Chapter 7

The desire to obtain a dry tunnel, and the methods adopted to secure it, were responsible in a great measure for the decision to build the arch in short lengths, as well as the reasons given under the head of arches. Had the tunnels been dry throughout, the method shown at _A_, Fig. 18, could have been used exclusively, and, except for the fact that monolithic concrete might not have been obtained, there would have been no objection to building longer lengths.

The quantity of water reaching the tunnel drains and flowing out of their lower ends after the completion of the lining was about 100,000 gal. per day, or 75 gal. per min.; of this it is estimated that considerably less than 1% comes through the lining in the form of leaks. The very general distribution of this water over the roof is indicated by the fact that, during the excavation of the first 1,000 ft. of both tunnels from the Weehawken end, oilskins had to be provided for the laborers to induce them to work at all. The success, therefore, of the rock packing as a means of diverting this water to the side drains, is shown, especially in view of the fact that, excluding the cut-and-cover section, only 10% of the length of the arch, 1,189 ft., was water-proofed.

Considerable care was taken to make all joints in the concrete which were in such a position that water might follow through them to the inside of the tunnel lining, in such a manner that they would slope outward toward the rock. The top of the sand-wall is shown by Figs. 14 and 18. The slope of the back of the foundation may be noted in Fig. 18, and the method of making the joint in the arch, in the few instances where a section was not completed at one operation, is shown at _A_, Fig. 18. These joints in the arch were not allowed to be made above a point 60° above the springing line.

HACKENSACK PORTAL AND APPROACH.

The approach cut at the western end is 300 ft. long, the alignment being a 2° curve, as shown in Fig. 19. The bench-walls and conduit lines built throughout the length of the tunnels are extended through the approach cut, the top of the former gradually sloping from the portal to the mouth of the cut, where they are just level with the top of the rail, the conduits also being depressed to the same relative position with the tops of the benches.

The top of the rock at the mouth of the cut, Station 327, was from 4 to 6 ft. below the top of the rail, and gradually rose through the approach until at the portal it was about 6 or 8 ft. above the roof of the tunnel. The rock was covered with hardpan. A profile of this part of the work is shown on Fig. 19. The rock throughout the approach was water-bearing to a considerable extent, and a face-wall was built at the sides with free drainage, through rock packing and vitrified and cast-iron drains behind it, to keep this water from flowing over the tops of the bench-walls, and also to keep the lines of conduits dry.

The retaining walls were built in 25-ft. sections, the joints corresponding to those in the benches, being at the even stations, +08, +33, +58, and +83. =V=-shaped joints were made down the face, and the ends of the sections were made as shown by Fig. 19. The back part of the joint was mopped with hot pitch before the next section was built, so that there was practically no bond between any two adjoining sections.

The concrete in these walls was placed late in the season, and the expansion cracks, which were entirely confined to the =V=-shaped joints, were quite small even in the coldest weather of the following winter, nor were there any indications during the past summer of any stresses due to expansion. The coping and drain at the top of the wall were built together, but separate from the rest of the wall, the joint being made as shown in the sketch on Fig. 19. Thus far, there has seemed to be no seepage through either the vertical or horizontal joints.

The portal is built of granite, a half elevation being shown on Fig. 19, the stone being supplied by the Millstone Granite Company, Millstone Point, Conn. Fig. 3, Plate XXVII, shows the portal and the cut-and-cover section after the arches were completed but not covered.

The forms for the concrete in the approach were made of ordinary dressed lumber, and the surface was rubbed twice after the forms were removed, which was as soon as possible after the concrete had set. The surface was first very lightly rubbed with a piece of soft, light-colored, sandstone to remove any irregularities, being wetted slightly if necessary while being rubbed. After the concrete had become fairly hard and dry, it was rubbed a second time and a uniform texture and color obtained. The completion of this work was delayed until the second week in January, and considerable difficulty was encountered in obtaining a good finish of that part which was built after cold weather set in, when it was necessary to protect it from frost. Unless extreme care was taken to prevent freezing after the rubbing, the entire surface was likely to scale off, although no cement or other material was added to it after the removal of the forms. A general view of the completed approach is shown by Fig. 4, Plate XXVII.

TABLE 6.

