What most people know about slate is its use for roofing and blackboards. Some will recall the line from the old song “School Days,” which went, “and you wrote on my slate, ‘I love you, so,’ when we were a couple of kids.”
Aside from all that, broken pieces of slate are being used on Great Cranberry Island to resurface three side roads that until recently were paved with asphalt. The John Goodwin Jr. Construction Co. of Southwest Harbor broke up the existing pavement, spread the fragmented asphalt, covered it with sand, spread broken pieces of slate, rolled the surface smooth and finally spread calcium chloride to hold down any dust.
Most residents seem to like the new road surface, although a couple of people have complained that the slate cut the tires of their cars. Selectman Richard Beal says continued use should compact and further smooth the roads. He adds that snowplowing in the winter could damage the new surface unless the plow blade is raised an inch or so to leave a thin layer of snow on the roads. He agrees with a resident who warns that any spinning of wheels for quick start-ups could dig ruts in the slate topping.
Mr. Beal and Dan Lief, the other selectman at the time who voted for the project, agree that slate surfacing will save money in the long run and cut the use of carbon by eliminating asphalt for that three-quarter-mile stretch of road. Total cost was $130,000, including expensive trucking and barging of the slate. Mr. Beal says the change in surfacing will save the town at least $50,000 a year, since patching and repaving with asphalt cost far more.
Residents of Little Cranberry Island, also known as Islesford, are scheduled to vote at the town meeting next March whether to convert to slate for some of their side roads.
The slate being used comes from the Monson Maine Slate Co. in Monson, which has exported black slate all over the world for more than a century. The company, once a thriving producer of slate roofing, supplied the tailings or broken slate left over from making shingles. The company presi-dent, Lauri Vainio, said slate has been used for road surfacing in that area and in Wales and parts of Canada, but he knows of no other such use of slate in Maine or the rest of this country.
So the Cranberry Isles venture is an experiment worth watching. If the slate roads hold up well through the winter, they could provide a model for other communities. They would save money and do their small bit to stave off global warming.