Heavy Demolition Tools: hydraulic hammers (rock breakers) and Bits
Hydraulic Hammers & Tool Bits Articles


Hard Hitting Performance Wherever It's Needed Most

Aggregate & Mining Journal ,
Volume 2, Number 2

When you ask almost anyone at Priestly Demolition for the secret of the company's success, the answer is simple and direct:

Match the equipment
to the unique requirements
of the job at hand,
large or small.

 

The company's growth is based on that one, simple concept. And when you add in the skilled equipment operators, the excellent planning, and the good work ethics, you have a formula that has led to a consistent demand for the company's services.

According to Ryan Priestly, president of the company, Priestly Demolition has been a family-owned contracting business since it was founded in 1971. The company provides demolition, abatement, and remediation services to commercial, industrial, and governmental customer. Its headquarters are in Aurora, Ontario. According to Priestly, the company's main competitive advantage is his team of 150 employees, along with a diverse equipment fleet that includes 60 track-mounted excavators and more than 150 pieces of wheel-mounted equipment.

Given the nature of the company's business, it is safe to say that its key demolition tools include a number of versatile hydraulic breakers, each of which can be easily moved from job to job. They can also be quickly attached to a variety of selected carriers.

BTI breakers (hydraulic hammers) can go almost anywhere to tackle the toughest jobs.
According to Ryan Priestly, president of Priestly Demolition, the BTI breakers can go almost anywhere to tackle the toughest jobs. In the photo, the company's BTI TB2580X breaker is working to help the general contractor excavate trenches for water and sewer lines in an upscale residential resort community that is being developed in Ontario.

Among these hydraulic breakers are four units that were chosen from the TB Series of hydraulic breakers that is manufactured by Breaker Technology, Inc. (BTI) of Thornbury, Ontario. Priestly has chosen TB Series breakers in a number of sizes, ranging from the compact BTI TB285ME in the 750 Mb (1,016 Nm) class, all the way up to the BTI TB2580X in the 13,500 Mb (18,300 Nm) class. Not too long ago, Priestly expanded his breaker arsenal so he could work on a $20 million demolition project at the Toronto Pearson International Airport. It was a massive undertaking that netted the company a Toronto Construction Association innovation award in 2004.

Tips on choosing the right breaker for the job

More recently, Priestly chose one of his BTI breakers-the TB2580X-for use on a rock-breaking project that was being conducted on the future site of a major, upscale residential resort community. The project involved the excavation of 2.5 mi (4 km) of trenching for water and sewer lines. The trenches were to be 8 ft. (2.4 m) deep and 3 ft. (0.9 m) wide. The general contractor had expected mainly dirt and clay during the excavation, but he had hit what Priestly referred to as quarry stone. Priestly Demolition was called in as a subcontractor to break the rock.

Priestly mounted the BTI TB2580X on a Link-Belt 5800 Quantum Series excavator in the 50-ton (45-tonne) class. "We chose this equipment for the project because we felt that bigger would be better," Priestly said, explaining that there is less consistency when breaking rock versus concrete. "Once you start breaking concrete, you know how hard it's going to be. But rock can be soft one minute and hard the next. So a bigger hammer would give us more production, at a desired rate, and would not be slowed by harder rock." Priestly added that the larger breaker will break the rock with fewer blows because it is hitting harder with each blow. A higher repetition hammer, he said, will often bounce right off the rock.

According to a spokesman for BTI, the company's engineers agree with the choice of the larger breaker in this application. The BTI TB2580X delivers longer piston strokes, creating more energy per blow but with less frequency. Alternatively, a shorter piston stroke results in more blows per minute but with less energy per blow. When breaking hard material such as rock, impact power is of primary importance. On the other hand, the striking rate is more important when breaking softer material, such as in lighter duty concrete applications.

In addition, BTI engineers recommend that the breaker should be large enough to quickly break the material, without drilling through it as might happen with concrete. Also, the breaker should be sized according to the carrier: It should be small enough to not overwork the carrier, but large enough not to be damaged by the carrier's weight. It is also considered important that the carrier's hydraulic system meets the breaker flow-and-pressure requirements.

Although breaker performance is significantly affected by choosing the correct hammer for the application, breaker design elements also play a part. BTI engineers point to the fact that the company's TB Series breakers contain only two moving parts, which means fewer parts are subject to wear. According to BTI specifications, the company also uses a low-pressure nitrogen-gas chamber to absorb piston recoil, throttle orificing to protect the carrier from pressure pulsations, and an anti-blank firing mechanism to prevent the piston from contacting the tool when it is not against the material to be broken.

Job experience is necessary in a breaker operation

 

"I think customers call us," said Priestly, "mainly because we have a good machine, a big hammer, and a good operator. They can call a rental company to get some good equipment, but it doesn't come with an experienced operator," said Priestly. He went on to explain that a lot of equipment operators can cut trenches or load material, but few have ever had experience on a breaker. "When using a breaker, the operator is a big part of the equation. An inexperienced operator cannot break as much or as fast as an experienced operator. In addition, a less experienced operator will often tend to activate the breaker too soon, before there is sufficient pressure on the point. This can cause blank firing and an overworking of the machine."

Terry McKague, customer service manager at BTI, said that a breaker will perform better and longer if it is properly operated and maintained. He then went on to explain why understanding carrier-boom downforce is so critical to proper breaking.

"The breaker needs to be held on the rock —so it is important to know how to use the carrier's boom cylinders to correctly hold a breaker with enough force against the rock. Remember that a hand-held chisel is most effective when held perpendicular to the stone. If it is angled to the surface, it will deflect off the stone when hit," McKague said.

Priestly Demolition moved its BTI TB2580 hydraulic hammer back closer to urban civilization to work on another demanding project along Ontario's Highway 26.
In the autumn of 2005, Priestly Demolition moved its BTI TB2580 breaker back closer to urban civilization to work on another demanding project along Ontario's Highway 26. The project involves breaking rock in order to permit the construction of new passing lanes on this stretch of a major highway. This is just one of four BTI breakers that are operated routinely by Priestly Demolition.
He pointed out that the hydraulic breaker needs a sufficient down force to hold it at a 90° angle to the rock. This prevents the tool from deflecting off the rock when the piston hits.

The equipment is ready to meet future demand

In the autumn of 2005, Priestly Demolition moved its BTI TB2580X breaker to yet another rock-breaking project along Ontario's Highway 26. The company is acting as a subcontractor for one of Canada's largest construction and infrastructure development companies. The project involves removing rock to allow for the construction of new passing lanes. The breaker is still mounted on the Link-Belt 5800 excavator.

"We have five Link-Belt excavators and we will continue to move the breaker from one to another," said Priestly. "If we have a job that is three hours away, we can just send the hammer in a smaller truck. The operator can easily change out the attachments in only about 15 minutes.

With so many different applications, and such a wide range of carriers and attachments on the market, choosing the most efficient tool for the task can be an difficult challenge. For Priestly, he feels that no matter what options are available, he will always lean toward the best support and service. "With my four BTI breakers," Priestly said, "I can take on about anything that comes my way."