By Chris Thompson, Vacuum Excavator Product Marketing Manager, Ditch Witch
Vacuum excavators are one of the fastest growing machine segments in the underground construction industry. Originally popularized by their role in daylighting existing utilities on directional drilling jobs, these machines are now being used for irrigation installation, landscaping, and even nursery tasks.
One reason for this growth is that vacuum excavators are designed to mitigate damage on the job with their versatility, ease-of-use, and soft excavation traits. This makes them the ideal machine for the damage-conscientious contractor, especially with today’s jobsites being more complicated and congested than ever. But even though vacuum excavators are designed for simple, safe excavation, contractors can’t realize the full benefits if they don’t understand how to properly use and maintain their machines.
Best practices for operating a vacuum excavator can be broken down into three categories: preparation, operation, and maintenance.
As with any underground construction job, preparation is the key to success. Preparation for vacuum excavation begins with identifying the ground conditions of the jobsite. Some will have soft, loamy topsoil, some will have clay, and others may have limestone or rock. Each of these conditions will require a different strategy, so it’s important for operators to understand their ground conditions before beginning work. Determining ground conditions can be a challenge when working in new regions, but your local Ditch Witch dealership is a great resource for understanding soil conditions around the area.
The next step is to decide between air and hydro excavation. Soil type comes into play here to because air excavation works best in softer soil types, making hydro excavation the best solution for rock and clay conditions. Hydro excavation is typically the traditional choice and is generally the more efficient solution but using air excavation eliminates the need for liquid spoils disposal. For contractors that are working far away from a spoils disposal site, avoiding disposal requirements can boost productivity. Determining which excavation solution is the best fit for the job and jobsite will set a contractor up for the most efficient and safe operation.
Once you have chosen your machine and have it on the jobsite, you need to keep it running efficiently and protect it from any unnecessary damage.
Operational best practices begin with the vacuum excavator’s wand. Operators should constantly move the nozzle around within the excavation area and keep the spray nozzle 8 inches from the ground or from the utility that is being exposed. Holding the nozzle closer than 8 inches or directly applying the excavator to a certain area could cause damage to an existing utility. It’s also important to never use the nozzle as a shovel or pry bar. Putting the nozzle into the dirt can cause damage to the wand and result in costly downtime. If an operator is struggling to excavate through hard soil or heavy clay, they should use a hot water heater rather than moving the nozzle closer. Hot water heater packages can help break down close without applying additional water pressure. However, water temperature should stay below 150 degrees Fahrenheit.
Operators should also be mindful of their water or air pressure. When using a hydro excavator, operators should always keep water pressure below 3,000 psi, whereas an air excavator should stay below 300 psi. That said, it’s also best practice for operators to consult the utility owner if they are using a vacuum excavator to expose utilities, as may have their own requirements for using hydro or air excavation. For example, some gas line owners recommend using a maximum of 2,200 psi when exposing their utilities with a hydro excavator to prevent any damage.
One of the biggest selling points of vacuum excavators is that they have minimal maintenance requirements – and the ones they do have are simple. Manufactures like Ditch Witch are designing their vacuum excavators to eliminate daily maintenance and grease points, allowing operators to focus on their jobsite tasks. The most important daily maintenance task for operators is to always dump and clean the debris tank and empty the freshwater tank at the end of every day. This prevents complications that could limit vacuum excavator productivity. Another maintenance best practice is to routinely check cyclonic, debris and water filters, as obstructions can reduce the suction power and water pressure of the machine.
Work Correctly, Work Safely, Work Efficiently
When used correctly, vacuum excavators are versatile machines that can improve a contractor’s efficiency and reduce the likelihood of causing damage to existing utilities or jobsites. The best way for contractors to set themselves up for success is to understand and follow best practices. This will keep operators moving quickly and keep machines in the best shape over the long haul. For further information and training opportunities, contractors should consult their local Ditch Witch dealer.
This material appears in the August 2021 issues of the ACP Magazines:
California Builder & Engineer, Construction, Construction Digest, Construction News, Constructioneer,Dixie Contractor, Michigan Contractor & Builder, Midwest Contractor, New England Construction, Pacific Builder & Engineer, Rocky Mountain Construction, Texas Contractor, Western Builder