For open-cut pipeline, power, water, sewer and underdrain installations in rocky ground conditions, a pipeline trencher can be an efficient option for your jobsite. To help get the most performance from these powerful machines, you need to pair the appropriate trencher with the right type of teeth for the ground conditions, as well as implement proactive maintenance practices.
“The right trencher setup can outperform up to 10 excavators in certain ground conditions,” said Barry Scieszinski, Vermeer Applications Specialist for pipeline trenchers and Vermeer Terrain Leveler® surface excavation machines. “Trenching is an incredibly efficient and productive solution for open-cut work and is a method contractors should consider incorporating to their list of services.”
Scieszinski and his colleague Gregg Van Roekel have worked with hundreds of contractors and dealers to help optimise their track trenchers’ performance in a range of locations and ground conditions. Here are the steps they recommend for choosing the right teeth setup on your next job.
1. Choose the trencher
Before you can choose the right teeth, determine what model of track trencher you’re going to be using. Now, your answer may be 'the one that’s available’, but Van Roekel cautions that this decision could have a significant impact on productivity. “In soft or looser rock formations, crews can usually get by with a smaller sized trencher, but solid and harder rock formations call for more horsepower,” he explains.
“Trying to get by with an underpowered machine in solid rock formations will take much longer, and crews will go through a lot more teeth in the process because the machine can’t produce the optimum cutting speed required for cutting through this type of material. Likewise, choosing a large trencher for digging in softer rocks is also inefficient because crews will burn through more fuel than required to do the job,” Van Roekel explains.
2. Select the tooth size
Different sized trenchers take different sized teeth. “The tooth shank for small- to mid-sized trenchers typically measure about 1 in. (2.54 cm) from the base of the tooth to the pocket clip,” explained Scieszinski. “Large trenchers require larger 1-½ in. (3.81 cm) tooth shank to support the higher horsepower those units will dig at.”
3. Determine the tooth style
Once you’ve selected the right size tooth, it’s time to pick the appropriate style for the ground conditions. Scieszinski said contractors should think about the available styles like 'sledgehammers and pickaxes’. “The head on a trencher’s tooth can range from rounded dull surfaces to pointed spiked styles,” says Scieszinski. “The rounded face teeth with a larger carbide surface hold up longer than more aggressive, smaller carbide-tipped teeth. The larger surface area teeth are effective at breaking up softer rock formations like sandstone and limestone. For harder rocks, contractors should employ a more aggressive tooth style for deeper rock penetration.”
Like a sledgehammer, teeth with a larger surface area can break the rock into large, thick sizes using less energy (horsepower). At the same time, the more aggressive pickaxe style produces smaller sized material with each percussion and will require more energy or chain revolutions to dig.
Van Roekel also points out that the smaller carbide tipped teeth will help deliver a smooth cut surface, which makes them a good option for contractors trenching through concrete or asphalt and trying to limit spalling.
4. Pick a tooth pattern
All Vermeer pipeline trencher chains come with a standard V digging pattern, and the number of chevrons a chain has varies by the boom length and chain width. “On wider chains, a chevron may start with a single center tooth and build to as many as three teeth on the outer plates,” said Scieszinski. “Each tooth bites off between 2 - 4 in. (5 - 10.1 cm) of material depending on the rock’s density.”
Van Roekel adds that when trenching crews are working in really hard rock, they may want to consider using a staggered pattern that incorporates short and long teeth. “For this pattern, longer teeth are placed in the middle of the chevron to make the initial impact, and then shorter teeth are used at the outer edges to pull the chips out of the way,” he explains. “Using a combination of smaller carbide-tipped teeth and larger surfaced carbide teeth is also another combination often employed. This configuration mimics the way a person chews their food. Teeth in the middle cut, and the outer teeth grind and reduce the particle size.”
5. Compare the tooth quality
If you’ve shopped for trencher teeth before, you know there are hundreds of options to choose from in a wide range of prices. Scieszinski and Van Roekel tell contractors to remember: you get what you pay for.
“Just because a low-cost tooth may look identical to a much more expensive one doesn’t mean it will perform the same and it probably will not last as long,” adds Scieszinski. “There is a lot that goes into the construction of trencher tooth shanks and the process for applying the carbide. Going with the low-price option can cost more in the long run due to more frequent teeth replacements, slower production rates and more extensive maintenance requirements.”
6. Practice good maintenance
Diligent tooth maintenance is also essential for getting the best performance from a pipeline trencher. “Each row of teeth on the chain is designed to work in conjunction with the one beside it, as well as the row ahead of and behind it,” says Scieszinski. “When a tooth or several teeth are worn beyond their service life, it puts additional strain on the other teeth on the chain.”
Van Roekel adds that if a tooth is worn down too far, it will begin to wear into the pocket, causing the tooth to fall out, break off or realign itself. When this happens, the pocket itself will need to be replaced. “While having to weld on a new pocket is a common occurrence, it is usually avoidable and certainly can slow production,” he says.
To help avoid premature wear, the two Vermeer application specialists recommend checking the condition of your trencher’s teeth regularly.
7. Seek additional support
While there are many variables involved with choosing the right teeth to optimise the performance of your pipeline trencher, you don’t have to figure it out alone. Your local Vermeer dealer is happy to assist you with determining which trencher and teeth are right for your next project. Give them a call to get started.
Also, if you want to learn more about Vermeer pipeline trenchers, visit vermeer.com/pipeline-trenchers.
Read the article online at: https://www.worldpipelines.com/special-reports/01122021/7-steps-to-optimise-your-pipeline-trencher-teeth-setup-for-rock/