Restoring the crumbling Bunker Hill monument takes more than granite. (Click her for a slideshow.)
By David Abel | Globe Staff | 6/11/2006
At 200 feet above the city, with briny winds howling off the harbor, Russ Burtt crawls out a small window and plops on a thin plank of plywood -- outside the granite pyramid atop the Bunker Hill Monument.
It's how the specially trained mason now starts a typical day at work.
"It's not bad, so long as you can stand the heights," says Burtt, 43, who ambles around the "crow's nest," a flimsy looking array of steel cables, brackets, and wood, sans any sign of vertigo.
The sunburned restoration specialist leads a four-man crew that's part of a $3.7 million project to renovate the 163-year-old obelisk and surrounding area. The job, which began last month and is scheduled to end next year, includes new lighting, improved wheelchair ramps, and a new museum in the old city library across the street. The monument could reopen as soon as September.
Some of the work is routine, but Burtt's sky-high tasks require special skills --beyond stomaching long views to the ground -- and immediate attention. For the first time in 25 years, the crew is "repointing" the monument, replacing much of the mortar that helps keep its massive granite blocks in place.
"We need to do this now because we've found moisture [in the mortar and granite] that has led to cracks that can stress the structure to failure," says Doug Ford, the project's quality control manager. "It's inconvenient to do it now, but summer's the best time to grout the masonry."
Burtt's men have already found 20 pieces of loose granite -- some the size of bricks -- that were in danger of falling. There are likely more, but the National Park Service only has enough money to repoint the north and east sides, which face prevailing winds and are more weathered than the other sides.
The lack of cash is an old story at the monument. A series of financial shortfalls delayed the monument's completion until 1843 -- 18 years after construction began. (In total, it took $156,218.14 to build the monument, according to the National Park Service, nearly all from private donations, save $7,000 from the Commonwealth.)
Burtt has recommended that the park service figure out a way to repair all four sides now. To put off repairing any of the sides, he says, would be significantly more expensive -- and potentially dangerous.
"There's definitely the possibility that some pieces could fall from the other sides," Burtt says.
From what he can see of the south and west walls -- the ones he's not working on -- they appear to have a similar number of loose pieces of granite, which are between roughly 2 by 2 inches and 4 by 4 inches. "I'd say there's surely some liability there. We're aware of it, so I think it should be addressed."
National Park Service officials overseeing the construction say they'll review any findings that could endanger the 170,000 or so people each year who visit the monument, the nation's first major memorial to commemorate the Revolutionary War. (The Washington Monument, more than 300 feet taller, wasn't completed until 1885.)
"We don't want to leave the monument in an unsafe condition," says Ruth Raphael, a planner at the National Park Service, which maintains the monument. "If it's a safety issue, we'll have to look at what's involved. But we need to know what we're talking about price wise."
According to the National Park Service, the total cost of the monument repair work is $314,300, which includes: $60,000 to build scaffolding atop the monument; $155,000 to repoint the exterior; $33,000 to repair exterior masonry; $66,300 for all other work to rehabilitate the monument.
One reason it's cheaper to do the repairs now, says Burtt -- whose Connecticut-based Joseph Gnazzo Co. would profit from the additional work -- is the crow's nest, a treehouse-like contraption that somehow supports 30 tons and can withstand winds up to about 50 knots. His crew's work depends on its intricately designed scaffolding, which they would have to rebuild to renovate the rest of the monument in the future.
To assemble such a sturdy platform atop the 221-foot-high obelisk -- a task akin to balancing a large object on the head of a pin -- took a week's worth of brawn and smarts. It also had to be done delicately enough to avoid scarring the monument's smooth stones.
The careful labor started last month when Burtt and his men climbed the monument's spiraling 294 steps, hauling heavy steel cables and other equipment to the observation deck.
There, they removed the monument's old, weathered glass windows and dropped four long ropes to the ground, where one of the men tied the ropes together in square knots, linking the windows.
Completing the crow's nest was like a ballet in work boots and hardhats: The men pulled up the ropes, tied them to a five-eighths-inch-thick steel cable, and threaded it around the 15 square feet at the top of the monument, until it reached all the way around. They set corner brackets on three sides of the monument and, using turnbuckles and fist grips, tightened the cable -- the scaffolding's spine -- until it was taut, reaching 130 pounds per foot of pressure.
The next step required poles to position large, load-bearing brackets, which they secured to the cable and attached, through additional 200-foot cables, to a 600-pound "electric swing."
With the mobile scaffolding, the men brought up more cables, two dozen brackets, a mesh fence, and 20 planks of OSHA-approved plywood, all of which they hammered and stitched together to create two well-ventilated floors, connected by a ladder.
"It's a step-by-step process," Burtt says. "You start smaller and get bigger."
With the scaffolding complete, the men got to work, using diamond-blade saws to remove as much of the old mortar as possible from the monument's two sides.
Moving up and down on the electric swing, the men are now using tools called trowels and hawks to fill the joints with mortar, made from a special solution of lime and sand that Burtt says should last 100 years.
The rest of the work involves pressure washing both sides of the monument, to remove several decades-worth of carbon buildup, and repairing the loose granite with what they call dutchmen. The men cut the replacement stones to fit exactly where they removed the loose granite. Then they attach them with stainless steel pins and seal them with epoxy.
"The goal is to preserve the historic look," says Burtt, whose crew recently completed similar work on the Bennington Monument, a 306-foot obelisk in Vermont. "We don't want it to look shiny or new."
Stepping off the electric swing, which supports three men and takes about 10 minutes to reach the top, James Lemanski is covered in dust, his safety harness and hard hat barely visible in a cloud of fine soot raining down.
Carrying a 5-gallon bucket of mortar, the 27-year-old mason says he's proud to be part of the team restoring the towering memorial to the bloody battle there on June 17, 1775.
As for the heights?
"You get used to it," he says.
David Abel can be reached at firstname.lastname@example.org. Follow him on Twitter @davabel.
THE STARTING POINT
Construction on the obelisk began in 1825, but work lurched along as funds were depleted, then cobbled together. To get the job done, the Bunker Hill Association in 1838 began selling off 10 acres of the battlefield as house lots, eventually hanging onto only the summit of Breed's Hill for use as monument grounds. Josepha Hale, editor of Ladies' Magazine, banded together with other women to hold a sale of crafts and baked goods, racking up $30,000 over a two-week run that fi lled the rotunda of Quincy Market. Now, 168 years later, Bunker Hill is in need of a monumental rehab.
To mix replacement mortar, construction will use: 8,000 lbs. hydrated lime, 14,000 lbs. sand, and 1,600 lbs. water.
Total weight of new mortar is 12 tons, a volume of 3,000 gallons.
Total linear footage of horizontal and vertical joints on monument is 11,500, or 2.3 miles, of which 1.2 miles will be replaced.
Tradesmen and inspectors will climb up and down the 221-foot-tall monument twice per day for four months, totalling 120 miles.
Energy required to lift mortar up monument stairs over project life could exceed a billion foot-pounds.
SOURCE: National Park Service