Читать книгу Report of the Hoosac Tunnel and Troy and Greenfield Railroad, by the Joint Standing Committee of 1866 - Tappan Wentworth - Страница 8

The work at the West End of the tunnel is under contract. Mr. B. N. Farren of Doylestown, Bucks County, Pennsylvania, by an agreement dated May 1, 1866, contracted to put in a stone and brick arch of the dimensions before stated, 26 feet by 26, for the following prices, viz.:—Earth excavation $3.50 per yard; brick masonry, $12 per perch; stone masonry, $6 per perch. Contractor planks the bottom and sides when necessary at $15 per lineal foot. The State furnishes the bricks at $9 per thousand and the timber at $16 per thousand for hemlock, and $18 for spruce and hard-wood. The length of arch contracted for is 174 feet, the whole of which is open. The State also furnishes the cement, which costs in Troy, New York, from $1.65 to $1.70 per barrel, to which is to be added the freight at 30 cents per barrel. A barrel of cement is used for a perch of masonry.

The contractor agrees to construct two hundred feet of under ground tunnel, and as much more as he can before August 1, 1867, at the following prices, viz.:—Earth excavation at $6.50 per yard; brick masonry at $13 per perch; stone masonry at $6.50 per perch. The timbering, from $40 to $50 per foot, lineal, depending upon the thickness of the wall. He may, under permission from the engineer, take stone and sand from the State's premises, without making compensation.

Payments are to be made about the 12th of each month for the work done the preceding month, at the rate of 80 per cent. of the finished work.

The decision of the engineer as to the method, quality, quantity and classification of the work to be final and conclusive. In order to facilitate the progress of the work and with a due regard to economy, the State has purchased the following lots of land in the vicinity of the West End, to wit:—A wood lot, containing sixty acres, at a cost of $9,900; the Harrington Farm; 130 acres with the buildings, inclosing the West End and West Shaft; and running half way up the mountain. This purchase was made January 26, 1866, price $3,000. The Kingsley lot, purchased March 16, 1866, at $2,793.87.

The timber used by Mr. Farren is obtained from these lots. The tops of the trees are cut into wood and used at the brickyard. About five hundred cords of wood has been cut on the Harrington, and one thousand cords on the Kingsley lot, for the use of the brickyard, and is now on hand.

The necessity of making the bricks required for the arch tunnel is apparent. They could not be furnished by individuals at North Adams. 120,000, before the yard at the West End was fitted up, were purchased at Springfield at $9 per thousand; the freight of which to North Adams was $6, and the teaming to the West End $2 per thousand. If to these prices be added the depreciation and waste from handling, the cost will reach $18 for all that could be used in the work. It is the opinion of the engineer and superintendent of labor, that the bricks made by the State will cost less than $9 when delivered to the contractor.

Mr. Farren began work under his contract June 7, 1866, and early in December the brick-work at the top of the arch had entered the mountain. The masonry was commenced about, twenty-five feet west of the point first selected, so that the open masonry will in fact be 200 feet long. About thirty feet of invert is left uncovered the present season, under an apprehension that the bricks on hand will only supply what will be wanted in the drift, in order to prosecute the work with dispatch. The invert has been properly protected, and its preservation may be expected.

At the beginning, the invert and the sides to the spring of the arch was laid with five courses of brick, and the arch with six. The masonry has been strengthened to meet the effect of the soft ground and increased pressure to eight bricks thick all round. Where rocks are found, it will be reduced at the bottom, and perhaps at the top.

The excavation of the drift is in progress and is carried on with two galleries. The lower one is of timber, and is at the bottom three feet below the grade of the road. This gallery is ten feet wide and ten feet high.

The upper gallery, also of timber, is ten feet wide and four feet high, and the space between the galleries is about ten feet. As the arch is driven in, the top of the invert is 41/2 feet below the grade of the road, and 18 inches below the timber of the lower gallery. The top timbers of the upper gallery constitute the top timbers of the tunnel during the excavation. They are supported above the masonry and the arch is turned under them.

Side drains, six feet high and four feet wide, are excavated ahead of the galleries, to assist the drainage of the ground through which the galleries and tunnel are driven. The water from these drains is let into the tunnel through its sides, and runs out with the general drainage upon the invert below the road-bed. Holes are left in the invert at proper intervals to facilitate this drainage.

The side drains are hereafter to be filled with stone, which will constitute a blind drain, and also afford a proper support to the masonry.

The work at this point is of difficult prosecution, but the performance of the contract may be confidently expected.

The Brickyard.

Twenty-four thousand bricks can be moulded daily. The drying yard is 300 feet long and 120 feet wide. The kiln shed is 300 feet long and 50 feet wide, and of capacity to burn all the bricks that can be moulded. There are six brick machines, four of which are in use. They are driven by an engine, and used alternately, two each day. The making of bricks at the yard commenced June 26 and closed October 24, 1860. About 1,700,000 bricks were made, of which 80 per cent. are sufficiently hard for use in the tunnel, which is estimated to be sufficient to complete the 374 feet of tunnel now under contract.

The clay for the bricks is found near the yard, and hitherto a sufficiency of sand has been found in the vicinity; but it is less abundant than the clay.