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averaging 58 feet lift each, of which one, near the western terminus of the canal, has a height of 100 feet.
These planes were, when first constructed, operated in connection with an ordinary lift-lock placed at the head of the plane, connected with the upper level or pool, irito the bottom of which lock the track (an ordinary railway-track) of the plane was laid, and led down the plane to the lower pool. The boats were carried up or down the plane on a wheeled carriage running on a railway-track operated by an endless chain passing around large horizontal pulleys, (fixed at the head and foot of the plane,) and attached to a large winding drum operated by a turbine motor, and the usual gearing and machinery for transmitting such power. The turbine with its machinery is located in a house on one side of the plane at about the middle of its length, and is operated by the head of water taken from the upper pool. The boats were taken into the locks at the head of the planes in the usuahnanner, and as the prism of lift-water was discharged the boat settled down into the carriage and was let down the plane to the lower pool, where the boat, following the inclined plane to a depth greater than the draught of the boat, floated and was detached, passing on its way. Boats moving in the contrary direction were drawn over the carriages as they stood in the lower pools at the foot of the planes and made fast thereto), and the machinery being put in motion, the carriage rising along the planes, the boats settled down upon them and were carried up to the head of the planes and into the locks, which were then closed, the prism of lift-water let in, and the boats were raised to the upper pool and passed on
The locks at the heads of the planes have been taken away, and the railways of the planes are carried over into and down to the bottom of the upper pools, where the boats are received and discharged from the carriages in the same manner as at the foot of the planes in the lower pools. This arrangement of the two planes is called a ** summit-plane," and this is the kind of plane I have considered in connection with the extension of the Chesapeake and Olio Canal, with special reference to their application on the mountain section of the Savage River route, between the mouth of Savage River and Salisbury, on the Castleman River, and at one or two places farther west on the route where their usefulness is apparent.
The loaded boats of the Morris Caval, together with the carriage, weigh about 110 tons. Observations made on the operating of a plane at Newark, rising one foot in ten, and having a lift of 70 feet, showed that boats were readily and efficiently passed from one pool to the other, over a horizontal distance of about 1,000 feet, in four minutes, equal to a rate of twenty-eight miles per hour.
DESCRIPTION AND ESTIMATE OF COST.
The accompanying drawings, showing a profile and plan of a single-track plane, and a plan of a double-track plane, illustrate the arrangements and dimensions of a summit-plane of 64 feet lift, rising one foot in 10 feet. H is the upper and L the lower pool or level of the canal, connected by the inclined plane. The summit of the plane at s is from 11 to 2 feet higher than the surface of the upper pool, and the second brano. of the plane descends to the bottom of the upper pool at the rate of 1 foot in 10 feet and the foot of each plane is continued beyond the ordinary depth of the canal to gain depth enough to allow the carriage to pass under the boat as it floats, as shown at A. The additional depth shown in this plan is about 6 feet, requiring a total depth of 12 feet. P and P are the horizontal pulleys around which the traction cable passes connecting the carriage with the winding-drum D. They are firmly fixed to masses of masonry. The turbine motor, connecting with the winding drum by suitable gearing, is placed in a suitable house at the foot of the plane to utilize the available hydraulic head between the pools.
The carriage is formed of two parallel trusses, each resting on two trucks of two iron wheels, each flanged like ordinary railroad-car wheels. The trusses are connected by bearing joists or floor-beams on which the boats rest while being moved up or down the plane. The trusses are carried by bolsters resting on axle-pivots at 0 0 in such manuer that the trucks may, in moving over the crest of the plane, adjust themselves to the plane of the track by turning about the axle-pivots. The track upon which the carriage runs consists of the ordinary T railroad rail laid on longitudinal string. ers, which are placed on a foundation wall of masonry, put deep enough in the ground to be undisturbed by the freezing of the ground in winter. The traction cable C is supported on grooved carrying-wheels placed at proper intervals, and iron rollers are used to carry the cable over the crest of the plane. The carrying-wheels placed between the drum and the horizontal pulleys move horizontally on their axles, adapting themselves to the horizontal motion of that portion of the cable as it winds off or on the drum. The planes are increased in length in proportion to the depth reached in each pool, and a portion of level track is laid in each pool for the carriage to rest on when receiving or discharging a boat, the pulleys being placed at the ends of the level portion of track.
