Page:The American Cyclopædia (1879) Volume XVI.djvu/44

 36 TUNNEL wealth, the road and property of the company ; such surrender having been authorized by the board of directors, by a vote passed on Aug. 18, 1862. This action was ratified by a vote of the stockholders, and on Sept. 4, 1862, the commissioners took possession of the road and its property. The commission after a full ex- amination made a thorough report (dated Feb. 28, 1863), embracing the three following most valuable sub-reports: 1, a report of Charles E. Storrow on European tunnels ; 2, a report by Benjamin H. Latrobe on the Hoosac tun- nel ; 3, a report by James Laurie on the Hop- sac tunnel and the Troy and Greenfield rail- road. In conclusion the commissioners re- commended that the work should be under- taken by the commonwealth. At this point the cost and estimates were as follows : Amount advanced by the state up to the date of the commission $1,431,447 Estimated cost by the commission of completing the tunnel (double track) 8,218,823 Estimated cost of putting the road from Greenfield to the mountain in running order 662,000 Estimated cost of construction of two miles of road from western portal of tunnel to North Adams. . Estimated additional cost of depot buildings, &c. . 75.000 Estimated cost of rolling stock 275^)00 Total estimated final cost of road and tunnel. . $5,719,330 At this time, according to the report of James Laurie above noted, the condition of the work proper was as follows : Whole length of the proposed tunnel, feet 24,416 Deduct portion already excavated at each end. 2,400 Deduct portion between shaft and proposed western portal of tunnel 1,850 4,250 Leaving to be excavated under the mountain . . 20,166 The shaft here referred to was on the western slope of the mountain, 325 ft. in depth. Mr. Laurie estimated that by sinking a central shaft about 1,000 ft. deep and working there- from (which was afterward done) the tunnel, advancing at the rates respectively of 55 ft. a month from the two end portals, and 40 ft. each way from the shaft, would be completed in 11 years from date, t. e., in 1874 ; this es- timate being based on the supposition that the central shaft would reach bottom in four years from its commencement. Work was resumed on the tunnel under the auspices of the state in October, 1863, under the control of the same board of commissioners, who appointed Thomas Doane chief engineer in charge. The governor at the same time appointed Benja- min H. Latrobe of Baltimore state consulting engineer of Hoosac tunnel. Mr. Laurie in his report to the commissioners says that shortly after the Troy and Greenfield railroad was chartered, the attention of inventors was turned to the subject of tunnelling machines. One was constructed at South Boston in 1851, es- pecially for the Hoosac tunnel, which weighed about 70 tons, and was designed to cut out a groove around the circumference of the tunnel 13 in. wide and 24 ft. in diameter, by means of revolving cutters ; the central core left was to be subsequently blasted out with gunpow- der. It is reported to have cut, on a trial made March 16, 1853, on a vertical face of rock near the proposed entrance of the tun- nel, at the rate of 16$- in. an hour, and under more favorable conditions at a previous trial 20 in. an hour. Various trials were made with this machine, the total distance cut by it amounting to about 10 ft., but it did not prove successful. A second machine constructed at Hartford, and known as the " Talbot tunnel- ling machine," also working on the principle of revolving cutters, and adapted to cut out a core 17 ft. in diameter, was tried about this time near Harlem, but proved a failure. A third machine was constructed in New York, adapted to cut a core of 8 ft. ; this was adopt- ed by Mr. Haupt during the continuance of his contract, in the early days of the tunnel, but also proved a failure. Experiments were instituted by Mr. Haupt himself, while engaged with his contract at Hoosac, toward the elab- oration of a percussion drill ; but in 1861 the termination of his contract for a time put an end to them. Afterward he again took up the subject, and in 1867 published a descrip- tion of the Haupt drill. By the time this invention had been perfected, the Burleigh drills, which have since attained so great a reputation (see BLASTING), had been adopted and were in full use at Hoosac. They were first tried in June, 1866, under the direction of the commissioners, and even in their crude and unimproved condition were favorably noticed in Chief Engineer Doane's report. In January, 1867, the office of chief engineer was abolished, and the engineer corps reduced to one resident engineer, W. P. Granger ; Mr. Latrobe still su- pervising as consulting engineer. In October, 1867, owing to the accidental lighting of some naphtha at the central shaft, the head house, shaft buildings, &c., were consumed, and 13 lives were lost. Previous to this time portions of the work had been let out by contract, Messrs. Dull, Gowan, and White having the east and central shaft headings, through rock, and Mr. B. N. Farren the west end, through soft ground, including the arching of the same. Owing to the above mentioned accident, Messrs. Dull, Gowan, and White voluntarily surrendered their contract, received their pay, and aban- doned the work, returning it to the hands of the commissioners. Benjamin D. Frost was appointed superintending engineer in May, 1868, and on Dec. 24 of that year a contract was effected between Messrs. Shanly brothers of Montreal and the commonwealth of Massa- chusetts for the final completion in full of Hoosac tunnel. The dimensions were to be : "in rock, unarched, 24 ft. wide and 20 ft. high, in the clear ; where arching required, 26 ft. wide and 24J ft. high (above the rail), in the clear." The prices bid in the contract varied in the different portions of the work, and also according to whether the work was "already begun," "to be finished," or for