# Light house, bulb type



## UVLaser (Aug 31, 2004)

What do light houses use?...HID?
Thanks alot /ubbthreads/images/graemlins/happy14.gif /ubbthreads/images/graemlins/thanks.gif


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## cheesehead (Sep 1, 2004)

Gigantic incandescents, with a fresnel lens, at least the ones I've been in. Nothing too fancy.

cheese


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## 4x4Dragon (Sep 1, 2004)

i washed a special on tv recently on of the most famous lighthouses(maybe among the first) built, can't remember the name of it but i believe it was in scotland.

it originally used just a candle and some [email protected]$$! copper(i think) reflectors. it was amazing to see how much light it could produce.


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## paulr (Sep 1, 2004)

It would surprise me if lighthouses didn't use arc lamps.


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## ledebuhr1 (Sep 1, 2004)

lighthouses are a thing of the past, they use old technology, no HID for them. Many lighthouses have been closed because there not needed anymore.


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## eluminator (Sep 1, 2004)

[ QUOTE ]
*4x4Dragon said:*
i washed a special on tv recently on of the most famous lighthouses(maybe among the first) built, can't remember the name of it but i believe it was in scotland.


[/ QUOTE ]

Well there was one built in Alexandria in 290 BC. Unfortunately it was destroyed by earthquakes 1600 years later. Shoddy workmanship, I suppose.
Lighthouse of Alexandria


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## Chris M. (Sep 1, 2004)

<font color="800080">_Gigantic incandescents..._</font>

Like:












...although these days they are probably a more ordinary tubular shape, mogul bipost kind of idea. That one is pretty old. Incidentally for a sense of scale, that bulb has a mogul size base. Its packing crate was 3 feet tall! And no, I don`t have one quite that big, though I wish I did. The picture came from an Ebay auction I wasn`t so lucky with.....

/ubbthreads/images/graemlins/ooo.gif


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## jayflash (Sep 1, 2004)

The one up the coast form me uses two incandescent lamps.


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## NewBie (Sep 2, 2004)

Many lenses stand about 8 ft tall, the fresnel lens was a huge advancement over the previous lossy parabolic reflectors. Now they use a small reflector in combination with the large lens.

http://www.molalla.net/~leeper/lens.jpg

Just a little six inch tall, 1000W bulb (not HID):





In the Pacific Northwest coastal areas where fog is common, lighthouses are extremely essential, and we have plenty of them, including new recently commissioned lighthouse boats to replace the aging fleet.

The fresnel lens was a landmark of huge porportions that greatly reduced the lightsource requirement, and extended the range of the lighthouse significantly over reflector only based designs. When made properly, they do an outstanding job at controlling and directing the beam to exactly where you want the light to go.


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## iddibhai (Sep 2, 2004)

1kW or 100W jar?


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## PeLu (Sep 3, 2004)

Apparently 1kw.
The little I know about lighthouses is that the most recent ones use incandescents. 
The Arc lights I know are not good for a long time use. 
Actually there is no need for more powerful bulbs as you cannot see them much further anyway. In sea maps you have stated about how far you can see them. This does not regard to their brightness as to their height. 
As they also have a distinctive blinking pattern, the bulbs have to survive the switching, too. AFAIK, the incandescents are not even driven very hard.

And they are still needed. Maybe not so much for the professional skippers, as for people with smaller boats on vacation. 
But I may ask a guy who had been for 15 years in a lighthouse in Canada.... (and merried a co worker now).


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## Quazar (Sep 3, 2004)

I have visited a few lighthouses. The lamps are on constantly, not switched. The "blinking" is achieved by the lens assembly rotating around the lamp. At one I saw, the lens assembly weighed 8 tons. It floated on a bed of mercury (sealed thankfully). You could rotate it by pushing with your finger. The lens array was a huge fresnel lens, it was made up from individual glass elements that looked like clear "toblerone" boxes. There were about 2-300 elements per lens unit and 3 lenses in total. They were cleaned daily using a feather duster as it fitted between all the gaps and didnt dislodge any of the elements.


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## cheesehead (Sep 4, 2004)

Actually, the arcs would survive blinking better than incandescents. But, again, it's just the rotating fresnel that gives the impression of blinking. Actually, very cool to see in person, and very very large. As far as the use of lighthouses for navigation, good grief, who the hell relies on lighthouses when you have GPS??? Lighthouses are for decoration.

cheese


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## jayflash (Sep 6, 2004)

Those "decorations" aren't completely useless, yet. Not everybody has GPS units and lighthouses can be used to confirm one's location in the event of failure. 

I suspect the government will attempt to balance the budget by cutting on the margins, like light houses. They tried to close the only coast guard station protecting 150 miles of Lake Michigan shoreline, about 15 years ago. Public protest resulted in that station getting rebuilt and another, larger, boat and staff were added. /ubbthreads/images/graemlins/smile.gif

FYI, Door County, in NE Wisconsin, has more lighthouses than any other US county.


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## NewBie (Sep 6, 2004)

For those that didn't bother to visit the link for the lighthouse lens, here it is in all it's glory (several people can fit comfortably inside of it):








Cheese, don't you know that it is common to not be able to pick up GPS during a bad storm????


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## cheesehead (Sep 8, 2004)

Jarhead, 

Yes, /ubbthreads/images/graemlins/thinking.gif I thought about the problem with GPS during a bad storm, but I figured a lighthouse wouldn't be that much more useful either. Eh, what do I know, I didn't know about Jayflash's note about Door County having the most lighthouses and I don't take out my little 18 foot aluminum in anything other than clear weather. Lake Michigan is as dangerous, if not more, than an ocean, the waves are closer together than in the ocean and it has no true bays to hide in. Plenty of shipwrecks. 

cheese

ps, /ubbthreads/images/graemlins/kewlpics.gif of the lighthouse fresnel, we have one in our neighborhood, very impressive. Although, they use it as a display and the one in use is just a very small unit.


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