氣軔系統概述

所有鐵路車輛 都安裝有機械式軔機 ，即機械式煞車。運作方式為透過手動操作手軔機 ，或以壓縮空氣推動閘瓦 ，物理性地使其擠壓車輪。

使用壓縮空氣緊軔較為迅速，因此部分車輛載有單獨車輛制軔 方式，而不僅依賴手軔機。更重要的，使用壓縮空氣得以使整組列車中的所有軔機同步緊軔，此稱貫通制軔 。構成氣軔系統的主要部件為：

主風缸

主風缸是動力車輛 上的大容量氣瓶。此容器儲有空氣，且通常以車輛搭載之風泵 加壓至 8 Bar 。主風缸為氣軔系統的壓力來源，同時也供應如喇叭 和雨刷 等其他車輛系統。

軔管

軔管是用於分配壓縮空氣至整組列車的管路系統。正確連結的列車中，車輛之間以軟管連結且氣軔角旋塞必須開啟，而列車兩端之氣軔角旋塞則維持關閉。此使整組列車的軔管在正常情況下被作用中的主風缸充至 5 Bar 壓力。軔管容納的空氣量相對要少，但加掛愈多車輛仍將提高空氣用量。

輔助風缸

輔助風缸是各列路車輛上搭載的中等容量氣瓶。它們隨著軔管充氣，在需要時以當中儲存的壓力為獨立車輛緊軔。取決於列車中的車輛數，為它們充氣可能需要一段時間，但壓力在運作期間幾乎不會被消耗殆盡。

軔缸

最後，各車輛都有一個或多個自己的「軔缸（Brake Cylinders）」。此為驅動軔塊所用的小型氣動活塞，將軔塊推向車輪使其減速。當「軔管」中的壓力改變，一個控制閥將依據壓力變化，使用車輛中稱為「輔助風缸（Auxiliary Reservoirs）」的另一氣瓶中的空氣推動軔缸內的活塞。

Brake cylinder pressure can be manually dumped in situations where that may be desired.

司軔閥

Compressed air brakes, be it independent or train , are operated by control valves found in motorized vehicles' cabs , usually in the form of levers. There are different types of control valves and they need to be properly cut in in order to function.

Train Charging

Due to leaks , no brake components can remain pressurized indefinitely. It usually takes some time to bring the components of unused vehicles to their nominal, high pressure level, before they can be set in motion. The two biggest factors are the main reservoirs, which will charge as quickly as the respective compressor(s) allow it, and auxiliary reservoirs, which may take a long time to charge, depending on how many vehicles there are in the train.

Adding additional locomotives to the train to improve charging speeds is a viable option, and so is revving the engine .

Automatic Stop Safety Mechanism

Crucial safety feature of the compressed air brake system is that, in case a vehicle connection is severed, such as due to a derailment , emergency brakes are automatically applied on both remaining train parts. This is because the brake pipe pressure is lost to the atmosphere, and it is integral to the compressed air brake system design in trains.