be kept in good and effective working condition and manned by competent operators. 6. Clearance gages.--The owners of each bridge shall provide and keep in good legible condition two board gages painted white with black figures not less than 6 inches high, to indicate the head-room clearance under the closed span at all stages of the tide. These gages shall be so placed on the ends of the draw-span fenders that they will be plainly visible to the navigator of a vessel approaching the bridge either up or down stream. HARBOR AND CHANNEL IMPROVEMENTS BY THE UNITED STATES Delaware River, Philadelphia to the Sea The Delaware River between Philadelphia and the sea has been under improvement since 1836, although the early operations were largely confined to the removal of shoals and bars obstructing navigation. Work under a comprehensive program for the permanent and systematic improvement of the river at and below Philadelphia was begun in 1885 and has since been prosecuted continuously under successive projects. The existing project was adopted by the following River and Harbor Acts: Act June 25, 1910 June 20, 1938 Document House Document No. 733, 61st Congress, 2d session. 73d Congress, 1st session. Senate Document No. 159, 75th Congress, 3d session. The above-listed acts provide for a channel 40 feet deep from deep water in Delaware Bay, about 4 miles below Brandywine Shoal Light, to the Philadelphia Naval Base and thence 37 feet deep to Allegheny Avenue, Philadelphia, a total distance of about 96.5 miles. For the first 30 miles in the bay to a point near Ship John Light, the channel has a project width of 1,000 feet, thence it is 800 feet wide in the straight reaches with a width of 1,200 feet at Bulkhead Bar and 1,000 feet at other bends and in Philadelphia Harbor. The existing project also provides for the following anchorages:- At Port Richmond, 37 feet deep and about 6,400 feet long; at Gloucester, 30 feet deep and about 3,500 feet long; in the vicinity of Mantua Creek, 37 feet deep and 1,400 feet wide, with a mean length of 11,600 feet; and at Marcus Hook, 37 feet deep and 1,400 feet wide, with a mean length of 10,500 feet. Other work authorized for the improvement of the Delaware River from Philadelphia to the sea includes the construction of dikes and training works for the regulation of tidal flow; straightening the channel and extending the 1,000-foot width from Philadelphia Harbor to Horseshoe Bend; maintenance of an area on the north side of the channel opposite the Philadelphia Naval Base between Shipway 3 and the Schuylkill River to a depth of 40 feet and a width of 150 feet on Mifflin Range and a width of 200 feet on Horseshoe Range; and the maintenance of any areas dredged by local interests to a depth of 35 feet between the channel and a line 100 feet channelward of the pierhead line between Point House Wharf and the Philadelphia Naval Base when, in the opinion of the Chief of Engineers, such areas are so located as to be of benefit to general navigation. All work on the existing project has been completed except the deepening of the channel between Allegheny Avenue and the Naval Base from 35 to 37 feet, including the Port Richmond Anchorage, and the deepening and enlarging of Mantua Creek Anchorage. All depths refer to the plane of mean low water. Portions of the channel are subject to constant shoaling. The latest controlling depths on the various channel ranges and related information are set forth in statements issued periodically by the District Engineer, Corps of Engineers, Philadelphia District, copies of which are furnished to shipping and maritime interests. Delaware River, Philadelphia to Trenton The upper Delaware River between Philadelphia and Trenton has been under improvement since 1872. Early efforts on this stretch were mainly directed toward the removal of insolated shoals and bars which obstructed such navigation as was then practicable. The first comprehensive project for the entire stretch from Philadelphia to Trenton was adopted in 1910 and was modified and amended by succeeding projects. The existing project was adopted by the following River and Harbor Acts: Act July 3, 1930 August 30, 1935 August 30, 1935 August 26, 1937 July 24, 1946 Document Rivers and Harbors Committee Document No. 3, 71st Rivers and Harbors Committee Document No. 11, 73d Rivers and Harbors Committee Document No. 66, 74th Rivers and Harbors Committee Document No. 90, 74th House Document No. 679, 79th Congress, 2d session. The above-cited acts provide for a channel 28 feet deep at mean low water and 300 feet wide from Allegheny Avenue, Philadelphia, to the Pennsylvania Railroad bridge at Delair, thence 25 feet deep and 300 feet wide to the upper end of the Municipal Marine