Finding the right excavator attachment

Finding the right excavator attachment

How contractors can boost productivity by choosing the right excavator demolition attachment.

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March 3, 2019

Sometimes, making the right choice is the differentiator between average and extraordinary. This can be said of many things: hiring an employee, buying a new car, ordering dinner at a restaurant—the list goes on. The same sentiment can also be said of choosing the right equipment for a demolition job. Many demolition attachments may work OK for a particular application, but selecting the perfect attachment for the task at hand has the potential to help contractors finish a project more efficiently and effectively than they otherwise could.

With hundreds of sizes and styles of demolition attachments on the market ranging from small grapples to massive pulverizers, contractors can’t expect to blindly pick an option, attach it to an excavator and get top production. Rather, today’s demolition professionals should refine their demolition attachment selection process in order to knock out jobs faster and easier. Considering the application, the carrier, the return on investment and other variables can help contractors better find the right tool for the job in question.

Attachment selection

Before selecting a tool, it is important to first consider the type of work the attachment will perform. From primary to secondary demolition and from rebar-enforced concrete to wood and brick, the application should be the first factor to guide an attachment choice.

When starting to demolish a structure, multi-quick processors, shears, crushers, pulverizers and demolition grapples tend to be the top picks for primary demolition. The choice between them depends on the type of material being targeted and how it needs to be broken up.

Crusher and pulverizer attachments, for example, best tackle jobs made up of mostly concrete. Choose a crusher if the structure is composed of concrete with little or no rebar and if it’s necessary to break the concrete into chunks large enough for easy sorting and recycling. A pulverizer attachment better handles concrete that’s heavily reinforced with rebar. Unlike the crusher attachment, the pulverizer will break the concrete into small pieces and cut through the embedded rebar, allowing the concrete to fall to the ground rather than hang onto the metal reinforcements.

Pulverizers also can be used to break concrete into manageable sizes during secondary demolition. If the demolition involves both crushing concrete and cutting steel, contractors should consider combi-crushers that incorporate both cutting edges and teeth.

If concrete isn’t part of the demolition picture but steel is, a demolition processor with shear jaws or a mobile shear attachment will work best since they’re able to cut through steel better than a tool meant for multiple types of material.

When working jobs with light materials (such as wood and brick, which are commonly found in residential demolition applications), use a demolition grapple. Besides breaking apart materials, rotating grapples work well for sorting during secondary demolition and increase versatility and productivity by allowing a wide range of movement.

For versatility across different demolition jobs, a multi-quick processor often fits best. The attachment’s interchangeable jaws can handle a multitude of materials. The jaw types found on multi-quick processors include crushers, pulverizers, a combination of both and steel-cutters. Some manufacturers offer additional specialty options, such as jaws for cutting through timber for forest industry applications; jaws for cutting steel tanks, pipes and vessels; and highly powerful jaws for heavily reinforced concrete.

While multi-quick processors may cost more than other attachments (approximately 15 to 20 percent more than crushers, for example), they more than make up for that difference in price with their versatility afforded by their interchangeable jaw sets.

Power source

After determining the best type of attachment for the job, contractors should consider the technology powering the tool. Cylinders power demolition attachments, and typically, the larger the cylinder, the more powerful the tool. Because of this, contractors seeking more demolition power in the past had to buy or rent a larger excavator to handle the larger attachment. That’s no longer the case.

As manufacturers incorporate more technology into the attachments they build, some are able to achieve as much as 25 percent more power without increasing the cylinder size. To pull this off, manufacturers build additional chambers into the cylinder to allow for as much as 20 percent more surface area. Often, this results in an attachment with the same power as a tool two sizes larger. This means that a section of concrete that may take a competitive crusher attachment five or six “bites” to break through only takes the tool with the enhanced cylinder technology one or two.

