Modern-Day Pump Hoists: an Evolution in Lifting

As known to do, I am going to put the text into reverse and write about something I forgot in my last column.

Last time I described an early pump hoist I knew of that used a block and tackle in reverse for lifting. This created a real advantage, but also a disadvantage. This method’s advantage, as I understand, was smooth, predictable control of the hoist line. The disadvantage? This line had a limit on how far it could move — about four times the movement of the hydraulic cylinder that pushed the pulleys. In most cases, however, this was not an actual disadvantage. This hoist still gave us a large step forward from chain hoists, block and tackles, and so forth.