SELF-ACTING SHIP VENTILATOR.

Globe, Volume IV, Issue 406, 30 September 1875, Page 4

SELF-ACTING SHIP VENTILATOR.

A simple-apparatus, which can befitted on board ship to act automatically, and serve as a ventilator, a fog alarm, and a bilge pump, is now being exhibited at Lloyd’s, and deserves to be brought to the notice of shipowners and f hipbuilders. The machine, which we have had an opportunity of carefully examining, was intioduced into this country some time ago, and submitted to the most crucial tests. The invention, which is patented by Mr Thiers, of New Orleans, consists of two small cylinders, placed on either side of a ship in-board, and connected by a pipe. The cylinders are partly filled with water, and, as the vessel rolls, the water rushes from the elevated to the depressed side of the ship, from one cylinder to the other, and, by creating a vacuum, draws up the foul air from between decks, or out of the hold, by pipes leading below. The air which is pumped up by this self-acting process goes out through a discharge pipe over the side, and such is the force of its exit that it serves to blow a foghorn when required. Fog-horns are used only by sailing ships ; but a powerful whistle, especially adapted to steamships, may be applied with perfect success, and the larger the cylinder the louder the signal. A similar application of this principle frees the vessel from bilge water, and, in fact, will keep under all ordinary leakage. The invention has been applied to a large number of ships of war and merchant vessels in the United States, therefore its merits are well known. Commander C. N. Cusham, of the Wachusset, in his report to the Rear-Admi-ral, stated that the slightest motion would set the ventilator in operation, so as to exhaust the foul air in any part of the vessel, or keep the fog-horns in constant blast, or pump up water if there were any in the ship. There are several reports to the same efiect, and among them is a resolution from the Board of Supervising Inspectors of steam vessels commending its general adoption. Admiral J. H. Strong, Lighthouse Inspector, in a document sent by him to the Lighthouse Board at Washington, writes as follows :

“In speaking of it as a fog-alarm, which it becomes by attaching a group of trumpets to the end of the pipe through which the foul air is discharge I (thus making a friend of a foe), the keeper of the Sandy Hook Lightvessel writes most warmly in its favour ; sends me the testimony of pilots who have heard the ‘ alarm’ from a distance of three miles, and gives me his own experience of having heard it on the pilot boat two miles to windward.”

Bearing in mind that there are fifty-two light vessels stationed around the coasts of the United Kingdom, and regarding the importance of making their position in foggy weather, the testimony of Admiral Strong as to this particular application of the invention comes very opportunely. The Trinity Corporation have given notice that, after the middle of this month, the fog signal on board the South Sand Head lightvessel will be a trumpet giving a blast of five seconds’ duration every two minutes, instead of a gong. The motion of that vessel would operate on a trumpet on one side and a whistle or screamer on the other, following up the blasts successively, and tins would denote a regular signal if the system of alternate trumpet and whistle were adopted. The cylinders are placed so as to be worked by the pitching or rolling of the vessel, and there is always a sufficient movement of the water to set these machines in motion. It is said that a 1 arrel rolled across the deck of a ship at N(W liork, by way of experiment, drew rip the air through the ventilator, and blew the horn. The Osborne yacht, set apart for H.R. H. the Prince of Wales, is titled with the apparatus, and the sound emitted is loud and clear. When the Osborne was up the Mediterranean her foghorns could be distinguished from all other sounds. One of the Peninsular and Oriental Company’s ships has just had this ventilator affixed, it will, therefore, be tested in a few days in the Bed Sea and Indian Ocean, where the heat between decks is excesssive and the ventilation not always perfect, or even tolerable. The constant action of such a pump as we have described would draw up all the impure mephitic vapour from the bilges and under decks, and pure air from the windsails, or ventilating funnels, must fill up the vacuum created. The noxious effluvia generated in a ship’s hold by the impurities which find their way there during a voyage, are too well known to require notice; but if those poisonous gases can be pumped up as quickly as they are formed—of which there seems to be no doubt—this ventilating process must tend to conserve the health of both passengers and crews. Medical evidence h«s been tendered in favour of this method of keeping the air uncontaminated; but we need not quote it. It is sufficient to learn that an automatic machine, occupying but very little space, will pump up noxious air and bilge water. This foul air pump will, we have no doubt, prove valuable in the preservation of perishable cargoes, and also prevent the decay of the vessel’s timber. Grain can be kept cool; and, where the ventilator has been applied, the lower tiers of fish have, it is said, turned out on discharge, in as good order as those on top. In petroleum or benzoline cargoes, or in gaseous coal, it is important to carry off everything tending to combustion or explosion, and this the machine in question is competent to effect. An ever active airpump, which does not depend upon manual labour or mechanical power to sustain its action, ought to lessen the sacrifice of life and property at sea .—Mitchell's Maritime Register,