What Is a Construction Elevator?

by David Gerson, Director of Marketing, NA

You've seen them hundreds of times, but do you know what those Erector Set-looking things on the sides of buildings under construction are? They're called buck hoists. They can also be referred to as construction hoists, materials hoists, man-lifts, construction elevators, material lifts, etc. But no matter the name, they all serve the same purpose.

They enable modern buildings to rise from the ground by moving people and materials vertically in a safe and fast manner when an interior, service or freight elevator isn't available. Sometimes, in industrial settings such as power plants, they are permanently installed on towers or other hard-to-reach areas that require inspection or repair from time to time. Most commonly, they are used on buildings that don't have a permanent elevator installed yet.

I've personally ridden a few, and it's quite an experience. I do not recommend it for anyone that fears heights. The walls of the cab are often made up of see-through metal grates. Whether you are 30 or 300 feet off the ground, you know exactly how high up you are. Additionally, they aren't as smooth or as quiet as a modern interior elevator. They can be a bit noisy, and you are completely exposed to the weather conditions outside. These cars are set up for function, not fashion.

Although they may seem simply designed, these amazing vertical transportation systems can rise over 1,000 feet up the side of a building and travel up to 300 feet per minute. Rather than using cables, belts or hydraulic jacks like in traditional interior elevators, these elevators predominantly use rack-and-pinion systems. In most situations, the drive assembly is installed directly on top of the car platform. In addition, there are no machine rooms, hoistways or overhead loads required.

The drive gear — also known as the pinion — is attached to the motor which drives the pinion gear and provides power to the system. Such a construction facilitates the use of a permanently mounted gear track. Essentially, the electric motor connected to the pinion drives the pinion gear and supplies vertical lift to the elevator. This construction allows the operator to move the car of the elevator up or down on command. When descending, rack-and-pinion elevators normally use electrical resistance or electrical regeneration to control their downward speed. As a result, a rack-and-pinion elevator is a no-slip system that is ideal for use in industrial environments and outdoor applications.

Although many of these buck hoists are temporary, they still need to pass rigorous inspections and drop tests like traditional elevator systems. There are also OSHA regulations that guide the initial construction and ongoing safe operation of these important devices.

Installing a traditional elevator would be significantly harder if not for these critical buck hoists. Although this is not my favorite form of vertical transportation, I recognize that they are vital to the construction industry and our entire new installation and modernization business at TK Elevator.