SAFE RAILWAY WORKING. 669 



regulating the system of train working, including details as to staff 

 and block working, is a problem belonging to the engineering branch 

 of a railway, including under that term the locomotive, permanent 

 way, and telegraphic branches. 



The subsequent discussion is divided into Sections in the follow- 

 ing order : — 



(a) Block telegraph and train staff working. 



(b) Arrangement of junction stations. 



(a) Block Telegraph and Train Staff Workixc. — If trains 

 could be run with unerring regularity as regards time, and were 

 always under perfect control, if signals were never obscure<l by fogs 

 or fiom other causes, if signal men and others never made mistakes, 

 and if the permanent way and rolling stock were always in jjerfect 

 order, accidents would become impossible. But such conditions 

 cannot be realised; for instance, even with the most careful super- 

 vision, latent flaws in materials may exist undetected, and may 

 develop at a critical moment. The possibility of mistakes in signal- 

 ling can be reduced by the use of a modern interlocking apparatus and 

 oilier safety appliances, whilst continuous brakes provide for better 

 control on the train itself. On the other hand, atmos{theric con- 

 ditions may at any moment enormously increase the risk owing to 

 " greasy rails "' and signals becoming obscured by fog. The possi- 

 bility of men making mistakes has to be borne in mind, and hence 

 it is generally recognised that a system to be safe should be such 

 that two men must each make a mistake, or one man must make two 

 separate mistakes, before an accident can become possible. For a 

 driver to overrun a vStopping signal is a most serious offence, deserv- 

 ing the severest punishment, but there is always the possibility that 

 from some unforeseen cause, such as greasiness of rails or failure of 

 brakes on a descending grade, or in cases of fog the signal not being 

 seen, a driver may overnin a stopping signal. Hence a system of 

 working to be safe should be such that before a driver can cause an 

 accident he must overrun two stopping signals at a reasonable 

 distance apart, and both indicalmg danger. With the block tele- 

 graph system (hereafter referred to) carried out in its entirety, such 

 provision is m.ade, and any attempt to reduce it should be most 

 vigorously resisted. 



It may not be out of place to remind members tliat at the 

 inception of the railway system attempts were made to secure safe 

 railway working by preseiTing a tirrie interval between following 

 trains. This, however, was not a satisfactory safeguard, as, for 

 instance, where for any reason the leading train was delayed between 

 stations, or if it broke down. The development of the electric tele- 

 graph made it possible for the officials at each station to advise those 

 at the station in the rear of the arrival of each train, and to obtain 

 from those in advance permission to send it on, such permission being 

 granted only after the pi'eceding train had arrived. Hence an 

 interval of space was substituted for an intei-val of time to secure 

 immunity from collisions between following trains, and in this is the 

 germ of the block telegraph system of railway working. The lines 

 Avere divided into sections, and under the absolute blocking system 

 only one train was allowed to be in a section at once. Hence, when 



