Although it retained most of its armor, there were not enough infantry units because of the defensive needs in the East. These 30 newly rebuilt divisions used some of the last reserves of the German Army. Among them were "Volksgrenadier" units formed from a mix of veterans and recruits formerly regarded as too young or too old to fight. Training time, equipment and supplies were inadequate during the preparations. German fuel supplies were inadequate. Materials and supplies that could not be transported by rail had to be horse-drawn to conserve fuel. The mechanized and panzer divisions would depend heavily on captured fuel. As a result, the start of the attack was delayed from 27 November to 16 December.