homeward convoys were frequently delayed by bad
weather, etc., on passage across the Atlantic, and, owing to the
insufficient range of the wireless installations, it was often not
possible for the commodore to acquaint the Admiralty of this delay in
time to stop the sailing of the outward convoys. Again, outward convoys
were often delayed by bad weather, resulting in the homeward convoy not
being met before entering the submarine zone. As the winter drew near
this was a source of constant anxiety, since so many of the vessels
outward bound were in ballast (empty), and their speed was consequently
quickly reduced in bad weather. The ships under these conditions became
in some cases almost unmanageable in a convoy, and the responsibilities
of the escorts were much intensified.

In September, 1917, the following was the position in respect to outward
bound convoys:

Port of Assembly. Frequency of Sailing. Destination.

Lamlash Every 4 days. Atlantic ports.
Milford Haven Every 4 days. Gibraltar.
Queenstown Every 4 days. Atlantic ports.
Falmouth Every 8 days. Gibraltar.
Plymouth Every 4 days. Atlantic ports.

About 150 vessels sailed every eight days in convoys varying in strength
from 12 to 30 ships.

There was still a good deal of Atlantic trade that was not sailing under
convoy. This comprised trade between Gibraltar and North and South
America, between the Cape, South America and Dakar, and the coastal
trade between North and South America. It was estimated that an
additional twenty-five to thirty ocean escorts and eleven destroyers
would be needed to include the above trade in convoy.

The Mediterranean trade is dealt with later.

The question of speed was naturally one of great importance in the
convoy system. As has been stated earlier, the speed of a convoy like
that of a squadron or fleet is necessarily that of the slowest ship, and
in order to prevent delay to shipping, which was equivalent to serious
loss of its carrying power, it was very necessary that convoys should be
composed of ships of approximately the same speed. In order to achieve
this careful organization was needed, and the matter was not made easier
by the uncertainty that frequently prevailed as to the actual sea speed
of particular merchant ships. Some masters, no doubt from legitimate