LZB

Linienzugbeeinflussung (or LZB) is a cab signalling and train protection system used on selected German and Austrian railway lines as well as the AVE in Spain. The system was mandatory where trains were allowed to exceed speeds of 160 km/h (99 mph) in Germany and 200 km/h (120 mph) in Spain. It was also used on some slower lines to increase capacity. The German Linienzugbeeinflussung translates to continuous train control, literally: linear train influencing. It is also called linienförmige Zugbeeinflussung.

LZB is deprecated and to be replaced with European Train Control System (ETCS). It is referenced by European Union Agency for Railways (ERA) as a Class B train protection system in National Train Control (NTC). Driving cars mostly have to replace classical control logic to ETCS Onboard Units (OBU) with common Driver Machine Interface (DMI). Because high performance trains are often not scrapped ore reused on second order lines, special Specific Transmission Modules (STM) for LZB were developed for further support of LZB installation.

In Germany the standard distance from a distant signal to its home signal is 1,000 metres (3,300 ft). On a train with strong brakes, this is the braking distance from 160 km/h. In the 1960s Germany evaluated various options to increase speeds, including increasing the distance between distant and home signals, and cab signalling. Increasing the distance between the home and distant signals would decrease capacity. Adding another aspect would make the signals harder to recognize. In either case, changes to the conventional signals wouldn't solve the problem of the difficulty of seeing and reacting to the signals at higher speeds. To overcome these problems, Germany chose to develop continuous cab signalling.

The LZB cab signalling system was first demonstrated in 1965, enabling daily trains at the International Transport Exhibition in Munich to run at 200 km/h. The system was further developed throughout the 1970s, then released on various lines in Germany in the early 1980s and on German, Spanish, and Austrian high-speed lines in the 1990s with trains running up to 300 km/h (190 mph). Meanwhile, additional capabilities were built into to the system.

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