How do you go about moving a 400-ton lighthouse? Very slowly, according to Joe Jakubik of International Chimney Corporation, the company that hopes to relocate the Gay Head Light in Aquinnah next year.

Mr. Jakubik, manager of International Chimney’s historic preservation division, said broad community support for the project would help the details fall into place. “When you see something like that, you see success,” he said. “The whole project is the better for it, because people cooperate.”

But the details are largely what drew a crowd of about 50 people to a presentation in the old town hall in Aquinnah on Tuesday. Mr. Jakubik was joined by the company’s president, Rick Lohr, who said he was looking forward to relocating the historic lighthouse. “Every one of these is different,” he said. “This one is particularly beautiful.”

International Chimney began about 80 years ago, building industrial smokestacks for steel mills along the Great Lakes. It still specializes in smokestacks, but began branching out to include lighthouses about 13 years ago.

The company relocated the Southeast Light on Block Island, the Cape Hatteras Light in North Carolina, the Sankaty Head Light on Nantucket, and many others along the East Coast.

Its more complex moves include the Newark Liberty International Airport in New Jersey, the Shubert Theatre in Minneapolis. The King of Prussia Inn, built in 1791 in King of Prussia, Pa., is the oldest building the company has relocated. Closer to home, last summer the company moved the Schifter house on Chappaquiddick, a large private home that was threatened by erosion. Compared to its larger projects, the Gay Head Light presents a relatively simple challenge. “The nice thing about a lighthouse is because all the mass is down below, the center of gravity is pretty low,” Mr. Lohr said. “So you’ve got a nice situation to work with.” Lighthouses are also symmetrical, he said, so they are easier to balance during a move.

As with many old lighthouses, the Gay Head Light is threatened by erosion. It stands only 46 feet from the nearest cliff, and the space required to safely move the lighthouse will soon be gone.

Mr. Jakubik said that about 36 feet between the lighthouse and the cliff would be needed for the move. “It doesn’t leave an awful lot toward the edge, but we feel that’s pretty stable,” he said.

The Gay Head Light advisory committee, which is helping to lead the relocation efforts, has chosen a new site about 140 feet inland from the current location. A move of that distance could take anywhere from three to 14 days, Mr. Jakubik said.

Preliminary work on the foundation revealed that the ground level may originally have been several inches lower than it is now. Below ground, the stone foundation includes two layers, both about 24 inches high. Part of the top layer is cut more finely, suggesting that it was once above ground.

The move itself will happen in several stages, which Mr. Jakubic explained to the audience in simplified terms.

The upper portion of the lighthouse will be reinforced with vertical staffs, held in place with cables. The door and lower windows will be reinforced with shoring.

When moving the Sankaty Head Light, engineers discovered that a newer concrete floor had been poured, covering the first two steps of the staircase. If a similar situation is revealed at Gay Head, the stairs will be exposed and the staircase will be reinforced.

Openings will be cut around the base of the lighthouse using high-precision tools that will hopefully not rattle the antique brickwork. A labyrinth of steel beams will be inserted through the holes, with a metal plate on top to keep it level. Using hydraulic jacks under the beams, the body of the lighthouse will be slowly cracked away from the foundation. Mr. Jakubik expected the so-called plane of separation to be about two feet below the current ground level.

He emphasized that because the weight of the lighthouse will be redistributed onto the areas above the beams, reinforcing the structure will be critical for a safe move.

Specially balanced hydraulic jacks will be used to slowly push the lighthouse on steel rollers across a bed of steel beams. The progress will be virtually imperceptible, just a few inches at a time. In the past, International Chimney has placed highway cones along the path so that onlookers could at least see the cones slowly being knocked over.

The company uses plain soap to lubricate the beams. Mr. Jakubik joked that on rainy days it prefers Ivory, since it floats, and for uphill moves it prefers Lever.

Sometimes even an extremely slow-moving object can be disorienting, he said. In Cape Hatteras, the lighthouse was near an intersection, and people began having trouble turning, since they were unconsciously trying to make the lighthouse appear in its usual place in their field of vision. The company put up a “lighthouse crossing” sign.

The new foundation at Aquinnah will be stronger than the original, since it will need to bear an uneven load as the lighthouse is pushed into position. “It’s going to deflect a little, but it won’t break,” Mr. Jakubik said. A separate contractor will prepare the foundation.

Conceptual plans developed by the advisory committee indicate that the original foundation will be preserved as a circular bench to memorialize the spot where the lighthouse has stood since 1859. But Mr. Jakubik anticipated that only pieces of the foundation would be left after the move. “Other lighthouses with shallow foundations, we’ve started to raise them, everything’s come up,” he said. But he also said it was too early to know all of the details.

Once the lighthouse is in place, the new foundation will be built up around the beams. The hydraulics will be relaxed and the beams will be removed.

Mr. Jakubik said International Chimney’s only concern will be the move itself, and that other aspects of the project, including landscaping, will be left to local companies. He hoped to develop a full design by early spring and to complete the move by Memorial Day.

But he pointed out that the move can only happen once the town owns the lighthouse. Len Butler, a member of the advisory committee, hopes to achieve ownership from the federal government by late winter or early spring. “We can do some of the preliminary stuff, but what really is going to be the trigger point is when we receive ownership,” he said.

The town has raised just over half of the $3 million needed to relocate and restore the lighthouse. In addition to several large private donations, all six Island towns have contributed Community Preservation Act funds to the project, and several public fundraisers this summer have raised both money and awareness for the project.

Last week, professional kayaker Dana Gaines circumnavigated the Island in his kayak, beginning and ending in Gay Head in record time. The 52-mile voyage raised about $12,000 for the lighthouse project through the crowd-funding website Indiegogo. The campaign goal is $20,000, and donations can be made online through August 19.

Larry Hohlt, president of the Aquinnah/Gay Head Community Association, said Tuesday that the various public fundraisers together would bring the town about $100,000 closer to its goal. He said the focus now is on larger donations and developing a broader base of support.

“Of every eight projects we would get, one goes to this point,” said Mr. Jakubik. “And you can always tell by the momentum, you can tell by the people involved, the enthusiasm — what happens next is that it moves.”

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