The total height of the main piaine from the bottom of the lower pool to its crest or summit is 77.5 feet, and the height of the plane in the upper pool is 13.5 feet. The horizontal lengths of the planes are therefore 775 feet and 135 feet, and their slope lengths are 778.86 and 135.67 feet, wbich, together with two level portions of 100 feet each, makes the track needed 1,114.5 feet long. [Fifteen feet are taken from each end, leaving 1,085 feet of track.)
The length of cable nsed is twice the lengths between the pulleys, measured on the planes, the circumference of one pulley, and the distance passed over by the carriage in going from one pool to the other, say 980 feet, a total length of 3,235 feet. The ends of the cable are separately fixed to the drum, and a length of cable equal to the distance passed over by the carriage is always wound on the drum. In the doubletrack plane the length of cable is twice the distance between the pulleys by the planes, once and a half the circumference of a pulley, the distance between the tracks, the distance passed over by the carriage, and twice the distance from the drum to the pulleys in the upper pool, in all 4,140 feet.
The gauge of the track is 18 feet, and the slopes of the canal-prism, if carried to a depth of 12 feet, will not provide room enough for the single-track plane, and the necessary widening and the excavation of the prism between the foot of each plane, and the surface of the pool is considered in the cost of the single-track plane; and in the cost of the double-track plane the expense of widening to a width of 75 feet for a distance of 300 feet in each pool is included.
The expense of deepening the canal to a depth of 12 feet for a distance of 100 feet in each pool is also included in the cost of the single-track plane.
COST OF SINGLE-TRACK PLANE.
Deepening pools, 2,150 cubic yards, at 40 cents.....
$860 00 900 00
150 00 2, 800 00 525 00
27 00 2,322 00
70 00 20 00 100 00 425 00 225 00 5, 337 75 1, 000 00 2,000 00
200 00 5, 640 00
450 00 1, 500 00 2,500 00
27,051 75 2,705 17
Cost of plane....
29, 756 92
COST OF DOUBLE-TRACK PLANE.
Cost of single-track plane....
To which add the following quantities :
1, 200 00
150 00 2, 800 00 525 00
27 00 2, 322 00
70 00 20 00 100 00 500 00
225 00 1,501 50
Boat-carriage, as figured .
39, 392 50 3,939 25
43, 331 75
ECONOMY OF COST AS SUBSTITUTE FOR LOCKS. In a mountainous country, where a considerable elevation is to be overcome in compaiatively short distances, and where the ordinary lift-locks must be placed in flights, so called, that is, adjacent to each other, or be placed so close together as to seriously retard navigation as to time, the pools being so short that the average usual speed cannot be acquired between the locks, (and the time lost in locking and attendant delays consume a great part of the time on the section where the locks are so close together,) or where, to avoid such loss of time, the lifts of the locks must be made so great that the requisite supply of feed-water cannot be bad, (such locks being also very expensive in their construction,) the locks in either case being a principal item of the cost of the canal, as well as a continnal source of delay in transportation, if there should be but one lock for each mile, the cost of locks would be but some $10,000 per mile; but if the levels of the canal, as in some well-known cases, were ten or twelve miles long, then the cost of the locks would be but some $1,500, or even only $1,000 per mile for the ordinary lifts of eight feet; on the contrary, if the canal s to be carried into a mountainous region, where the slope of the valleys must be followed at a rate of 50 or 60 feet rise per mile, requiring 6 or 8 locks per mile, their cost becomes the principal item of expense, and may reach as much as $130,000 per mile.
Considering the section of the Chesapeake and Ohio Canal between Cumberland and Connellsville, via the Savage River route, as presented in my report of January 30, 1874, we find the cost of locks between Cumberland and the month of Savage River equal to 28 per cent of the whole cost of the canal-321,000 per mile-the locks occurring at intervals of three-quarters of a mile. At the mouth of Savage River the ascent of the mountain begins, and between that point and the summit, a distance of sixteen miles, there are 140 locks, aggregating more than 75 per cent. of the estimated cost of the canal for that section.
If, to avoid this high ratio of cost of lift-locks on the line of canal, we consider the substitution therefor of the single-track inclined-plane, as described above, we find that one plane overcomes the lift of eight locks of 8 feet each. [This lift of the plane was assumed with special regard to this section of the canal, as, in my judgment, they can be economically placed at average intervals of about oue mile.] Eighteen planes wonld be required to overcome the elevation of the Savage River section, where there are 140 locks, and two planes for the section between the western end of the Summit Tunnel and the mouth of Piney Run, where there are 16 locks in 6 miles. On these two sections the slopes of the hill-siiles are favorably conditioned for supporting the levels of the canal for such use of the planes.
