A million tons of rock that have lain idle for almost a hundred years after being cut from the heart of Hoosac Mountain to make its famous tunnel are going to be put to work.
Because of an easing of the state’s specifications for road stone, the huge pile on Shaft Road in North Adams has become eligible for use in blacktop and other types of surfacing.
Kenneth D. Conway of Pittsfield, owner of Western Massachusetts Asphalt & Stone Inc., and of the tunnel stone, today started the crushing operations that will transform the blocks of traprock and granite into useable material.
“It should cut the cost of road stone in half in this area,” Mr. Conway said this morning.
He acquired the property some time ago from H.D. Moore, Williamstown contractor, who used some of it for riprap work.
Most of the stone was brought up from the main shaft through a 90-foot vertical shaft during the long and bloody building of the famous tunnel. After 24 years, the expenditure of $15,000,000 and the loss of 195 lives, the tunnel, four and three-quarters miles long, was finally opened in 1875.
The state Department of Public Works specifications for road stone are based on the so-called “Los Angeles rattler” test, in which the material to be tested is put in a perforated “squirrel cage” and revolved at high speed. The extent of abrasion is then measured.
Up to May 23, when the specifications were eased, stone for Massachusetts roads had to meet an index number of 30 in the Los Angeles test. According to Commissioner William F. Callahan, little quarryable rock in this state could meet the specifications, making importation necessary. Many quarries in the state however are able to meet a slightly lower standard and yet fulfill both state and federal requirements. The test minimum was therefore lowered to 25. According to Mr. Conway, the Hoosac Tunnel rock has a test number of 28.
The North Adams Zoning Board of Appeals on Monday night gave the Conway firm permission to erect a stone-crushing plant on the Shaft Road property. The stone is located within an area zoned as residential.