Anti-jackknifing
A jackknifing brake , and trailer brake called a brake for truck-trailer combinations (is saddle or road trains ) while driving on the air brake acts only on the trailer or semitrailer. The brake thus acts independently of the towing vehicle or the service brake.
The anti-jackknifing brake is operated in the driver's cab using its own, step-by-step adjustable lever. By stretching the combination, especially when driving downhill, the trailer can be prevented from running into or even buckling on the towing vehicle.
This braking system has been banned in Germany since the 1980s, as accidents have increased due to the frequent misuse during normal driving (to protect the brakes on the towing vehicle).