they were unloaded. The escorts which we were able to supply for such groups were thus much weaker than absolute safety required, and sometimes we were even forced to send vessels across the submarine zone with few, if any, escorting warships. This explains why certain homeward-bound transports were torpedoed, and this was particularly true of troop and munition convoys to the western ports of France. Only when we could assemble a large outgoing convoy and despatch it at such a time that it could meet an incoming one at the western edge of the submarine zone could we give these vessels the same destroyer escort as that which we always gave for the loaded convoys bound for European ports.
As soon as the destroyers made contact with an inward-bound convoy, the ocean escort, the cruiser or pre-dreadnought, if an American, abandoned it and started it back home, sometimes with a westbound convoy if one had been assembled in time. British escorts went ahead at full speed into a British port, usually escorted by one or more destroyers. This abandonment sometimes aroused the wrath of the passengers on the inbound convoy. Their protector had dropped them just as they had entered the submarine zone, the very moment its services were really needed! These passengers did not understand, any more than did the people at home, that the purpose of the ocean escort was not to protect them from submarines, but from possible raiders. Inside the danger zone this ocean escort would become part of the convoy itself and require protection from submarines, so that its rather summary departure really made the merchantmen more secure. As the convoy approached the danger zone, after being drilled all the way across the ocean, its very appearance was more taut and business-like. The ships were closed up into a much more compact formation, keeping only such distances apart as were essential for quick manœuvring. Generally the convoy was formed in a long parallelogram, the distance across the front of which was much longer than the depth or distance along the sides. Usually the formation was a number of groups of four vessels each, in column or "Indian file," at a distance of about five hundred yards from ship to ship, and all groups abreast of each other and about half a mile apart. Thus a convoy of twenty-four vessels, or six groups of four, would have a width of about three miles and
