Chinese railway signalling

Semaphore signals based somewhat on British practice. Use Red and White home signals, and Yellow and Black distant signals. [5]

Apart from Red=Halt and single G=Clear, the lights of a semaphore signal at night do not match match their colour light equivalents. There also more colour light aspects than semaphore aspects.

Colour lights: single green means full speed on straight, red means stop, with remainder meaning something in between, [6]

Were double green was less restrictive than a single green, then there would be no need for "lamp proving" should there be a lamp failure. Lamp failure means lamp burnt out or equivalent.

But in China, double green is more restrictive that single green, so that if a lamp fails, a less restrictive aspect is displayed. This is potentially dangerous. However lamp proving can be easier said than done.

In general, the railway specifications are based on the Chinese National Railway Class 2 Standard.[7] However, with explicit demand by the Ethiopian Railway Corporation, some changes were made and adapted, which do not fit the Chinese standard, such as double stacking.

The railway characteristics were first specified and used for the Addis Ababa–Djibouti Railway and in many cases had to be used for other railways as well to keep the installations compatible with each other. Trains should be able to use different railways without having to switch locomotives (as an example). The most straightforward example of compatibility is, that there is no break-of-gauge. The first railway was standard gauge, so all following railways also had to be standard gauge. The power supply had to be the same for all railways, the train protection system as well.

In the following, common features and specifications of all railways are shown. If there are differences between railways, this is indicated by a range given for values:

• Gauge: Standard gauge (Britain)
• Couplers: Janney AAR (America)
• Brakes: Air Westinhouse (America)
• Electrification: Overhead catenary 25 kV AC / 50 Hz (France)
• Target speed (passenger): 120 km/h (75 mph)
• Target speed (freight): 80–90 km/h (50–56 mph)
• Maximum train load (freight): 3,000–3,500 tonnes (3,000–3,400 long tons; 3,300–3,900 short tons) gross[8]
• Designed transport capacity: 10-20 million tonnes annually
• Length of arrival & departure track at passing loops: 850 m (dual locomotive: 880 m) [resulting max. train length ~800 m]
• Minimum railway curve radius: 800–1,200 m (2,600–3,900 ft) [600–800 m (2,000–2,600 ft) at difficult locations]
  • See Minimum railway curve radius
• Maximum (ruling) gradient: 1.85-2.65 %
• Maximum vehicle loading gauge height: 5300 mm
• Trains run on the: Left (Britain)
• Railway signalling: semi-automatic block or automatic block
• Train protection system: ETCS-2 SIL4[9]
• Level crossings: permitted (no full grade separation)
• The loading gauge width for new standard gauge railways in Africa is 3,400 mm (11 ft 2 in) the same as the original Shinkansen in Japan, and copied by China, South Korea, Ethiopia, Kenya and possibly Tanzania and Nigeria.

px300