Jet vac units carry two maintenance regimes on one chassis

Look at a jet vac unit in a yard and you see one vehicle. Look at its records and there should be two sets of checks: one for the lorry, one for the high pressure water and vacuum equipment mounted on it. Operators who treat the body as an accessory to the chassis tend to discover the gap at a bad moment.

The chassis side

Combination units built on heavy goods vehicle chassis bring the usual roadworthiness duties into play. Where the vehicle requires a goods vehicle operator’s licence, the operator must also meet the associated undertakings, including planned safety inspections and effective defect reporting. Licensing requirements depend on the vehicle’s use and any applicable exemption. A laden unit carries a full water tank and, after work, a recovered load of silt, sludge and washwater. That makes weight management, braking performance and tyre condition daily concerns rather than inspection-day concerns.

Liquid loads also move. A part-filled tank surges under braking and cornering, and a driver used to dry freight needs to understand how that feels on a roundabout or a downhill junction.

The equipment side

The jetting pump, hose reel, lances, nozzles, vacuum system and tank seals carry their own risks. A damaged high pressure hose or a worn fitting can cause serious injection injuries, and water jetting equipment is generally expected to be inspected and maintained to recognised industry guidance, with operators trained to use it. Those checks sit alongside the vehicle inspection rather than inside it, and the people doing them may not be the same.

Where the two meet

• The driver’s walkaround check should prompt a look at the equipment as well as lights, tyres and mirrors.
• Defect reports need a clear place for equipment faults, so a leaking pump seal is recorded and acted on like a brake defect.
• Inspection sheets and equipment service records should be filed together, so anyone reviewing the vehicle sees its whole condition.

The driver is also the operator

On many jobs the person who drove the unit to site is the person running the jetting. That blends drivers’ hours with long periods of physical work on site, and the distinction between driving, other work and rest needs recording correctly. Training records should cover the applicable driving licence and professional qualifications, together with competence in operating the jetting equipment and following the safe system of work.

Water in, water out

A jetting job uses clean water and produces dirty water. Where the unit recycles water, its filtration needs maintaining too. When recovered washwater and deposits are removed as waste, the load needs the appropriate waste documentation and an authorised destination. The receiving arrangements matter as much as the equipment used to recover the material.

High Pressure Jetting describes high pressure water jetting for drains, industrial equipment and surfaces, with washwater controlled, and makes the point that pressure is only one factor in the method. The same thinking applies to the vehicle. A roadworthy chassis does not establish that the pump and hoses are fit for use. Equally, maintaining the jetting equipment does not replace the vehicle’s roadworthiness checks. The records should prove both halves are in order.