+----------------------+-----------------------+ | DAY. | NIGHT. | Title. +-----+-------+--------+-----+-------+---------+ | No. | Rate. | Amount.| No. | Rate. | Amount. | ---------------------+-----+-------+--------+-----+-------+---------+ Walking bosses | 2 | $5.00 | $10.00 | | | | Timekeeper | 2 | 3.00 | 6.00 | | | | Watchmen | | | | 5 | $2.00 | $10.00 | Waterboys | 1 | 1.50 | 1.50 | | | | Carpenter foremen | 2 | 3.50 | 7.00 | 1 | 4.00 | 4.00 | Carpenters | 14 | 2.50 | 35.00 | 8 | 2.50 | 20.00 | Pipe-fitters | 1 | 3.00 | 3.00 | | | | Pipe-fitter's helper | 1 | 1.75 | 1.75 | | | | Wheelwright | 1 | 2.75 | 2.75 | | | | Wheelwright's helper | 1 | 1.75 | 1.75 | | | | Blacksmith | 1 | 3.00 | 3.00 | | | | Blacksmith's helper | 1 | 1.75 | 1.75 | | | | Foremen riggers | 1 | 3.00 | 3.00 | | | | Riggers | 6 | 1.75 | 10.50 | | | | Foremen trackmen | 1 | 3.00 | 3.00 | | | | Trackmen | 6 | 1.50 | 9.00 | | | | Machinist | 2 | 3.00 | 6.00 | | | | Machinist's helper | 1 | 1.75 | 1.75 | | | | Electrician | 2 | 3.00 | 6.00 | 1 | 2.50 | 2.50 | Electrician's helper | 1 | 1.75 | 1.75 | | | | Lampman | 1 | 1.50 | 1.50 | | | | Pumpman | 1 | 1.50 | 1.50 | | | | Finishers | 3 | 2.50 | 7.50 | | | | Hoist engineers | 12 | 3.00 | 36.00 | | | | Dinky engineers | 5 | 2.75 | 13.75 | 1 | 2.75 | 2.75 | Brakemen | 5 | 1.75 | 8.75 | 1 | 1.75 | 1.75 | Switchmen | 1 | 1.50 | 1.50 | | | | Barnmen | 1 | 2.00 | 2.00 | 1 | 2.50 | 2.50 | Drivers | 9 | 1.50 | 13.50 | | | | Foremen ductmen | | | | 2 | 2.50 | 2.50 | Ductmen | | | | 5 | 2.00 | 10.00 | Foremen laborers | 13 | 3.50 | 45.50 | 2 | 3.50 | 7.00 | Laborers | 120 | 1.75 | 210.00 | 20 | 1.75 | 35.00 | Compressor engineer | 1 | 3.50 | 3.50 | 1 | 3.50 | 3.50 | Firemen | 2 | 2.50 | 5.00 | 1 | 2.50 | 2.50 | Oiler | 1 | 1.75 | 1.75 | | | | Coal passers | 2 | 1.75 | 3.50 | 1 | 1.75 | 1.75 | ---------------------+-----+-------+--------+-----+-------+---------+ Totals | 334 | |$469.75 | 50 | | $108.25 |

Total daily labor expense $578.00 ---------------------------------------------------------------------

The water finding its way into the side ditches in the approach, which of course included all rain falling in this area, was intercepted just inside the portal and carried back to the mouth of the cut through 24-in. cast-iron pipes laid beneath the conduits in the central bench-wall, thus disposing by natural drainage of a not inconsiderable quantity of water which would otherwise have flowed through the tunnels to the sump at the Weehawken Shaft, from which it would have had to be pumped to the surface.

About 100 ft. of the tunnel immediately east of the Hackensack Portal was built by the cut-and-cover method, and the arch section used in the tunnel was modified by widening the haunches, the thickness of the arch at the crown being gradually increased from 22 in. at the portal, Station 324, to 34 in. at Station 323, where the regular segmental timbering at the tunnel commenced. A general view of the approach during construction is shown by Fig. 1, Plate XXV.

CONTRACTOR'S ORGANIZATION.

Table 6 shows approximately the number of men employed daily on the tunnel lining, by both the contractor and the sub-contractors, their occupation, the average rate of wages and the total daily expense for labor when the work was in full swing.

ENGINEERING ORGANIZATION.

