WW1 and typical battles on the western front like the somme often had large artillery that would pummel the enemys lines 24/7. These machines are not like todays weapons where 1-2 men can fire off huge cannon type devices! Look at the number of men it took to load, hold it in place and fire the thing. 12 men in the picture around the Howitzer :) I bet the kickback on these was deadly if not setup correctly.