Kitabı oku: «Report of the Hoosac Tunnel and Troy and Greenfield Railroad, by the Joint Standing Committee of 1866», sayfa 3
Miscellaneous
In addition to the property enumerated under the preceding heads, the State has at North Adams, a freight house, cashier's office, engineer's office, stable and two coal sheds, and opposite the West End on the Pittsfield and North Adams Railroad, an additional freight house. There are also two instrumental station houses on the east and west summits respectively, all of which are occupied by the State for the purposes of the enterprise. There is also one seven-horse engine and three small compressors. Tho State has also four mule teams, three of four, and one of two animals, making fourteen in all. There were also used on the work in the early part of the year, twelve or fourteen horses, employed in hauling clay, sand, wood, &c. Six of these have been sold to Mr. Farren, and the remainder are to be disposed of. To this enumeration should be added five horses and three or more carriages kept at the stable at North Adams for the transportation of the engineers, superintendent, master mechanic, &c., from point to point along the line of operations wherever their presence and services might be needed.
for the expense of keeping five horses, and the repairs; which is about five dollars per week in all. The charge for keeping horses at the stable in North Adams, is five dollars per week for feed; and the cost for the use of one horse and wagon from North Adams to the East End, is four dollars. These horses were also used to transport the commissioners and the committee visiting the tunnel, when required for that purpose.
The Road between the Tunnel and North Adams
It is proposed to change the course of, the road as it emerges from the tunnel, and two lines have been surveyed, which, diverging near the approach cut, unite again about midway from thence to the village. The difference in length is about thirty feet. The northerly line is the least expensive to construct, and best favors the landholders on the route. It has the recommendation of the engineer, and the approval of the consulting engineer, and will probably be selected. There are reasons for an early location of this portion of the road which call for a prompt action in this behalf on the part of the commissioners, which will undoubtedly be taken.
The following table shows the expense of the tunnel and the land and works connected therewith under the administration of the commissioners, as found November 1, 1866:—
The following table shows the cost of the works under the classification of outside and inside expenditures, as given by the consulting engineer.
The exact correctness of any classification of the expenditures is not very important, inasmuch as the sum total is chargeable to the construction of the tunnel; but the Committee do not see the propriety of charging the engineering and superintendence exclusively to the outside expenditure. They have seen a classification which gave,—
General Summary of the Force Employed on the Tunnel,
Experiments
The interest awakened by the magnitude of the undertaking to tunnel the Hoosac Mountain, and the anxiety manifested for its early completion, prompted the commissioners to the discovery of means to accelerate the progress of the work. Their attention was naturally directed to the operation of drilling, and with a view of improving upon the machine drill used at Mont Cenis; scientific mechanics have been employed to devise and construct a drill that should attain that end.
As a first step Gouch's patent of the hollow piston-rod, was purchased for New England, for the sum of five hundred dollars. After which, a Mr. Gardner was employed to construct a drill; but his efforts failed of success after an expenditure of thirteen hundred dollars. A Mr. Butler was engaged to devise a machine, but in the course of studying the subject, his health failed and his services were lost.
A Mr. Hanson completed a machine which promised some success; but on trial it proved a failure.
A second machine called the Brooks, Burleigh and Gates drill, was made under the direction of the commissioners at Fitchburg. This machine was put upon the works and used for several months.
A third machine, called the Burleigh drill, an improvement upon the preceding one, was next produced, which is now at the works on the East Heading.
About $13,000 was spent upon these experiments, resulting in the construction of the Brooks, Burleigh and Gates drill, and the manufacture of four of them. About one-half of this expenditure may be charged to these last drills; the other was unproductive of anything of value.
The Brooks, Burleigh and Gates drill was patented, but the Commonwealth has the right to use them in the construction of the tunnel.
These machines will now be described.