The whole of the work of the North River Division was designed and executed under the direction of Charles M. Jacobs, M. Am. Soc. C. E., Chief Engineer, and James Forgie, M. Am. Soc. C. E., Chief Assistant Engineer, the construction of Section "K," Bergen Hill Tunnels, being directly in charge of the writer as Resident Engineer.

[Transcriber's Note: The two organizational charts, Figs. 20 and 21, have been reformatted for space.]

[Chart: Fig. 20.

PENNSYLVANIA TUNNEL AND TERMINAL RAILROAD COMPANY, SECTION "K"--BERGEN HILL TUNNELS.

Organization of Staff of Resident Engineer.

Organization Previous to the Holing Through of the Tunnels.

Resident Engineer. _______________|________ | | | Assistant | Assistant Engineer. | Engineer. _________|________ | | | | | | Cost and Office Field Inspection. Alignment. Records.

Cost and Office Records. Inspector. Two Clerks. Stenographer. Telephone Operator. Messenger. Janitors.

Field Inspection. Weehawken. Chief Inspector. Inspector, N. Tunnel " S. Tunnel. " Mixer. " Excavation and Force Account. Inspector, Night. Cement Warehouseman. Conduit Inspector. (_one position_) Hackensack. Chief Inspector. Chief Inspector. Inspector, N. Tunnel " S. Tunnel. " Mixer. " Excavation and Force Account. Inspector, Night. Cement Warehouseman. Conduit Inspector. (_one position_)

Alignment. Weehawken. Chief of Party. Instrumentman. Rodman. Chainman. Hackensack. Chief of Party. Instrumentman. Rodman. Chainman.]

[Chart: Fig. 21.

Organization After the Tunnels Had Been Holed Through.

Resident Engineer. ________________|_______________ | | | | Assistant | | Assistant Engineer. | | Engineer. _______|______ | | | | | | | | Cost and Office Field Inspection. | Alignment. Records. _____|_____________| | | Tunnels. Conduit Inspector.

Cost and Office Records. Two Inspectors. Two Clerks. Stenographer. Telephone Operator. Messenger. Janitor.

Tunnels. Chief Inspector. 8 Tunnel Inspectors. 2 Mixer Inspectors. 1 Night Inspector. Conduit Inspector. Inspector, Hackensack Approach.

Alignment. 1 Instrumentman. 1 Draftsman. 2 Rodmen. 3 Chainmen.]

The general organization of the staff is shown by the two diagrams, Figs. 20 and 21. Fig. 20 shows the organization previous to the holing through of the tunnels, during which time a separate office was maintained at the western end for the use of the men stationed there; Fig. 21 shows the organization during the latter part of the time, after the tunnels were holed through. The Assistant Engineer in charge of the construction was J. R. Taft, Assoc. M. Am. Soc. C. E.; the Chief Inspector, J. S. Frazer, Jun. Am. Soc. C. E., had charge of about 75% of the work of the lining of the tunnels. The alignment has been from the beginning under the charge of R. L. Reynolds, Assistant Engineer.

* * * * * * * * * * * * * *

Errors and Notes:

Each Plate was printed with the same header: PLATE __. TRANS. AM. SOC. CIV. ENGRS. VOL. LXVIII, No. 1154. LAVIS ON PENNSYLVANIA R.R. TUNNELS: BERGEN HILL TUNNELS. These headers were omitted for the e-text. Captions beginning in "K" with a number were printed directly on the photograph; some readings are uncertain and are indicated by question marks (?).

In the tables of Figures 1-4, variation between "to" and "-", and formatting of table entries, is as in the original.

[Fig. 1, table] Per cubic yard, whole tunnel section: 3-33 _may be error for "3-3.3"_ [Fig. 1, last line of table] Total Pounds _text reads "Pound"_ Figs. 3 and 4, and Plate XXIV _apparent error for "Figs. 3 and 4, Plate XXIV" (usual form)_ [Figure 15 A, B, C...] _letters other than "B" do not appear in the printed Figure_ [Figure 15, caption] DETAILS OF "WEASEL" _quotation marks look hand-written, but printed text has spaces_ [Figure 15, "Index" (small table)] Multi-Duct Mandrel _text reads "Mult-Duct"_ which would be satisfactory to the engineers _text reads "satifactory"_

Missing or superfluous punctuation was silently corrected.