QUESTION 506. _How can an accident by running into the opening at a draw-bridge be avoided?_ _Answer._ First by ALWAYS coming to a dead stop before reaching it, and second by not starting again until it is absolutely certain that the draw is closed. Of course if a locomotive runner of an approaching train finds a draw open, the only thing he can do is to stop as soon as possible. QUESTION 507. _What measures should be taken to prevent locomotives from escaping without a responsible person on them?_ _Answer._ In the first place when a locomotive is left standing the throttle-valve should always be _closed_ and _fastened_, the cylinder cocks should also be opened so that if any steam leaks into the cylinders it will not accumulate there, but will escape, and the reverse lever should be placed in the centre of the sector, so that if by any accident the throttle should be opened the engine will not start. QUESTION 508. _If a locomotive should escape, what should be done, and how may it be captured?_ _Answer._ The first thing to be done is to telegraph to the stations towards which the escaped engine is running, either to keep the track clear, or, if there is a train approaching, to open a switch and thus let the engine run off the track. An escaped engine may be captured by a swifter engine following it, but this is always attended with great danger, as the first engine may leave the track or become wrecked. A safer plan is to telegraph ahead of the escaped engine and have an engine placed in a position where the track can be seen for a long distance in the direction in which the runaway is expected. As soon as the latter comes in sight, the waiting engine should start in the same direction, so that when they get near to each other they will both be running in the same direction and at nearly the same speed. By regulating the speed of the front engine, the following one may be allowed to come up to it quite gently, and then a man can easily climb from the one engine to the other, and thus both be stopped. QUESTION 509. _What should be done in case an engine gets off the track?_ _Answer._ The first thing to do is to close the throttle-valve and “signal for brakes,”[114] or apply the continuous brakes if the train is equipped with them, and then reverse the engine. If its position after it stops is much inclined, it is generally necessary to draw the fire to prevent injury to the heating-surface, a part of which is then usually exposed to the steam, and therefore not covered with water. [114] This expression means, among railroad men, to signal to brakemen by blowing the whistle to have them apply the brakes. QUESTION 510. _How is a locomotive replaced on the track in case it gets off?_