Automatische TreinBeïnvloeding or ATB (English: Automatic Train Control) is a Dutch train protection system first developed in the 1950s. Its installation was spurred by the Harmelen train disaster of 1962. ATB operates by the train collecting electrical signals from line-side apparatus and will override the driver's controls in the following situations: a) failure to reduce speed at a caution signal (ATB will slow the train sufficiently to stop at the next signal). b) failure to observe speed limit (ATB makes an immediate emergency brake application) ATB-EG ATB-EG (ATB Eerste Generatie English: ATB First Generation) is based on the American Pulse Code Cab Signaling system. It is installed on all major Dutch rail lines Technical overview ATB-EG controls 5 speeds: 40 km/h, 60 km/h, 80 km/h, 130 km/h and 140 km/h. Just like Pulse Code Cab Signaling the system works by sending pulses along the AC track circuit. When the circuit is closed by the train's front wheels an electromagnetic field is created with each pulse. These fields electromagnetically energise two coils in front of the leading axle which feed the pulses to the ATB-system. The onboard ATB system works out the amount of pulses per minutes and translates this to the 5 codes Yellow, Yellow6, Yellow8, Yellow13 and Green with corresponding speeds of 40, 60, 80, 130 and 140 km/h or so-called volle materieelsnelheid (full train speed). If the train's maximum allowed speed is lower (as for instance the SGM), the speed settings above its maximum speed will be omitted. Operation The speed limit enforced by ATB-EG is presented to the driver by a row of lights, with the current cab signal illuminated, (Mat 64, SLT, PROTOS and THALYS) which can be integrated into speedometer (ICM and SGM) or either a red needle (VIRM, DDAR and Loc 1700) or yellow LED (FLIRT and GTW) on the outside of the speedometer. The driver will be informed of a speed change with a short "ding". If the a driver exceeds the current ATB-speed by 5 km/h a bell will start to ring continuously. If the driver does not brake within 3 seconds the ATB will initiate an emergency brake application. When a stretch of track has an ATB code for a lower speed, due to a lower track speed or a diverging switch etc., the section before it will carry that code as well. A signal or sign guarding the first section