"1261 In pouring the portal structure for the upper portals of Diversion Tunnels Nos. 2 and 3, 4-cubic-yard Rex Moto Mixers were lifted from trucks and concrete poured directly in the forms. June 19th, 1932.
1266 View of the upper portal of Diversion Tunnel No. 3, showing the method of cableway operation in pouring portal structures with 4 cubic yard agitators. June 19th, 1932.
1264 Close-up of Rex Moto Mixer discharging directly into forms for the portal structures. June 19th, 1932."