While shrapnel made no impression on trenches and other earthworks, it remained the favoured weapon of the British (at least) to support their infantry assaults by suppressing the enemy infantry and preventing them from manning their trench parapets. This was called 'neutralization' and by the second half of 1915 had become the primary task of artillery supporting an attack. Shrapnel was less hazardous to the assaulting British infantry than high explosives - as long as their own shrapnel burst above or ahead of them, attackers were safe from its effects, whereas high-explosive shells bursting short are potentially lethal within 100 yards or more in any direction. Shrapnel was also useful against counter-attacks, working parties and any other troops in the open.