The Hanson Machine
This machine has a cylinder and valve motion, similar to a steam-engine. The piston is hollow, the drill-bar which may be of any required length, passing through it, is moved with the piston, by means of four wedges or cams on each end of the piston; these cams are pressed on the drill-bar by means of sliding collars forced upon them by a complex arrangement operating alternately. The drill-bar is rotated by means of a ratchet operated by a spiral groove in the shield of the machine. The main difficulty in this machine was in the complex arrangement for forcing the collars upon the cams or wedges. It did not work well in a horizontal position. The machine consisted of one hundred and twenty pieces, and weighed five hundred and ninety-five pounds.
The Brooks, Burleigh and Gates Machine
This machine has a hollow piston, the drill-holder being a screw passing through the piston, moving with it, and fed through it, by means of a nut on the end of the piston-rod. This nut is held by means of a cap or union nut, as it is called, the union nut being screwed on to the coupling, and the coupling nut screwed to the piston-rod. The feed-nut protrudes through the union nut, and is allowed to turn round in it. On the end of this feed-nut is a ratchet gear covered by a ratchet-band with an arm upon it, all moving with the piston. The ratchet arm moves up and down in a spiral groove, the groove being in a shield attached by screws to the cylinder; on the ratchet-band there is a pall and two springs, one under the other. One of the springs holds the pall in gear, the other holds it out of gear. As the piston moves down, the outer spring comes in contact with a trip which is on the shield and is lifted up, allowing the under spring to throw the pall into the ratchet, and as the piston is moved back, turns the nut round, thereby feeding the screw forward. At the extremity of its backward stroke, the pall comes in contact with another trip on the shield which lifts it out of gear, the outer spring having a catch upon it which holds the pall when thus lifted out. The rotary motion is given by a ratchet on the coupling-nut, covered by a ratchet-band the arm of which moves in a spiral groove in the shield similar to the other, only having a spring to hold the pall in the ratchet; this rotates all the parts on the piston except the ratchet-bands and cross-head. The latter is held between two check-nuts on the coupling-nut. To this cross-head is attached a bar which communicates with a valve which opens the port when the piston moves back, and shuts it when it moves forward; the air is always on during its backward stroke. The piston having a greater area on the forward than on the backward stroke, overcomes the backward pressure and moves the piston ahead, and when cut off, the continued pressure forces the piston back.
This machine is automatic; generally running until some portion of it is destroyed. No part of the machine has been found strong enough to withstand the friction upon it for any considerable portion of time. The union nut has proved its weakest point, and the breaking of this generally destroys that part of the piston to which it is attached. Another point of weakness is the feed ratchet-band, the springs of which are almost continually breaking.
The machine consists of eighty pieces; twenty-three of which are screws, fifteen pins, and seven pieces of cast iron. It weighs 240 pounds, runs about 200 strokes per minute, and costs about $400. Its longest run without breaking has been five days. The run of one of them two days without breaking during the time, is considered fortunate. The average breaking is more than one a day. A table showing the list of breakages will follow this description.
The piston-head of this machine has a diameter of 45/8 inches. The diameter of the piston-rod is 4 inches at the large end and 21/4 at the small end.
So there are 1287/100 square inches of air area to drive the drill ahead into the rock, and 423/100 to draw it out; but as the air is not taken off from the front end, the actual pressure is upon an area of the difference between the two, or 864/100 square inches.
Table showing Number of Drilling-Machines Broken, &c.
About forty of the Brooks, Burleigh and Gates machines have been used at the tunnel; of these eight or ten were originally vertical, and intended for use at the Central Shaft. At the commencement of their use, the machines were new and had their best wear in them; there were from twenty to twenty-four at the beginning. In a short time they began to break down, but by putting on a large repair force and converting the vertical machines into horizontal ones, a fair supply was kept up for from two to three months, at the end of which time the greatest machine progress was attained, viz., fifty-four feet and six inches, in September. After that the progress diminished very much, and in proportion to the giving out of the machines. It is the opinion of the engineer that if a constant supply of machines could have been furnished, that the progress would have reached a point much beyond that obtained by hand labor; but with the stoppage of the supply, the number of machines that could be kept in working order was daily reduced, and at last it fell down to two or three, and finally, at times, none were in condition to work. The frames were, however, kept in the tunnel to await the completion of the Burleigh machine, the reception of which was retarded till late in October; much beyond the time anticipated by the commissioners, although the work of their construction was carried on continuously night and day. They came at intervals of several weeks, two at a time; the first of which were put into the tunnel on the thirty-first day of October. Through the month of December, four of these machines were at work.
