research on lighthouses and the one thing that is eluding me is the range of light of all the different kinds of ways that lighthouses illuminated the coastal and sea areas. Help!
Start with wikipedia.
Then, perhaps ask a more specific question?
Lighthouses don't illuminate the surrounding area; they provide a beacon of warning, so that ships know where land masses are located, and thus can avoid them.
Start with wikipedia.
That is where I started.
Then, perhaps ask a more specific question?
How far out is illuminated?
How far out is illuminated?
I'm going to ballpark modern lighthouse illumination at 50+ million candela . But I don't think they reach 100 million.
For comparison, the candela of sunlight in a 1m x 1m square is only about 100,000 candela. But the *entire* sun's output is about a few hundred thousand million million million candelas.
This chart might help.
Meteorological Optical Range Table
Code No. Weather Distance
0 Dense fog Less than 50
1 Thick fog 50 - 200 yards
2 Moderate 200 - 500 yards
3 Light fog 500 - 1000 yards
4 Thin fog .5 - 1.0 nm
5 Haze 1.0 - 2.0 nm
6 Light Haze 2.0 - 5.5 nm
7 Clear 5.5 - 11.0 nm
8 Very Clear 11.0 - 27.0 nm
9 Exceptionally Clear Over 27.0
If you’re asking how much does the lighthouse light up the immediate area, I would say equivalent to torchlight up to 30 feet, half that out to 60.
I am currently doing some research on lighthouses and the one thing that is eluding me is the range of light of all the different kinds of ways that lighthouses illuminated the coastal and sea areas. Help!
I made nautical charts many years ago, so I can tell you that lighthouses are not designed to illuminate the coast or the sea. They are designed as "aids to navigation", or in lay terms they provide a fixed point of light that a pilot can aim a ship at. They have 3 colors, white, red and green, at least the one I charted only came in these colors. White was visible the farthest, to about 3 nautical miles. But this was not the important feature. If there were hazzards, like rocks, the light would not be visible over the rocks. So, you could only see the light over safe area. The different colors were for more complex navigation. For example, white is safe for 2 NM in to 1 NM then it is hazardous. Navigate to a red sector and continue toward shore. Some lighthouses have upwards of 16 sectors.
|
As a retired Coastie (USCoastGuard), what Wise Meerkat stated is spot on. On a related note, you may want to also google USCG Light Ships (Manned stationary vessels with a similar elevated rotating light).
But to better answer your question straight from the the experts, try this link and also feel free to give them a call. It's what they do.
USCG