The 156 locks, estimated on this section of the canal at $16,500, (with 10 per cent. contingencies,) would cost $2,574,000, while, on the contrary, the 20 planes would cost but $395,138.40, a difference of $1,978,861.60 in favor of the planes, equal to a saving of 76.88 per cent of the cost of the locks, and reducing the cost of this section of the canal by 58.58 per cent. Comparing the cost of the plane with the cost of the eight locks it would take the place of, there is a difference of $102,243.08 in favor of the cost of the plane, overcoming the same height of lift by the plane as by the eight locks, at 22.5 per cent. of the cost of the locks.
There are no natural indications that planes could be used between Cumberland and the mouth of Savage River, and the cost of supporting the levels of the canal on the hill-sides might be a greater increase (in the cost of high embankments, or the crossings of lateral ravines or valleys, and high aqueducts) than would be saved by the planes of less lift than described above.
There are, however, two places on the line of the canal west of Meyer's Dale City where planes could be advantageously used. Referring to the report of the Board of Internal Improvement, (1st subdivision, western section,) there is a reference to the Ohio Pyle Falls, where the fall is 96 feet in the distance of one mile. The cost of a plane of this height would be, in addition to the cost of the 64 feet high plane, the cost of 321.6 of track and traction-cable and their accessories, amounting to $3,068.45, including 10 per cent. contingencies, making the total cost of the plane $32,825.45; while, on the other hand, twelve locks of 8 feet lift each would cost $198,000, a dittorence of $165,174.55 in favor of the plane. The other place I refer to as indicating the substitution of a plane for locks is at the mouth of Castleman River. The use of a plane at this point would save $102,243, as found above. These items of difference in
cost aggregate $2,246,279.15, which is applicable to the reduction of the cost of the canal as estimated in my former report, reducing the cost from $19,937,285 to $17,691,006, a reduction of 11.25 per cent.; a sum that, rated as an invested capital, at 6 per cent. per annum, is equal to a saving of $134,776.75 in annual expense of maintaining the canal.
This character of inclined plane could also be applied on the Wills Creek section of the Wills Creek route ander very similar conditions, as will be seen by reference to the report of the Board of Internal Improvements, “eastern portion" of middle division, where the intervals between the locks are given as 180 yards, equal to 540 feet, and the average of six locks per mile obtains between Cumberland aŅd the summit of the mountain.
EXPENDITURE OF WATER IN OPERATING THE TURBINE MOTORS.
In determining the work to be done in moving boats over the plane, the weight of the boat is taken at 30 tons, the weight of the cargo at 120 tons, and the carriage at 35 tons, making an aggregate load of 185 tons, or 414,400 pounds. Resolving this weight with reference to the plane rising 1 on 10, we have for the pressure perpendicular to the plane 412,343.4
pounds, and for the weight acting downward, parallel to the plane, 41,234.34 pounds. This weight, together with the friction of the load, is to be overcome in moving the load up the plane. Taking the friction at eight pounds per ton of the weight normal to the plane, we have for the rolling friction 1,472.66 pounds, which gives the force to be applied in moving the load 42,707 pounds-moment poundsparallel to the plane.
To raise the load one foot high, the travel along the plane will be 10.05 feet; and the corresponding foot-pounds will be 429,205.35. To move the boat at a rate of 2} iniles per hour gives a rate of 3.66 feet per second horizontal, or 3.685 feet along the plane, and the corresponding foot-pounds are 157,375.44 pounds. As 550 foot-pounds are rated as one horse-power, we require 286.20 horse-power to move the load 3.685 feet in one second, or to raise it one foot high in one second. Adding five per cent. for friction of machinery, we get quite nearly 300 horse-power as the measure of work per second required for the turbine motor,
To determine the diameter of the turbine to do this work, and the quantity of water expended per second, in cubic feet, with a height of head of 64 feet, we have, by the formulas and proportions deduced from the Lowell hydraulic experiments, (by Mr. James R. Francis, C. E.,) for the diameter of the turbine 3.71 feet, and the water discharge 56.26 cubic feet per second. To move the carriage over the distance from the average place at the foot of the main plane until the rear wheels are over the crest of the planes toward the upper pool, whence the force of gravity will take it to the foot of that plane, a distance of $25 feet, will require 3.75 minutes' time and expend 12,433 cubic feet of water. [These formulas consider the useful effect of the turbine as 0.75 of that due to the hydraulic head.]
