Narrative of the Voyages and Services of the Nemesis from 1840 to 1843 / And of the Combined Naval and Military Operations in China: Comprising a Complete Account of the Colony of Hong-Kong and Remarks on the Character & Habits of the Chinese. Second Edition

by Sir W. H. Hall; W. D. Bernard

The equipment and destination of the Nemesis, however, was kept a profound secret, except to those who were personally concerned in it, and even they (with the exception of the authorities) had little notion of the precise service upon which she was to be employed.

The Nemesis was at length finished, and sent to sea as a private armed steamer. She was never commissioned under the articles of war, although commanded principally by officers belonging to the Royal Navy; neither was she classed among the ships of the regular navy of the East India Company. In short, the Nemesis was equipped under very peculiar circumstances, which, together with the novelty of her construction, caused her to become an object of very general interest. The "wooden walls" of England had, in fact, been so long identified with her proudest recollections, and had constituted for so many centuries her national "boast," that it seemed an almost unnational innovation to attempt to build them of iron. Indeed, it was rather looked upon as one of the dangerous experiments of modern days. Moreover, as the floating property of wood, without reference to its shape or fashion, rendered it the most natural material for the construction of ships, so did the sinking property of iron make it appear, at first sight, very ill adapted for a similar purpose. It was sometimes forgotten that even wooden ships are composed of wood, iron, and copper together, and that the bulkiness of these necessary materials greatly diminishes the buoyancy of the wood.

A minute and scientific description of the structure of the Nemesis will be found in the United Service Journal for May, 1840, and it will therefore be sufficient, in this place, merely to notice one or two peculiarities, in which it differs from that of wooden ships in general. With the exception of the great paddle-beams, across the ship, and the planks of the deck and the cabin-fittings, together with one or two other parts, the names of which would be only intelligible to the scientific reader, the whole vessel was built of iron.

Credit is due to Mr. Laird, of the Birkenhead Iron Works, Liverpool, for the admirable manner in which she was constructed, and for the elegance of her form and model, which fully answered every purpose required of her.

Her burden was about 680 tons, and her engines of 120-horse power, constructed by Messrs. Forrester and Co., also of Liverpool; and with twelve days' supply of coals, together with water and provisions for four months, and stores of all sorts for two years, with duplicate machinery, &c., and all her armament complete, her mean load draught of water was only six feet. But commonly, in actual service, she drew little more than five feet. Her length over all was 184 feet, her breadth 29 feet, and her depth 11 feet. Her keel-plate was laid, and the vessel built and launched, in the short space of three months.

Strictly speaking, the Nemesis has no fixed keel, but the lower plate of iron, which connects the two sides of the ship together along its middle, is called the keel-plate. She is, therefore, almost perfectly flat-bottomed; and, in order to obviate, as much as possible, the disadvantages attendant upon this peculiar construction, there are two sliding or moveable keels, capable of being raised or lowered to the depth of five feet below the bottom of the vessel. Each of these keels is about seven feet in length, one being placed before and the other abaft the engine-room. They are each enclosed in a narrow case or tank, one foot wide, running from the bottom of the vessel up to the deck, and which, of course being open below, allows the water to rise in it, to the level of the sea on the outside of the vessel. In this, the keel, which is of wood, 4½ inches thick, works up and down by means of a small winch, and a strong chain which is attached to it. Thus it is evident, that either the foremost or the aftermost keel can be raised or lowered, independently of the other, if circumstances require it.

As it would, however, be impossible to steer with accuracy, a vessel of this construction, with a rudder merely of the ordinary description, and which, from its shallowness, would, in a heavy sea, be in a great measure out of water, there is a contrivance by which a moveable or false rudder is attached to the lower part of the true or fixed rudder, and which descends to the same depth as the two false keels, and, like them, can be raised or lowered at pleasure.

The main or true rudder was composed of wood, but the lower or false rudder was made of iron, and was so constructed as to grasp the lower part of the upper or fixed one, firmly on either side, but was bolted through in such a way as to be moveable, as if it were fastened by a hinge, so that, by means of a chain run up to the taffrail from its outer edge, it could be hauled up to any height required.

The next striking peculiarity in the construction of the Nemesis was, that the entire vessel was divided into seven water-tight compartments, by means of iron bulkheads; so that, in fact, it somewhat resembled a number of iron tanks, cased over, so as to assume the external form of one connected vessel. By this means, the occurrence of any accident, such as striking on a rock, or shot-holes, &c., which might occasion a dangerous leak in one compartment, would have no effect upon any other part of the vessel.

The advantages of this arrangement were often tested, during her three years' hard service; and, indeed, within a few days after her first departure from Liverpool, as will be presently related, this contrivance sufficed to save her from the almost certain destruction which would otherwise have awaited her.