The Montgomery advertiser., 1906-09-04
PENNsYLMANIA TUNNELS.
Sections of the First of the Huge Hud-
 son River Tubes Will Soon Meet.

Sections of the First of the Huge Hud- son River Tubes Will Soon Meet.
 New York Special.
 | At 12 o'clock Saturday night all work
 on the Pennsylvania tunnels under
 North River ceased. The engineers
 will tomorrow begin a thorough "re-
 urement will be verified even down to the thousandth of an inch. Five or six
 days will be devoted to this work, after
 which the boring of the enormous ed that about September IS, the tunnel shields which have been pushing for | ward from the two sides of the river will meet The Pennsylvania Railroad will then have for the first time a
 means of reaching Manhattan Island entirely over land. This event will
 pietion of what is probably the boldest
 engineering feat In history.
 When work was stopped last night
 the shields were 125 feet apart The
 determine how accurate were the pre- liminary surveys and preparations
 which extended over period of year.
 It is believed by those in charge Of
 al 'gnment of both these huge tubes will be found to rest within an inch
 of where they ere supposed ta be. If there Is even so slight variation as
 this, 1t will be corrected so that when the shields finally meet under the mid dle of the river, they will telescope as 1CCuratelY as the HllulAB OL que iuDS within another.
 In order to make this checking as accurate as possible the south tunnel from the Jersey shore has heen run ahead of its mate, so that now 1t over laps the northern tunnel starting from the New York shore. Pipes will be driven across the fourteen feet that separate the tubes. and angles run \ which will show how nearly the en- | gineers have kept to the line and ele- Vation planned
 This thorough review upon Wnlch so much depends. will be under the personal direction of Charles M. Jacobs. Chier Enginee", and James Forgie, Principal Assistant Engineer. of ths improved instruments science has pro- duced win be utilized The entire dis | tance of both tunnels, 1000 feet De tween the shafts on each side or the | ured No chances of any kind will be | taken.
 W ork uf this character may he gath CT ed from the fact that during the yrogress of thls work, measurements ot the most exact character have oesl work has gone on continuously. Every variation in temperature has been carefully regarded. In making meas- srcments and alignments, 1T an error or as much as ne-thonsandth Of a foot was found the work was re-sur- veyed.
 Charles M. Jacobs, the Chief EnGineer )f this part of the work, and who has lad to do with the building of more tunnels probably than any other living nan, said today:
 we have now reached stage where ,N our fine preliminary Instrumental work must prove it's accuracy. Here We have two enormous steel tubes of feet In diameter driven or 6 000 feet under water ana yet eX- 1e cted to join as accurately as the sec ions of a bridge which can he contin ially measured with regard to their .eIafed parts. We feel confident that ,ur work will be a success. Neverthe- ess. 1t is only when the actual fact Ia ,roVed that we can heave a sigh If re- ief and be refreshed to continue our abors toward a completion of our ask"