QMC Cranes Blog

Boom VS Knuckle Weigh In

What’s better for precast concrete?

For the typical precaster who’s running in multiple directions all day, there’s no time to waste and inefficiency is not an option. One of the things that keeps a precast business moving in the right direction is a solid crane fleet. When it comes to choosing between a telescoping boom crane or a knuckleboom crane, the telescoping boom has clear advantages in the precast world. Let’s take a look.

A big issue for most precast concrete projects is weight. A lighter crane means more axle weight for payload at a time when precast structures are getting bigger, heavier, and more complex. The ability to add more payload to a single vehicle also may reduce the need for additional trucks and drivers having to transport products to the jobsite. That cost savings often makes telescoping boom cranes a better choice over knuckleboom cranes.

Beyond transportation considerations, weight impacts crane maneuverability and surefootedness to, from, and at the jobsite. The lightness of telescoping boom cranes has a lot to do with the geometry of how they’re built.

“A lot goes into building cranes specifically for precast concrete businesses,” says Brent Petring, General Manager for QMC Cranes in Sparks, Nevada. “We use what we call the Modular Design Theory to assist with customizing models for specific use needs. It allows us to create the right configurations for types of demands you will likely encounter.”

Level Set

Tom Anderson breaks down the boom vs knuckle difference as onetime owner of Glacier Precast in Kalispell, Montana. He’s sold on boom trucks and ran a fleet of five QMC rear mounted cranes across mountainous terrain for years. One of his cranes is mounted on a shorter truck that can traverse the steep, winding roads around the high country in northwestern Montana.

“I call it my mountain truck,” Anderson says. “We’re up here in the mountains where you don’t always get ‘level’ and the QMCs will do way more on an uneven surface than a knuckleboom. They’re way more user friendly too. We do a lot of things for our customers with the QMCs that would be a lot harder with a knuckleboom. Like setting a wet well down in a hole. With the QMCs, it’s just effortless.”

That means Glacier Precast can offer outstanding customer service in less time with greater efficiency. Who wouldn’t want that? 

Fundamentally Better

The fundamental design of the two types of cranes makes it easy to spot the advantages of the telescoping boom. The straight boom gives you a much higher capacity to reach for the weight you’re lifting. Think of it in terms of how much weight you can lift and how far away you can set it. Let’s say you need to lift 18,000 pounds at 20 feet. You would need a much bigger – and heavier – knuckleboom to manage that lift.

Another big difference between the telescoping boom crane and the knuckleboom crane is reliability. The simpler design of the telescoping crane makes it possible to protect the components from the elements. The articulating nature of the knuckleboom means that it has multiple exposed cylinders subject to solar, dust, and heat damage – an especially dubious prospect in severe climates. Knucklebooms are feature-laden and part-laden. More moving parts means more maintenance.

And finally, it’s important to know that QMC cranes are made by QMC Cranes, not assembled from a kit at a dealership. We manufacture our cranes with American steel and are proud to say we’re a Made in the USA crane company.

If cranes are a weighty issue in your precast company, check with us for expert advice and support and elevate your business. After decades of working with precast experts and listening to their suggestions, we place a lot of stock in keeping our QMC products as light as possible.

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