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that the hour angle, 7h22m=110°30', is not given, so we enter with the supplement of this hour angle, 4"38'n and the supplement of the corresponding azimuth, 115°30', or 64°30'=4*18m, is the hour angle required.

The right ascension and declination here found correspond to a Leonis (Regulus).

After finding the hour angle and declination enter the Azimuth Tables with these to see whether the azimuth so found agrees with that given, thus verifying the work.

5. When the star is on or very near the meridian, so that its hour angle is practically o, the star's right ascension may be assumed equal to the local sidereal time and its declination may be readily found by applying its zenith distance to the latitude by dead reckoning.

6. The writer has found Plate II very convenient for finding the altitude at which to set the sextant in order to pick up a particular star in the early evening twilight, or to find Venus or Jupiter by day.

From the local apparent time, at which it is desired take the observation, find the local sidereal time, to which apply the star's right ascension to obtain its hour angle and take its azimuth from the tables.

Enter Plate II with the hour angle on the margin; the intersection of the horizontal line through this point with the declination curve of the body fixes a vertical line, the intersection of which with the horizontal line through the given azimuth determines the altitude curve of the star.

Example 4.—In the early evening twilight, at sea, February 26, 1901, Lat. 35° N., Long. 60° W., what was the altitude of a Andromedæ at 6.30 p. m., L. M. T., when the star's hour angle was 4"49"128 and its azimuth N. 74° W.? Star's declination 28° 30' N.

From Plate II the altitude was 29° 30'. Set the sextant to this altitude and at the proper time by watch sweep the horizon over the pelorus set at N. 74° W. Thus the reflected image of the star may be easily seen on the horizon long before the eye can catch the direct image in the sky.

[COPYRIGHTED]
U. S. NAVAL INSTITUTE, ANNAPOLIS, MD.

FUELING AT SEA
By COMMANDER H. C. DINGER, U. S. Navy

In time of war the question of fuel supply for patrol, convoy, and scouting vessels, and for all men of war operating on extensive overseas operations becomes most important. It is unhandy, dangerous, and sometimes impossible to go to a port to refuel, and, therefore, the problem of fueling at sea requires a solution. In smooth water, the problem of taking on board either coal or oil becomes quite simple, but it is at times undesirable to stop the vessels en route, and a dead calm is not always at hand. What is desired is to fuel vessels while underway at fair speed in an ordinary swell or seaway. This can and has been done.

In a dead smooth sea, the vessels can be taken alongside and tied up much the same as in port, but if there is any swell or seaway, this is dangerous. To accomplish the transfer of fuel in anything but a smooth sea, one of the vessels must be towed.

Numerous experiments have been made with special coaling at sea gears, in which the vessel taking the coal is towed by the fuel vessel, and the coal is carried by a special cableway, from the stern of the collier to the forecastle of the vessel. These installations require a great deal of special gear, and require a long space of time to rig, and the rate of delivery is so slow that this system is impractical, and is not used in actual practice. The files of the PROCEEDINGS of the Naval Institute contain several accounts of such coaling-at-sea experiments. In general, the transfer of fuel by towing astern has not been a practical success. There is an alternative method, towing abreast, which has much greater promise of success, and requires little or no extra gear on the fuel vessel, and no extra gear or attachments on the vessel receiving the fuel.

It is a comparatively easy operation to take a vessel in tow abreast and maintain her position-a steady almost exact posi

tion-well clear of the side. With a vessel maintained in this position, coal can be transferred by bags from boom ends, or by means of movable pipes from fuel vessels fitted with coaling towers. A coaling tower is a device operating a self-filling bucket chain, or coal elevator. The coal being dumped at the top of the tower into a hopper, from which coal pipes are led to the point where coal is to be landed. These devices have been used successfully for years on coal barges, and for unloading ore, sulphur, etc. The bucket chain is adjustable, and end can be lowered as necessary into the hold. The coaling tower can be mounted on tracks, so as to be capable of being moved to any point of the coal hold. Designs of these towers have been prepared, which are adaptable to naval colliers. Two or three of such towers, each operated by an electric motor, would replace all the elaborate winch, bucket and derrick gear now fitted to our naval colliers; and would be a big improvement in cost of operation as well as safety.

