New York State, in building the Barge canal, has accomplished a great engineering feat. The task of making the plans for this large project has involved an immense amount of engineering work and much of this work has been within the field of new design or along the line of adapting old principles to new conditions. The result of all this study and planning is the completed canal as it stands today, which probably would not be greatly changed, were its construction to begin anew. In order that this work of the engineers may in no particular be lost but may serve its fullest usefulness and be of lasting benefit to the engineering profession, assisting in the design of future public or private works, the present volume is published.
Much has already been printed in official reports and elsewhere, descriptive of the Barge canal; also the account of the inception of this project and of the events leading to it, as well as the history of the whole State canal system from its beginning, has been set forth in a previous volume. These subjects, therefore, need not be dwelt upon at present, but a few brief statements may be made, simply in aid of a clearer understanding of this book of plans, in case other volumes are not at hand.
The Barge canal project is distinctively a river canalization scheme, wheras the canals which it supersedes were largely independent channels, or land line canals. This radical change of procedure in canal-building has resulted in a divergence of channels throughout a considerable portion of the canal system. Thus the Erie branch, utilizing natural streams for most of the extent from its eastern terminus to the vicinity of Lyons, is coincident with the old channel in but few places throughout this portion and in some cases diverges from it by several miles. But west of Lyons it follows generally the old canal location. Also, the Champlain branch occupies the Hudson river bed and the valleys of Bond and Fish creeks, thus paralleling but not coinciding with the old canal, which ran on higher ground a little back from these streams. In the Oswego and the Cayuga and Seneca branches, however, the divergence is not so marked, since considerable portions of these canals were already river canalizations.
The map printed on the first plate in this volume shows all parts of the Barge canal system by means of a heavy black line. The name Barge canal has been applied, chiefly by popular usage, to the whole stretch of canal which has been under construction during the past few years, but in reality this work has consisted in the improvement and enlargement of four main branches of a previously existing State canal system. In a note on this map the various branches of the system are listed and their limits are briefly described. Certain portions of the superseded canals are retained as parts of the new system and these are enumerated in another note.
The natural flow in the streams which are canalized supplies in large measure the needs of the various canals. But these supplies require reinforcement at certain places and for this purpose most of the reservoirs and feeders which the State has built to supply the old canals are retained for the new system. The critical points in supplying water to canals are usuall, of course, the summit levels. The Erie canal has one summit level — in the vicinity of Rome — and one half-summit — at the Lake Erie end. The profiles on the canal map show the summit levels on the several canals. The greatest independent water-supply required for the Erie canal at any point is that needed for the western portion. At the extreme western end an almost unlimited supply is obtained by tapping the Niagara river. From here it is necessary to carry a continuous supply easterly to the point where the canal enters the Seneca river near Montezuma. In order to pass this water in requisite volume, the canal bottom on the long levels has been given a proper grade, which provides for carrying at least 1,237 cubic feet per second. For the Rome summit level existing sources of supply have been retained and two new reservoirs have been built. The existing sources comprise, on the north, reservoirs on the headwaters of the Black river, and on the south the supplies from Oriskany, Oneida, Chittenango, Limestone and Butternut creeks and also from certain portions of the headwaters of the Susquehanna drainage basin, which have been made tributary to the old Erie canal feeders through diverting channels. One of the two new reservoirs impounds the waters of the upper Mohawk river. it has a capacity of 2,750,000,000 cubic feet and is known as the Delta reservoir. The other, Hinckley reservoir, is situated on the headwaters of West Canada creek and is capable of storing 3,445,000,000 cubic feet, which must reach the Rome summit level through a diverting channel and Nine Mile creek. Both of these two new reservoirs are shown on the canal map. The summit level on the Champlain canal receives its supply from the Hudson river, being taken out at a point a little above Glens Falls, the water coming through the Glens Falls feeder, which has been improved for the purpose. The Oswego and the Cayuga and Seneca canals receive adequate supplies from natural sources, the former from Seneca and Oneida rivers, and the latter from Cayuga and Seneca lakes, which are large natural reservoirs.
Following these words of description there is printed a list of the plates contained in this volume. The title of each plate describes in a generally accurate and comprehensive manner the contents of that plate and as this list comprises an enumeration of titles, arranged so as to show the relation of each plate to both particular and general classification, it becomes an analytical table of contents. It is considered that this list also will serve well as an index and that the usual form of index in the case of this volume, unless it were exceedingly comprehensive, would be little besides this table of contents arranged alphabetically, and therefore may be dispensed with.
Plate 2 shows typical channel sections and also the various types of walls and bank protection commonly employed. It may be said briefly that the channel dimensions are the same for all four branches of the new canal system and that the law authorizing construction required a land line channel at least 75 feet wide at the bottom and having 12 feet depth of water.
