CAUSES OF COLLISION. 



the stations ; and as the stations, on the average, are not four 

 miles asunder, these trains must be almost continually in a state 

 either of retarded or accelerated motion. They scarcely get up 

 their speed after starting from one station, before they are 

 obliged to slacken their pace, in order to stop at the next. The 

 average speed of such trains is therefore comparatively small. 



Between these and the express trains, which present the 

 extremes of speed, there are several which move at intermediate 

 average rates, stopping fess frequently than the one, and more 

 so than the other, and, when at full speed, proceeding with a 

 less velocity than the express trains. 



When all these circumstances are taken into account, and 

 when it is also considered that, on some of the great trunk lines, 

 such as the North- Western, as many as fifty trains pass over the 

 same rails every twenty -four hours, much more than the half of 

 which are worked during the day, and therefore succeed each 

 other at very short intervals, the wonder is, not that collisions 

 occasionally occur, but that a movement so crowded and com- 

 plicated can be conducted at all, without most imminent danger. 



The most frequent source of accidents from collision, arises 

 from single waggons or trucks being left standing upon the rails. 



When express trains have to be stopped, the steam must be 

 cut off, and the brakes applied at a considerable distance from 

 the place where they come to rest. Hence arises the greater 

 liability of accidents by collision with these trains. If an 

 obstacle is observed upon the railway by the engine-driver, it 

 must be noticed at a distance so great as to render it possible to 

 stop the train, otherwise collision must take place. 



One railway accident is often the cause of another, and colli- 

 sions frequently arise in this way. When an accident occurs to 

 a train, by which it, or part of it, is detained upon the line for 

 any length of time at a place where, in the regular course of the 

 railway traffic, it ought not to be found, trains following on the 

 same line of rails, not expecting to encounter such an obstacle, 

 are liable to a collision with it. In all such cases, the guards or 

 conductors run back upon the line, and if the accident take place 

 at night, make signals with their lamps to warn the approaching 

 train of the obstacle. 



In certain classes of accident, both lines are obstructed, and 

 such precautions must be taken in both directions as, for 

 example, when a train or part of it running off the rails, the 

 engine, carriages, or waggons are thrown some on one line of 

 rails and some on the other. In this case, one messenger is sent 

 along the up and another along the down line to warn approaching 

 trains to stop. 



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