In a 2018 photo, an overview of the deep 250-foot quarry area at Swenson Granite. It is time-consuming and expensive to move things and people into and out of a 250-foot hole. The difficulty isn’t just in hauling up 20-ton blocks of stone after they have been cut. (Photo by Geoff Forester)
The company that owns the Swenson Granite quarry in Concord says it plans to resume cutting slabs of stone there by next summer and in the meantime will continue processing material into smaller pieces known as aggregate.
Polycor, the world’s largest processor of natural stone, ceased operations at the quarry in July, seemingly ending more than 140 years of continuing work on Rattlesnake Hill off North State Street. In response to queries from the Concord Monitor, a spokesperson recently said the pause was only temporary, done “in order to focus on quarry improvements that are necessary to continue our dimension stone and aggregate quarrying operations at Concord in the long term.”
The company currently expects that by June 2025 it will resume quarrying what is known as dimension stone – large slabs of the granite known as Concord gray, most of which is turned into curbing but also into posts, steps, pavers and other retail products.
Ann-Julie Nadeau, communications manager for Polycor, wrote in an email that, “The improvements being undertaken involve a number of changes to the quarry footprint and are ultimately designed to bring the cost of quarrying dimension stone at Concord to sustainable levels.”
The “deep hole” of the quarry is some 300 feet deep and six acres wide at the surface.
While the quarry remains closed, leftover stone known as “grout” will continue to be processed into aggregate, she wrote.
“The quarry improvements themselves necessitate the blasting and movement of granite, which is also transformed into aggregate,” Nadeau explained. “Given how long the quarry has been operating and the ongoing improvement work, there are significant quantities of grout on the site that can be crushed into granite aggregate.”
Nadeau wrote that this is part of a company-wide shift after Polycor reviewed all the company’s quarries and production facilities.
“This resulted in a number of changes to our operations, including our recently announced transformational investments in advanced manufacturing in Quebec and Indiana and changes to operations in many of our quarries in Canada, the United States and France,” she said.
No changes will be made in Swenson Granite retail operations, she wrote, including those on North State Street. It remains unclear how many jobs will be filled when the quarry reopens.
“The improvements being undertaken involve a number of changes to the quarry footprint and are ultimately designed to bring the cost of quarrying dimension stone at Concord to sustainable levels. … A number of factors could impact employment levels at Concord and at other Polycor sites, including notably customer demand. At this time, it is not possible to estimate future employment levels at the Concord quarry,” Nadeau wrote.
Granite has been gathered since before the Civil War from sites on Rattlesnake Hill – which hasn’t had any rattlesnakes for a very long time – while quarrying in the “deep hole” that is now the main quarry dates back to 1883. By the turn of the 20th century, 44 different operators were quarrying stone in west Concord, according to the city history, after which John Swenson, who came to the U.S. from his native Sweden in the 1880s, bought most and consolidated them into Swenson Granite Works.
The company owned the site, which covers some 200 acres on the hill, through four generations during which the main quarry was extended down some 250 feet and huge pieces of Concord gray granite were sold to build government and office buildings throughout the country, including the First Church of Christ Scientist in Boston, CBS Broadcasting’s “Black Rock” building in New York, and the Library of Congress in Washington, D.C.
Many changes took place during that time, including a disastrous foray into going public after buying Vermont’s iconic Rock of Ages, the creation of a retail operation that later expanded into several states, and the transition to curbstone production that included cutting a new entrance into the north face of the quarry, making it easier to truck out cut granite.
In 2016, the family sold the business to Canadian investment firm TorQuest Partners, which also bought Quebec-based Polycor to manage this and other quarrying sites, including Rock of Ages. Birch Hill Equity Partners of Toronto now owns Polycor and its businesses.
These articles are being shared by partners in the Granite State News Collaborative. For more information, visit collaborativenh.org.
