Sand bars keep filling up the mouths of these channels, necessitating frequent dredging and extension of the breakwaters, work undertaken by the Federal government, which also maintains a most comprehensive and completeystem of aids to navigation, including lighthouses and lightships, fog alarms, gas and other buoys, life-saving, storm signal and weather report stations.
The port is protected by breakwaters enclosing a portion of the lake front.
The harbour, in which ships of all nations may be seen, as well as great numbers of the picturesque sailing craft engaged in the coasting trade, is somewhat difficult of access to larger vessels, but has been improved by the construction of new breakwaters and dry docks.
The outer harbour was formed by two breakwaters enclosing an area of 2 m.
Elsewhere huge breakwaters had been constructed, the fragments of which may still be seen stretching away for a distance of from 2 to 3 m.
Embarkation operations were carried on almost entirely at " V " and " W " beaches, at both of which there were provisional breakwaters in existence furnishing some shelter when there was an onshore breeze.
By means of breakwaters it is continued beyond the coast-line and is at its mouth 328 ft.
The great artificial harbour, enclosed by breakwaters, is bounded on the south by a slight promontory.
On the other hand, when the bottom was rocky so that the piles could not be driven, they were steadied at their bases by being enveloped in a mound of loose stones, in the manner in which the foundations of piers and breakwaters are now constructed.
By the construction of extensive piers and breakwaters a fine harbour of refuge has been created; and its inner harbour is deep enough for the largest lake-steamers.
The works, begun in 1877 and completed in 1886, connect the town with Tanjong ("cape") Priok by a canal, and include an outer port formed by two breakwaters, 6072 ft.
Tampico and Coatzacoalcos, however, have been improved by breakwaters or jetties, and the deepening of the Channels across the bars, into safe and commodious harbours.
The outer harbour is formed by two breakwaters which protect the entrance to the canal; altogether the harbour covers about 570 acres and accommodates ships drawing 28 ft.
Pelto has ancient breakwaters for the protection of small boats, erected, as many believe, by the Mongol conqueror, Kublai Khan, who in 1273 built on Quelpart one hundred ships for the invasion of Japan.
The harbour, protected by breakwaters, with a lighthouse at the entrance, is well defended from the north winds, but those from the south, south-east, and south-west prove sometimes highly dangerous.
These improvements comprise a series of inner breakwaters and piers and an outer breakwater of stone and cement, 4 m.
So popular has it become that besides being used for massive constructions like breakwaters, dock walls, culverts, and for foundations of buildings, lighthouses and bridges, it is also proving its usefulness to the architect and engineer in many other ways.
Depositing concrete under water for breakwaters and bridge foundations requires special skill and special appliances.
This is afforded, either by means of a so-called sleeping dike (slaperdyk) behind the weak spot, as, for instance, between Kadzand and Breskens in Zeeland-Flanders, and again between 's Gravenzande and Loosduinen; or by means of piers or breakwaters (hoofden, heads) projecting at intervals into the sea and composed of piles, or brushwood and stones.
The first of such breakwaters was that constructed in 1857 at the north end of the island of Goeree, and extends over loo yds.
Two long jetties or breakwaters have now been constructed, about 350 acres of harbour area have been dredged to a depth of 30 ft., and two wharves of steel and concrete, one 600 ft.
The tidal harbour is enclosed by stone breakwaters, and large vessels enter and load frozen meat direct from the refrigerator cars.
The scheme comprised three enclosing breakwaters - on the west an extension of the Admiralty pier in a south-easterly direction for a length of 2000 ft.; on the south an isolated breakwater, 4200 ft.
These three breakwaters, with a united length of rather more than 14 m., are each built of massive concrete blocks in the form of a practically vertical wall founded on the solid chalk and rising to a quay level of 10 ft.
In 1899 the Uruguayan government entered into a contract for the dredging of the bay, the construction of two long breakwaters, the dredging of a channel to deep water, and the construction of a great basin and docks in front of the city.
In 1908 the breakwaters and the greater part of the dredging had been completed, and the entrance channel, with a minimum depth of 242 ft., permitted the admission of large steamers.
The harbour is formed by breakwaters enclosing a space of 50 acres.
Newcastle has a fine harbour, with an area of S40 acres, protected by two breakwaters; the breadth of the channel at its entrance is 1200 ft., and the depth at the bar is 25 2 ft.
Corps at or in rear of Kirk Kilisse, with the fortress of Adrianople and the works of Kirk Kilisse acting as breakwaters in front.
Marquette, Mich., Presque Ile Point, Mich., Agate Bay, Minn., Grand Marais, Minn., and Ashland, Wis., are on bays which have protective breakwaters across their mouths.
The accommodation for shipping includes two graving docks, two patent slips, &c. The entrance to the river is protected by two breakwaters named respectively the North Gare and South Gare.
The large traffic on Lake Erie has brought into existence a number of important harbours on the south shore, nearly all artificially made and deepened, with entrances between two breakwaters running into the lake at right angles to the coast line.
Under powers obtained from parliament in 1896, the Midland Railway Company constructed, and opened in 1904, a harbour, enclosed by breakwaters, for the development of traffic with Belfast and other Irish ports, a daily passenger-service of the first class being established to Belfast.
The entrance to the harbour, the best on the Prussian Baltic coast, is protected by two long breakwaters, and is strongly fortified.