Derailment by misplaced switches and draws.
Derailment by obstacles upon the rails.
Breakage of machinery.
Failure of track or bridges.
Fire.
Boiler explosions.
Those causes which are aggravated by fast travelling are the first, second, fifth, and sixth; the effects of all are worse at high speeds than at low.
The proportion of accidents due to each of these causes, taken at random from one hundred cases on English railways, are as follows:—
| Collision, | 56 |
| Breaking of machinery, | 18 |
| Failure of the road, | 14 |
| Misplaced switches, | 5 |
| Obstacles on rails, | 6 |
| Boiler explosion, | 1 |
| 100 |
In collision by opposition, the engines, tenders, and baggage cars must be demolished before the shock reaches the passengers; in collision by overtaking, the engine of the rear train plunges at once into the last passenger car of the leading train; the force in the last case is the difference of the speeds, in the former the sum. The increase of danger from this cause, attendant upon express trains, is due, first, to the longer time required in stopping, and second, in the greater shock if collision occurs.