However, as the war became bogged down in the stalemate of trench warfare, few opportunities arose to exploit the tactical mobility of the MMGS batteries. The units did perform useful service on occasion, for example during the Battle of Neuve Chapelle (March 1915); and the MMGS received an official acknowledgement from BEF HQ in April 1915 of the "invaluable" work it had rendered in the fighting line. Nevertheless, up to that date, only seven MMGS batteries had been deployed on the Western Front. Their potential for future use continued to be acknowledged, and by the date of the Battle of Loos (September–October 1915), there were 18 MMGS batteries serving with the BEF.