Tag: Coast Guard

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Engineer who removed original Fresnel lens returns to Graves

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Engineer Ron Fiore explains to Dave how he devised the system to remove the original Fresnel Lens from Graves.

On the deck of Graves Light for the first time since 1975, engineer Ron Fiore explains to Dave how he devised the system to remove the original Fresnel Lens from Graves.

Well, the best part of this whole lighthouse experience continues to be all the great people we meet.

Today we met Ron Fiore, the structural engineer who devised the method of removing the gigantic First Order Fresnel lens back in 1975.

That lens blasted out a 3.2 million candlepower beam for 70 years straight. The lamp required a full-time crew to operate and maintain, so the Coast Guard had it taken out and replaced with an automated electric beacon.

Ron told us all the details about how he built a custom crane to gently lower the priceless lens – it weighed 2 tons and measured 12 feet tall and 9 feet across – down one story into the watch room.

Then he and the crew removed part of a wall to slide the lens past the sloping tower and drop it 60 feet to the dock, where a Coast Guard boat plucked it onto the deck. 

Legendary New England maritime history author Edward Rowe Snow made an appearance, instructing the crew to wave (as he was filming the feat) but the workers were too busy – and scared – to respond.

The next year Ron and his wife visited the lens again, this time at the Smithsonian!

The Fresnel lens was made in France by Barbier, Benard & Turenne in 1904, and was installed in 1905. After the 1975 removal, the Coast Guard installed an automated electric beacon, powered from land by an underwater cable. That cable broke, so in 2001 the Coast Guard installed the present solar-powered lamp, the Hydrosphere Vega VRB-25, made in the U.K.

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Discovered: Original Fresnel Lens rotation mechanism

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Polishing a century of grime from one of the brackets of the original First Order Fresnel lens rotation mechanism.

Polishing a century of grime from one of the brackets of the original First Order Fresnel lens rotation mechanism.

Ever wonder how the giant First Order Fresnel lens rotated to produce that smooth, sweeping beam lf light?

The good guys at the US Coast Guard revealed the secret by sending us the old engineering drawings of parts of the original mechanism, which are still bolted to the 5th level ceiling.

Since that ceiling is being restored, we figured we’d take the mechanism down and clean it up, which we did this week at home.

Here’s how it worked: Every two hours the Keepers wound a 300-lb weight up a 50-foot tube using a hand crank. The weight was connected by a series of pulleys (pictured) and connected to a big clockwork device, which regulated the speed and drove a gear that spun the two-ton lens.

The system was converted to an electric motor long ago, but happily the Coast Guard left all the old stuff in place, which made it possible for us to tell the story.

 

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Coast Guard stops by on maintenance visit

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USCG Harley

Harley of the US Coast Guard climbs the ladder to do maintenance work on the navigation aids.

The US Coast Guard stopped by Graves Light recently to do a regular maintenance visit.

Even though Graves Light is privately owned, we have a commitment with the Coast Guard to provide regular access to maintain the beacon and fog horn.

Harley and Dave of the US Coast Guard maintain the solar-powered batteries in the Graves Light watch room.

Harley and Dave of the US Coast Guard maintain the solar-powered batteries in the Graves Light watch room.

Coast Guard AToN (Aids to Navigation) crew members Harley and Dave stopped by in their red Mustang outfits to do the maintenance work on the light and fog apparatuses.

(Coast Guard Dave is not to be confused with Light House Dave, who took the pictures.)

They patiently showed us the operation of the various devices and back-up devices used to make the lighthouse operate reliably for mariners.

The first picture shows Harley climbing 20 feet up from the rocks to the dock, with our granite blockhouse, called the Oil House, in the background.

In another picture, Harley and Dave are 80 feet up in the Watch Room, and Dave is topping off the primary batteries with USCG-distilled water. The light and fog apparatuses are solar powered, and the energy is stored in the batteries.

And 100 feet up in the Lantern Room, Dave replaces burnt-out bulbs in the automatic bulb changer.

Dave of the Coast Guard maintains the lantern in the Lamp Room, 100 feet up.

Dave of the Coast Guard maintains the lantern in the Lamp Room, 100 feet up.

Thanks for the tour, Harley and Dave!

We’re glad to serve the Coast Guard any way we can.

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