The Stairway Access Tank (SAT) is custom-built to fit most haul truck designs. Featuring the company's ‘Water Wise' system, the tanks start at a capacity of 14,000 litres and include all spray equipment.

The first tank off the production line has been created to fit a Cat 793C haul truck. With a capacity of 198,000L, Austin Engineering is touting it as Australia's largest water truck.

"The most obvious external feature of the Austin water tank is a stairway from the top of the tank structure down to a large (137cm x 259cm) access port for easy entry and exit for personnel and maintenance equipment to the tank interior," the company said of the new release.

"The fill port is located behind the water dam to ensure any overflow flows away from the cab and deck to the rear of the truck."

In its design, Austin considered operator access and ease of movement once inside the tank; issues that were recently addressed in a 10-year study by the US-based National Institute for Occupational Safety and Health (NIOSH).

Access inside tanks is traditionally through semi-circular portholes (generally 60cm wide x 74cm high) in the baffle system. While these are adequate, they can slow and restrict access and movement.

The new SAT from Austin, however, features a series of oversize rectangular access ports (63cm wide x 155cm high) in a unique baffle system that replaces traditional portholes and can significantly improve safety and comfort inside the tank.

"The engineered corrugated baffle system, which interlocks the baffles for increased structural integrity, controls both transverse and longitudinal water surging and reduces the overturning forces by 19% to improve truck stability," the company explained.

"Maximum overturning force is delayed by about one second, providing an increase in the time to react to any side force."

The company also designed the baffle system to allow for lighter-weight tanks, resulting in additional payload and less operating costs as needed.