Слике страница
PDF
ePub
[graphic][merged small][ocr errors]

[COPYRIGHTED]

U. S. NAVAL INSTITUTE, ANNAPOLIS, MD.

NOTES ON HANDLING DESTROYERS

By COMMANDER C. C. SLAYTON, U. S. Navy

INTRODUCTION

The writer has been hoping for a long time that some of the many really expert destroyer commanders would write about some of the results of their experiences and observations of handling destroyers.

Finally in sheer desperation, perhaps with the idea of "starting something," some observations of three rather busy years. handling and watching others handle them under many and varied conditions have been jotted down. These notes are not intended as a treatise on "How to Handle Destroyers"; they are simply a few observations concerning some of the mistakes often made. It must be remembered that no two vessels handle alike; also, that no two men will handle their ships exactly the same. No fixed rules can be laid down, and it is not the writer's desire to have these remarks considered as such. After all, experience is the best teacher, but it is hoped that these notes may be of value to the new men coming to command destroyers.

The handling of a destroyer alongside a dock or alongside other other vessels is to most destroyer men a never-failing source of fascination. A destroyer is a light vessel, very much affected by the wind, which has an effect on the high bow like that on the jib of a sailing vessel; a vessel of high power; swift; quick to answer the rudder; with fairly small turning circle; and withal so delicate that a little misjudgment may quite easily result in torn plates, a mowing down of your own or another's stanchions, bent gun training gears, damaged torpedo-tubes, damaged propeller guard, or propeller.

And never are the conditions exactly the same! How many times the young skipper, exasperated by what he thinks is landing not 100 per cent seamanlike, exclaims, "Now why in the name of all that's holy didn't the darned stern swing in as it

usually does!" It is so easy to overlook one of the many little points, as wind, eddy currents, etc., a forgetfulness that may mean overtime work for the repair gang.

When many destroyers are based on a port, it becomes necessary for a great deal of this kind of ship handling, and experience has shown that under such conditions there will be a good many cases of minor damage. Our destroyer repair ships overseas will testify that the hull and upper deck fittings are frail structures, judging from the way they had to work to keep the destroyer on the job.

DIFFERENT DESTROYER TYPES

Before proceeding with an account of the mistakes commonly made, it would be well to examine some of the points wherein the several types of destroyers differ, in regard to maneuvering qualities.

The vessels before the 700-ton class are not considered in this article.

1. Triple Screw 700- and 750-Ton.-These have small fast moving screws, small turning leverage and small backing power.

In order to turn in a short space it is best to use the rudder and get way on, shifting rudder when dead in the water. The kick of the "inboard screw " backing as it churns when started is of great assistance.

The wind effect on the high bow of these destroyers is most marked, especially when backing.

The twin-screw boats have better turning leverage, but have the disadvantage of less backing power than later boats.

2. Thousand-Ton Destroyers with larger and slow moving screw, greater turning leverage and greater backing power, can ordinarily be turned in a very small circle, using one screw ahead and the other backing. They turn best with a little ahead motion of the ship. The wind has less "jib effect" on these on account of the high boat skids aft.

3. Twelve-Hundred-Ton Destroyers having more power are still easier to handle, but care must be taken to use this power judiciously, in order not to start ahead or astern with a rush. It has also been noted that one must anticipate a little, for a signal from the bridge does not result in a reversal or starting of the engine as quickly as in the smaller ones, and when they do start, as one captain said, "You know it." This slowness of starting may apply to only a few of the boats, for another captain says

that you get the effect of a reversal or change of engines very quickly,

The destroyers of the latest design should be particularly easy to handle, on account of their cut-away stern. This makes them very sensitive to rudder changes. Their deeper draft when loaded will make them less susceptible to the wind, which is a bugbear to most destroyer men, when it cannot be used to help. It may be remarked that the officer of the deck and steersman will have to be very much on the job when running before a quartering sea, due to excessive yawing, especially in shallow water.

REASONS FOR MISTAKES

1. Insufficient knowledge of the maneuvering qualities of the ship; how wind and tide effect its handling, and how to make allowances therefor.

2. Use of excessive speed.

3. Use of too little power.

4. Lack of confidence; indecision.

5. Insufficient or improper use of lines.

The remarks in this article are chiefly applicable to vessels of the " 1000-ton " type, except where a certain type is specifically mentioned.

INSUFFICIENT KNOWLEDGE

The knowledge of how ships will act under varying conditions is one which cannot altogether be learned from books, tactical data, or the thorough analysis of the effect of the rudder and screw in Knight; these should all be studied, but before one can become an expert at handling his ship a certain amount of experience must be had to round out his knowledge.

The quickest way to turn, in point of time, is at a fair speed, both engines ahead, and with full rudder. The slowest is with practically no way at all, one engine ahead, the other astern.

Therefore, desiring to get around in the shortest time, you should turn with as much headway as possible, consistent with safety. Ordinarily, to turn in a limited space with boats of the 1000-ton class, it will be found best to so regulate the speed that the effect of the engine going ahead is a little greater than that of the engine going astern. And, moreover, the more power (not speed) the quicker the turn.

But with the lighter 700- and 750-ton boats, especially those with the Parsons' installation, it will be found that it is almost

« ПретходнаНастави »