Williams news., 1921-01-28
SUSPENSION BRIDGE
 ACROSS THE CANYON
Materials for Bridge to be Transported Down Trail by Horse-Span Will be 500 Feet-Wiu Make Possible Travel By Horse Across to North Rim.

To permit tourist traVel py
 means of animal transportation
 from the south to the north rim
 in Grand Canyon National Park
 Arizona, the National Park Ser
 vice of the Department of the
 Interior is to build a suspension
 bridge across the Colorado
 River. The north side of the
 park, or the north rim as it Is
 called, is today practically un- visited owing to the difficulties
 attendant to getting horses or mules across the Colorado. Those who have made the long journey from railroad points in Utah have been tremendously impressed with the scenic gran deur of the north rim. It is about 1,5OO feet higher in alti- tude than the south rim and the great chasm viewed from this side reveals new and allurlng aspect. With the construction of the suspension bridge rim-to- rim travel is destined to become one of the most fascinating of park trail trips.
 The construction of the bridge presents number of problems, one of the most in teresting of which is the trans Dorta tion of the bridge mater ials down the trails 10 the con- struction site. The bridge will he thrown across the river in the Granite Gorge which at this point is 9 Dproximately APO feet wide with almost rerDendicular sides. TI,e span lenoth If the and will be susDended 40 feet above the general water level and at least 13 feet ebove the highest indicated water lnvo1 The trail distance over whioh the materjal will have to be packed is abo11t 10 miles. das- cendino i,,+o the convoo a di~- lance Of slightly over one-half
 mile. The trails are tortuous having switchback after switch back: and in many places grades exceed 40 per cent
 In designing the bridoe 1t was necessary to secure a structure which would be light and at the same time have sufficient to accommodate the trav el and to have the units of such size or weieht that they could be packed by mules down the trail. The main cables are to be of special tramway blow stell, each weighing between 700 and 800 pounds, requiring four mules to transport it. It Is planned to divide the cable into four pairs of coils, one pair being placed on each mule with an intervening length of cable of about 20 or 30 feet. Each mule will be placed in charge of 9 packer and the intermediate men will. in addition to leading the mulescontrol the slack of 20 or 30 feet of cable so that they can successfully negotiate the switchbacks.
 The floor system of the bridoe will be susDended from the main cables by special 3-S inch steel wire ropes. placed every six feet apart which are attach ed to the floor beams by 3-8 inch steel stirrup rods every three feet apart. The hanger cables will be packed in small coils and the stirruD rods will be folded on themselves so that they will be of sufficient length to permit hacking. The floor system will be cut into pieces not more than 9 feet long in order that they can be readily packed. but even timber of this 1ength will make it difficult and Interesting work for the men in charge of the pack to successfully guide them down the trails.
 The bridge will be five feet wide with guard rails of heavy mesh wire and because of the