Truck towing a boat rolls into ditch along Lemon Tree Passage Road at Salt Ash

The driver of a truck towing a boat that rolled into a ditch on at Salt Ash early on Friday morning has escaped injury.

Emergency services including police, Rural Fire Service, NSW Fire and Rescue and Hazmat attended the crash scene which happened about 7.30am in the 60km/h zone of Lemon Tree Passage Road.

It is believed the driver of the laden truck lost control of his vehicle on a slight bend in the road, causing it to plummet down the embankment. It came to rest on its side in a muddy ditch.

Early reports suggest that the driver was left shaken but unhurt.

FRNSW crews from Raymond Terrace and Newcastle attended the scene, as did the nearby Williamtown/Salt Ash Rural Fire Brigade.

A FRNSW spokesperson said no other vehicles were involved in the incident.

The boat that the truck had been towing at the time of the accident began leaking diesel into the ditch.

Hazmat was called to contain the leak and booms were put in place.

While crews were containing the spill, it is understood that one of the responding emergency vehicles caught alight.

A FRNSW spokesperson said a "small mechanical vehicle" on site overheated and began to smoulder.

RFS and FRNSW crews on site worked to put out the small fire.

Lemon Tree Passage Road is open to traffic, however emergency services are still on scene.

Motorists are advised to allow extra travel time and to give way to responding emergency vehicles.