Being in the ASC he had a much better chance of surviving than a lot of soldiers, as a lot of what they did was behind the front lines, although they obviously suffered heavy losses especially from enemy artillery, but percentage wise it was safer than most units.
Your soldier in a normal infantry regiment, the highest percentage of the army, was most at risk of being killed when the allies attacked when going across the open no-man's land. While a defender had the protection of the trench so was safer relatively.
The army unit with the highest percentage of casualties was the machine gun corps, which suffered terrible losses. This was because a few well positioned machine guns could decimate an infantry attack, so as soon as one was located it became a prime target for the artillery supporting an attack.
I have just found these figures: A total of 170,500 officers and men served in the MGC, of which 62,049 were killed, wounded or missing . Over 36% casualties, and a lot of those that served would have only been in the last few months rather than the duration of the war, so you can see how poor the chances were for anybody assigned to machine guns at the start of the war.
Some how it seems strange to realise that the odds of surviving the war or being killed depended largely on luck by which unit you were assigned to, which was largely random. Although in this case it does appear that common sense was applied (or was it luck?) in that he was assigned to a job where his pre-war civilian skills as a dreyman could be used.
). Most unusual to find them now though. Also lots of cap badges. 
