In August I submitted an estimate of the cost of the abut ments, pier and bridge according to my original plan to the Chairman of the Committee on Streets. By direction of the Committee on the Suffolk-street District the plans were re-drawn so as to cover only one span, that from Indiana place over the railroad, - as there seemed to be a probability that Orange street would be raised, and, in that case, the space between the central pier and the southerly abutment would be filled solid. The plans were to be so arranged, however, that the second span could be added if negotiation with the railroad company for the raising of Orange street should fail. New plans and specifications were accordingly prepared in October; and, Nov. 3d, proposals for the stone work were advertised for. The contract for this portion of the work was made with Mr. Charles W. Parker, of Rockport, on the 26th of November; the work to be completed on or before May 1, 1871. Dec. 7, proposals for the superstructure were invited, and bids received ranging from $13,900.00 to $22,286.41. The contract was awarded to G. W. and F. Smith, they being the lowest bidders, and the agreement executed Dec. 30, 1870. The contractors are to commence putting on the structure by the 1st of May, or as soon as the abutments are ready, and to complete the work within thirty days. BRIDGES. The following is a list of the Bridges which the City has to maintain in whole or in part: 1st. BRIDGES OVER TIDE-WATERS, RIVERS AND CREEKS. * Albany street bridge, over the Roxbury Canal. * Dover street across entrance to South Bay. * Mt. Washington Av. bridge, over Fort Point Channel. * Bridges provided with draws, or opening for the passage of vessels. All the bridges marked with an asterisk in the first list and the Winthrop bridge are, or will be, when completed, in the charge of Superintendents, under the direction of the Committee on Bridges. All the others except the water-pipe bridge at Tremont street are in the charge of the Superintendent of Streets, under the direction of the Committee on Paving. ALBANY-STREET BRIDGE (OVER ROXBURY CANAL). There is no official superintendent of this bridge; but Mr. F. Winchester is employed by the Committee on Bridges, and by the Committee on Harbor, receiving $300 per annum from the former, and $200 from the latter. There has been expended in repairs on this bridge, $1,164.86. DOVER-STREET BRIDGE. No radical repairs have been made on the draw of this bridge as I recommended in my last report; but considerable work has been done to keep the draw in a movable condition. The piers have been extended southwardly, replanked, and oak ribbons or girders fitted to the sides. The cost of this work, including stock and labor, was $2,077.50. The ordinary repairs for the year amounted to $1,729.80. FEDERAL-STREET BRIDGE. I have nothing to add to the statements made in my last report relative to this structure, except, perhaps, that subsequent reflection has confirmed the opinions there expressed "that the expense of permanent foundations and an iron superstructure as an adjunct of the present patched-up bridge and at its present grade would be quite unwarrantable." I am strongly inclined to the opinion that an iron structure resting upon screwpiles, placed in piers or rows forty to fifty feet apart, and at a grade sufficiently high to place the running gear and machinery above the reach of tide-water and ice, will be found cheaper in the end than any attempt to widen the bridge and draw, in its present condition. A plan has been prepared, showing a proposed arrangement of a screw-pile pier; but no estimates of cost have yet been prepared. The cost of repairs on this bridge during the past year was $3,641.39. MERIDIAN-STREET BRIDGE. It was found necessary to make quite extensive repairs of the drawbridge, involving the stoppage of the travel for several days. The wheels were all removed and their running faces. turned down true. A new wrought-iron band was attached to the axle-rods on the side of the wheel next the centre pivot, and braced to the former band on the outer side of the wheels. The tracks were levelled, and heavier wrought-iron plates interposed between the track plates and the oak plank beds. These changes made the draw move easier for awhile; but the superintendent complains that it still runs very hard. The cost of the repairs on this bridge during the year amounted to $2,091.76. The draw will have to be replanked, the concrete sidewalk repaired, and some of the loose plates under the tracks secured by stouter lag screws. A portion of the draw pier also needs. replanking. CHELSEA-STREET BRIDGE. Very little has been required or done on this bridge during the year; the repairs amounting to only $43.56. The drawbridge and the planked portions of the approaches will have to be replanked or partially so this season. WINTHROP BRIDGE (BREED'S ISLAND TO WINTHROP). An examination of this structure was made early in the year, and the concealed defects alluded to in my last report were made quite apparent. By direction of the Committee on Bridges, I prepared a plan of proposed repairs, and specifications and schedule; but it was extremely difficult to prescribe the amount of old material that should be replaced with new without having the bridge entirely stripped. I proposed to the Committee that, in view of the uncertainty of the amount of stock and labor required, it would be good policy to purchase the stock and employ day labor; but it was decided to let the work by contract. Accordingly Proposals were invited on Specifications calling for a definite amount of new stock and the labor required to substitute it for the old. The contract was awarded to Salma E. Gould, of East Boston, for There was a subsequent agreement to pay for removal of earth covering For keeping the bridge open during repairs $3,130 00 500 00 100 00 $3,730 00 The removal of the earth covering, which was about twenty inches deep, showed the flooring almost entirely rotted away, as I expected; but the removal of the planking exposed a much worse state of affairs among the stringers. By direction of the Committee, Mr. Gould removed all the stringers which I condemned, and an exact schedule of all extra stock ordered, was kept. The bill for extra stock and labor amounted to $1,990.44, making a total of $5,720.44 paid to Mr. Gould. Other payments made the total cost of rebuilding $5,824.44. NEPONSET BRIDGE (OVER NEPONSET RIVER). An examination of this structure was made in company with the Committee, in February, and I reported to the Committee in writing as follows: |