The New Tunneling Machine 



Above: The fourteen hammers are ar- 

 ranged on a longitudinal axis and are 

 fitted with chisels which cut into the 

 solid rock in great concentric circles 



The carriage of the machine consists of 

 a two-wheel main truck at the rear and 

 a guide truck at the front. The wheels 

 rest on a light track of standard gage 



79 



