| Show TUNNELING FOR ZION PARK SCENIC HIGHWAY by T J welcker during the past two or three years enterprising tourists have brought back enthusiastic accounts of the wonderfully der fully picturesque country found in southwestern utah in zion national park bryce canyon and cedar breaks of the natural beauty of the kaibab national forest and of the grandeur b ran deur of the trip which terminates on oil the north rini rim of the grand canyon of arizona the glowing sandstone statuary of the region has been pictured in all the brilliance of its remarkable coloring by photography and an all increasing number of tourists visit this wild new country every season it is miles southwest of salt lake city on oil the los angeles salt lake railroad which one leaves at lund taking 6 a branch line to cedar city timbered section of the highway tunnel note ther the ease with which this sandstone pulverizes ve as shown by the roadway much has already been done clone in opening automobile highways as shown by the accompanying compa nying section of a utah road map at the present time a large program of improvement pro i s under way to shorten distances between stra strategic tepic points and to open up lip yon and alid to cut the necessary travel between parks to a minimum minimum it was decided to make a loop of the road system by constructing a cutoff cut off from springdale ringdale Sp to mt carmel approximately 26 miles in length the distance to bryce canyon is reduced from miles as at present to 88 miles while the distance to cedar breaks now miles by road will be cut down to 70 the distance to the grand canyon will be reduced from miles by road to just over miles this new road runs through exceedingly rugged broken country and includes approximately two miles of 0 tunneling the first tunnel described in this article is is a little over one mile in len lenth length 6 th and is included in the first lira r and second sections now being built the balance balan ce of the tunneling comes in shorter lengths in the third section which will not be started until the present two are coll completed wal besides vertical tunneling through an canyon and building a number of bridges it was necessary t to 0 make nia very heavy tills fills and cuts the entire distance with props provisions for drainage the united states government bureau of public roads mr finch district chief ila as the first three sections which are not quite eight mil miles length while the state of utah will build tile the remainder outside the limits of the national park coll contracting at the government end of the road the nevada the job JO tr company of fallon nevada is handling mr E S berney is president and general manger at fallon pa j while stanley bray is superintend superintendent ten lent and richard richar dscott aco is in direct charge of the tunnel work the contract price of the job is work was started nearly a year ago section no 1 of the job consisted of building a road up the practically vertical walls of the canyon involving a climb of feet in f AL az 4 J the he switch backs in in the highway leading up through the canyon canon to the tunnel portal are ht 3 miles the road winds back and forth up tip the slope making b seven different switch backs in its course to the base of the perpendicular cliff where the tunnel through the cliff begins the second section includes the tunnel proper which is about feet in length details of approach work some idea of the magnitude of the approach road may be gained when it is known that more than cubic yards of overhaul alone were required for the rock drill ilig g required on oil the approach work a sullivan ft ti onless type compressor was employed to together 6 ether with two other portables many immense loose boulders were vii encountered which had to be drilled also in some places solid lock ck had to be removed excavation was handled with three gasoline shovels the sandstone disintegrates into a powdery Y sand making haulage difficult A number of dit dif crent types of motor trucks were employed those with pneumatic tires giving thi the best results in the sandy section owing to the difficulties of haulage up the terrific grade it was lle necessary essary to adopt some other method of getting ettin the heavy avy machinery for tunneling up tip to the location selected elected for the tunnel portal an feet in ill length was aerial cable way one thousand resorted sorted to giving a ft rise in this distance A 40 ft tower tolver was erected at the top of the slope under the base of the cliff to land the illa machinery chinery properly dorills Di rills tran fliers compressors shovels motors etc were handled by Y this means the heaviest pieces handled were vere the ab frames ames of the compressors tunnel started from side galleries at the site selected for the tunnel portal made it impossible to begin drilling at this point to overcome this difficulty galleries were opened on the tunnel grade line along the face of the cliff in some cases scaffolding was erected at the top of the talus slope at the base of the cliff in other cases working platforms were suspended from the summit of the cliff itself the scaffolds varied in hei height