Plates 3 and 4 show two stretches of canal where especially interesting engineering problems were encountered. At the eastern end of the Erie branch the canal passes in a land line from the Hudson river to the Mohawk river around the Cohoes falls. Within a distance of about a mile and a half along this stretch there are located five locks which have an aggregate lift of 169 feet, forming thus the greatest series of high lift locks in the world. The lifts range from 32 1/2 to 34 1/2 feet and the locks are founded, one on piles and the others on rock. These locks, the pools on the short levels, the concrete docking through the pools, the by-passes, the guard-gates with by-pass gates, the high retaining walls, the deep rock cut at the upper end, the long, high dam in the Mohawk, the power-plant at one end of the dam, the transmission line, the power substations, the railroad crossing and the several other bridges, all added their numerous individual problems to make this short section one of the most interesting in both planning and construction and also to make it now in its completed state a Mecca for the visiting engineer.
At Medina the bed of the Oak Orchard creek changes abruptly from a shallow channel to a deep gorge. The old canal circled this gorge. Good alignment demanded the elimination of this devious route for the new canal and gave rise to more numerous studies and plans than any other short stretch on the canal, among them the plan for a single-span concrete arch aqueduct, which by virtue of its length of span, its width and its enormous load was startlingly unique, being the largest single-span concrete structure ever planned up to that time and designed to carry many times the greatest load. For many good reasons none of these plans could be carried out and the new canal follows the old route. To alleviate the difficulties of sharp curvature, an unusually wide channel was constructed. Long stretches of wall were built and as the channel borders the gorge so closely some of these walls are high and interesting in design.
The most important structures on the canal are the locks and the dams. Accordingly they have been given chief prominence in this volume. The number of bridges is large and therefore these structures receive considerable attention.
The locks are built of concrete throughout, both side and cross walls and floor. At a few points, where favorable rock was encountered, the concrete floor has been dispensed with. The side walls are 5, 6, or 7 feet wide at the top, according to local circumstances, and vary in height and bottom width with the lift of the lock and certain other conditions. In some cases, where one side of a lock is exposed to a river channel, the top width has been increased to 12 feet. The lifts range from 6 feet to 40 1/2 feet. Both the differences of lift and fluctuations between normal and high navigable stages govern the heights of the side walls, which vary from 28 feet to 61 feet, with an extreme at one point of the lock at Little Falls of 80 feet. The bottom widths of these walls, which range between 13 and 34 feet, are determined by the height of the walls, the nature of the foundation and certain incidentals of design at each lock. Unless a rock or hardpan foundation was obtained, piles were driven under practically all locks.
Within each side wall runs a culvert for filling and emptying the lock. The culverts are connected with ports that open into the chamber at the bottom of the walls. These culverts vary in size, the dimensions being 5 by 7 feet for locks of 12 feet lift or less, 6 by 8 feet for lifts between 12 and 23 feet, and 7 by 9 feet when the lift is 23 feet or more. Connected with the 5 by 7 culverts are 16 ports, 8 on either side, while the number is increased to 22 with the 6 by 8 culverts and 28 with the 7 by 9 size. The ports have been made both by imbedding cast-iron pipes in the concrete and by leaving rectangular openings in the walls, the latter being the more recent method. The area of opening in either case is about 7 1/2 square feet each. In some of the locks there is another culvert through one of the side walls — a feature of the hydro-electric development for operating and lighting the locks.
The lock-gates are of the mitering, girder type, carrying the principal load as beams. In general they are built of steel, with single skin-plates, but have white oak quoin and toe posts. The quoin post swings on a cast-steel pivot, set in the concrete, and is held at the top by an adjustable anchorage. The bearing is against cast-iron quoin plates set into the side walls. Wooden gates are employed at three locks. The plans of these wooden gates, as well as of the steel gates, are included in this volume.
The lock-gates are each opened and closed by a steel spar equipped with a rack, actuated by a 7-horse-power motor acting through a train of gears. The spar is also equipped with a heavy coil spring, to absorb shock. To open or close the gates requires about one minute.
Movement of the gates is controlled from four operating stands, one near each gate. The operating stands are equipped with drum type master switches, by means of which magnet type controllers automatically regulate the acceleration and speed of the motors. Limit switches are provided to arrest the motion of the gates at each end of their travel.
Signal lights indicate to the operator the position of the gates. In the event of failure of power or damage to the motor, it is possible to disconnect the motor and operate the gates by hand by means of sweeps provided for this purpose, which have been so designed that but two men will be required for such an operation.
