WOOD TRANSPORT BY LANJX 



by chains from two wheels (a a Fig. 225) running on the wire 

 and kept at a suitable distance apart by a rod (/>). This 

 arrangement is termed a truck. Were the laden truck left 

 to itself, it would descend with constantly increasing velocity 

 down the wire, and smash the wood and itself at the end of its 

 course. In order to prevent this and control the course of the 

 truck, a second and more slender wire (S Fig. 225) is attached 

 to the rod (b), and is wound round two rollers at the upper end 

 of the tramway, so that the truck may be let down and drawn 



Vig. 224. Lower end of a wire tramway. 



up again empty. These rollers also serve as a brake to regulate 

 the speed of the truck. 



The wire-tramway at Giindlischwand in the Grindelwald, 

 which is shown in Figs. 223 and 224> is 4,300 meters (say 

 14,000 feet long), and the wires hang quite freely without any 

 support at an angle of about 26 degrees. Another double 

 wire-tramway has been constructed in the forests of the Count 

 of Stolberg-Wernigrode. It differs from the preceding one 

 owing to its moderate gradient and because the wires are 

 supported at several points' by bent iron rods (Fig. 226) 

 attached to horizontal poles (ni) supported by trestles. 



In Fig. 226, (a) is the win; and (<) wheel of the truck. 



