信令is a crucial part of the railway infrastructure, enabling trains to move safely around the network.
但它如何工作以及它在延迟中发挥着什么作用？
What is signalling?
信令is essentially a sophisticated traffic light system for the railway. The complexities of moving trains around such a large network, keeping them safely apart, and allowing for their long stopping distances, means the signalling system is very complicated and comprises a great many parts.
The signals themselves are the lineside pieces of equipment that tell train drivers when it is safe to proceed and what route their train will take.
更广泛的信令系统还包括用于确定列车位置，控制铁路和操作时间表的系统，以及控制方向列车的点。其他系统确定了什么动作是安全和培训保护系统防范司机错误的动作。
信令系统被设计为不能安全的状态，因此故障的组件通常可以导致剩余红色的信号，导致火车延迟。
Signals and points
我们的信号看起来像什么，我们如何改善信令？
大多数信令系统使用轨道方向信号来控制列车的安全运动，并告诉驱动程序该怎么办。
彩色光信号显示不同颜色以授权列车移动。许多人有额外的指标来显示火车设置的路线以及它必须走的方式。
Modern signalling systems provide the necessary information to the driver on displays in the train cab.
我们在整个网络中拥有大约40,000个信号，主要是彩色光信号，并且来自LED技术的许多受益。还有一些传统的机械信号量信号。
我们的网络受到不断增长的压力，以满足容量需求，使我们的老龄化信号传导系统的现代化成为我们对乘客更好的铁路愿景的重要组成部分。大约一半的网络仍超过30岁。
什么是信号故障？
当乘客听到有关信号故障的公告时，它通常是更广泛的信令系统的失败，这意味着它不再拥有它所需的所有信息。
The loss of vital data, such as the exact position of trains or the status of the track ahead, results in delays because the system can only allow train movements when it knows it is safe to do so.
So, when a signalling system fails, is it possible to switch it off and turn it back on again? Sometimes, yes, but very often it is a component that needs to be located alongside the track which has failed. These failures require staff to physically access and repair the component, which all takes time.
Meanwhile, multiple trains will have been stopped by red signals and so it’s not necessarily a quick fix to get the things moving again.
信号系统也容易受到从洪水泛滥的广泛风险的影响。这些可能导致难以解决的故障难以解决。
信号故障的一些最常见的原因
Points failure –A fault with the movable pieces of track or their operating equipment that enable trains to change tracks. Points are interlocked with signals, so you can’t tell a train to proceed if the points have failed.
电源（检测）失败 -A national grid problem or an issue with the power supply’s backup system. They often occur in places where our cables are older or have been stolen. Power failures can affect systems covering a very large area.
火车/轨道检测失败 -用于检测每个轨道上的列车的系统的失败。
Extreme heat –非常高的温度会影响信号系统，导致它们关闭。它们还可以影响火车检测系统。
有缺陷的组件 -所有类型的电子，电气和机械部件中的故障都可能导致系统故障。完整的系统由数千个单独的组件组成，并不总是可能的复制。
Glossary:
Signals– the lineside pieces of equipment that tell drivers if they can pass safely.
驾驶室信令– a signalling system where the indication to proceed is given to the driver on a display within the cab rather than by lineside signals.
信令- 控制火车运动的更广泛的系统。
Points- 可移动的开关轨道，可直接在连接线上进行火车，通常由信号系统控制。
火车检测- 确定一段曲目是否清除或占用火车的系统。