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Henderson, R.N., and its organization and business management to Paymaster-Capt. H. W. Manisty. The first homeward-bound Atlantic convoy started on May 24, and by June 1917 convoys were being regularly run.

The system may be considered under two heads: (i) the organization at the ports of assembly and at the Admiralty, (2) the system of command at sea and the tactical measures of the convoy and escort. At the ports of assembly, escorts had to be provided to conduct ships from the ports of loading and to the ports of discharge. The convoy had to be assembled, the masters mustered and given their instructions, and the convoy handed over to the commodore. This work was done by port convoy officers, who were appointed at home to Lamlash, Devonport, Falmouth and Milford Haven and abroad to Sydney (N.S.), New York, Halifax, Gibraltar and Dakar. At all ports of any size, there were shipping intelligence officers who were now merged in the system and issued route instructions to the masters. At the British Admiralty the two principal tasks were assembly and routeing. The general management of the system lay with the organizing manager of convoys (Paymaster-Capt. H. W. Manisty), who worked in close coordination with the shipping controller. In the task of routeing he was assisted by naval officers and by a large convoy chart which showed continuously the latest movements of submarines and convoys. This chart was of the greatest value, for it made it possible to alter at once the course of a convoy if a submarine was reported in its vicinity, a system much more elastic and more exact than altering the routes blindly every five days. The three principal ports of assembly were Lamlash or Buncrana (Lough Swilly) in the N., Queenstown, Milford Haven and Falmouth in the S. Escorts were provided by the admirals commanding these areas, and orders for convoy were passed to them. An escort generally consisted of six to eight destroyers for a convoy of about 25 ships. A large portion of the work at Queenstown was gradually taken over by the U.S. navy, who worked in the closest harmony with Vice-Adml. Sir Lewis Bailey, the local commander-in-chief. The whole question hinged on the provision of destroyers. In Feb. 1917 there were only 14 destroyers at Devonport and 12 sloops at Queenstown available for convoy, and it was estimated that 81 destroyers or sloops would be required to provide escort for homeward-bound convoys, and 44 additional destroyers or sloops for outward-bound convoys. It was here that the aftermath of Jutland was severely felt. For the Grand Fleet still had to be prepared to meet the German fleet again, and insisted on a minimum margin of destroyers to enable it to do so.

The destroyer position in 1917 is shown in the table (A = modern new destroyers and flotilla leaders; B=old destroyers).

small staff of signalmen. He took general charge of the convoy until it met the escort, when the commodore then took his instructions from the senior officer of the escorts. A considerable equipment had to be provided for each convoy, including fog buoys, masthead angle tables, station-keeping instruments, and signalling lanterns. A convoy usually consisted of 25 to 32 ships. They were organized in five or six columns with ships 500 yd. and columns 800 yd. apart. The proportion at a later date was eight destroyers to a convoy of 22 ships and six to a convoy of less than 16.

The convoy came across by itself and was met by the escort on approaching the submarine zone, some 300 m. out at sea, and brought in by it. In daylight or in suspected areas or on a submarine report the whole convoy zigzagged, an operation which consisted in an alteration of one or two points (11 to 22) on each side of the navigator's course (course of advance) for some 10 minutes. These alterations of course were intended to make it more difficult for the enemy to estimate the exact course of the ship, a necessary factor in adjusting the sights for firing a torpedo. Another protective element was the system of camou- flaging ships, which rendered it more difficult to distinguish the fore and aft line of a vessel, a necessary preliminary in estimating its course (see CAMOUFLAGE : Naval).

The first convoys in May 1917 were all homeward-bound to Great Britain, but by Aug. outward-bound convoys were run- ning too. The main designation of convoys was into H. and O. (homeward and outward), with subsidiary letters indicating the port of departure and a series number for each convoy.

The principal convoys were as follows:

Homeward (H.)

Outward (O.)

H.H. H.N. H.B. H.X. H.S. H.E. H.G. H.J.D.

Hampton Roads New York to Brest to Liverpool Sydney (N.S.) and Halifax Port Said (Eastern) Gibraltar Rio de Janeiro, Dakar

O.K. Buncrana O.M. Milford Haven O.Q. Queenstown O.K. Falmouth O.D. Devonport O.L. Liverpool

By the end of Oct. 1917, 99 homeward convoys had come in comprising 1,502 steamers with a loss of 10 vessels sunk in convoy and 14 after dispersion, giving a total loss of 24 or 1-57 per cent. By the end of Nov., 77 out ward convoys had goneout, with a loss of 0-57 per cent.

The time lost by fast ships remained a distinct disadvantage of the convoy system. In a voyage of 3,200 m. the time lost in waiting at ports of assembly (24 hours) and through slow travelling (133 hours) amounted to 157 hours or six and a half

Destroyer State, 1917.

Convoys

Jan. 1917

Destroyers A B

Grand Fleet

Scapa

Harwich

Dover

Nore

Ports- mouth

Devon- port

Queens- stown

Bun- crana

(Scandin.) Humber

Medir.

107

IS

47

21

ii

9

13 16

u

6

.

9

29

8

June 1917 A B

105

ii

26

33 10

7

\l

38 5

32

4

5 29

29 8

Nov. 1917 A B

112

II

28

32

IO

12

9

8

37 4

35

29

4 30

32 8

Summary:

Grand Fleet and Harwich Dover, Nore, Portsmouth Convoys ....

It was not sufficiently appreciated that the adoption by the Germans of the strategy of the guerre de course would mean their abandonment of fleet operations on a large scale, and that the protection of Allied merchant shipping was now just as important as the defeat of the enemy's fleet. The command of the convoy at sea was vested in a " commodore of convoys," usually a captain or commander R.N. or R.N.R., who hoisted his broad pennant in the largest ship of the convoy and was attended by a

Jan. June Nov.

172 142 151

70 81 71

29 113 139

days, for a steamer of 5,000 tons. This was eventually diminished by the institution of fast and slow convoys, but on the other hand there were certain advantages which tended to compensate for the delay. Ships did not have to call anywhere- for orders, and they were not affected by suspension of traffic, which often held up independent sailings.

The introduction of the convoy system had the effect of forcing the German submarines to attack nearer the shore. In