water. Break The two sides of the hold of the vessel are calculated each to contain eight of these loaded trucks, which, at five tons on each truck, gives 80 tons of stone for one cargo. The stones thus placed on the trucks remain till the vessel arrives at the point in the line of the Breakwater where they are to be deposited. By means of a crane on the deck of the vessel, the two trucks nearest to the two stern ports are then drawn up the inclined plane, and run upon a frame on moveable hinges, called the typing frame; by the falling of this frame, in the manner of a trapdoor, the stone or stones are discharged from the trucks on the slope of the Breakwater; but the typing-frame remains, by means of a catch, in the position in which it is left at the moment of discharging the stones, until the empty truck is pulled up by the crane to the after-part of the deck, from whence it is run forward to make room for the second pair of loaded trucks in the hold. The catch being now disengaged, the typing-frame returns to its former position, ready to receive the next pair of loaded trucks, and so on till the whole sixteen have been discharged, and the light trucks run upon the deck of the vessel, ready to be run out at the quay, and from thence to the quarries, to take in fresh loads of stone. In this manner a cargo of 80 tons may be discharged in the space of 40 or 50 minutes. The vessels are placed in the proper places for deposit ing the stones by means of buoys, and the exact line of the Breakwater is preserved, by observing lights or staves placed at a distance on the shore. by hinges. This moveable deck, when raised, as at D Is a common windlass for heaving the trucks Ten vessels of this construction, for carrying large Of this quantity, the proportions of the different sizes of the blocks deposited are nearly as follows: Of one ton each stone and under The following description, referring to Plate three to five tons each XXXIX., will convey an accurate idea of these excel- five tons and upwards lent vessels for the purpose they were constructed. Fig. 1. Shows the stern of the vessel, in the act of depositing the stones. The runner R being hooked to the fore-part of the truck, raises it up, and by that means tips the stone overboard. When the stone is in the act of being drawn up out of the hold, on the inclined plane B (fig. 3.), the runner is hooked to the fore-part of the truck, and lashed down to the after-end, over the stone, which prevents the latter from sliding off the truck, in its progress up the inclined plane. The empty trucks are, for the most part, lodged on the fore-part of the deck, and some placed on an edge against the side of the vessel. Fig. 2. Shows the stern of the vessel when loaded, with the ports up, or closed. Fig. 3. A longitudinal or sheer-section of the vessel, when loaded, with the trucks on one side of the hold and deck, showing the number which the vessel usually stows on each side. The stones being frequently longer than the trucks, the number carried in the hold must be proportioned accordingly. In bad weather it is unsafe to send many trucks on deck; and, in general, not more than four are sent into the Sound, in that way, at one time; the a mount of the cargoes, therefore, vary according to circumstances, from 40 to 65 tons; the largest stone hitherto deposited being about eight tons. The after-part of the deck, under the tiller, is divided into two parts, length ways, and made to move up and down; the fore-parts are secured to a beam VOL. II. PART II. Tons. 423,904 309,706 150,593 12,760 The original contract price for quarrying the stone was 2s. 9d. per ton, and the original contract price for conveying it to the Breakwater 2s. 10d. per ton, since which the former has been reduced to 28. 5d., and the latter to 1s. 10d. per ton. The cost of each ton of stone sunk in the Breakwater, including the building of quays, purchase of land, salaries, and every other expence, according to the nearest calculation that can be made, amounts to about 8s. 1 d., which, upon the whole quantity deposited, gives the total sum expended up to 12th August 1816, equal to L. 364,000. And as the work may be considered as more than half completed, it will be finished considerably within the original estimate, and, if parliament had thought fit to grant the money, within the time. The greatest quantity of stone sunk in any one week was 15,379 tons; and the part of the Breakwater, at the above mentioned date, above the level of low water spring-tides, was in length 1100 yards. The length completely finished to the height of three feet above the level of the highest spring-tides, and thirty feet wide at top, was at the same time 360 feet. The large stones of the upper part of the Breakwater are deposited to any nicety by means of a vessel constructed for the purpose, having the same sheer or slope at the bow with the side of the work, so that by a projecting beam or mast, the largest stones can be taken out of the vessel, and placed on 3 M Breakwater. Breakwater, Beneficial this Great Work. the opposite side, or middle, or any other part of the Breakwater. The small establishment, and the quick manner with which this great work has been carried on, form a curious contrast with the multitudes employed on the Breakwater of Cherbourg, the time occupied by that undertaking, and the parade and ostentation with which it was conducted. The whole establishment for carrying on the Ply. mouth Breakwater is as