This advancement in technology gives contractors access to amplified crushing and cutting forces they previously couldn’t have achieved without the expense of investing in a larger tool, as well as a bigger carrier to operate that tool. In addition to the cost of the tool itself, larger carriers also come with higher operating costs. The high power-to-weight ratio made possible by more efficient tools—higher on attachments with this technology than any other tool in its size class—also opens the door to more efficient high-reach demolition. This is both because contractors can use smaller carriers and because the attachment’s lightweight and superior cylinder technology improves tool performance and fuel efficiency.

Some attachments with innovative cylinder technology reduce carrier fuel consumption by up to 20 percent compared to other models. In some cases, the attachment’s efficient design allows it to function normally when the carrier is set in economy mode, achieving the same performance as competitive attachments on an excavator running at full throttle.

In addition, this advanced cylinder technology allows manufacturers to better design high-performing attachments. When combined with double-acting speed valves, the advanced attachment designs not only offer improved power and efficiency, but also improved productivity. Together, the enhanced cylinder design and double-acting speed valves deliver faster cycle times—from 3.8 seconds to 5 seconds on bigger tools—and as much as 20 percent more power than conventional cylinders.

Ensuring the proper fit

Of course, the best attachment in the world still needs a suitable carrier to perform well. Contractors should be sure to match the attachment to the appropriate carrier size and weight. Heavier attachments, naturally, require larger, heavier carriers that cost more to operate. Using too heavy of an attachment can cause excessive wear to the excavator and will affect performance. In addition, tools that are too heavy for a machine present a safety risk for other workers near the carrier. Conversely, an attachment that is too small reduces productivity.

Professionals should also ensure the carrier has enough hydraulic capacity to feed the attachment when considering the right tool for the job. Inadequate flow or hydraulic pressure will slow the tool’s cycle times, reducing productivity. Too little pressure also results in less closing force or torque, depending on the attachment.

Another item to check is the attachment’s hydraulic circuit requirements. Is the excavator equipped with enough auxiliary hydraulic circuits for the attachment? For example, rotation shears and multi-quick processors require two double-acting hydraulic circuits—one circuit for opening and closing the jaw and one for 360-degree rotation. Attachments that don’t rotate, such as static pulverizers or shears, only require one double-acting circuit.

Maintenance needs

When determining the attachment best suited for the application and power rating, look for a product that is durable and easy to service. Some attachments may seem like a great investment at first but end up resulting in a nightmare of downtime and repair costs when put into operation.

One method for choosing a low-maintenance attachment is to find a tool with no (or very few) protruding parts, such as hydraulic hoses. These can be easily damaged during operation, particularly in harsh demolition environments. Instead, contractors should look for attachments that have components that are enclosed within the tool, yet are still easy to access through service openings.

Contractors will also be wise to keep wear part service life in mind when choosing a tool. For example, shear and crushing attachments’ cutting edges and teeth need to be replaced when worn. While exchangeable cutting edges are an industry standard, it’s still smart to ensure they are available.

When considering multi-quick processors, operators should pay attention to how quickly jaws can be switched out. Some manufacturers build multi-quick processors with jaws that operators can change within minutes on-site, compared to the hours needed to bring many other attachments back to the shop to exchange. Workers may only need to manually remove one pin from quick-exchange models during change-outs, compared to the three pins that need to be removed from many other manufacturers’ processors. The rest of the jaw exchange process is done hydraulically from the safety of the cab. This system not only removes the hassle of pounding out two or three pins, but also virtually eliminates the danger of the jaw falling and injuring a worker after the last pin is removed.

Choose carefully for success

With most jobs, the best tool depends on the situation. Seasoned buyers and industry newbies alike can benefit from taking a careful look at their options and requirements while searching for a new attachment. Additionally, it’s always a good idea to get advice from the dealer and manufacturer.

Picking the best pairing of tool and carrier goes beyond the application and the power that can be achieved. Contractors should examine every aspect of the attachment and the subsequent carrier to form a pair that will boost productivity and ROI and, potentially, open up opportunities to work in new applications. While making a wise equipment choice might take a little foresight, selecting the right tools for the job can help demolition professionals take their job site performance to new heights.

Francois Martin is the general manager of Kinshofer North America. He can be contacted at f.martin@kinshofer.com.