Thursday, April 13, 2017

The Granite Industry, Part 2 of 6 - Technology

Prior to 1800 granite was available only for the roughest or the most luxurious building purposes in Massachusetts. With little or no shaping required fieldstone contributed to boundary walls, sheep enclosures, and house foundations. Fine granite structures like King's Chapel in Boston (1749) were constructed laboriously, that is, expensively, by splitting boulders with fire and smoothing the surfaces with hammers.
A boulder partially drilled and split for dimension stone1
The invention of drilling and splitting methods popularized granite as a durable building material. Applications grew rapidly through the nineteenth century. Above-ground boulders were the easiest source of stone. Rows of round holes were drilled several inches deep by rotating the square drill between hammer blows. Wedges tapped in between pairs of shims ("plugs and feathers") could split massive stones quickly and cleanly.

Round-hole plug and feathers1
In a variation of this technique slots were made by a cape chisel and the splitting accomplished by flat wedges.
Boulder drilled for splitting by flat wedges, Halibut Point
Martin Ray photo
Cape chisel1
Boulder fields and exposed ledges close to the shoreline made commercial granite works possible on Cape Ann from an early stage in the industry. In 1823 Nehemiah Knowlton cut 500 tons of stone near Pigeon Cove. Quarrying operations proliferated along the coast over the next few decades. Building stone was shipped as far away as San Francisco in 1852 and paving blocks to New Orleans in 1857. About this time the first steam engines for blasting and pumping appeared, making below-ground quarrying practical.2
Splitting high-quality stone from a deep quarry3
Incremental advances in technology proceeded on many fronts to enable commercial quarrying and the teams of men who worked there. Gunpowder was adapted to the purpose of loosening massive blocks for further cutting into dimension stone. Blasting caps first with fuses, then by electrical detonation, introduced a more reliable way to fire the charge. Increasingly powerful pumps kept up with water infiltration as the quarries went hundreds of feet down into the highest quality deposits of granite.
Hand-powered derrick, Halibut Point
Sandy Bay Historical Society photo
The celebration of nationhood in the Bunker Hill Monument proposal gave occasion to ingenious developments in hoisting machinery by Solomon Willard in the 1820s. His inventions and advances in derrick design formed the basis for apparatus used throughout the century in the largest quarries as well as the small-scale 'motions' operated by independents. The 'mast' and 'boom' terminology suggests that rigging concepts derived from maritime experience which was plentiful on Cape Ann.

Steam-powered derricks provided the muscle and reach for a broad variety of quarry jobs in addition to hoisting granite blocks, moving workers, equipment and buckets of debris around the site. Underneath a web of stabilizing cables radiating from the guy plate at the top of the mast the boom rotated in a full circle. Industry historian Paul Wood notes that in Barre Vermont "derrick sticks" made of Douglas fir up to four feet in diameter and up to a hundred and fifteen feet long were brought in from Oregon and Washington on three forty-foot flatcars.4
Powered derrick rotating on bull wheel, using chain and stone dogs
Blood Ledge Quarry, Lanesville, 1917
Sandy Bay Historical Society photo
The Rockport Granite Company introduced the first steam drill to Cape Ann in 1883 to revolutionize quarrying operations. Pneumatic drills began replacing them by the end of the century. Compressed air could be transmitted more conveniently and safely through pipes and hoses, and it could be easily subdivided for use by many tools and machines. The energy came from coal-fired turbines in a central power house.
Guy boom derricks at the Babson Farm Quarry, Halibut Point c. 1909
Charles Cleaves photo, Sandy Bay Historical Society
The disposal of undesirable stone challenges the efficiency and economy of quarry operators. Ideally it can be processed and sold as rip-rap or crushed rock. It may have to be put aside in inconvenient piles or transferred by rail lines within the site.
Blondin, Bay View quarry
Richard Lewis postcard collection, Annisquam Historical Society
Grout could also be removed by a blondin, an aerial cableway that carried a suspended grout box for dumping at a distant grout pile. The tower and cable device was named for French daredevil Charles Blondin who crossed Niagara Falls Gorge by tightrope in 1859.
Surfacing machine, Pigeon Cove quarry
Underwood stereograph, Cape Ann Museum
Even-grained stone lent itself, in skilled hands and operations, to useful quarry manufactures. Shaping and finishing tools that may have been developed for rendering softer stones into useful or beautiful purposes, required advances in metallurgy, design and technique for granite applications. The bush hammer patented in 1828 incorporated removable blades or fixed points on each side of the head to achieve flat surfacing by repeated blows—the greater the number of cuts the finer the dressing of the stone. Eventually the principle was extended to pneumatic surfacing machines attached to the end of a sliding horizontal bar or mounted on a trolley.
Advances in electrical engineering brought the granite industry into the modern era with lighter, more versatile tools and equipment. Power could be obtained more favorably from public utilities and dispersed to motors large and small throughout the facility. Machines for fine work came into play. Electric lighting improved visibility within the sheds, under overcast skies, and on short winter days.
Carved and polished capital of column for Winters National Bank, Dayton Ohio
Rockport Granite Company photo c. 1920
Sandy Bay Historical Society
The cumulative effect of technology was to multiply the productive capacity of granite producers and artisans at all levels, with desirable potentials to individual workers, corporations and the broad economy. Technology also added to troubling aspects of 'progress,' tradeoffs of life in modern society that we will consider in the next essay.
1. Photos from the website Stone Structures of Northeastern United States.
2. Lemuel Gott, History of Rockport, 1888.
3. Photo from James J. Tobin, "Granite Street Construction," The Granite Paving Block Manufacturers Association of the United States, 1925, courtesy of Baker Library Historical Collections, Harvard University.
4. Paul Wood, "Tools and Machinery of the Granite Industry, Parts I-IV," The Chronicle of the Early American Industries Association, 2006-7.

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