Black River Harbor is in the collection district of Cuya- $62 50 currency. 22 00 coin. 84 50 No statistics are given for the year just passed, for the reasons stated in my annual report on Conneaut Harbor, Ohio. D 8. Report of operations in the improvement of Cleveland Harbor, Ohio, for the year ending June 30, 1869. The west pier, which at the close of the last fiscal year had been extended four hundred and fifty feet, has been extended fifty feet further, and completed. The east pier had been extended three hundred and eighty-five feet by the beginning of December last, when the setting in of winter brought our operations to a close. By the end of June this pier had been extended to something over four hundred feet beyond the end of the beacon pier, and by the close of September it will be completed throughout its entire length of five hundred and seventy-five feet. These extensions, it will be recollected, consist of the pile pier designed or claimed by General T. J. Cram, and for which mode of construction he claimed a great saving in cost over the old method of crib construction, which has been employed on the lakes for the last forty or fifty years. This method of construction, being an experiment only, was authorized by the Engineer Department only on the score of the great economy claimed for it, and then only for situations where the existence of a clay substratum furnished reasonable ground for expecting that the piles, which constitute the chief feature of this system, would retain their places after being driven. I now propose to show that this system is neither as strong nor as durable as the system of crib construction; that it is almost impossible to repair any injury to the under-water portions, except by clumsy patchwork; and, from evidence that cannot be disputed, that the cost is actually greater than that of an equal amount of crib-work. It is not as strong as the crib construction because in twelve feet depth of water the points of bearing of the piles, supposing the sand at one extremity and the sill and binder at the other may offer resistance enough to entitle them to be called points of bearing, are eleven and a half feet apart, while in the crib construction the ties which bind the side timbers together, thus constituting points of support, are but ten feet from center to center. The piles, again, are independent of each other, while the side timbers of the cribs are bolted to each other at about every two feet of their length, so that each receives direct support from the first and second timbers both above and below it, and indirect support from all the others. The center of pressure being at the same distance beneath the surface in both cases, (taking the average in case of the timbers,) we have, in order to resist the cross strain, in one case, a round 12-inch pile with points of support eleven and a half feet apart, and in the other case, a square 12-inch timber with points of support at the ends ten feet apart, and at every two feet along each side. To suppose any greater depth of water, or to take the clay into which the piles penetrate instead of the sand as the lower point of support, makes the case still worse for the piles. But, again, the points of support in the crib construction are firm and unalterable, the resistance which they offer being due to the tensile strength of the ties; while in the pile pier, as designed for Cleveland, the point of support at the lower end is sand, and at the upper end two timbers, a sill, and binder, the former 6 by 12 inches, and the latter 4 by 8 inches, each placed with its smaller dimension in the direction of the cross strain which it is intended to resist, and fastened at every five feet by a bolt passing through the longer dimension of the sill into the lower timber of the superstructure, which, being between the high and low water levels, is subject to wet rot. Against the impact of a vessel it offers nothing like the resistance of the crib construction; for, the resistance of the superstructure and of the stone filling being the same in both cases, we have in addition, in one case, the resistance of only one or two piles, while in the other we have every timber of the superstructure lending its aid to resist the cross strain to which they are subjected. All this is supposing that the pier can be constructed just as it was designed; but at Cleveland, at least, this cannot be done. It is found to be simply impossible to drive the piles either in contact or in the same vertical plane. The consequence of the former is that openings occur at the bottom, through which the stone filling leaks out, and which it is not easy to close. In the latter case, the contractors at Cleveland have been compelled to employ jack-screws, and even a tug, in order to haul the piles into line, so that the sills and binders could be placed; and on several occasions, the spring of the piles, when released, has been sufficient to snap both sill and binder, and the process has had to be gone over again, and the binder strengthened by the bolting on of a long and heavy piece of oak. It is easy to see what the effect of this, added to the inside pressure of the stone filling, would be, in case of accident to or rot in the sill of lower timber of the superstructure; and I have accordingly endeavored to provide in some measure against it by introducing iron-tie rods with heads, nuts, and washers at every ten feet of the structure and just below the water level. In my last annual report I mentioned that "an entrance through this piling being once effected by the sea renders the whole structure insecure; but a similar entrance being effected in a pier, constructed as ordinarily with cribs, hurts that crib only which it has entered, and which may be entirely replaced without affecting the stability or safety of the remaining cribs." I may add, that while with such an injury to the pile pier immediate repairs would be necessary to prevent greater extension of the damage-repairs which it would not always be possible to make immediately a similar injury to a crib construction might be allowed to run for some time without endangering the remainder of the pier. To avoid this danger as much as