The Hippo


Nov 13, 2019








Photo by Liz Van Steenburgh.

Just scratching the surface
N.H.’s granite industry thriving

By Ryan Lessard

A lot has changed with the granite quarrying industry in the state named after its abundant sturdy mineral. There have been highs and lows, but with recent advances in mining technology, New Hampshire’s quarrying industry may be on the rise again. In fact, Swenson Granite Works, which mines from its quarry on Rattlesnake Hill in Concord, said this year has been the best year the company has ever had — and it’s been quarrying in New England since 1883.

Cutting it
About 10 years ago, Swenson Granite Works invested in diamond wire saws to cut out chunks of granite from Rattlesnake Hill. The long thin saw blades look, from a distance, like wire wrapped around a block of stone and attached to a machine that keeps the wire spinning and tightening. At first, the company wasn’t sure if the investment was going to pay off, or if the upkeep of the machine would prove too costly.
“It’s really just developed in the last five years as the wires have gotten cheaper,” Kurt Swenson, the chairman of the board at Swenson Granite, said. “We’re wire-sawing in all of our quarries now.”
He says it’s become a far more efficient way to mine granite. It requires fewer employees, it’s safer, and it’s less noisy. But most importantly, it allows them to produce more granite for less. The thinner wire blade means an extra inch and a half of stone with every cut, and the smooth-cut sides are more valuable than the jagged sides that come from splitting granite.
“We’ve had a terrific year, frankly. It’s the best year we’ve ever had,” Swenson said.
Swenson says sales and profits are up but would not say by how much.
Where it comes from and where it goes
Swenson Granite’s executive vice president, Scott Herrick, says most of the granite that’s cut from Rattlesnake Hill is used for road curbing. New Hampshire and Maine are the primary market, but they sell the road curbs in all New England states. Curb setters working in construction crews and general contractors purchase the curbs for their projects. They are used mostly for state and municipal roads.
Sales are up in the retail operation as well, according to Swenson. In the past 15 years, Swenson has gone from having a single stoneyard in Concord to seven locations throughout the state.
Swenson Granite also owns Rock of Ages, which has quarries throughout the Northeast. In fact, about 90 percent of the landscaping and hardscaping products that Swenson retails at its stoneyard locations come from Vermont. The company’s largest buyers of 10-feet-by-5-feet blocks of granite are in China. The blocks are used in the construction of high-end buildings in China and in other countries where Chinese firms have contracts to build. 
There are two other quarries still considered active in New Hampshire, besides Rattlesnake Hill. They are located in Mason and Milford and are both owned by Rhode Island-based Granites of America. The company says those quarries are only mined on an as-needed basis.
“We are the only quarry in New Hampshire, quarrying full time for dimensional, deep-hole quarrying for cut-stone products,” Herrick said.
Granites of America focuses on hardscape products and also some building material. Using granite for building is considered something of a luxury since the advent of concrete.
Meanwhile, the 180-year-old quarry in Concord is still going strong. Swenson produces hundreds of thousands of cubic feet of usable stone each year in New Hampshire.
The heyday
In the mid-1830s, a local printer and bookseller named Luther Roby purchased part of Rattlesnake Hill and turned it into the first true quarry in Concord. Donna-Belle Garvin at the New Hampshire Historical Society reports in an article she wrote on the subject that Rattlesnake Hill later came to be known as “the gold mine of Concord.” 
The first use of Roby’s granite was in the building of Concord’s first train stations. The trains were later used to transport the stone over long distances.
By about 1875, the industry was employing about 500 men while at least 11 other quarries had opened. 
Herrick says even though the quarries were more crowded back then, they produced a lot less.
“In those days, without the aid of machinery and hydraulics and electricity … deep-hole quarrying was not what was done. They extracted the stone off the top and once the beds of stones got thicker, they generally abandoned the quarry because it couldn’t be handled by oxen, horse, mule or manpower,” Herrick said.
Competition was fierce. Largely in response to Roby’s success selling granite to Massachusetts builders, businessmen from Massachusetts bought up most of the quarries in New Hampshire, including Roby’s. Rattlesnake Hill was honeycombed with several different quarries.
The granite was used for major buildings, bridges and dams and the period following the Civil War became characterized by monument building as well. Perhaps the most notable project that used Concord granite was the construction of the Library of Congress.
But by 1920 only a quarter of the quarriers active in the late 19th century were still in business because steel and concrete began to replace granite as a building material.
Swenson says other granite businesses closed during the Great Depression and World War II and after increased international imports in the 1970s.
While economies boom, bust and evolve, New Hampshire’s granite remains the same and will be abundant for thousands of years, Herrick said.
“Certainly, for centuries we’ve really done nothing but scratch the surface,” Herrick said. “We’ll be on Rattlesnake Hill for as long as the business exists.”  

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