Terminal at Trenton, and for a turning basin 500 feet wide and 1,700 feet long at the terminal. The project provides for widening the 25-foot channel above Delair at the bends and for the maintenance of a channel 12 feet deep and 200 feet wide from the upper end of the 25-foot channel to the Pennsylvania Railroad bridge at Trenton, which was dredged under a previous authorization. Other work authorized by the existing project includes an auxiliary channel 20 feet deep and 200 feet wide east of Burlington Island, extending easterly from the main channel to the upper end of the United States Pipe & Foundry Company's property at East Burlington, with a turning basin 450 feet wide at the upper end and an anchorage 22 feet deep, 100 feet wide, and 400 feet long along its west or landward side and 800 feet long along the west side of the ship channel, opposite Biles Creek, Pa. Initial excavation, only, of a cross channel 8 feet deep and 200 feet wide through the artificial island opposite Delanco, N. J., is also authorized. The total length included in the existing project for improving the upper Delaware River is about 30 miles, excluding the auxiliary channel east of Burlington Island, which is 1.4 miles long, and the cross channel opposite Delanco. Work on the existing project has been completed except for the anchorage opposite the mouth of Biles Creek. Portions of the channel are subject to shoaling. Periodic statements showing the controlling depths on the channel ranges and related information are furnished to maritime and shipping interests by the District Engineer, Corps of Engineers, Philadelphia District. Tributary Waterways Below and Above Philadelphia A number of tributary waterways enter the Delaware River, both on the right or Delaware shore and on the left or New Jersey shore, several of which have been improved by the United States for navigation purposes. From the right or Delaware shore such improved tributaries, all of which are located below Philadelphia, include the Smyrna River, the Appoquinimink River, the Chesapeake and Delaware Canal with the branch channel connecting it with the Delaware River, and the Christina River. On the left or New Jersey shore are Alloway Creek, the Salem River, Raccoon Creek and Mantua Creek, all entering below Philadelphia, and the Rancocas River, which enters the Delaware River at a point opposite the upper limit of Philadelphia Harbor. The Christina River and Mantua Creek are the only tributaries on which extensive terminals for handling water-borne commerce have been constructed. The Christina River is described fully in Port Series No. 8 covering the port of Wilmington, Del., and the improvement of Mantua Creek is discussed in the following paragraph. The Chesapeake and Delaware Canal is also described in this report as it constitutes an important, protected, and short route between the Delaware River localities and points on Chesapeake Bay. Mantua Creek, N. J., enters the Delaware River opposite Hog Island, Philadelphia Harbor, at Paulsboro, N. J. The borough of Paulsboro has a frontage of about 6,600 feet on the Delaware River and a frontage of about 15,000 feet on Mantua Creek. The existing project for the improvement of Mantua Creek provides for a channel 20 feet deep and 110 feet wide from that depth in Delaware River to the Grasselli Chemical Plant of E. I. du Pont de Nemours & Co., a distance of 5,400 feet; thence 12 feet deep and 100 feet wide to the Paulsboro plant of the Strathmann Sand & Gravel Co., 5,900 feet; thence 10 feet deep and 60 feet wide to Friars Landing, 2,000 feet; and thence 7 feet deep and 60 feet wide to Parkers Landing near Mount Royal. It also provides for a dredged cutoff 3 feet deep and 50 feet wide across a bend in the creek 9,000 feet above Mount Royal and for twin jetties at the mouth of the creek. This project was completed in 1940. Chesapeake and Delaware Canal.--In addition to the main ship channel through Delaware Bay, an alternate approach to Delaware River points is provided by the Chesapeake and Delaware Canal. This canal extends 14 miles from the Delaware River at Reedy Point, Del., to Back Creek at Chesapeake City, Md., thence 5 miles to Elk River, an arm of Chesapeake Bay. Its eastern or Reedy Point end is 41 miles below Philadelphia and 60 miles above the Delaware Capes. It is a government owned toll-free, sea-level canal, which not only affords an inland water route between points on the Delaware River and Baltimore and other Chesapeake Bay ports but also is a link in the Atlantic Intracoastal Waterway from Boston to Miami. The existing project for the canal was authorized by the River and Harbor Act of August 30, 1935, and provides for a channel 27 feet deep, 250 feet wide 813917 O 48-3 |