18 pdr gun crews

[Gunboat]

Hi this is my first time using the forum and I am going to be greedy and set two topics.

My Grandfather served in Royal Field Artillery as a driver. He signed on for six and six in 1907 and had just four months on the reserve list before war broke out and he was mobilised to France in August 1914

He spent time in Brigade Ammunition Column and then in a battery.

I know that drivers were responsible for driving the guns into the firing line but what were their duties once this was done, did they form part of the gun crew?

All the pictures I have seen of RFA crews on the move shown six horese teams three soldiers mounted and two or three men on the limber. Are all those mounted ranked as Driver or just the lead?

I am trying to build up a picture of what he would have done.