Many thanks to:
■ Judy Bass, Publisher, Industrial Press Inc., who envisioned this work and suggested viable approaches
■ Janice Gold, copy editor, and Patricia Wallenburg, compositor, who together wrote the book on competency and accuracy
■ Judi Howcroft, supreme nature and industrial photographer, who showed me the way, departed, and lives on among the stars
■ Deidre Schardine, an ongoing inspiration, who knows what is right and how to get there
Elevator Troubleshooting
& Repair
It is likely that animal- and human-powered elevators predated written history. Unlike masonry and stone buildings, the cars were probably woven baskets or wooden platforms with or without guardrails, and the support structures built of wooden logs, so these remains would have decayed centuries ago. We can only surmise that they existed, powered by domesticated animals on the ground, who worked long hours at a turnstile. Alternatively, occupants of the car may have pulled a looped rope that turned a pulley with more ropes that lifted the car, as shown in Figure 1-1.
FIGURE 1-1 The rope was operated from within the car. The hoistway was primitive, but it did the job.
Vitruvius (c. 80–15 BC), a Roman author, architect, and engineer, provided the first extant written reference. He reported that the Greek mathematician Archimedes (c. 287–212 BC) built a bank of elevators operated by hoisting ropes wrapped about a drum. It was turned by humans and this torque was applied to a capstan, causing platforms to lift gladiators and fierce animals through vertical shafts into the arena. In the seventeenth century, English and French monarchs built “flying chairs” to discreetly transport their mistresses to upper palace levels. These machines, powered by humans and animals, were eventually eclipsed by steam, water, and finally electric motors.
Where it gets interesting, from our point of view, is in the nineteenth century. During this 100-year period, the elevator evolved from steam-powered platforms used to move coal in English mines, to electrically-powered elevators that lifted passengers to ever greater heights in comfortable rooms with plush furniture.
In the late 1790s, William Strutt (1756–1830), shown in Figure 1-2, assumed control of his father’s textile mills in England. Among many projects, including fireproofing and improving the heat system, he designed a combination passenger and freight elevator, known then as the crane. It was adjacent to the main stairway and was used to transport workers within the five-story building. Strutt’s elevator was powered by a flat belt, running off of power shafting that ran throughout the building, presumably powered by an outside water wheel.
The principle components were a brake wheel, two fixed and two free pulleys, two endless belts, and a belt shifter. A crossed belt permitted the direction of car motion to be reversed, as needed in any elevator.
FIGURE 1-2 William Strutt (1756–1830) (Wikipedia)
A pinion gear was attached to one end of the main shaft, and its teeth meshed with those of a spur gear attached to the hoisting pulley shaft.
This was the first in a long series of working elevators that spanned the nineteenth century. Strutt’s Teagle, as it was known, was complex in the sense that it had a lot of ropes, belts, and pulleys, but simple in that these things worked smoothly together to deliver the power to where it was needed so that the car could deliver workers throughout Strutt’s five-story textile mill.
By the 1840s, two trends in vertical transportation merged. Increasingly, elevators were optimized to carry freight exclusively or to transport only workers, residents of tall buildings, and hotel guests from ground level to the growing number of floors in taller buildings that began to crowd the cities. Also, of necessity there was greater emphasis on safety.
Previously, lower-powered lifting machines had their share of accidents, sometimes resulting in well-publicized fatalities. This was true not only in elevators, but throughout the world of increasingly mechanized, more powerful and faster machinery that characterized the new industrial age. Accidents took two forms. In one, the suspension rope and associated rigging that raised and lowered the car in a traction elevator failed, causing the car, which was slowed only a little by the air column below, to free fall to the bottom of the shaft. The inevitable result was severe injury, often fatal. The other type of accident involved the absence of reliable door interlocks, which would prevent a door from opening when the car was moving and/or prevent the car from moving when the doors were not closed and locked.
Without these interlocks, an occupant of the building could step through an open door assuming that the car was at the landing, and fall to the bottom of the shaft. Another equally great hazard was that an occupant of the car could be crushed between the car floor and the top of the door opening at any floor while the car was ascending. We shall see how mid-nineteenth century advances in elevator technology confronted these hazards and greatly reduced the number of injuries resulting from them.
Before midcentury, freight elevators were typically designed in-house to meet the needs of the many industrial facilities that were appearing, especially in England and eastern U.S. Then, beginning around 1845, industries and commercial operations such as hotels and office buildings began to look to certain emerging elevator manufacturers to meet these needs. Henry Waterman in New York City was a freight and passenger elevator manufacturer. One of his early machines, built in Manhattan for Croton Flour Mills, was operated from within the car so that an outside attendant was not required. Car motion was initiated by moving a simple iron lever, rather than tugging on the shipper rope. For passengers, the trip became smoother and more user-friendly. The control lever moved an attached chain that passed through openings in the car roof and floor, then engaged devices at the top of the shaft. The mechanism consisted of a friction clutch driven by a conventional power shaft, eliminating the need for pulleys and a belt shifter as in Strutt’s Teagle.
The operator caused the car to ascend by pulling the handle, which released the brake and engaged the clutch. Upward travel continued as long as the operator maintained pressure on the handle. The clutch disengaged and the brake was applied when the operator released the handle. To descend, the operator applied an intermediate amount of pressure on the handle, releasing the brake, and the car would descend, its speed regulated by the brake.
The innovation in Waterman’s elevator was that it was controlled from within the car by means of what we would call a joystick, rather than the bothersome shipper rope that is prohibited today.
By 1850, George H. Fox and Co., a Boston firm, was building freight elevators that were safer and more efficient. Fox replaced meshing spur gears with a worm gear attached to the winding shaft. This arrangement is superior because it is self-locking. The worm can turn the gear, but the gear cannot turn the worm. Consequently, a separate