Focus on: Hydro excavation

When it comes to excavating material around buried utilities such as sensitive communications data cables, power cables, or gas and water mains, it can be a challenge to dig effectively without potentially damaging something.

However, an innovative method referred to as hydro excavation is getting more common in areas where conventional digging with excavators can prove to be tricky. Hydro excavation uses water to turn the ground to be dug out into soft mud, which will in turn be vacuumed out.

Vacuum Truck Supplies (VTS) is one such company manufacturing turn-key products specific for hydro excavation and is located in Mansfield, Victoria, roughly a two-hour drive north of Melbourne.

VTS Managing Director, Rod Glue, his right hand man, Mike Fischer, and local DAF trucks dealer Twin City Trucks’ Neville Farrugla were all on hand to demonstrate and answer questions about the company’s new hydro excavation unit which was mounted on a DAF LF55 chassis.

“We are finding that more and more councils are not allowing traditional methods of digging, such as with an excavator or jack hammer in their city streets,” Fischer explains.

“It is for this urban city council work that we chose this nimble DAF LF55 chassis with the short wheelbase so it can manoeuvre in, out and around tight city spaces and still pick up a decent payload.”

Hydro excavating

Hydro excavation is essentially a non-mechanical, non-destructive process that uses pressurised water and an industrial strength vacuum to simultaneously excavate and evacuate soil.

“Because hydro excavation safely breaks up soil, the soil and water slurry is conveyed by vacuum to a debris tank,” Fischer explains.

“Unlike conventional manual or mechanical digging methods, hydro excavation virtually eliminates any risk of underground utility damage and that’s vitally important with all the optic-cables now networked across the nation.

“The hydro excavation process results in safe, fast, precise excavations that require less backfill, labour, restoration, and has less environmental impact than traditional excavation techniques.”

VTS has fitted a 1200 CFM blower on its vacuum unit which Fischer says delivers a huge air flow and is designed to pick up gravel, sludge, or any other material that would need to be excavated.

“Basically whatever you dig up can be sucked into the tank,” Fischer says.

“The water system is run by a high pressure pump which is fed by two 1000-litre fresh-water tanks that are fixed to either side of the main external barrel. A self-retracting hose reel attached to a high-pressure wand is used for digging.”

The pressure in the wand can be reduced and it can be used for washing down the truck when required.

“Most road authorities take a dim view of muddy tyres leaving a dirty trail on the bitumen leading away from job sites, so the ability to be able to clean itself is a great bonus,” Fischer adds.

Emptying the debris from the truck is a simple operation. The rear door with hydraulic locks, opens to 90 degrees and the barrel can be lifted the same way as a conventional tipper. The high-pressure wand can then be used to flush out the barrel.

DAF delivers

When asked about VTS’ decision to use DAF Trucks for their fleet, Fischer cited the products’ reliability, exceptional economy, driver comfort and their unique body builder module.

“Simple, firstly we have a great relationship with our local dealer Twin City Trucks,” Fischer says.

“We have found that DAF trucks’ national dealer network is one of the best around. Because we sell our vacuum trucks throughout Australia and New Zealand, and we offer a comprehensive back up support package with all our products, we need to be able to support our products quickly no matter where they are and through the DAF dealers, we’re able to achieve this.”

He adds the size and manoeuvrability of the LF55 are not the only reasons the company settled for this particular truck.

“Right from the moment you open the driver’s door, you immediately experience the quality of the LF interior,” Fischer explains.

“Indeed, the styling and standard of the finish resembles that of a luxury passenger car. The colour schemes and materials used mean that the LF cab offers a practical, pleasant and comfortable working environment, which is easy to clean and maintain and that’s really important in this business.”

A modern dashboard and instrument panel, an adjustable steering wheel with integrated controls and airbag, and well positioned handles and switches further add to the operator experience, Fischer says.

“We also find that our customers comment on the wide, deep windscreen and narrow pillars which provide excellent visibility, while green-tinted glass helps keep the cab cool. They also rave about the six-mirror layout that provides a larger field of vision when negotiating tight spaces for greater safety.

“The LF has four-point cab mountings to maximise comfort. Noise and vibration levels are even lower due to engine and cab mounts, resulting in more driving comfort, less driver fatigue and more safety.”

The DAF LF55 is powered by a 6.7-litre, six-cylinder Euro-5 PACCAR GR engine that punches out 285hp. This is matched to a six-speed AS Tronic automated gearbox, with an 11.5 tonne single reduction drive axle completing the driveline.

“It’s easy to see why we’ve chosen DAF trucks as the basis of our turn-key vacuum truck models,” Fischer says.

“However, we do fit up our systems to other brands which customers may have a preference for, but for people who want one of our machines that they can jump in, turn the key and go to work, it will be on a DAF chassis.”