follows: A superintendent, with proper officers and clerks, to keep and control the accounts Warrant officers and masters of the ten stone vessels in the immediate employ of the public Seamen and boys to navigate these vessels Seamen employed in the superintendents' vessels, the light vessel, boats' crews, &c. Masons, blacksmiths, carpenters, sailmakers, and labourers, employed at Oreston In the immediate pay of Government Seamen employed in the contractors' vessels Quarrymen, labourers, &c. employed at Oreston by the contractors Total establishment Persons. water. six feet higher than the usual height of spring-tides. BreakThe Jasper sloop of war, and the Telegraph schooner, being anchored without the cover of the Breakwater, were driven to the head of the Sound, and both lost; but a collier deeply laden, and under its cover, rode out the gale. No damage was sustained by any of the shipping in Catwater; but it was the general opinion, from former experience, that, if no Breakwater had existed, the whole of the ships therein must have been wrecked, and the storehouses and magazines on the victualling premises, and most of the buildings on the margin of the sea, been entirely swept away. Till this tremendous gale, the Breakwater had not sustained the slightest damage from the heavy seas that, through the winter, had broken against it with unusual violence, not a single stone having moved from the place in which it was originally deposited; but after the hurricane above-mentioned, and the high tide which accompanied it, it was found that the upper stratum of the finished part, extending about 200 yards, and 30 yards in width, had been displaced, and the whole of the huge stones, from two to five tons in weight each, carried over and deposited on the northern slope of the Breakwater. In no other 170 part could it be discovered that a single stone had been displaced. 10 21 90 45 39 205 300 675 The result of this great work has completely anResults of swered the expectation of its warmest advocates. The good effects of it were, indeed, very sensibly felt at the end of the second year, when about 800 yards of the central part, where the water was shallowest, were visible at low water spring-tides. The swell was then so much broken down and destroyed at the head of the Sound, that the fishermen were no longer able, as heretofore, to judge of the weather outside the Sound; and ships of all sizes, and, among others, a large French three-decker, ran in with confidence, and anchored behind the Breakwater. Since that, near 200 sail of vessels of all descriptions, driven in by tempestuous weather, have, at one time, found safe shelter within this insulated mole, where a fleet of 25 to 30 sail of the line may, at all times, find a secure and convenient anchorage, with the additional advantage of having a stream of excellent water from a reservoir constructed above Bouvisand Bay, capable of containing from ten to twelve thousand tons, or a quantity sufficient to wa*ter 50 sail of the line. This water is brought down in iron pipes to Staddon Point, opposite to the anchorage, where it is intended to build a jetty from which the water will descend through the pipes into the ships' boats. The whole expence of this most useful appendage to the Breakwater is calculated at about L. 16,000. During the winter of 1816-7, the gales of wind were more frequent and tremendous than had been known for many years; and, on the night of the 19th January, such a hurricane came on as had not been remembered by the oldest inhabitant. The tide rose Portland The want of a harbour, or any place of safety to Propriety which ships can resort in bad weather, or in distress, of a Breakbetween the ports of Plymouth and Portsmouth, led water in to the suggestion of Portland Roads being convert- Roads. ed into a secure harbour by means of a Breakwater. It was estimated that the construction of such a stone dike, extending from the north-east part of Portland Island, about two miles and a quarter in length, covering an anchorage of about four square miles, and completely sheltering the pier, harbour, and bathing place of Weymouth, would require about four million tons of stone, five years to complete it, and an expence of about six hundred thousand pounds Sterling. The capstone alone, which covers the Portland stone, and which, not being marketable, is not only useless, but a great incumbrance, would be sufficient to complete this great undertaking; and the elevation of the quarries, being 300 feet above the level of the sea, would admit of the stone being sent down on rail-ways to the water side, without the aid of either engines or horses; and, on this account, would be deposited at less than one fourth part of the expence which is incurred at the Plymouth Breakwater. Such a secure anchorage in this situation, in which the largest fleets, either naval or mercantile, would ride at anchor in all winds, and the most stormy weather, in perfect security, is not unworthy the consideration of the public; and, perhaps, in the present increased state of our population, and the difficulty of finding employment for the labouring poor, there can be no truer policy than that of carrying on great national works of public utility, were it only for the sake of encouraging industry, instead of expending an equal, or probably a far greater sum, for the support of idleness and the encouragement of vice, in those parochial buildings, too frequently miscalled work-houses. (K.) |