Great War Destroyers - Handling
No hard and fast rules could be laid down for the handling of destroyers any more than of battleships. It rarely happened that conditions are identical on any two occasions, even for the same vessel performing the same maneuver in the same place. A destroyer will make more leeway when her oil-tanks are light than when she is fully fuelled. The head will fall off rapidly in making a dock at low speed if the forward tanks are empty and the after tanks full; while if the reverse conditions exist, she may decide to lie broadside to the wind and drift bodily to leeward.
To pick up a buoy, approach on the weather side at slow speed and, if a boat is not in the water, lower a man to the buoy by means of a bowline from the forecastle. It was advisable to lower a boat to expedite the work of securing and to avoid possible injury to personnel. Little difficulty is usually found, by skillful use of engines and by taking advantage of wind, in keeping the ship in position long enough to enable the man on the buoy to make fast a line, after which the end of an anchor chain is led through the ring of the buoy and made fast on deck.
The facility with which destroyers could be handled when going astern, especially when backing into wind or current, may in some cases render it advisable to make landings or enter slips stern first. With gentle sternboard, motion of one screw astern will ordinarily push the stern away from the side of that screw and delicate control is often possible under these circumstances. A special case in which this method of handling is recommended is when running into port with following wind or current, when it is intended to pick up a mooring buoy. Rounding to under these circumstances will be a long and troublesome operation, especially if the channel be narrow; and under these conditions the bow may be run up to the buoy and held there indefinitely with stern to wind and tide by skillful backing of first one engine and then the other.
Destroyers were light craft with very powerful engines and there is an easily understandable fascination in handling them which frequently led to the taking of unnecessary chances. A good destroyer officer was one who used the powers at his command daringly when necessary, but who does not invite disaster by rashness. It happens from time to time that an engine will not follow tlie signal, through fault of either personnel or material; and if this happens when the commanding officer is charging into a landing at high speed, trusting to his backing power to stop in time, the result may be a smashed bow or some worse accident, resulting not from an effort to perform some important service, but merely from bravado.
The light scantling and high power of the destroyer made it especially important to exercise care in warping or springing around docks. If the fact be kept in mind that the horsepower of the latest type destroyer is equal to that of a 32,000-ton battleship, and that the hull is at the limit of lightness, it will at once be realized that the engines can only be worked against chocks, cleats, etc., with extreme care. This caution applied not only to the fittings of the vessel itself, but to the lines by which she is to be handled. The largest mooring line with which destroyers are at present equipped is a 5-inch manila, and this is none too strong. The foregoing should not be taken to mean that power cannot be employed while springing the vessel on a line, as it is often necessary to work the engines in opposite directions at considerable speed. What is meant is that great strain cannot be brought on the line by imparting motion to the vessel.
In formation underway, the standard distance between ships, bridge to bridge, is 300 yards; and it is safe even at high speeds to keep well within this distance, for collision can easily be avoided by quick use of rudder. However, with a following or quartering sea it is unwise to manoeuvre too close, for under these conditions the best helmsmen cannot steer a steady course and the bow as it yaws from side to side may strike the stern of the destroyer ahead before the rudder can become effective. When lying-to in a seaway, the destroyer will invariably work broadside on, into the trough, rolling heavily and drifting rapidly to leeward. If she is backed from this position, her stern will tend to point up; but the quantity of water shipped over the stern will prove very dangerous.
The destroyer's quick period made a short steep sea more trying than any other and if forced into heavy weather in partially-enclosed waters such as Long Island Sound she may pound more heavily and suffer more damage than under the same weather in the open sea, where the waves are longer and where the vessel will seem to slide over the crests.
During the Great War an escort of five destroyers had to abandon their 22-knot convoy, the Mauritania, between Liverpool and The Skerries, where short high seas were thrown up by the wind ahead; several destroyers sustained severe damage from collision and all returned safely. The Shaw, whose bow was completely severed at the forward end of the bridge by S. S. Aquitania, made port under her own engines, her forward oil tanks on fire. All American destroyers stood up splendidly so far as damage from seas was concerned and proved that they can operate in the worst weather.
At high speed, in depths of forty feet or less, the screws draw down the stern causing the vessel to drag and to be materially slowed. This drag is very perceptible and the speed of the vessel through the water cannot be increased above a certain point (about twenty knots) regardless of the speed of the screws. The stern will squat until the fantail deck is flush with the surface of the water, and the resultant wave will prove very destructive to harbor craft, and even to sea-walls and large shipping. So many complaints have been received and so many bills submitted to the government for parted lines and damaged property that present orders prohibit destroyers from using a speed greater than twelve knots in entering and leaving harbors. For this reason many units of the flotilla made it doctrine to use a standard maneuvering speed of eighteen knots. Channels are entered and left at two thirds speed, or twelve knots, and all speed signals except cones are thus eliminated in getting underway and coming to anchor. It was unsafe to pass operating dredges at more than six knots.
Most cruising was done at fairly high speeds so that a slight error in compass course, under weather conditions adverse to observation of sun or stars, will result in large error in the position by dead reckoning. Most destroyers are equipped with the Sperry two-wheel gyro compass, but little dependence can as yet be placed on the gyro in this type of vessel. Unquestionably the gyro compass will in time be developed and made suitable for destroyer work.
The motion is at times so excessive that it is difficult to use navigational instruments, and the navigator must learn to take sights while holding on to a stanchion or bridge rail to keep from being thrown from side to side, at the same time endeavoring to keep his sextant mirrors free from spray. He must become accustomed to "bringing down" stars under conditions of most violent rolling and learn to eliminate errors due to a rapidly changing dip, and to plot his positions with instruments that are constantly getting adrift.
To summarize: although it may justly be said that practically all methods of navigation are less reliable on Torpedo vessels than on larger craft, the navigator can with diligence and practice overcome these difficulties; and it has been demonstrated that destroyer navigation can be made to compare favorably with that of the largest vessel. Skillful navigating in destroyers is of the utmost importance because of the duty required of these vessels. In scouting work and in trailing the enemy, contact reports and other information sent out by the scout may be very misleading to the commander-in-chief unless based upon the most accurate navigation.
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