As turbines are so arranged that the expenditure of water is in proportion to the work done, we have an expenditure of 4,368 cubic feet of water to draw an empty boat, 65 tons, (with carriage,) up the plane, and, to move the same loads from the upper pool over the crest of the plano a distance of 200 feet, we have an expenditure of 3,014 cubic feet for a loaded boat, and 1,059 cubic feet for the empty boat. These quantities need not be necessarily fully expended, as a part of the work is done in moving the load over whatever distance the rear trucks of the carriage may be from the foot of the plane when the movement begins, and in carrying the rear trucks of the carriage over the crest of the plane; times, in which the full power of the turbine is not required.
The movement of boats up or down the slopes of a canal, whether operated by planes or by locks, are somewhat analogous. When the canal is operated by locks, each loaded boat passing up the canal draws from the upper pool one lockful of water, plus the boat's displacement, and an empty boat one lockful, plus its displacement; and in passing down the canal each boat draws off from the upper pool a lockful of water less its displacement, when the locks are found empty; but if the locks are found full, the down-going boats will force the quantity of their displacement out of the locks into the upper pool. [A lockful of water is considered as part of the lower pool.] In the case of the locks under consideration, the prism of lift contains 12,000 cubic feet, and a loaded boat displaces its weight of 150 tons, 5,391 cubic feet, and an empty boat its weight of 30 tons, 1,078 cubic feet, of water; and in making a comparison of the expenditure of water in the two systems of working the caual, the displacement of the downward-going boats will be credited for the case of finding full locks.
To make the conditions of comparison equable in the two systems, we will first consider the expenditure of water by four boats (two loaded and two empty) going up, and two loaded and two empty going down, giving the benefit of full locks to one loaded and one empty boat going down
Showing a difference of 42 per cent. in favor of the inclined-plane system.
If, for a second comparison, we consider only loaded boats going in each direction, taking for example two boats each way, and giving one boat the benefit of finding a fall lock going down, we find as follows:
Showing a difference of 14 per cent. in favor of the inclined-plane system. If we apply this method of comparison of the expenditure of water to the summit-level of the canal, we shall find that, when we consider the system of inclined planes, each loaded boat passing the suminit draws off from the summit-level 15,447 cubic feet of water, and each empty boat 5,427 cubic feet of water, in the operation of the two summit-level planes, an average of 10,437 cubic feet to each boat; and if we take the case of the locks, each boat passing the summit, loaded or empty, draws off either 24,000 cubic feet or 12,000 cubic feet, as the lock by which the boat leaves the summit-level is fonnd empty or full, an average of 18,000 cubic feet for each boat, a saving in the expenditure of water of 42 per cent. in favor of inclined planes. If we consider only loaded boats passing the summit we find for the inclined-plane system an expenditure of 15,447 cubic feet of water for each boat, and for the lock-system an average (again) of 18,000 cubic feet, or 14 per cent. in favor of the inclined plane. This is the best practical comparison that can be made in favor of the lock-system, and shows that the expenditure of water by tbis system of inclined planes is 86 per cent. of the expenditure by locks.
The most favorable assumption that can be made in favor of locks is that which presumes that the boats alternate in direction regularly and continuously day by day, and month by month, throughout the season, in which case each boat would expend but one lockful of water in passing the summit-level; but this recurrence of boats is not presumable, and any derangement of this order for one day is not compensated by a similar disorder of recurrence on following days, and consequently presuming that two boats may go in one direction to one boat in the contrary direction, one and one-half lockfuls of water are estimated to be expended by each boat passing the summit-level. This irregularity of directions of boats increases the expenditure of water at the summit by 50 per cent. in the lock-system, but with the system of inclined planes such irregularity in directiou makes no change in the quantity of water expended at the summit, thus avoiding any doubt as to the supply required for a given number of boats, as each boat requires a given expenditure in passing the summit-level. In the case of locks, if twenty or thirty boats should pass the summit in the same direction and following each other they would each expend two lockfuls of water, or more than double the quantity that would be expended by the same number of boats passing in the same order by the system of planes.
There is, however, a general condition of commercial transportation, which considered as a basis of comparison between these systems of operating the canal with especial regard to the expenditure of water in its daily operations, gives great weight to the system of inclined planes. ;