ht from froin 30 to 90 feet the headings s were driven on oil the grade line of the tunnel feet in size starting in each direction from the galleries of which two ware were opened up tip at first the completed size of the tunnel in 22 feet in width by 16 in hei height ht As soon as the headings were sufficiently advanced butler shovels operated by compressed air were installed for mucking g when the main portal was ivas opened up tip a bucyrus erie airas air gas as shovel chonel was inas brought in and ii made lade ii more ore rapid progress in the mucking prior to this time a scraper slide had also been employed in the pilot tunnel equipped with a sullivan HDA 2 nair double drum slusher hoist air was supplied by two sullivan WJ Y 3 angle compound compressors each 17 inches in size and each operated by a I 1 IP HP fairbanks morse V electric motor electric power is furnished by the dixie power company from their hydroelectric hydro electric station at la verkin on the virgin river arver twenty five miles distant the portable compressors were used to supply air for foi the drills for a period of about two and a half months before the transmission line was completed and the electrical equi equipment pili ent started up tip later the sullivan WK compressor was avas used as a booster or auxiliary supply ly behind the bucyrus erie shovel tunnel enlargement after the pilot heading is sufficiently advanced the tunnel is enlarge eel e d to full diameter and height by a modification of the ring ing r drilling drillen system sy stelli first used at the moffat tunnel in colorado As shown by the illustration several columns are set at regular intervals on oil the center lindof line of the tunnel these columns til lills are equipped with arms on which are mounted A A compressed air shovel at the east tunnel portal drills such as the sullivan DU 48 water jet sto stoper P er of the self rotating type with reverse feed cylinder as shown in the picture the mounting is equipped with a quadrant plate with lines radiating from a center at uniform angles all of the holes required for one round were drilled from a single sing le setting of the column in the same plant as shown in the illustration several drills could be used at the same time from different columns in this way and this work progressed very rapidly in this work the softness of the sandstone permitted rapid drilling progress the sullivan stoper in a single 8 hour shift put in as many as 45 seven foot holes a total of feet for ventilation and to a certain extent for light six galleries are being opened up throughout the len lenth length th of the tunnel from the tunnel line to the edge of the cliff the length of the galleries varying in in each case according to the nature of the rock and the contour of the cliff wall aa 4 V t 7 MM V ON ar ac 7 V ale 0 jat 1 4 A 0 44 1 I al 4 c t t 7 4 N W 26 2 6 W N ring rine drilling for the tunnel enlargement the of holes row already put in may be seen in the roof and side walls portal of ono of the side galleries with view from the edge of the cliff showing method of haulage and dumping damning they range from 60 to feet in length and are from to 1200 f feet act apart they are being opened sufficiently large to permit an automobile to turn i in ii ahem h e in the tunnel is driven on a 5 grade rising from the western or portal end to the eastern end a distance of nearly feet in height As shown by one of the illustrations muck cars are pulled from the face by means of sullivan HA 2 compressed air portable hoists as the 5 grade is too steep for hand bughi pushing ng the cars w were ere brought out to the face of the elm cliff through the galleries and there dumped by proper prope r placing of pulleys and sheaves cars were handled readily from either direction it was choti thought ht at first that the rock in t the he tunnel would stand without vit hout timbering owing however to its softness and ease of disintegration r a it was vas found necessary to timber a coils considerable id portion of its len lenth length th as shown in one olie of 0 the illustrations the view from the side galleries ies out over the precipitous cliff and across the cany canyon ollo is magnificent in the extreme work on the tunnel proper has been bee I 1 delayed delaye by timbering and other factors but has ada advance iced 1 at an average speed of about feet pe per r inon in all headings at the time of writing it t avas wa estimated that the tunnel would be callip feted about november 1 state section under way of th state of utah has all of its portion ro road ad approximately 18 miles under tinder coli construe tion the contractors include the raleigh lan the company and the reynolds ely colell company aily fornier former is employing portable compressors including one ft sullivan 11 WK unit and hand for their rock excavation hani hammer nier drills the reynolds ely section is mostly earth excavation the author is indebted to the officials of the nevada contracting company and to mr finch of the bureau of public roads for information used in this article the photographs were taken especially by cliff bray salt lake photographer engineer sullivan machinery co salt lake city |
