Map 6. Harassing fire map, Loos sector, August 1917. An immense amount of intelligence could be accumulated in a quiet sector. This map contains not only a great deal of counter-battery information but also details about the routine German trench garrisons and their standard travel routes. With this information in hand, the BEF could fire to inflict casualties, fire to block some or all routes of travel, or to lull the Germans into patterns that could be exploited later.