THE BLOCK SYSTEM:
7: Different types of train
Is Line Clear? signals
There are a range of different Is Line Clear? bells signals to help the signalman with his responsibilities. They apply to different kinds of train, guiding him on speed, whether a stopping train or through, and whether or not it is conveying passengers. The latter is important to assist him in applying the correct regulations.
In 1960, there were eleven classifications of train, lettered A to K, although these were superseded by a similar range numbered 0 to 9 in 1962, when the four character headcode system was adopted on diesel and electric locomotives.
The bell signals are detailed at this web site, surprisingly enough, on the Bell Signals page.
A few types of train warranted special signalling arrangements, these are detailed below.
Trolleys in tunnels
An Engineer’s hand trolley on the line would normally be protected by a handsignalman located a safe distance in rear of it, and through coordination with the signalman would be removed in sufficient time to avoid delays to trains. In certain tunnels (these were defined in a publication known as the Sectional Appendix) this method was considered inadequate, and special arrangements were necessary.
In our example, if there were such a tunnel between Box A and Box B, Arthur at Box A would, on receiving a request from the Ganger to put a trolley on the Up Line, offer the trolley to Bert at Box B using the Is line clear? bell signal 2-1-2 (2-2-2 on the Southern Region).
Bert will always accept a trolley under the Warning Arrangement (see Chapter 5). This is one of the occasions where special authorisation is not required for the use of that Regulation.
If the ganger subsequently contacts Bert to advise him the trolley has been removed from the line, Bert may send Train Out Of Section to Box A. Alternatively, if it is more convenient for the ganger to advise Arthur of the removal of the trolley, Arthur can send the Cancelling bell signal to Bert. The Cancelling bell signal is detailed below.
Trains requiring to stop in the section
If there is a station in the section, it is only natural that trains will need to stop in section. That is not what the circumstances described here are about.
Should a train in any of the following categories require to stop in section, special arrangements apply:
- Freight train, working at intermediate sidings controlled by a ground frame.
- Ballast Train, involved with engineering work.
- Officer’s Special Train, stopping for management inspections to be carried out.
If a train of the above three categories is required to stop in section, the signalman will be advised in advance by the guard of the train. Then, instead of using the normally prescribed signal, the Is Line Clear? bell signal 2-2-3 must be used. As with trolleys (above), a train signalled 2-2-3 is always accepted under the “Warning Arrangement”.
If, for example, Bert has offered a train to Charlie which should be routed via the Branch Line to Box D, Bert can cancel the train by sending the Cancelling bell signal 3-5 to Charlie. Charlie will acknowledge the bell signal and return his block indicator to Normal.
Trains wrongly described
If Bert has sent the incorrect Is Line Clear? signal to Charlie, Bert sends Last train incorrectly described bell signal (5-3) to Charlie and, when acknowledged, sends the correct Is Line Clear? signal. Charlie will not alter the position of the block indicator.
Engines assisting in rear of train
Where there are steep gradients, trains may be assisted by one or locomotives at the rear of the train – bank engines. The locations where this can be done are defined in the Sectional Appendix. It is crucial for the signalman to know which trains have bankers, and how many bankers there are (up to four used to be used on the Lickey incline!) because he must not give Train out of Section just on seeing the train’s tail lamp. He must ensure that all bank engines have also left the section. A tally on the number of bank engines in the section is assured by the use of the Engine assisting in rear of train bell signal (2-2). This is sent immediately after acknowledgment of the Train Entering Section signal, and has to be acknowledged. It must be sent once for every assisting engine. There is also a corresponding bell signal (2-3-1) for Engine with one or two brake vans assisting in rear of train.
If for any reason a bank engine does not enter the section after signalman has sent the 2-2 bell signal, he must advise the signalman in the next box by telephone.
It should be understood that these arrangements do not apply when a failed train is being assisted in the rear. In such a case, the arrangements are advised verbally from signalman to signalman.
Light Engines, and Engines and Brake Vans, running together
In order to identify when more than one engine (or engine and brake) are coupled together, they are treated as bank engines and signalled with the 2-2, or 2-3-1 for every additional locomotive. Special authority is not required for this particular use of the bell signals.