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Show III PARKJTUNWEL CONSTRUCTION Over 900 Feet of Pilot or Working Tunnel Now Completed; 175 I Men Employed; Pushing Excavating With Three Shifts in the ' Tunnel and Two on Outside Work. Over 900 feet of pilot tunnel has now been completed in the Zion park end of the Mt. Carmel highway, according ac-cording to R. A. Brown, chief construction con-struction engineer on the project, who was in St. George last Friday. Over 175 men are now employed, and the work is being . pushed rapidly with three eight hour shifts in the tunnel and two shifts on outside construction.' The total length of the tunnel when completed will be 5700 feet, and in this distance there will be six galleries, or side tunnels or openings drifted from the face of the cliff to the main tunnel. tun-nel. These galleries will average from thirty to one hundred feet in length, and from 11 to 30 feet in depth. The openings are built primarily for vent ilation purposes m tne mam lunnei, and also to aid in lighting, and will provide motorists with a space off the main tunnel where they may park their cars out of the way of traffic, and enjoy the wonderful view of Zion canyon. The main tunnel will be electrically lighted. The distance from the west portal to gallery No. 6 is 600 feet; from No. 6 to No. 1, 175 feet; from No. 1 to No. 2, 1200 feet; from No. 2 to No. 3, 1300 feet; from No. 3 to No. 4, 1200 feet; from No. 4' to No. 5, approximately 1000 feet, and from No. 5 to east portal approximately 1000 feet. No. 6 tunnel was not called for on the original plans but was incorporated in the work after construction started. Work was originally started at gallery gal-lery No. 1, which is about 775 feet from the west portal. No. 6 gallery was then incorporated in - the plans and crews worked openings into the face of the cliff at both locations. To accomplish this difficult task steps are cut in the solid rock up the slooe from the foot of the canyon for approximately 100 feet, and the ladder is then continued for another 100 feet up the face of the perpendicular perpendicu-lar wall to the point from where the gallery is to be drifted. A foothold is cut from the cliff and holes drilled into the rock into which are inserted steel bars to support a working platform plat-form which is erected approximately 200 feet up the side of the canyon wall. Shots are then placed and a working space blasted out. The gallery is then drifted in to the tunnel line, the muck being dumped over the edge of the cliff. As soon as the tunnel line is reached crews start drifting the pilot tunnel east and west. This tunnel tun-nel is eight by nine feet. Crews are now opening up No. 3 gallery, gal-lery, and other crews are drifting both ways from No. 2 gallery. Tunneling is being pushed from No. 1 and No. 6 toward the west portal and are within with-in less than 100 feet of the open. As soon as pilot tunnel is completed from gallery No. 1 to the west portal and the open pioneer road is completed to the entrance of the tunnel, which will be in about a week, an Erie air shovel will commence at the west portal to enlarge pilot tunnel to the full bore which will be 22 feet wide and 16 feet deep. While the air shovel is taking out the pilot tunnel from the west toward the east, the tunnel crews will be continuing con-tinuing on other units of the pilot tunnel toward east portal. The men are boring approximately 12 to 15 feet of pilot tunnel each 24 hours at each head, or in other words crews working both ways from galleries galler-ies are making 12 to 15 feet daily in each direction from each gallery." Muck from the pilot tunnel is removed on narrow gauge cars and dumped out of gallery tunnels over the cliff. All inside work is being done with compressed com-pressed air from a Sullivan stationery compressor, run by electric power. Air muckers clear the pilot tunnel after af-ter each shot, and a small air shovel isused in the tunnel. Outside work is being done with three gas shovels. A five per cent grade is being maintained main-tained on this construction which under un-der ordinary circumstances is a high gear grade. |