Arizona republican., 1903-08-07
DEEP EXCAVATIONS
Interest Attending Wonderful Engin-
 eering Work in New Ycrk.

1 New York has been provided with a new spectacle. The throngs which con- l stantly move up and down Broadway | may watch the progress of perhaps the most interesting engineering feat to be | seen anywhere on Manhattan island.
 The problem consists in digging al
 Forty-second street and Broadway the | deepest hole in New York. Stand on
 either side of the great triangle which
 is being sunk in the earth at this point
 and the great depth of the excavation
 and the many mechanical appliances
 scattered on every hand cannot fail to
 take a peculiar hold upon ones imag | in0 tion.
 The corners which surround the great | excavation are such busy ones, the streams of traffic on all sides so contin-
 uous that the contrast of the rough eX- | cavation is the greater The difficulties of such work, literally in the heart of the city are of course enormous. It has been necessary to carry on the | work continuously without for an hour | interrupting the travel on three of New York's busiest streets. On all sides of the triangle rise great buildings which would be endangered by violent blasts. | The enormous volume of rock to be re- | moved has been raised to the surface 1 and carted away without appreciable ! hindrance to the surface cars which constantly rush along all three bound | aries of the excavation.
 The peculiar setting of all this activ- | ity renders it strongly picturesque. Were such 9 hole to be drilled in some great quarry in the open country it would still be interesting from the me chanical point of view. When such work is undertaken practically under America busiest thoroughfare the in- terest is naturally increased. From the trolley cars. as they speed along the dizzy edge of the excavation, one can look directly down into this deep, arti- flcal valley.
 Never before, doubtless. has similar undertaking been watched by so great an audience. The excavation is espec- tally interesting by night. The brilliant illumination Of Broadway scarcely reaches to the well like depths of the great shaft. The jagged rocks stand out in striking relief against the shad- ows. The great thrOng which surges along the brightly illuminated side walks of Broadway look down at an abrupt angle into what appears to be a bottomless abyss.
 The work of excavation at this point IS UtlllS cdIIleu OH DS lHe ltlli Ol Clil- tractors who are excavating the sub- way for the rapid transit road between Fourth avenue and Seventh avenue. Were this hole merely being dug for the foundations of a building the problem would have been considerably simplified; as it is, the rapid transit tunnel musr enter the great hole on the east and pass out again at the north.
 It has, therefore, become necessary to transform both Forty-second street and Broadway into bridges to span the nec- essary excavation. The intersection of Broadway and Forty-second street is one of the busiest crossings. both by day and night, to be found anywhere in New York city. possibly in the entire country. Despite these difficulties. how ever. the traffic on these streets has not been impeded for single hour through out the work of excavation and the worst is now past.
 The problem of detaching so great a volume of rock from the earth is prac tically identical along Fortysec street and in the especially deep eXca- vation at the intersection. The rock to be removed is as solid at this point as at any place along the entire subway route. It could only be loosened by vio- J only the most slillful rockmen have been employed. The danger, which is necessarily great, has been reduced to 8 minimum.
 In the work in the subway proper un- der both Broadway and Forty-seccnd street a narrow channel was first cut along the route of the tunnel, while lateral shafts were cut at regular inter- vals to the full width of the subway.
 As quickly as those were completed. heavy piling was placed beneath the roadway alone sufficient to maintain any possible pressure. When those timbers were in place the intervening walls of rock were carefully cut away and new beams and supports took their place. The iron frame work of the sub- way which is to support the streets permanently was then put in place.
 In digging the great hole at the june ton of Broadway. Forty second street and Seventh avenue the entire nature of the work was changed. The ground to be removed, being exposed was nat urally easier to attack than the rock beneath the streets. On the other hand. however, the depth of the excavation being greater and the rows of build ing along it's sides both high and con- tinucus, the difficulties, though trans formed. were scarcely lessened.
 In removing the earth at such depth, | the workmen are now fully 90 feet be- low the street level there is of course. the chance of the sides of the triangle suddenly slumping into the great hole and carrying the buildings along into it. In the blasting under the streets. again. there was little danger to the above, though perhaps much inconven- fence. The workers themselves might occasionally be hit by flying stones, out the pedestrians above knew nothing Of the blasting, save at times the deer subterranean rumblings beneath their feet.
 In blasting in the open and near the level of Broadway the danger was, Of course, considerable. There has inevit-