The valves regulating the flow of water in the culverts are suspended on two chains, which pass over chain wheels near the top of the valve wells to cast-iron counterweights. The chain wheels are mounted on a shaft rotated by a motor operating through a train of gears designed to raise or lower the valves at a speed of about six feet per minute.
The motors of the 5 by 7 and 6 by 8 valves are rated at 3 horse-power, while those operating the 7 by 9 valves are rated at 7 horse-power.
The movement of the valves is controlled in a manner similar to the movement of the gates, and the master switches are located in the same operating stands. Signal lights indicate to the operator that the valves are fully open, two-thirds open, one-third open, or closed. Like the gate machinery the valve machinery may be operated by hand whenever this is necessary or desirable.
Electric capstans, one at each end of each lock, are provided to control the movement of boats along the approach walls and to tow them into and out of the lock chamber. A 20-horse-power motor operates each capstan at a speed of about 60 feet per minute with a pull of 8,000 pounds. The operation of these capstans is controlled by a magnet type controller and master switch located near the capstan.
All the motors incorporated in the lock operating machinery are of the mill type.
In general a power generating station has been installed for each lock. But if two locks are close together, one station suffices for both. In one instance a single station supplies power for five locks. These power stations, constructed of reinforced concrete, 20 by 30 feet in plan and about 20 feet high, are placed adjacent to or near the various locks. Thirty-three hydro-electric stations, 10 gasoline-electric stations and 3 substations supply the power for operating the 57 locks of the Boarge canal system. Two guard-locks, one on each bank of the Genesee river near Rochester, are operated by power purchased from a local power company. Power is supplied also for lighting approximately twelve 75-watt Mazda lamps, set about 200 feet apart on both sides of each lock and along the approach walls. The stations at those locks which are beside movable dams supply power for operating the dams also. These are the locations where gasoline-electric stations are installed. At the gasoline-electric stations on the lower Mohawk it has been found advisable to purchase current for the lighting. Also the movable dam in the Genesee river at Rochester is operated by power supplied by a local company. A few guard-gates, which are near locks, are operated by power obtained from the lock power stations.
The hydro-electric power stations, operated by water from the canal, are each equipped with two vertical-shaft turbines, which in all but a few cases are directly connected to 50-kilowatt vertical-shaft generators, supplying direct current at 250 volts. Horizontal-shaft generators are installed at the locks of low lift, where only a small head of water is obtainable. At a few of the stations 75-kilowatt generators are employed. Where power is furnished to another lock not more than two miles distant, booster sets are installed in the power stations.
The gasoline-electric stations are each equipped with two 25-kilowatt generators directly connected to gasoline engines designed to operate at a speed of 600 revolutions per minute. These gasoline-electric generators supply direct current at 250 volts, each of these units being designed to furnish sufficient power for operating the locks and the adjacent movable dams.
In the city of Oswego there has been constructed a siphon lock — the only lock of this type on the Barge canal, also the first to be built in this country and the largest employing the siphon principle yet built. The general design of the culverts is similar to that of a lock of ordinary type, except that at the upper and lower ends the culverts are curved up so as to form necks, which rise a little above the highest water-level and which at the same time are shut off from all communication with the outer air, except through the operating pipes. The flow of water is started in the siphons by means of tanks, one being built in each wall near the upper end and communicating through pipes in the upper and lower levels and with both siphons in the same wall and being shut off from all other communication with the outer air. To perform an operation the tank is first filled with water; then the intake valve is closed and the outlet opened. There results a body of water suspended by its weight, but tending to escape into the lower pool, thus producing the necessary vacuum. On opening the air valve, air from the siphon rushes into the vacuum and water begins flowing over the crest in the neck.
At Little Falls there has been built a lock notable for its high lift — 40 1/2 feet. The lower gate of this structure is of the lift type — the only instance of lift-gate on any Barge canal lock, except the guard-locks at the Genesee river crossing and the upper gate of the Utica terminal lock. Another novel feature of this lock is the side pool. Its purpose is to conserve the water-supply by storing water drawn from the upper half of a chamberful and discharging it to fill the lower half of the chamber at the next lockage.
At two places, Lockport and Seneca Falls, there are combined, or tandem, locks, a flight of two locks at each place. In each case also the normal combined lift is 49 feet.
Forty dams were needed for the Barge canal. Of these a few existing dams could be used without change and a few others could be utilized by adding new crests. Of the fixed dams the four largest are the two reservoir dams — at Delta and Hinckley — and the two across the Mohawk below Schenectady — at Crescent and Vischer Ferry. Plans of the Delta, Hinckley and Crescent dams are contained in this volume. Most of the fixed dams have some movable parts that will regulate the flow of water to a greater or less degree.
