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the sea in rough weather, together with suitable means for applying it.” Thick and heavy oils are the best. Mineral oils are not so effective as animal or vegetable oils. Raw petroleum has given favorable results, but is not so good when refined. Certain oils, like coconut oil and some kinds of fish oil, congeal in cold weather, and are therefore useless, but may be mixed with mineral oils to advantage. As a general rule, probably the best way to use oil is by filling the closet bowls forward with oakum and oil, letting the oil drip out slowly through the waste pipes. Another simple and easy way to distribute oil is by means of canvas bags about a foot long, filled with oakum and oil, pierced with holes by means of a coarse sail needle, and held by a lanyard. Running before a gale, use oil from bags at the catheads or from forward waste pipes; if yawing badly and threatening to broach-to, use oil forwards and abaft the beam, on both sides. Lying-to, distribute oil from the weather bow. With a high-beam sea, use oil bags at regular intervals along the weather side. In a heavy cross-sea, have bags along both sides. Steaming into a heavy head-sea, use oil through forward closet pipes. There are many other cases where oil may be used to advantage, such as lowering and hoisting boats, riding to a sea anchor, crossing rollers or surf on a bar, and from life boats and stranded vessels.
114. The Drag, or Sea Anchor.—The drag, or sea anchor, shown in Fig. 16 is a contrivance used at sea to prevent the ship drifting too fast during a violent gale under bare poles, and to keep the bow or the stern of a vessel toward the sea. The drag is constructed on the same principles as the ordinary log chip; the ship being exposed to the full force of the wind will drift faster than the drag, which is practically submerged, hence the latter will act as a check to the backward progress of the former. Several patent drags are now in use, the cornucopia drag being the one commonly found on board American ships. It consists of an iron ring, varying in diameter according to the tonnage of the vessel, to which is laced a horn-shaped canvas bag, at the apex of which a small iron ring is attached. The whole is weighted by cork fenders in such manner as to keep the mouth of the drag below the surface of the water in order to insure the greatest resistance. The hawser to which the drag is attached is usually led in through the hawse pipe and secured to bits, in cases where the bow is
held against the sea. When taking in the drag the trippling line attached to the small ring is manned; by this line the bag is turned over and the contrivance easily pulled on board. In cases where a vessel is not provided with a patent drag, a substitute may be readily constructed from such materials as may be available. For instance, spars may be lashed together, bridled, and weighted with kedge anchor or chains so that the whole will float even with the surface of the water. This substitute is then thrown overboard, secured, and used exactly the same as the patent drag.
115. As a rule, drags, or sea anchors, are seldom, if ever, used by large steamships, the reason for this probably being that when encountering winds of such violence as to make the use of a drag desirable the work of getting out and putting in shape so heavy a drag, as is required by the size of the steamer, is out of the question. Besides, the drag, once out, will materially hamper the prompt execution of any maneuver that must be made. For small-sized steamers and sailing vessels the drag is undoubtedly very useful in riding out a gale with safety and comfort, although many shipmasters, with a lifelong experience at sea, profess never to have used it.
116. Jury, or Temporary, Rudder.-In case a rudder becomes disabled so that it cannot be used, it should be unshipped or secured in such manner as to prevent its doing damage to the hull. As to the rigging of a temporary rudder no particular rules can be framed; circumstances and materials at hand will suggest the method to be adopted. The simplest, and perhaps the handiest, method of rigging a jury rudder is as follows: Lash several spars together (see Fig. 17) so as to form a float; to the under side, or lower edge, of which attach chains so that the whole will float nearly submerged when put in water. When ready, secure to it a good, suitable line, or hawser, and launch overboard; pay out as much line as is deemed necessary and fasten the line to the center part c of the stern. From each quarter have a tackle attached to the line at a suitable distance from c, as shown in the figure. Lead the running part of these tackles through the snatch blocks a and b, respectively, aud thence to the barrel of the wheel zo, to which they are applied in the same way as a common tiller rope. The ship can now be steered in exactly the same manner as with a rudder.. As a substitute for spars lashed together, as shown in Fig. 17, a drag may be used in nearly the same manner. This is done by towing the drag from the center of the taffrail, the apex of the drag being attached to the towing line. In this case the iron ring, or hoop, is not used; instead, the mouth of the drag is bridled and connected by lines to each quarter. By pulling one of the lines attached to the bridle, the drag will inflate and produce resistance. Before a temporary rudder is ready for service, the course of the vessel should be controlled by a judicious use of sails, or by sails and machinery in combination.
Rules of the Road and Safety Arrangements
METHODS FOR AVOIDING CONCEALED DANGERS
THE DANGER ANGLES
1. The danger angle, which may be either vertical or horizontal, is the name given to a method that is used when sailing along a coast to avoid hidden dangers, such as rocks, shoals, sunken derelicts, or other obstructions, situated immediately at or below the surface of the water. By its proper use any such dangerous obstacle may be passed or rounded at any desired distance. For this reason its proper name should be safety, instead of danger, angle, although the latter expression is the one most commonly used.
2. The vertical danger angle is based on the known height of a lighthouse, or other known object, the height of which is given on the chart or in the list of Lights and Fog Signals, and the distance corresponding to such and such angle subtended by this height.
3. The horizontal danger angle is based on the angular distance or the angle subtended by two known objects given on the chart and visible at the same time; it is an application of the geometrical properties of the circle, viz., that angles in the same segment of a circle are equal. For notice of copyright, see page immediately following the title page