With these coaling towers, coaling might be accomplished through flexible tubing, which would be almost the same thing as coaling through a hose.

As far as is known, the first actual oiling of vessels at sea in rough weather was done by the U. S. S. Maumee in May, 1917, when a division of destroyers was oiled on the way across the Atlantic.

The gear used was as follows:

A 10-inch manila line was led from the bow of the fuel vessel, taken outboard and stopped along the rail; a 2-inch messenger was bent on the end. Two 6-inch breast lines were provided with heaving lines. Two 3-inch lines of oil hose were connected to the oil line, and were supported on a wooden carrier suspended from boom end, the line supporting this carrier being led to a winch, and tended by winch man.

The manner of coming alongside, taking lines, etc., is indicated in the instructions prepared for the occasion, quoted as follows: PREPARED ON U. S. S. “MAUMEE" FOR GUIDANCE OF DESTROYERS OILING

AT SEA

1. Gear.-All supplied by fuel ship.

10-Inch Bow Spring.–This line is led from the bow of the fuel ship and stopped along the rail; a 2-inch messenger is bent on about 50 feet from

end and stopped along to end. This line should be taken in on destroyer bow through bitts just forward of bridge. Take messenger to capstan and assist handling by hand; cut stops as they come to bitts. Take turn around base of gun mount as indicated on sketch and secure end to bitts on opposite side. Be sure that hawser is secure around base so that it will not ride up on mount. As soon as end is secured notify fuel ship, which will then heave in to place destroyer in proper position. Put lashings around and over bitts to prevent hawser jumping.

2. Breast Lines, 6-Inch.-Forward, take in through bitts forward of forward gun, then to bitts forward of capstan. Do not secure to capstan as it may be damaged. This line must be securely fastened as a very heavy strain may come on it.

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3. After Line.-Take through bitts in wake of deck house, secure, and stand by to tend.

4. Hose.—The hose, two lines, are led together through a wooden carrier supported from boom. Near end of hose, there is a wooden yoke to which is attached a handling line. The hose should be handled on board destroyer with this line, not with end of hose. Rail should be broken down and clear where hose is taken on board. Get ends of hose and hose yoke on destroyer, secure yoke and then put ends of hose in tanks. Pumping will start as soon as destroyer reports ready.

5. Handling of Destroyer.-Come along on parallel course, speed about 8 knots, distance about 50 feet from fuel ship; slow down to keep abreast fuel ship, ease in or out as necessary, but do not drop aft too far and get under counter. When 10-inch spring is fast, drop down on it slightly and let fuel vessel take in on breast lines till desired position is reached, about

40 feet from side, then maintain about 4 knots, just keeping slight or occasional strain on 10-inch spring. Destroyer will then ride to 10-inch spring and forward breast. Do not head out suddenly as this will break away the forward breast. Speed up if necessary to take strain off 10-inch spring and keep from swinging in too close.

The breast lines keep the destroyer in and prevent hose being carried away. Destroyers can come abreast and make connections in moderate sea without danger if precautions mentioned are adhered to. The principal danger is coming too close and throwing stern in. There is a suction under counter and destroyer should keep out of this. A speed of about 5 knots is maintained by fuel ship. This is necessary in order to steady fuel vessel and enable her to steer a straight course. The fuel vessel must

JNING!

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steer a straight course; rolling is not objectionable, but yawing is,-hence sea should be abeam or slightly forward of beam.

6. Before coming alongside destroyer should have her forecastle clear, rail clear for hose, have lashings ready, capstan ready and men instructed where the lines are to be led. Lines must be very securely fastened.

In smooth weather one destroyer can be taken on each side, and in calm, destroyers can make fast and receive oil as in port.

The first time that this was tried was in a moderate sea, as the attached photograph will indicate. The destroyers were each oiled in about two hours, and oil was delivered at from 30,000 to 40,000 gallons an hour. In some cases destroyers were connected up and oil being pumped on board in 15 minutes from the time the destroyer passed the stern of fuel vessel, this being done with a

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