Oversize & overmass load limits, explained

Heavy haulage on the Sunshine Coast is governed by the National Heavy Vehicle Regulator (NHVR) under the Heavy Vehicle National Law. A load becomes oversize when it exceeds standard dimension limits, and overmass (OSOM) when it exceeds axle or gross mass limits. Once a load crosses either line it can no longer travel under general access — it needs a permit that fixes the route, the time of travel and the escort configuration. Kawana Heavy Haulage arranges the permit, surveys the route and coordinates the escorts as one package, operating from Kawana Waters across the Sunshine Coast.

Dimension thresholds

The common dimension triggers are width over 2.5 metres, height over 4.3 metres, and length beyond standard trailer limits. A load between 2.5m and 3.5m wide is oversize but generally runs with a single front pilot outside curfew hours. Above 3.5m the escort requirement steps up — a second pilot is added, and at the higher thresholds Queensland Police escort becomes mandatory. Over-height loads above 4.3m need a surveyed route that clears every bridge, overhead service and sign gantry between pickup and drop-off, which on the Sunshine Coast includes checking the Caloundra roundabouts, the Nicklin Way corridors and the hinterland range roads.

Mass thresholds

Overmass loads exceed the axle group or gross mass limits set out in the NHVR mass schedules. A load that is heavy but within general mass limits can move on a low loader without a permit; anything over-mass needs bridge and pavement checks along the route and a permit that may restrict travel to specific roads and windows. Tracked machines are a frequent trigger — a machine's transport weight is higher than its operating weight, so the loaded mass is always confirmed before booking rather than read off a spec sheet.

Trailer selection

The trailer follows the load. Smaller machines up to roughly 8–10 tonnes run on a tilt-tray, which tilts to ground level so the machine drives or winches on. Heavier and taller machines go on a low loader with a low-slung deck to keep transport height down, and long or over-dimensional freight uses an extendable low loader that spreads the load over more axles. Hydraulic decks and removable goosenecks drop the load angle further for low-clearance tracked gear. The right trailer avoids a permit where one isn't needed, and ensures the load sits lawful and stable when one is.

Permits, pilots and timing

Every oversize and overmass move is subject to assessment and permit approval. The permit sets the route, the travel window and the escort count; curfews, school zones and night-only restrictions are common on Sunshine Coast corridors. We lodge the permit, brief the pilots and any police escort, and run the move as one planned movement from pickup to drop-off. Because every job is quoted to spec, the final dimensions, weight and route determine the scope — every move is quoted to spec, and no move proceeds until the route checks out.