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26. For a vessel in advance of the storm and on the track itself, the southeasterly wind will hold comparatively steady, and the barometer will fall rapidly until she is overtaken by the center of the depression; then there will be a brief period of stationary barometer, with sudden and irregular shifts - the wind backing and hauling without warninguntil the center is past, the barometer starts to rise, and the wind comes out strong from the northwest. With the wind come the heavy seas, from the same general direction, but sometimes lagging behind as much as 2 or 3 points. Should the storm become one of such violence that it becomes necessary to heave-to, it is evident that this must be done on that tack which will cause the wind to draw aft as the storm advances, and thus keep the vessel head-on to the old
Which tack that is, whether port or starboard, will be evident from what follows.
27. Management of a Vessel in Storms. - Although seamanship under sail does not apply on the Great Lakes in the same degree as on the seas, the management of sailing vessels in storms is given herein as tending to explain the management in general more fully than could be done by limiting the subject to the management of steamers alone. Let Fig. 9 represent a storm, whether on the ocean or on the Great Lakes. For simplicity its form is made perfectly circular, and the winds are made to incurve 2 points everywhere. Assume that this storm is advancing about NNE, or in the direction of the long, heavy arrow. Then the ship at a has the wind from EN E; she is to the left of the track, or in the left semicircle. The ship at b has the wind from ES E, and is in the right semicircle. As the storm center ( advances along the heavy line, these ships, if lying too close-hauled, take the successive positions a,, a,, etc., bı, bu, etc., respectively. The wind of ship a shifts to the left, as shown by the arrows; so in lying-to on the starboard tack, as shown, her wind will draw ahead and she may be struck aback, for the shifts are sometimes sudden and violent. Since the sea changes less rapidly than the wind, the old sea will draw aft as the ship falls off; she runs, therefore, in addition to the risk of gathering stern board, that of getting stern-on to the heavy sea- a position of great danger, unless driving fast before it. Evidently, then, ship a should be laid-to on the port tack in the left semicircle, in order that
the wind may draw aft, and that the ship in coming up to the wind will keep head-on to the old sea.
The other ship b, laid-to in the right semicircle, will have shifts of wind to the right, and being laid-to on the starboard tack, her wind in that semicircle will draw aft, as shown. As she comes up to the gradually shifting wind she will likewise come head-on to the old sea. Plainly, then, b is on the proper tack.
28. Rule for Heaving-To. – From the preceding explanations the following rule may therefore be formulated:
In the left semicircle, with respect to the storm track, the wind shifts to the left; lie-to, if at all, on the port tack (left tack).
In the right semicircle the wind shifts to the right; lie-to, if at all, on the starboard tack (right tack).
There is a further advantage that may at times be taken of this known rotation of the winds, especially in lake navigation. A vessel on a weather shore, informed by her barometer that the storm center is moving rapidly, and that rapid shifts may therefore be expected, will often profit by lying-to, anchoring under or hugging that shore, confident that the wind in shifting will afterwards afford her a continuous lee under the land.
29. Further Differences Between the Front and the Rear of the Storm. - In addition to the fall of the barometer and the southerly winds, the approach of a barometric depression is marked by a rise in temperature of 5° to 10° F., and particularly by the increasing quantity and the character and motion of the clouds; these having a soft, oily look, and coming from a direction 1 or 2 points to the right of the wind.
To recapitulate, we have then, as the distinguishing features of the
Clouds hard and tending to break up. 30. When apprehensive of the weather, the mariner should make each of these points the subject of independent observation, not once only, but at hourly intervals. Having convinced himself that a storm is approaching, and having fixed his position with regard to the storm center and its probable path to the best of his ability, he is enabled to predict with some certainty what the direction of the coming wind and sea will be, to take due and seamanlike precautions, and, if necessary, to seek shelter before his vessel has been damaged, instead of after.
SUGGESTIONS RELATING TO THE HANDLING OF
STEAMERS IN HEAVY WEATHER
31. To Lie-To a Steamer in a Gale. – While the term "heave-to" has been frequently used in connection with the subject of storms, and while it properly comes under the heading of seamanship, we feel that a brief explanation of the operation meant by that term may not be altogether out of place here.
The best way in which to heave-to, or lie-to, a steamer in a gale will depend to a great extent on the peculiarity of the steamer herself. By the “peculiarity of a steamer” we mean the tendency in motions, and otherwise, that distinguishes her from other ships of the same class under similar conditions. Some steamers seem to lie-to more easily and more comfortably with their bows toward the direction of the sea, that is, against the waves, than in any other way, while others will lie-to best with the sea 3 or 4 points on the bow. In both cases the engines are used sufficiently to give the steamer proper steerageway. In violent gales, and in cases where the machinery is disabled, it is sometimes necessary to use a drag, or sea anchor, in order to have the ship lie-to. This applies to small and mediumsized ships. As for steamships of large tonnage, with considerable length and depth, the opinion is that such vessels will lie-to best in the trough of the sea, or in a direction parallel to the crest of the waves. This opinion, however, is not entertained by all seamen. To cause a vessel to lie-to in the trough of a heavy sea is a risky undertaking, especially for lightly loaded vessels or for vessels in ballast, as they are apt to turn turtle without warning. This may not occur from the first enormous sea striking the vessel; one sea may, however, list the ship to such an extent as to cause the cargo to shift and the next one will complete the catastrophe. Among the several instances where this has actually happened may be mentioned a 5,000-ton British tramp steamer, grain laden, which turned over
on San Francisco Bar - drowning her entire crew – by her officers allowing the ship to get broadside in the trough of the sea. The theory generally accepted is that the easiest position for a ship in heavy weather, when unable to pursue her course, is the one that she would take if left at rest and relieved from the constraint of engines, rudder, and sails. As a rule, she will then fall off until she has the sea abaft the beam, the propeller acting as a drag on the stern. If under such circumstances she is rolling dangerously, she may be kept more steady by using head sails, or by keeping the engines going sufficiently to give her steerageway, in combination with a judicious use of oil, since experience has proved that a steamer may safely run with the sea aft or on the quarter, provided she runs very slowly.
32. Lieutenant-Commander A. M. Knight, U. S. Navy, in his admirable treatise on seamanship,* after a lengthy discussion of the various phases of the behavior and the methods of handling a steamer in heavy weather, sums up the result of his investigations as follows:
“A ship will, as a rule, be safest and most comfortable when end on, or nearly end on, to the sea, and drifting before it. If by the use of sails, a drag, or any other means, she can be held bows on, while still being allowed to drift. this is probably the best way to lay her to, but if she cannot be held up without being forced into the sea, it will be because of the natural drag of the stern and the propeller, and in this case advantage should be taken of this drag to hold her more or less directly stern on, allowing her to drift in this way. Even if the position she takes in drifting is nearly in the trough of the sea, it will usually be found that she is easier in this position than in any other, the use of oil in this case being of particular importance. If the position
* Modern Seamanship, D. Van Nostrand Co., New York, 1900.