The strain on the German defenders on the Somme grew worse in August and unit histories made frequent reference to high losses and companies being reduced to eighty men before relief. Many German divisions came out of a period on the Somme front with at least and some German commanders suggested a change to the policy of unyielding defence. The front line was lightly held, with reserves further back in a defensive zone but this had little effect on the losses caused by the Anglo-French artillery. Movement behind the German front was so dangerous that regiments carried rations and water for a four- to five-day tour with them. Behind the line, construction work on new rear lines was constant despite shortages of materials and rail lines becoming overloaded with troop trains. Supply trains were delayed and stations near the front were bombarded by artillery and by aircraft. The local light railways were insufficient and lorries and carts were pressed into use, using roads which while paved, needed constant maintenance, which was difficult to ensure with the troops available.