. Strutture ferroviarie e stime . ylolUliitfin«lt>i(i4l llittt i .JMiiuvluif ofIvHvk* Kin. I.A. KI: A riiniicl (Ifanur»im. Sono mostrati, liu. I. Kor tuiinf. On ciiiNcd tnulv llu^ Mcction-hould essere aumentato e la traccia shitlcd oltre .mo a.^ a provid(<i he sain« clearance come per langeni ; il rale > Per criil, IR ..i batti llial olthe regulating grade la forma e (hinen.Mion-t del lonrliackliergen Hill i unn(<ls sul IJie Hailioad Arc HJiovvn, lig-• !•dislance Ixlweeii harks i.s lit Fi, E io giace la distanza di i giace innertracks è K Fi. li in. Dal centro lo faccia della parete. Un Bo
2347 x 1064 px | 39,7 x 18 cm | 15,6 x 7,1 inches | 150dpi
Altre informazioni:
Questa immagine potrebbe avere delle imperfezioni perché è storica o di reportage.
. Railroad structures and estimates . ylolUliitfin«lt>i(i4l llittt I .JMiiuvluif ofIvHvk* Kin. I. A.K.I: A riiniicl (Ifanur»iM. are shown, liu. I. Kor tuiiinf. on ciiiNcd tnulv llu^ Mcction-hould be increased and the track shitlcd over .mo a.^ to provid(<I he sain« clearance as for langeni ; the rale > per criil, Ir ..i I ban llial olthe ruling grade The form and (hinen.Mion-t of the lonrliackliergen Hill I unn(<ls on the IJie Hailioad arc HJiovvn, lig-• !•dislance Ixlweeii harks i.s lit fI, and I lie clearance of I lie innertracks is K fI. li in. from center lo face of wall. A box in built al.tach .side of Immel loi dranla^e and I m. tile in iiv.ed al low npolM.The track.s are carntd on a IJ m Ix-d of balla.-.l on a bioKt-n .iloncjba.^e 64 TUNNEL DRIVING. ojilsiiiJise of o. I DETAIL OF COVER AT A Fig. 2. Cross Section Four-track Tunnel Bergen Hill Tunnels, Erie Ry. Tunnel Driving. — The drilling methods adopted for tunneldriving on the C. C. & 0. Ry. are typical for this class of work, Fig. 3. One of these was by first driving a bottom heading andthen throwing the superincumbent mass downward into a muckpile to be removed by steam shovels and cars as per sketchA. & B. In this case where the muck pile was high enough thedrills were put straight into the face of the top heading as persketch C, but when the muck pile was not high enough for this, the drills were driven in from beneath, as in sketch D. Themethod principally used however was to first take out a top head-ing with a semi-circular roof 9 ft. high at the center, forming thearch of the tunnel, sketches E, F and G, and then blast out thebench and remove by steam shovel. In the tunnel work 60 per cent dynamite was principally used, making less fumes and securing quicker ventilation of the tun
