SU BM AK INK T I' N X KUNO 



215 



ing the water that air pressure was again put on, and it was 

 decided to line the brickwork with a circular cast-iron lining 

 (Fig. 116). Although this brickwork was only 10 ft in in- 

 side diameter, a lining was designed 10 ft 2 ins. in the clear, 

 as it was now desired to make the tunnel bore as large as 

 possible. To put in this lining, some of the brickwork had to 

 be cut out, which was then removed in sections, enough for 

 one ring of plates at a time. The lining consisted of rings 



of plates or segments, 

 each segment being 

 about 3 ft. long and 

 1 ft. 4 ins. wide, with 

 internal flanges 4 ins. 

 deep, from the back of 

 the plate. The metal 

 in both the back of 

 the plate and the 

 flanges was 1| ins. 

 thick. All the joint- 

 faces of the segments 

 were planed, and 1-in. 

 bolts used for fasten- 

 ing them together. A 

 complete tunnel ring 

 was composed of nine segments and a small inverted key, 

 about 8 ins. wide. 



Difficulties between the company and the contractors, which 

 had been brewing for some time, now culminated and the 

 courts were appealed to, to settle their differences. This 

 caused a cessation of work for a short time until the com- 

 pany were empowered to take possession and resume the work 

 of construction for themselves. The work of putting the cast- 

 iron lining into the brickwork was necessarily a very slow 

 operation. The lining was exteinlc.1 well into the rock on 

 both sides of the soft vein, and a wall built at both ends, be- 



Fio. 118. Sections of Cant Iron Lining, East River 

 Gas Tunnel. 



