Robertson notes that a 40-foot self-propelled boom typically weighs somewhere in the neighborhood of 10,000 pounds. Towables, on the other hand, hover around the 3,000-pound mark, enabling them to work on the upper levels of structures where a lot of weight is undesirable. They are also less damaging to turf, so landscape professionals can operate them with less fear of disturbing lawns or flower beds.

One way that towables achieve a lighter weight is through the use of outriggers as opposed to counterweight, which provides self-propelled models with the stability necessary to rise to high heights. As a result, a towable's footprint is larger, usually about 14 feet across. Despite the wider wingspan when in use, towables can fold up to just 3 feet 6 inches, making it possible for them to fit into tight spaces like backyards and around buildings, etc.

In addition, says Mohn, "The outriggers offer a leveling capability and a firm lifting base of operations that is beneficial in areas of great land undulation."

Dilling at Genie agrees, noting that Genie towables can level themselves on up to an 11-degree slope, while most self-propelled booms have a 2 1/2-degree slope capability.

A question of stability

If their lightweight and leveling capability are defining characteristics of towable boom lifts, the next question to follow is often, "How stable are they?"

According to Robertson with Niftylift, towables are just as stable as self-propelled boom lifts. They are required to meet safety standards just like self-propelled models. It's the perception of stability that's sometimes in question. "When you're up in the air, you don't look down on a big base beneath you, but you've got a 14-ft. spread from the outriggers," Robertson notes.

Still, as Dilling at Genie points out, operators might notice a different "feel" when using a towable as opposed to a self-propelled unit. "There's a bit more deflection, so the boom might feel a little softer," he says. This deflection, or slight movement of the boom when extended, is due to the use of lighter materials. Because self-propelled units are not restricted in terms of weight, the booms can be constructed to be a bit more stiff, and this is sometimes perceived to be more stable, when in fact, there is no technical difference in stability.

What to look for

Towable boom lifts today offer many of the same basic features, such as drive and set systems, self-leveling hydraulic outriggers and towing speeds up to 65 mph. The main difference between brands is often after-sale support.

"As a rental business shopping around for a towable boom lift, it's important to choose a reputable manufacturer that will support the product with training, parts supply, etc.," says Mohn. Other factors to consider include the design of the machine. Is it rugged enough to hold up to the rigors of over-the-road transport? How are the "feel" of the platform controls and the outrigger deployment system?

Power options are another area to think about when choosing a towable for your fleet. Some models are electric, which makes them ideal for indoor use, and some are gasoline powered. There are also bi-energy models which combine the best of both worlds and make it possible to perform more applications with just one machine.

Whatever model you choose for your rental inventory, it's crucial that you educate your staff and customers about safe operation. Make sure your counter employees are knowledgeable enough to effectively train customers on the equipment before it leaves the yard, particularly on the required use of safety harnesses. Towables are the ideal lift equipment for the weekend warrior, but homeowners are frequently novices on such equipment, so keep safety in mind when renting to this market.