The Burleigh Machine
Has a solid piston (so called,) which has a hole in its back end to allow the feed-screw to pass in without touching; the drill is secured to this piston. On the back end of the piston is a section of a ball used as a cam, which works the valve and the feed-motion. The valve is rotated by a rod lying on the band of the cylinder; upon this rod are two cams which perforate the band of the cylinder. The action of the piston brings the ball on its end in contact with these cams, rocking them up and down; the rod to which they are secured being connected with the valve, imparts to that its motion. This machine is fed altogether on ways, or a bed-piece, upon which is the feed-screw; the feed-nut is upon the end of the cylinder-band. To this feed-nut is attached a feed-ratchet, which is held between two collars, allowing it to turn round. Upon the cylinder-band is a lever, one end of which passes through the band; upon the other end is a pall. The motion of the piston raises the lever up, pressing the end containing the pall against the ratchet which turns the nut on the feed-screw, thus moving the machine forward. The rotating ratchet is in the band of the cylinder and has a spline in it, and a pall on its outside. The piston having a spiral groove is turned by this ratchet as it moves down. On the return of the piston, the pall drops into the ratchet and then the piston is turned. The piston is not encumbered with any machinery, and moves alone; its area of air is greater on the forward than on the backward stroke; the alternation of the valve admits the air. The machine, like the one last described, contains eighty pieces; it has the same number of screws and pins, and weighs 372 pounds including the ways or bed-piece; without the ways its weight is 212 pounds. Its number of strokes is about 300 per minute, and its blow somewhat lighter than that of the other. This machine is not entirely automatic; the feed-motion not working regular; when it does not, it is fed by hand, which is a simple process.
These machines stand the work much better than those first made at Fitchburg. Their average time in the tunnel without repairs in the interval, is about five days; they have needed repairs in two days; one remained at work fourteen days. They accomplish double the work without repairs that those do which were made after the previous pattern. There is a further advantage in using the Burleigh machines; their breaking, when it occurs, is not very serious, the injured parts consisting mainly of cams, can generally be replaced at the tunnel; whereas for the repairs on the Brooks, Burleigh and Gates machine, the dependence to a very great extent has been upon the machine shop at Fitchburg.
The piston-head of this machine has a diameter of 425/100 inches. The diameter of the piston-rod is at the large end, 3 inches, at the small end, 275/100 inches.
So the number of inches of air area, is 820/800 when the drill is propelled upon the rock, and 77/100 when returning from it.
A full complement of men to work the machines first used, would be, perhaps, thirteen. Mr. Gates, who superintended their operation in the first instance, began with fourteen, but they were reduced to thirteen. The Burleigh machine practically requires feeding, and a full set at work would probably demand fifteen men for their successful operation.
The value of these machines has not yet been ascertained. The Committee are of opinion that when a full complement shall have been obtained, so that the workmen can have at all times a full supply upon the frames, that greater progress can be obtained by them than by hand drilling; and after a few months operation, the cost of using them, in comparison with hand labor, can be fairly tested. But as the Brooks, Burleigh and Gates machine has been abandoned, no useful results would be obtained by comparing the expenses within the tunnel during the months of July, August and September, with three corresponding months when hand drilling was carried on, and no satisfactory comparison can be made between the working of the Burleigh machine and hand drilling, until a sufficient number of machines has been introduced into the tunnel to keep the men fully employed. It is to be hoped that machines sufficient to make the test may be soon obtained, and that this desirable information may be made known.
