RAILWAY CONSTRUCTION. 



SOFT STEKL. ANALYSIS OF Six STEEL RAILS WHICH STOOD THE TEST WELL, AND 



BENT FREELY WITHOUT SHOWING ANY SlGN OF FRACTUBE. 



Many rails which have been broken in the line under traffic 

 have been analyzed, and proved to be hard steel ; while others, 

 which have been bent into all sorts of shapes, but not broken 

 during accidents or derailments, have also been tested, and 

 proved to be of soft steel. 



Some engineers are advocates for a hard steel rail, and claim 

 for it greater durability and longer wear ; but even supposing 

 such hard rail should possess a slight superiority over the soft 

 rail, it is well to consider whether such assumed advantage is not 

 obtained at the risk of incurring greater liability to fracture. 

 It must be borne in mind that a rail, once placed in the road, is 

 exposed to all the changes of temperature from heat to frost, and 

 has frequently to sustain increased strains arising from loose 

 sleepers, where the gravel or ballast has been disturbed during 

 heavy rains. 



When writing a specification for steel rails, it is usual to state 

 the number of tons per square inch in tensile strain which the 

 steel must be able to sustain without fracture, and also to 

 stipulate that some of the rails will be tested by the falling- 

 weight test. In the latter test a rail is placed, say at 3 feet 

 bearings, and in a similar position to what it would occupy in 

 the road, and a weight of eighteen hundredweight, or one ton or 

 more, according to section of rail, is allowed to fall from a height 

 of 9 or 10 feet, on to the rail, at the centre between the bearings. 

 With three blows from the given height, the rail must not bend 

 or deflect more than a specified amount. The falling-weight 

 test is, perhaps, rather a rough and ready one ; but it is always 

 reassuring to prove that the rails will withstand such a severe 

 ordeal, as it must be a very exceptional circumstance in the 

 routine of railway working which will produce a blow or shock 



