Going over the top in World War One was when soldiers climbed from their trench to attack enemy trenches. At the battle of the Somme a British general ordered his men to walk towards the German trenches and not run. ' We don't want the enemy to think the British are cowards.' Thousands died because of his command.

Birds no longer sing
Where young men cower in trenches
Rifle and bayonet fixed
Wondering if they will live or die
Wanting the comfort of a mother's kiss.

Officers blow whistles
And the brigade climb out of trenches
Walking over shell craters and through barbwire
On towards waiting machine gunners
Surmounting terrors that make men mad.

There is no sound
But beating of each soldier's heart
As he steps forward into hell
Trying to control his fears and panic
Thinking of his loved ones back home.

Machine gunners open up
With chatter of bullets raking the ranks
Noise is deafening, screams as men are hit and fall
With wounded struggling in the mud
And for the dead grieving mothers to mourn.

Colin Ian Jeffery

http://www.poemhunter.com/poem/over-the-top-6/