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Tools and Machinery of the Granite Industry, Part II
Chronicle of the Early American Industries Association, Inc., The, Sep 2006 by Wood, Paul
Later, hoists were located in an engine house and were driven first (circa 1870s) by steam, then later by compressed air, and finally by electric motor. The typical steam, compressed air or electric hoist (Figure 9) had two drums, one for the fall rope and one for the boom rope. A separate, smaller hoist was used for the swing rope. Each drum had a friction clutch on one side and brake on the other side. Each brake foot pedal had a holding ratchet. Pushing down on the foot pedal released the ratchet. Above each foot pedal was a hand lever to apply power via a friction clutch to the corresponding drum. Usually, the engineer sat in a seat suspended from a chain attached to a roller on a ceiling track. Although some large derricks could lift sixty to eighty tons, the typical capacity was forty tons. The average saw block shipped to the sheds weighed about twenty tons-leaving a wide margin of safety. Today, most wood derricks have been replaced by steel derricks with 110 to 160-foot tall masts and capacities ranging from 100 to 250 tons (see front cover).
The derrick was also used for moving equipment -for example, channel bars, drill bits, oil barrels and tanks, and warming sheds. Usually a head quarryman worked with each derrick. He was the one who called for the derrick. Also, he periodically checked the derrick ropes for wear or cuts. Given the distances involved and the high noise levels in the quarry, the head quarryman used hand signals to communicate with the derrickman, including signals to raise (thumb up with arm rising) or lower (palm down with arm falling) the boom, to raise (hand open with arm rising) or lower (hand bent at the wrist and palm down with fully-extended arm falling) the hook, and to swing the boom left (a sweeping motion with the left arm) or right (a sweeping motion with the right arm). A rigger had to grease derrick sheave (pulley) bushings twice a week, but later, following the introduction of ball bearings, that task was reduced to weekly. One of the sheaves, the "rooster sheave," was located at the very top of the mast, and at first riggers had to climb up the mast ladder to reach it. The initiation of novice riggers often involved their making the scary climb up the mast to grease the rooster sheave. Some froze part way up and had to be brought down in a sling! In later years, riggers were pulled up by the derrick. Riggers were also responsible for the formidable job of moving the derricks as the locations of active quarrying changed. The boom would be raised to its maximum height, temporarily guyed and used to lift and move the mast.
Ropes and Cables
The saw blocks that were split by wedges and shims were "glutted out" with steel gluts (Figure 10) wedged between the blocks to make room for a rope to be put around them. Notches were cut in the block edges to hold the rope. After the rope was attached to the block, the rope was tightened by the derrick to see if everything was secure, and then the load was lifted out of the quarry.
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