If you look carefully at old photographs of NYC, particularly if taken from a higher vantage point such as the Brooklyn Bridge or some of the taller buildings over in Brooklyn, you will see many buildings have small plumes of steam coming off their rooftops. These were most often from the steam elevator engines. ANother clue is if a non-industrial building (such as an office bldg) has a small "inverted cone" shaped "exhaust head". These were devices to separate condensate and cylinder oil from steam exhausted to atmosphere, as well as to muffle the sound of a steam engine or steam pump exhaust. As Con Edison began steam distribution to buildings in Manhattan, many got rid of their boiler plants. They tied their existing steam equipment such as fire pumps, elevator engines, and even some steam engines into Con Ed supplied steam.
The result was buildings with no working chimney or smokestack still had exhaust steam coming off them. One particularly interesting case was the old Gouverneur Hospital in lower Manhattan. This hospital had stationary steam engines producing DC power. It ran those engines and was partially on DC power into the 1970's. What occurred was the boiler plant reached the point of being beyond any kind of reasonable repair. Since the hospital itself was quite old and slated for demolition and replacement, the engines were tied into Con Ed steam for the last few years. I'd drive by on the East River Drive and see the pulsing plume of steam coming off the old hospital, but never stopped in to ask to see the engines.
Conrad Milster related a crazy story some years back about one of the last steam elevator engines running in NYC. Seems a new NYC Buildings Inspector (known as a "Code Enforcement Officer" in environs outside NY City), o rpossibly a Fire Department inspector, was doing a routine inspection of this old building. SInce the building had a basement with the elevator machinery in it, the inspector took a look at it. He started to write a violation of building or fire code, citing some portion of the code which called for elevator machinery to be in a fireproof room isolated from the rest of the surrounding space. The building owner or maintenance man told the inspector the elevator was steam powered, non electric, and pre-dated the codes. An argument ensued, with the building's people contending that since the elevator was non-electric and had no switchgear with "contactors", there was no need to enclose the machinery. This crazy argument went up and back for some little time, and no one at the regulating agencies had a clue as to the fact there were once steam powered elevators that did not run on electricity. Finally, to shut up the inspectors and make the violations go away, the building management agreed to build a "fire rated assembly" (walls with a fire rating) around the steam hoisting engine with self-closing door, fusible link... the works. Of course, a few years later, this engine and elevator were taken out of service.
Some of the old buildings had hydraulic freight elevators which came up from the basement thru the sidewalk. These elevators had a platform which had a steel arch over it. As the elevator ascended up from the basement, the arch pushed the "leaves" of the steel basement entry doors up. A warning bell would sound as soon as the elevator was set in motion, and a sign warned pedestrians. These elevators would ascend slowly, and the doors (usually heavy diamond tread steel deck plate) would begin to open. The elevator was worked in the old days by a small steam pump and dead-weight hydraulic accumulator. The dead weight accumulator was what did the real work when the heavier flow of water to the lift ram was needed. The steam pump worked automatically with a pressure regulator to open and close the steam supply valve.
The Otis Elevator steam hoisting engine was quite interesting in its own right.
It was quite close, if not the same, in operating principal as a "steam steering engine" used on ships. In this application, when the ship's wheel is turned to steer the ship, a pointer in the wheelhouse would move to the desired rudder position. This worked a shaft and gearing down to the steering engine, which moved a stop and unbalanced a valve as well as setting the direction for the steering engine to run. The steering engine then played "catch up", moving the rudder until the mechanism "balanced" or centered the valve and stopped the engine. A second pointer linked to the rudder itself would move until it was coincident with the first pointer. The rudder would remain in that position until another change to the rudder angle was needed. The elevator worked similarly, with the persons in the elevator car (usually an assigned operator) working the controls on the steam hoisting engine via a rope that ran thru the car.
I've seen steam steering engines in actual operation on the Great Lakes years ago, and always was intrigued by their mechanisms. It struck me that the Otis Elevator steam hoisting engines were quite similar. Another old feature of cable elevators was the governor. This lived on until recent time when enclosed "speed switches" replaced it. Typically, a large open flyball type governor, large enough for a good sized Corliss steam engine, woul reside in the elevator penthouse (shaft head) or down in the basement machinery room. It was connected to the shaft the hoisting sheaves ran on. If the elevator "ran away" due to a lack of control or mechanical failure, this governor would bring in a spring actuated brake to stop and hold the elevator. Some of these old elevator governors have been turning up in antique/art type places.