HIGH SPEED RAILWAY CONSTRUCTION AND WORKING. XXXIX. 



as far as centrifugal force is concerned, derailment or 

 unequal pressure on rails is less liable on such express lines, 

 notwithstanding the speed, than on ordinary ones. Then, 

 if the constant speed from end to end, and fixed intervals 

 between trains are duly maintained, combined with the 

 non-existence of points and crossings, there can be no 

 collisions, while, owing to single car trains, there can be 

 no breaking of couplings. The causes of accident therefore 

 are limited to derailment through effects of curvature, 

 other than centrifugal force, to defects in the substructure 

 of the rolling stock or in the road, and to obstructions upon 

 the line. As collisions usually cause the greatest disasters 

 on railways, the immunity from these is a great point. As 

 regards derailment through curvature, Mr. Behr, in his 

 proposed line from Manchester to Liverpool, is adopting 

 the mono-rail system, by means of which he expects to run 

 his cars safely round 30 chain curves, at 110 miles per hour, 

 and he has actually attained, on an experimental line at 

 Brussels, 83 miles per hour on a 25 chain curve. The 

 Brussels to Antwerp proposal is also on this principle, but 

 the other lines mentioned which are on the ordinary bi-rail 

 system, escape the curvature difficulty by making the 

 alignment practically straight. Derailment from defects 

 in the cars, and in the road, can only be avoided by increas- 

 ing their strength and solidity, and from obstruction on the 

 road, by more effective fencing, and watching, matters of 

 expense only. 



Though the liability to accident is greatly reduced on 

 these special lines, certain discomforts to passengers arise 

 from the great speed. In order to save time, and to utilize 

 as much as possible, the whole length of a short line for 

 the maximum speed, the acceleration and retardation at 

 beginning and ending must necessarily be severe. As 

 much as 4 ft. per second per second is proposed on the first 



