MF4 (funkgesteuertes Inspektionsfahrzeug)

A radio-controlled inspection vehicle for rooms where no human should go: the MF4 belongs to Kerntechnische Hilfsdienst GmbH (KHG) in Eggenstein-Leopoldshafen, Germany's nuclear emergency service founded in 1977 by power-plant operators, the fuel-cycle industry and research centres and today run under BGZ.

KHG is operator and in-house developer rather than a commercial maker, keeping a remote-handling fleet from a 22 t radio-controlled excavator down to small inspection vehicles. The MF4 weighs 350 kg, measures 130 × 85 × 108 cm (height 40 to 108 cm depending on superstructure), carries 150 kg and runs on two tracks at 0 to 30 m/min (1.8 km/h); its 48 V battery lasts 2 hours and it climbs 32 degrees.

Radio carries control, video and audio over up to 1 km, with cable control as an alternative. On board are the KM20 articulated manipulator with six degrees of freedom, a 1,600 mm arm and 20 daN at the gripper, interchangeable tool jaws, a high-dose measuring system and a black-and-white camera on a pan-tilt head with microphone and lighting; a trailer system carries power tools and a special truck brings the vehicle to the site.

Fraunhofer studied its radiation sensitivity in 1995, and the MF4 took part in the EU exercises EnRicH and the CENTAURO project. As KHG's own equipment it has no market price, and the datasheet (December 2025) gives no build year. Japan's Quince at Fukushima weighed a tenth as much but lacked a manipulator.