ICC and EHM Save Gay Head Lighthouse from Crumbling Cliffs
Afive-story lighthouse on the island of Martha’s Vineyard was recently moved back from the edge of a disintegrating cliff, saving the historic structure from almost certain destruction.
General contractor International Chimney Corporation (ICC) and moving contractor Expert House Movers (EHM), teamed up to roll the 400-ton structure over a temporary “railroad” of steel beams to a newly constructed foundation pad about 135 feet inland. Located in the town of Aquinnah on the west side of the Massachusetts island, the 160-year-old Gay Head Lighthouse was perched about 45 feet from the edge of an eroding cliff, and was described by soils experts as being destined to topple into the Atlantic Ocean in about two years.
The ICC/EHM team executed the move in a carefully engineered, highly coordinated operation that took less than three days, although preparations had taken several weeks. It was a well-orchestrated move, with seasoned employees of both companies having worked together on many similar large-scale moves, according to Tyler Finkle, ICC Project Manager. Established more than 80 years ago in Williamsville, New York, ICC specializes in the design, construction and repair of tall masonry and steel structures, while EHM, founded in 1954 by John Matyiko Sr., in Virginia Beach, Virginia, is a four-generation company that has specialized in moving hundreds of structures of all sizes, including all of the masonry lighthouses ever relocated in the U.S. Jerry Matyiko, EHM President, supervised the move.
The actual move of the Gay Head Lighthouse took place on Thursday, Friday and Saturday, May 28, 29 and 30, 2015, but preparations had been underway since April. As part of this, the building had to be braced thoroughly inside and out.
Bracing for the Move
A 50-foot-tall conical-shaped brick masonry structure, the lighthouse tapers from about 20 feet in diameter at the bottom of a 4-foot-deep granite plinth foundation, to approximately 12 feet in diameter at the roof eave.
Inside the lighthouse a 12-inch diameter cast-iron pipe, which bears on a 2-foot thick granite block foundation, serves as a central support column for an iron spiral staircase that rises nearly 30 feet through three floors. The fourth floor consists of a “watch room” while the fifth level houses a sensitive DCB-224 lighthouse lens. For durability, the original lighthouse builder fabricated steel pie-shaped plates to form the circular floors of the staircase landings.
In order to protect the brick façade of the watch room, workers wrapped the entire fourth level in a layer of 1/4-inch plywood with vertical 2x4 wood staves 2 feet on center held in place by horizontal tensioned 3/8-inch diameter cables.
Later, when excavation exposed the structure’s foundation plinth, crews wrapped it with a “corset” of vertical 4x4 wood staves 3 feet on center held in place by horizontal tensioned 5/8-inch diameter cables.
Meticulous, labor-intensive work was needed to brace anything that might shake during the move. This included the lighthouse lens, which required non-invasive bracing to be installed. And to support the iron spiral staircase, the contractor connected tensioned cables from three points on the staircase to existing anchorage.
Since the central support post itself would no longer be supported by the granite foundation block during the move, it also had to be braced. To this end, workers infilled the lighthouse door and opposing window openings with solid masonry to support two 15-foot-long W10x22 beams that were inserted through the openings.
Next, they placed a riser clamp made of 1/2-inch steel on the central post, positioned the clamp to bear on the two beams, and tightened this friction fitting with 1-inch-diameter high-strength steel bolts. In addition, two smaller steel posts to help support the overhead landing were clamped to the beams. Other interior work included excavating by hand down to the elevation of the central post’s granite foundation block.
Lifting 400-Plus Tons
Moving the braced structure required a lifting and travelling framework, a temporary road, and a means of propulsion.
The lifting and travelling framework, essentially a steel crib measuring overall about 33 feet by 40 feet, consisted of four layers of steel beams, with each layer placed on top of, and perpendicular to, the preceding one. The top layer comprised of 11 W8x48 galvanized needle beams, shimmed up to the lighthouse foundation. Beneath these were the cross steel consisting of two sets of two W14x145 beams near the center and a W14x233 outlier on each side. Next were the two sets of two W24x94 main beams, and finally, a bottom layer of W10x75 transfer beams.
Putting together this outsized framework was an engineering and construction feat in itself.
Work began with the insertion of needle beams beneath the lighthouse foundation, and the excavation of two small tunnels beneath the structure. The tunnels were dug by a skid-steer tractor equipped with a jury-rigged long scoop – a piece of equipment referred to by workers as the Snout. At the tunnel entrances oak cribs were built to support heavy-duty hydraulic jacks. Next, center cross steel consisting of the two sets of two W14x145 beams were placed in the tunnels over the jacks. This procedure was repeated for the two W14x233 outlier cross steel beams. Once the cross steel was in place the needle beams were clamped to the cross steel then the jacks were activated, lifting the lighthouse free from the ground. Beneath the raised structure the contractor assembled the main beams and the roll beams, then lowered the structure on the main beams.
Traveling On The ‘Railroad’
Welded to the bottom of the 33-foot-long main beams at 4-foot 6-inch intervals were eight 50-ton hydraulic jacks. In operation, the jack pistons pressed downward on heavy-duty steel rollers that rode on the temporary railroad.
The railroad for this travelling framework was a set of hardened surface W14x145 roll beams spaced 26 feet apart on top of continuous timber cribbing.
EHM controlled all jacks used for the move with a unified hydraulic jacking system. This system allowed each jack to receive an equal volume of oil, no matter the weight or pressure, to raise the structure and keep it level throughout the move.
Propulsion for the traveling framework was provided by two hydraulic push jacks, one on each rail beam. Push jacks were anchored to each rail by clamps locked in place by bolts. The jacks’ pistons extended slowly against the ends of the main beams, pushing the entire framework forward. A crew of two workers attended the push jacks. Every five feet or so, they quickly unbolted the anchor clamps and re-anchored the jacks at the next forward position. And so the sequence continued until the new foundation pad was reached, about 135 feet from the starting point.
On Saturday morning, May 30th, the lighthouse arrived at its new foundation, reportedly greeted by a Dixieland band and hundreds of spectators. The lighthouse is said to be safe for another 150 years. Work continues on the new foundation and final restoration of the lighthouse, which is expected to be operating once more by mid-summer 2015. This is important, because this is not only a historical structure, it is a working lighthouse that provides navigation aid to mariners along the rocky coast.