How high a boom lift do I need?

Three numbers, three meanings

Platform height is how high the floor of the basket rises. Working height is how high a person standing in the basket can reach with their hands. The usual rule of thumb is that working height is about six feet more than platform height.

Horizontal reach, also called outreach, is how far the basket can sit from the machine's center when the boom is extended. It is not a fixed number. A boom with 50 feet of outreach does not have 50 feet at full height, because the range chart trades height for distance.

Real figures that show the six-foot rule

Manufacturer and rental pages show the gap clearly:

• A JLG 600S has a platform height of 59 ft 6 in on its spec sheet, and a rental company lists its working height as 65 ft 8 in. The gap is about six feet.
• A 19-foot-class electric scissor lift lists a working height of about 25 feet. A 32-foot-class unit lists 38 feet. Again six feet more than the name suggests.
• A 40-foot-class electric articulating boom lists a working height of 46 feet.

Why the class name misleads

Yards often call a machine by its platform height: a 60-foot boom, a 40-foot scissor. A customer who says I need 60 feet may mean the work is 60 feet up or may mean the platform has to be 60 feet up. Those are two different machines. The difference is a full size class.

Say it plainly: the highest point my people must touch is 60 feet above the ground. That sentence gives the yard what it needs.

Example: 60 feet on Monday

A property manager calls on Wednesday. A sign on a building sits with its top edge 60 feet above the ground, and the crew wants to start Monday.

Step one is working height. If a person must touch something at 60 feet, the platform floor has to reach about 54 feet. A 60-foot-class boom has a platform near that height and a working height in the mid-60s, so it clears the job with a margin. A 50-foot-class boom does not.

Step two is reach. Where can the machine stand? If it can sit directly below the sign, outreach is small. If a parking lot island, a canopy or a ditch forces it 30 feet out, the range chart matters. Rental specifications for 60-foot-class booms show about 40 feet of maximum horizontal reach for the articulating models and between 40 and 50 feet for the straight ones, but that maximum is available at lower heights, not at the top.

Step three is the ground and the path. A 60-foot-class boom is 8 ft 2 in wide, and a straight 60-foot-class boom weighs about 17,750 to 21,650 pounds. See the site requirements guide.

Step four is timing. Monday depends on stock and the yard's schedule. Send the request early, say the job is urgent and give a second date. No page can promise a machine for a given day.

What to tell the caller

When a yard phones back, have these ready. Reading them out takes under a minute and prevents the wrong machine.

1. The height of the highest point your crew must reach, in feet, from the ground.
2. How far from the machine that point sits horizontally, and what is in the way.
3. The ground under the machine: concrete, asphalt, gravel, grass or dirt, and any slope.
4. The narrowest gate, door or aisle on the delivery route, in inches.
5. Whether power lines run near the work, and how far away.
6. Dates, and how many people go up at once with their tools.

Leave margin

Work you can reach with fingertips is not work you can do safely. If the task needs both hands and a tool, add a few feet to the working height. If a jib or extension is needed, tell the yard. For a choice between booms and a straight-up platform at the same height, read boom lift vs scissor lift. For what the extra height costs, see the cost guide.

Common questions