possible, I have had cross walls or bulkheads of piles, at intervals of thirty feet, put in that portion of the work constructed since last winter; which modification, I understand, has since been employed in some of the harbor works on Lake Michigan. Lastly, the wash of the sea through the openings left by the natural taper of the piles, removes the sand from the inside and causes a settlement of the stone filling, which has to be replaced, adding materially to the cost of the pier; this, in the west pier at Cleveland, half of which was constructed when I took charge of it, and under General Cram's immediate supervision, amounts to four feet, the filling having settled below the level of the sills and binders. This might be remedied by riprapping or the use of brush; but perhaps it is better to let it settle, and then to refill it. As to repairs of the piling, they must consist of outside patching, or the removal of the stone filling and inside patching, or the removal of the entire superstructure above the opening in order that the piles may be driven in place. Either of the former methods would give a very awkward appearance to the pier, and the latter would be very expensive. I now approach the subject of cost, and as indisputable facts are especially necessary here, I am fortunate in being able to give them to you as furnished by General Cram's scheme of a pile pier for Cleveland Harbor, and his scheme of a crib construction for Grand River Harbor, both of which works were executed by the same contractors. The prices are taken from his Cleveland contracts for the pile pier entered into between the 6th and 15th days of October, 1866, inclusive, for iron, piles, labor, stone, and lumber; the quantities are taken from his plans and the bills. As the superstructure is the same in both, its consideration is omitted; and as the cribs are usually thirty feet in length, I compare with the cost of one of these the cost of thirty feet of the pile pier, both being brought up to the water level. Any increase in the length of the crib will of course show a more favorable result for that mode of construction. at 30 cents per lineal foot. 350 $405 00 CRIB PIER. 16 joists, 18 feet by 8 by 12 8 floor plank, 28 feet by 12 by 12 = 24 pounds 10d cut nails, say, at 72.00 11 64 41 18 10 529 92 which is a reduction of $151 below the cost of the crib construction, or about 12 per cent., instead of 33, as was claimed in the report of 1866. But to this we must add the cost of the extra stone required to remedy the settling of the original filling, which amounts to- 30 feet by 16 feet by 4 feet = 15 cords, at $12 50 per cord..... $187 50 1,223 55 $1,187 68 an actual increase of $36 over the cost of the crib construction, or $1 20 per lineal foot; and if we add still the cost of a row of cross piles at every thirty feet, and the cost of the iron tie rods at every ten feet, both of which are essential to the security of the pier, we have― a difference of $158 in favor of the crib work, a reduction of about twelve per cent. on the cost of the pile pier, or $5 30 per lineal foot. It will be remembered that the above is a comparison of facts-quantities that have been used, and prices that have been paid, under General Cram's contracts. I will remark, in addition, that the prices for the piles are very much below the rates paid under contract at the other works of which I have relieved General Cram, while the price of timber is considerably above what it can now be had for. The price which the contractors get for putting on the sills and binders, i. e., sixteen cents per lineal foot, is most markedly inadequate, in view of the extraordinary exertions necessary to bring the piles into line; and no future contract could be made with them or with any one else knowing the difficulties to be encountered in the prosecution of this labor without a largely increased allowance therefor. The conclusion to be deduced from these facts is inevitable: the close pile pier is an expensive blunder not to be sanctioned, except in shoal water with clay bottom, and when through the fluctuations of the lumber market the cost of the piling may chance to fall below the cost of a crib construction. Of the appropriation for the improvement of this harbor, There has been received and expended during the year ending June 30, 1869, the sum of... Balance June 30, 1869. $30,858 99 17,000 00 12,000 00 59, 858 99 39, 427 05 20,431 94 all of which will be expended by the close of September, the work completed, and the appropriations and allotments exhausted. Required, according to previous estimates, to make the harbor available for vessels of fourteen feet draught, the sum of $39,000; all of which could profitably be expended within the next fiscal year. It is probable that small appropriations will occasionally be required to repair the loss of stone and injury to the piers, probably not less than $1,000 per year. The large number of tugs and steamers passing in and out of this harbor seem to exercise a beneficial influence in keeping down the bar. This harbor is situated in the collection district of Cuyahoga, and is a port of entry. The absence of information concerning its revenues for the past year is explained in my report upon Conneaut Harbor. There was collected here from customs during the preceding year ending June 30, 1868, the sum of In currency In coin.. $30,022 59 53,970 62 83,993 21 which is the only index the collector furnished in respect to the amount of commerce likely to be benefited by the completion of the improve ment. D 9. Report of operations in the improvement of Grand River Harbor, Ohio, for the year ending June 30, 1869. The east pier extension, of which four cribs had been sunk at the close of last year's operations, has been completed by the sinking of six more, and the completion of their superstructure. In view of the great settlement which had taken place in the exposed end cribs during the preceding winter, I deemed it advisable to riprap the last two cribs of the extension on both sides and at the end-the riprap extending inward from the extremity of the pier sixty feet, rising to within four feet of the surface of the water, and taking its natural slope. |