The introduction of the first machine into the tunnel, before its capacity, strength, and expense of working had been fully tested, was unfortunate, inasmuch as its use there delayed the progress of the work. The second machine gives such promise of success, that it will be continued in use in the tunnel until a fair test has been made. But should the Burleigh machine prove unsuccessful, and further attempts with machines be attempted, the Committee recommend that their usefulness be tested outside of the tunnel, and meanwhile the excavation with hand drills be resumed.
Experiments with Dr. Ehrhardt's Powder
The first blast was fired in the tunnel at the East End on the 20th of November, but owing to the presence of charcoal or some other substance in the article, a poisonous gas was evolved which effected the miners disagreeably, and drove them from the work. The subsequent experiments at this point were not satisfactory, and were discontinued, and subsequently resumed at the Central Shaft, where it was used most of the time for a week, varying its composition from time to time. At the close of the week, while preparing for the last blast, a premature explosion took place, resulting in the death of one of the miners, and the injury of three or four others.
The material result of this experiment was as follows:—With 261 days' work and 1391/2 lbs. of powder, 202 buckets of stone were removed; while in the preceding week, using common powder (schaghticoke) with 2513/4 days' labor and 236 lbs. of powder, 168 buckets of stone were taken out. The cost of the experimental powder is about twice as expensive as the common powder, and its superior strength is apparent from the above result.
Experiments with Nitro-Glycerine
During the summer, some experiments have been made with this explosive agent. A quantity, costing $934.29, was brought to the works by Colonel Schaffner, who exhibited the action of the material in various ways, with a view of testing its power, and the comparative safety of introducing it instead of powder. After repeated trials outside of the works, during which about three-fifths of the material was consumed, it was introduced into the tunnel at the West Shaft with the following result: It was used for three days at the East heading of the West Shaft; the advance made in the heading was for the time, 141/2 feet;—being an advance of 4.82 feet per day, and at the rate of 125.33 feet per month.
The progress made at the West Shaft on the East heading the present year, ending December 31, 1866, is 626 feet and 8 inches. This progress was somewhat lessened by the influx of water in December. The monthly advance has been 52 feet and 2 inches. The average of the eleven months ending with November is 53 feet and 6 inches. Assuming the progress made with glycerine during the three days of its use to be obtainable throughout the year, the monthly progress, using that material, would be 120 feet and 10 inches, on a calculation of twenty-five days to a month, which would give an annual advance of 1,450 feet.
Without vouching for results so favorable to the progress of the work, it is impossible to overlook the importance of the experiment; and the Committee are of opinion that this material, if it can be procured, should be introduced into the tunnel and shafts, and a thorough experiment made, in order to determine whether it can be used with an advantage even approximating to that shown by the first trial.
Experience has proved that the rock at the Hoosac Mountain is of a peculiar character: comparatively easy to drill, but extremely hard to displace, and that its advantageous excavation requires a strong explosive agent. The difference in the use of weak and strong powder is at once observed, and the effect of simultaneous blasting, by the aid of electricity, is proved by the increased progress of the work since it has been used. It would seem evident, then, without the aid of experiment, that an explosive agent, possessing eight times the power of common powder, would be a valuable auxiliary to this undertaking; and that if such an one could be obtained, and safely used, no time should be lost in procuring a supply.
The use of nitro-glycerine in England is not uncommon; its components are well known; and the Committee are informed that it might be advantageously manufactured at any point where it is used.
Electrical Firing
The experiment of simultaneous blasting by electricity has been made with admitted success. The increased progress in the Central Shaft from an average of about 181/2 to 23 feet per month, demonstrates its utility, and will undoubtedly insure the continuance of that mode of firing in preference to the method formerly practised.
The Troy and Greenfield Railroad
The completion of the railroad from Greenfield to the tunnel has been contracted for with B. N. Farren, for the sum of $545,000, exclusive of the cost of depot buildings, turn-tables, and engineering expenses. The road to be opened for travel to Shelburne Falls by the 15th of November, 1867, and to the tunnel by the 15th of July, 1868. A lease of the same has been executed to the Fitchburg and the Vermont and Massachusetts Railroad Companies, at a rent of $30,000 per year, to expire on the completion of the tunnel, or whenever the work on the same shall be stopped, by competent authority.
