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Amelia Island Light

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(North Carolina, South Carolina, Georgia, Florida, Mississippi, Alabama, Louisiana, Texas)

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Postby Grover » Tue Oct 04, 2011 1:40 am


"There are two pips in a beaut, four beauts in a lulu,
Eight lulus in a doozy, and sixteen doozies in a humdinger.

No one knows how many humdingers
there are in a lollapalooza."
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Postby island » Tue Oct 04, 2011 7:05 am


Of interest in the photos included are those of the single story dwellings as compared to the two-story dwellings common for northern light-stations. The large roof area of the southern structures would capture more rainwater to replenish the dwelling water supply, rainwater being the primary water source of many lights in earlier years. On the other hand the two-story dwellings were easier to heat in the winter northern climate.

The tower clockwork with a 40 pound weight --- I wonder when winding the clockwork how many turns of the were required to raise the weight. I also wonder if there was a way to operate the clockwork with a hand crank to rotate the light in the event of a failure of the weight operated part of the clockwork mechanism.
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Postby Fred » Wed Oct 05, 2011 2:03 pm


The only Scottish light I remember the number of turns was with a 90 pound weight requiring 60 turns every 90 minutes.

Some lights you could choose to use a direct drive to raise the weight or a 3 - 1 reduction gear if you were feeling tired?,

I don't think there was a standardised turns per hour run?

I have read where the clockwork drive failed the keepers disengaged the drive and turned the lens by hand,I've never seen one that could be hand cranked?
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Postby island » Wed Oct 05, 2011 7:11 pm


Fred, Thanks for the information.

I would guess that clockwork design would differ in size and driving power depending on the weight and desired rotational speed of the lens or associated the flash apparatus. This would also determine the optimum weight to drive the clockwork. As to winding frequency there would be less distance for the weight to descend in a short tower and would require more frequent winding.

In some instances the weight (s) were suspended from a single cable. In others the weight was suspended from a pulley with cable running down and back. (gun tackle style arrangement). Point Adelaide (AU) had such and with link chain but in the photo it appears it had a counter weight in place of a windup drum.

Image
[url]http://www.lighthouse.net.au/lights/bulletin
/0312/bulletin%20dec%2003.htm#Adelaide[/url]

In the earlier years of Point Reyes Light "the keeper wound the clockwork mechanism, lifting a 170 pound weight, which was attached to the clockwork mechanism by a hemp rope, nine feet off the floor. The earth's gravity would then pull the weight, through a small trap door, to the ground level 17 feet below. The clockwork mechanism was built to provide resistance so that it would take two hours and twenty minutes for the weight to descend 17 feet."
http://www.flickr.com/photos/vmbrasseur/4593333659/
http://www.nps.gov/pore/historyculture/people_maritime_lighthouse.htm
Last edited by island on Fri Oct 28, 2011 9:45 pm, edited 1 time in total.
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Postby Fred » Thu Oct 06, 2011 3:36 am


For an explanation of chain drive try my webpage at :-

http://homepages.manx.net/fredd/m-machinery.html
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Postby island » Thu Oct 06, 2011 7:02 am


This is another photo showing the opposite side of the Port Adelaide clockwork showing the bronze flywheel and disc.

Image

Photo caption text: "The lighthouse lens rotation mechanism that was still operational. It is run by a chain weight system via gears and a spinning disc which lifts with speed (supports blurred in pic) until it comes up to oiled stops which limit and regulate the speed. At some stage during the lighthouse history the mechanism was bypassed for an electric motor probably because the keepers became weary of pulling up the chain weight every 1.5 hours."

:?: Fred. What causes the disc to lift? The smooth "pinion" in contact with the wheel?
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Postby Fred » Thu Oct 06, 2011 9:07 am


Dave
The blurred bit of the picture is probably two weights on arms and a lever mechanism,as speed increases the weights move out and lift the disc,apply the brake and regulate the speed?

Looking at the earlier picture is your smooth "pinion" not a bevel gear?
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Postby Fred » Thu Oct 06, 2011 9:50 am


Looking at the Port Adelaide site :-

http://www.lighthouse.net.au/lights/bul ... m#Adelaide

One picture shows the dog clutch and a seperate wheel to hand rotate the lens,I would think more to position it than actually rotate the lens for a long period?
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Postby island » Thu Oct 06, 2011 10:50 am


Fred,

The gear teeth are much more visible in the first photo. Also, there appears to be a horizontal support arm for the disc shaft missing in that image.

The dog clutch can be seen in both photos at the bottom of the Adelaide page and the hand wheel in the right-hand photo. I had not closely examined those photos. Thank you for pointing this out.

Would like to see the apparatus but Port Adelaide is a fair distance from Maine. However, I understand there are closer three lights in the Bahamas that have operating hand-wound clockwork, and are also kerosene lit. I have a recent email contact with a member of their lighthouse preservation group, a possible source of information about that clockwork.

Somewhere the must be design drawings for this apparatus, Trinity House perhaps.

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Postby Fred » Fri Oct 07, 2011 8:42 am


Plans etc,all of Northern Lighthouse Board plans,documents etc. pre-automation have been transferred to National Archives of Scotland where they are being catologued,hopefully some day they may be on line.
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Postby Fred » Thu Oct 13, 2011 2:42 pm


Just been re-reading "Guiding Lights" by Anthony Lane,all about British lightships,mentioned there was that there was provision for hand cranking to enable repairs to be carried out on the drive.

So far no mention of hand cranking at lighthouses.
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Postby island » Thu Oct 13, 2011 10:00 pm


Hand cranking seems most appropriate when working in limited space at the top of a lightship mast and with the rocking motion of the ship greatly amplified at that elevation above the deck.
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