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are required, they are best applied in the middle, at equal distances from the ends of 
the tie. 
The niaiu difficulty of long-tie systems lies in their defi cient drainage, two " backs " 
forming alongside the tie in the road-bed. This objection is increased when the cross- 
connection has a flat surface. 
Of all long-tie systems Haarmann's (employed ou Berlin City Railway) appears besi, 
exception being taken only to the form of cross-connection. Hilf's system is found in 
all points inferior, the former showing all the advantages required for an elegant and 
simply constructed superstructure ; the only objection to it is that to which all loug- 
tie systems are open — deficient drainage. 
(b) Cross -ties. 
The parts of the rail lying between the support and a point half way between 
supports receive less wear, and an uneven use of the rail is the consequence. Con- 
nections of rails to ties can never be made too rigid. The foot of the rail should 
preferably not be supported in its entire breadth, but only on its flanges to a sufficient 
breadth, thereby insuring more stability, permitting the use of rails not having a 
perfectly smooth foot, and avoiding au extra demand of resistance against tilting on 
the part of fastenings. 
Bed-plates are most desirable for wooden as well as metal cross-ties, making the 
manufacture of the latter ties less expensive and less difficult. 
By use of bed-plates the eating into parts most used, and the consequences result- 
ing therefrom, on all parts of the superstructure, can be avoided. The best mode of 
fastening is presented by bed-plates with hook bolts. 
The best length for metal cross-ties is given as 227.7 cm. (7 feet 5-^ inches); and 
in order to diminish the strain on the tie and counteract the tendency of every cross- 
tie system to change the gauge in consequence of a bending of the tie, there should be 
no tamping underneath for a length of 52.7 c. m. (20.7 inches). A trough, open only on 
the lower side, divided into three compartments by two cross-ribs placed 20.35 cm. 
(10.3 inches) from the center of the tie, the outer parts filled with bed material, the 
central part empty, will answer to this requirement. 
At 10 c. in. (3.93 inches, the height of a cross-tie), a metal cross-tie system furnishes, 
even in the most unfavorable bed material, at least 1.33 times greater resistance to side 
strains than a wood superstructure. 
The distance of ties, at 1 m. (3.28 feet), used on the Prussian profile, the author 
considers too great, and 0.95 m. (3.12 feet), or even less on curves, just permissible. 
Against longitudinal forces the transmission of the shock from the rail to the tie is 
more imperfect with metal systems than with wooden ties ; yet the resistance of a 
good metal system to displacement in the direction of the track is very much greater 
than with wooden ties. Iron ties of 10 c. m. (10.3 inches) height withstand the effects 
of longitudinal forces. 
RESULTS IN REGARD TO METAL CROSS-TIES. 
The cross-tie with short steps leaning somewhat outward is the most perfect. 
The need of bed material is smaller than in any other sujjerstructure. 
Bed-plates with bolts offer very firm connections, and can be easily moved or re- 
placed. Chauges of gauge can be as easily and accurately effected as with other 
connections. The mode of fastening is independent of the form of tie, and can be ap- 
plied to any iron tie at any later time. 
The weight per running foot ought to be somewhat. greater than that of ties now 
used, but the greater weight refers to such parts as are little subject to wear, and 
it does not exceed that required in the long-tie system. 
C. — Comparison of wood and metal superstructures. 
The superiority of well-devised metal superstructures over those with timber ties 
as usually applied, is more clear if we consider the more or less secure mode of fasten- 
ings in both svstems. 