Mr. Farren commenced work under his contract about the 20th of October. At this time there were about four miles of track,—exclusive of that which had to be removed with the trestle-bridges,—built by Mr. Haupt. Some portions of the track were in fair condition; but the larger part of it must be relaid. Many of the ties are of hemlock; they are all decayed and must be removed, and new ones substituted. None of the bridges were strong enough to be used, and the timber of which they were constructed is too much decayed to be used for building purposes: There is on hand in addition to the track laid, chairs, or connecting joints, sufficient to lay five miles of rails; also about ten thousand chestnut ties. Such of these as had been properly piled are sound. Many of them, however, are so much decayed, as to be unfit for use.
The road-bed has in many places been injured by rain and frost. At exposed points near the river, it is entirely destroyed. Comparatively speaking, there was little masonry on the line. With the exception of one pier, the bridge masonry at Green River will be taken down. All the deep ravines were crossed by trestle work, and consequently there were but few culverts. Of these some small ones are still standing in good condition. Of the bank wall built, about one-half remains,—the remainder has either fallen down, or will be taken down and rebuilt.
Very little alteration will be made in the general location of the line or its gradients. The curvature will be very much modified and improved. Some sharp and reversed curves will be entirely saved by the substitution of straight lines. Others, where the expense of reduction is not very heavy, will be materially changed. The alterations below Shelburne Falls are substantially as follows:—
The same plan for improving the line above the falls will be pursued, so that when completed, the road combining the alignment with the gradients will, in the judgment of the engineer, be "superior for doing economically a heavy traffic, to any railroad in New England which runs east and west."
At Green River there will be substituted for Mr. Haupt's bridge of 700 feet built on a curved line one of 470 feet, to be constructed on a straight line. The remainder of the ravine to be made a solid embankment. All the bridges on the line are to be "Howe's Truss," and equal in strength and durability to any in New England.
The trestle-work has been removed, and the ravines where it was placed are being filled with substantial masonry and solid embankments.
On the first day of November Mr. Farren had about fifty men employed; on the first day of December, two hundred and seventy-five, and on the 14th of December, when one of the Committee visited the line, he had over three hundred.
About one-third of the masonry for Green River bridge has been built, and the stone is quarried for the other bridges. Nearly one thousand yards of culvert masonry and three hundred yards of bank wall have been constructed, and from forty to fifty thousand yards of earth removed.
The timber for Green River bridge is sawed and will be framed in January. The material for all the bridges below Shelburne Falls has been contracted for, to be delivered early in the spring. Twenty thousand ties have been purchased, together with posts and boards for fences. The work at the rock-cut near Shelburne Falls will be commenced in the month of January.
On the line below Shelburne Falls, there will remain in the road, the following sharp curves, to wit: In the track as laid and not disturbed, four of six degrees, and in the remainder of the line, six of six degrees, three of seven, and two of eight. One of the eight degree curves, is through a long heavy cut, and cannot be reduced without great expense. The other is near the Deerfield River crossing, where all trains will be required to run slow. It cannot be avoided without a tunnel or a curve over the entire bridge. The three seven degree curves occur in heavy rock-cuttings, and these are all the sharp curves that are contained in a space of thirteen miles.
Above Shelburne Falls the alignment and grades are more favorable. From the tunnel to the Deerfield River crossing, below Shelburne Falls, a distance of twenty-two miles, there is but one ascending grade going east; its location is about two miles west of the falls; it is one-half mile in length, and is thirty-five feet to the mile. Within the same space going east, there are the following descending grades, to wit: One of forty-five feet per mile for 2,000 feet, one of forty feet for 6,000 feet, one of twenty-eight feet for 2,500 feet, and one, near the village of Shelburne Falls, of fifty feet per mile for 5,300 feet. The remaining grades are from five to twenty feet per mile.
