Gruen Other models

The register lists here 10 versions with unladen weights from 730 to 2,250 kg, gross weights from 935 to 3,500 kg and widths from 1,580 to 2,050 mm.

As towed working equipment rather than classic transport trailers, tar-boiler trailers are common in road and civil engineering, where they bring jointing compound, bitumen or hot asphalt up to working temperature on site; the unladen weight stays deliberately low so that even smaller tow vehicles can bring the equipment to the worksite; heating time also varies with boiler size, which is why construction firms often keep several sizes side by side in their fleet.

When buying used, the condition of the boiler, burner and thermostat matter most, along with the tightness of the welds, the condition of the chassis, brakes and lighting, and the date of the last burner inspection; spare parts for the boiler and burner are available from dealers specialising in bitumen equipment.