Of the movable dams those of the bridge type are of chief importance. There are eight large bridge dams, ranging from 370 to 590 feet long, and one smaller one, all located on the Mohawk above Schenectady; also in the Genesee river at Rochester and in the Seneca river at May's Point this type is used. The plans of the Rochester dam were chosen for publication because they are best suited for reproduction and embody the results of the latest studies and also because another and rather novel type of movable dam is employed as a part of this same structure. This sector gate type drops into a recess and is decked over, so as to pass flood wood, of which there is a considerable quantity in the Genesee river.
The Taintor gate type of movable dam is also important on the Barge canal and is used in a wide variety of ways — as the whole dam, as a regulating section in conjunction with a fixed dam, as a gate to fill a notch in a fixed dam, as a by-pass gate beside a lock, as a by-pass gate around a guard-gate, or as a crest across the top of a low fixed dam. An unusually large example of this type exists on the canal, a structure having six gates of 50 feet clear width and a vertical height of 17 feet above the sill.
The dam with automatic crest included in this volume is unique, having been originated in the course of designing the Barge canal.
In the western part of the state there is one level which is more than sixty miles long. At certain places long this section the canal lies above the level of the surrounding territory. In this level, therefore, the law authorizing construction required guard-gates to be placed at stated intervals. Numerous other guard-gates have been built along the canal — where hazardous conditions call for such protection as they can give.
The siphon spillway is another unique structure, this, too, having been originated in Barge canal design. It is automatic in operation, in both starting and stopping the flow of water. It is especially adapted to locations where there is not space for an ordinary long spillway and yet where it is advisable to make the regulation of the water-surface automatic.
Since the Barge canal occupies in large part natural stream beds, numerous tributary streams are taken into the channel. This condition has necessitated some form of stream entrance, retention dams across the bed of the entering stream often being required. A structure of this kind is shown in the present volume.
Another consequence of this same practice of occupying stream beds is the absence of long aqueducts, which were among the outstanding features of the old canal. The largest aqueduct of the new canal is here shown. It has but a single span of fifty feet. The longest of the old aqueducts consisted of twenty-six spans and had a length of 1,137 feet.
The number of bridges across the canal is large and their types of design cover a considerable variety. There are bridges on the canal other than those shown here which might well have been included, but the limited space confined the choice to such as are typical and most common or are somewhat unique. In explanation of the three-hinge steel arch bridge it may be said that local conditions required a structure as wide as the distance between two parallel city streets, and also that the roadbed could be but little above the necessary clearance above the canal water surface.
Local conditions at certain cities and villages prescribed the use of lift-bridges. This was esepcially the case in the western part of the state. For the same reason bascule bridges were occasionally used. Also, an amendatory canal law ordered either bascule bridges or bridges which can be converted into the bascule type along the Oswego branch.
Aside from these few words of explanation the present volume consists only of plates which have been reproduced from contract plans. The drawings shown, therefore, even those of channel sections, prism walls and bank protection, represent real, not imaginary conditions, but they have been so selected that they are either typical of the general work or present some special and somewhat unique feature. Moreover, the selection is so comprehensive that nearly every type of construction on the canal is included, except the terminal work. Only sufficient space could be devoted to terminals to show the various types of dockwalls and piers.
It was not practicable to redraw any considerable number of the plans for this special volume and so the contract plans have been used, being reduced to as small a size as possible and still remain legible, thus producing a book not too bulky in its dimensions. As a matter of fact no course was open but to use the contract plans. To redraw the sheets would have been so costly as to preclude even the possibility of publishing this volume. In numerous cases, however, the plates have been made up by assembling on one sheet drawings selected from two or more contract sheets. New titles have been placed on all the sheets, scales to reduce proportionately with the drawings have been affixed, in some cases the sheets have been relettered, and occasionally explanatory notes have been added. Also a few special new sheets have been made.
It has been considered that the exact location of any particular structure was not at all pertinent and therefore no attempt has been made to indicate which structures have been selected, otherwise than by the contract and sheet numbers, which appear in the lower right corner of each plate, and even these numbers have been placed there simply for the purpose of identification in case someone who may be using the book needs to refer to the original contract drawings, which are on file in the State Engineer's office.
Should the reader desire a detailed record of any part or all of the work involved in the whole project, he may examine the annual reports of the State Engineer, which are transmitted to the Legislature early in each annual session and are printed as legislative documents. For greater detail in progress of work he may consult the pages of the Barge Canal Bulletin, a monthly publication issued for eleven years by the State Engineer, beginning February, 1908, and ending with the January, 1919, number. The Bulletin contained also many descriptive articles on both general and particular canal subjects.