A description of the dock yard at Portsmouth, England, written by John Griscom 1 August 1818

This sort of descriptions are quite useful if we want to compare the dock yard facilities available for the European, African and North American navies. (1)

P. 162: “8th month, 1st. The town of Portsmouth is very strongly fortified. The battery, or side next the sea,-presents an agreeable promenade; Gosport, on the opposite side of the harbour, the Isle of Wight, and the ocean, being comprehended in the perspective. The population is about 50,000, and that of Gosport, nearly 10,000. The son of the collector called this morning to conduct me to the Dock Yard, his father having engaged the attention of one of the officers of the yard, in favour of my admission. I was also provided with a letter from London, to another of the officers. Thus favourably introduced, I spent several hours in viewing the very extensive and ingenious operations, here carried on. The Dock Yard contains 110 acres, surrounded by a high wall, and strongly defended on the land side. Within these limits, almost every operation, connected with ship-building, is conducted with a surprising degree of energy and perfection. About 2500 men are constantly employed, and in time of war 3000. Six dry docks are included, in each of which, vessels of the largest size, can be built under cover ; and, when finished, the water is let in, they float, and are towed into the stream. The main canal, or opening into the yard, instead of being closed by gates, is shut and opened in an extremely ingenious manner, by means of a boat, constructed for the purpose. This boat is placed transversely, in the opening of the canal, and having a strait keel, and perpendicular ends, it moves up and down in grooves, in the walls of the canal, and the keel fits a groove, adjusted to the bottom. When the boat is empty, it swims, and can then be loosened and moved out of the way. When brought back, it is filled with water, and then it sinks to the bottom, and stops the passage. The bottom of the dry dock is about fourteen feet below low water mark; and as it is almost impossible to prevent leakage from the gates, a steam engine is employed to keep them dry. Two engines are used in the yard, one of the power of fifty-six, and the other of thirty horses. Either of them is sufficient, not only to keep the docks empty, but to drive the block-making machinery, the rollers and presses for making sheet copper and sheet iron, bolts, blowing the bellows for the furnace, &c.

p.163: But by far the most ingenious part of the machinery in the yard, is that by which the blocks are manufactured. This is the invention of Brunel, a Frenchman, whose surprising talent, in practical mechanics, has been patronised by the British government, and greatly to its advantage. Such is the nature of the block machinery, that the saws, the augers, the chisels, the planes, the gouges, the polishing tools, in short all the instruments by which a large beam, or tree, of ash or other wood, a hard stick of lignumvitae, and a rough bolt of iron, are converted into a block and pully, move by steam, and with such velocity and precision, that it is believed, this single manufactory might supply the whole world with blocks, and at a cheaper rate than they can be made any where else. The saws are mostly circular. That which is used for dividing a stock or tree of lignumvitae, into flat sections for the wheels or pulleys of the block, is surprisingly ingenious, in its adjustment and movement. The saw is placed horizontally in an upright iron frame ; which frame itself, has a circular movement round a vertical axis. To this axis or centre, a stick of lignumvitae, cut from the natural stock, of two and a half feet in length, (a little more or less,) is firmly fixed, and is raised or lowered by a ratchet, so as to place that spot precisely against the saw, which will enable it to take off a piece of the requisite thickness. The saw, revolving with extreme rapidity, is then pressed against the wood by a hand lever, and at the same time, by the slow revolution of its frame, it moves round the stick and cuts into it in every part of its circumference. By this means the saw will cut through a tree of nearly twice its own radius, and separate from it a section perfectly flat, and or the same thickness in all its parts. Trees or stocks of different thickness, can be adjusted to the same saw, by the varying grasp of the clamp or chuck which holds it. The saw which trims the pully to a true circle, is shaped like a surgeon's trephine, or the crown wheel of a watch. They all move with extreme velocity. I was witness to the motion of a plank, about eighteen feet in length, by which it passed under a saw and had a slit cut halfway through it, from end to end, in ten seconds. A necessary part of the operation, is to turn the blocks in a sort of lathe, so as to give them the requisite oval shape and smooth surface. For this purpose, ten oblong blocks, having the corners roughly sawed off, are rapidly adjusted to the hollow circumference

p. 164: of a large wheel, which being put into geer, the blocks move round very swiftly, and are brought at pleasure against a tool, which, pressed by the hand, mores at discretion round the corner and sides of the blocks, and turns them down, with the utmost precision, in the form required. Copper and iron are taken from the pig in this factory, melted, recast, and rolled into sheets. Bolts are also fashioned by the roller, both of copper and iron. I observed that when the sheets of copper come from the rolling press, they are covered with a hard coat of oxide. To separate this, they are heated again to redness, and then plunged into water. This increases so rapidly the coat of oxide, as to loosen it from the plate. It is then simply rinsed off, leaving a bright metallic surface, and the oxide of copper thus collected, is afterward reduced in the furnace. The apartment in which anchors are forged, is vastly extensive, and so highly charged with smoke, fire, steam, and noise, as forcibly to remind one of the fabled caves of the Cyclops. Many of the anchors which are wrought here, weigh from 70 to 90 cwt. each.”

Source

John Griscom. A year in Europe, comprising a journal of observations in England, Scotland, Ireland, France, Switzerland, the north of Italy, and Holland In 1818 and 1819. Vol 1. New York, 1824. Digitized by Google.

Note

1. See on this weblog for instance the notes dealing with the facilities in the United States, France, Hellevoetsluis, Amsterdam and Rotterdam in the Netherlands and Antwerp in Belgium.