What your trencher can do for you

In most instances, burying a pipeline requires digging a trench. A range of methods can be used to complete the excavation work, allowing a pipeline to be laid and buried. Tesmec’s Flavio Villa and Kris Phillips outline the benefits of choosing a trencher to complete excavation work in pipeline projects.

“First of all, in almost all ground conditions, using a trencher leads to highly increased productivity and lower excavation costs compared to other excavation means such as excavators, rock breakers or drill and blast.

“Second, the use of trenchers always leads to a reduction of logistic costs and easier management of the site. One single trencher can replace a huge fleet of other excavators to achieve the same daily productivity. This means less machines and operators onsite, easier site management, and lower costs of logistics.

“Last but not least, the use of a trencher also reduces the environmental impact of the excavation by minimising the negative environmental effects of truck haulage and waste disposal by reducing or eliminating the risks, costs, vibration and noise arising from use of explosives, and also through the reduction of carbon dioxide emissions, due to the reduction of the number of machines.”

The Tesmec duo also highlight that trenchers always bring a valuable cost reduction in terms of bedding and backfilling.

Astec’s Al Bender agrees, saying “When using a trencher the most important impact on schedule and budget is the ability to use the spoil without further processing.

“As a trencher excavates a trench in rock, it also grinds the rock into useable sizes. Alternative methods of digging a trench in rock, such as blasting or hydraulic hammers, leave large boulders that must be hauled off and processed before they can be used. This added feature of a trencher saves money and time,” says Mr Bender.

He adds “Most pipelines laid in trenches require padding material around the pipe before the trench is backfilled. A trencher cuts a perfect rectangle in rock, while other methods end up with trapezoidal trenches much larger than required. The amount of material required to pad a trencher-cut trench is almost halved. Whether you are buying padding material or making your own this is a significant saving.”

What you can do for your trencher

Vermeer’s Chris Lynch knows the stress under which trenching machines often operate.

“A trencher is typically operating at full load when in service, which means the unit takes a fair amount of vibrational abuse depending on digging conditions. All this leads to a machine that needs daily service and attention.”

Ditch Witch's Jason Proctor says “The average life span of a trencher can be significantly affected by proper maintenance.” He adds that machines should be serviced based upon the manufacturer’s recommendations found in operator and service manuals.

Mr Bender agrees, saying “Trenchers need to be serviced daily because of the nature of the work and the environment. Daily maintenance involves greasing, checking oil and coolant levels, cleaning or replacing of filters and general inspection. The teeth need to be inspected and replaced as needed. Hydraulic oil and engine oil need to be changed as recommended.

“With proper maintenance and overhaul of engine and transmission, a trencher can last for many thousands of hours. There are examples of trenchers with over 60,000hours of operating time,” says Mr Bender.

Trenching safely Mr Bender says “A trencher is much safer than alternative methods of digging a trench. One trencher can replace 10 to 14excavators and rock hammers. Fewer items of equipment to do the same job require fewer people to operate reducing the chance for accidents.”

Trenchers have a number of safety features including:

• Roll-over protection structure cabs;
• Movement alarms;
• Emergency shutdown capabilities; and,
• Protective guards.

Although, as Mr Villa and Mr Phillips point out, safety features must be combined with safe operational practices and procedures not just around the trencher, but on the job site as well to secure the safety of all workers.

Mr Proctor notes that trencher operators should be knowledgeable in proper machine operation and be able to confidently identify jobsite hazards.

“The primary consideration when selecting an operator is ensuring proper training is made available. An experienced operator can have a positive impact on achieving project timelines and budget,” Mr Proctor says.

Make the initial investment and save

Trenchers are a major investment for pipeline construction companies. While the initial outlay for the equipment will always be a consideration in selecting the size and model of a trencher, factors such as the rate of production and service support are also important.

Mr Lynch says that evaluating the profile of the ditch, soil/rock conditions, scheduled daily production and terrain in advance is critical in selecting the correct machine and digging configuration to suit the specific ground conditions.

“While contractors may be tempted to choose a smaller trencher to save costs, pushing smaller units to do more than they are designed for often leads to much higher maintenance and service expenses,” Mr Lynch says.

Choosing the wrong configuration for a job can be crucial in terms of lost productivity and associated costs. Taking the time to research the different trenchers available on the market and discussing equipment capabilities with local dealers is an important part of choosing the right trencher for the job.