The sharp curves remaining after the proposed improvements will be as follows, to wit: Near the depot grounds at Shelburne, and running through the village, there is necessarily one eight degree curve, and on the seventeen miles between the falls and the tunnel, there occur thirteen six degree curves. A slight change in laying the track will increase the radius of these curves to 1,000 feet. This in some cases can be done.
The county commissioners have been called out and have made an adjudication in regard to the public crossings and alterations of highways between Greenfield and Shelburne Falls.
The whole work below the falls is under good progress, and is being prosecuted with great vigor. The laying of the track can be commenced as early in the spring as the season will admit, and its extension to Shelburne Falls, may, in the opinion of the engineer, be expected early in October.
It appears from the foregoing, that of the work now in progress on the road and tunnel, their is performed by contract,—the construction of the railroad from Greenfield to the East End of the tunnel; the enlargements east and west in the tunnel at the West Shaft; the excavation of the New Shaft; and the arch masonry and excavation at the West End; while the work at the East End, at the Central Shaft, the heading and lifting at the West Shaft, the lifting at the New Shaft, and the work at the brickyard has been performed by the State. No criterion has been afforded enabling the Committee to determine upon the comparative economy of the different modes of operation.
The commissioners in their able report in 1863, speaking of the manner of constructing the tunnel, say: "It would not be wise nor according to any precedent for the State to expect to get the work done at the contract price if it should turn out to cost more. It would certainly get no abatement if the price was found to be exorbitant. We are clearly of the opinion that it should not be constructed by contract, excepting in so far as parts of the work may be in detail to the men actually at work upon it, and even such contracts should' not be permanent in their character." That the commissioners in April last entertained the idea of inaugurating and continuing the contract system so far as the same should prove economical for the State, satisfactorily appears in the following letter:
BOSTON April 25, 1866.
Hon. Tappan Wentworth, Chairman of Hoosac Tunnel and Troy and Greenfield Railroad Committee
Dear Sir:—Hearing that questions have arisen in regard to the propriety of contracting the work upon the Hoosac Tunnel, it may not be improper for me to say that that subject (contemplated in the Act of 1863,) has for a long time engaged the serious attention of the commissioners, who have already a contract for constructing a portion of the West End, before the governor and council, awaiting their approval under section 3 of chapter 214 of the Acts of 1863.
When the economic value of their new facilities shall be demonstrated, they expect further to avail of this system 80 far as the interest of the State (as represented by the rapid, economical and certain progress of the work,) shall warrant.
While the high prices now prevailing will probably render the letting of large jobs at this time injudicious, they are not of short contracts, or of letting portions of the work to the miners by the piece.
Very truly yours,J. W. Brooks, Chairman.
The Committee coincide with the views of the commissioners. And the justness of their remarks, that the State must not expect to have the work done at less than its cost, is borne out by the operations under the contract for the West End enlargement, where the State has increased the contract from four to seven dollars and fifty cents a perch, in order to insure the miners a compensation for their labor.
It may be proper to state in this connection, that the labor done upon the road and tunnel by early contractors, has not tended to a "rapid, economical and certain progress of the work," and that if even the whole work should be put under contract, the interest of the Commonwealth would require the continuance of a commission, and the services of an engineer of the highest skill and integrity to superintend its performance in order to avoid a loss and damage similar to that which occurred to the State while the work was under the nominal control of the Troy and Greenfield Railroad corporation.
The retirement of all the gentlemen who comprised the board of commissioners, first appointed under the legislation of 1862, affords the Committee an opportunity to acknowledge the eminent talent and ability which they respectively possessed for the discharge of the important duties assigned to them, and to bear testimony to the industry and intelligence displayed in their elaborate and comprehensive report upon the subject of the railroad and tunnel in 1863. It was fortunate for the State in that crisis in the affairs of this enterprise to be able to command so much practical information upon a question so interesting and important, and at the same time so difficult of solution.
