Mobile Plant Working in Close Proximity to Each Other

Hi there,

I am making a design method statement for the installation of soldier piles/king posts and lagging to support an excavation. However, I am unsure of the safe distances between the mobile plant that work togther in unison to complete the job. The mobile plant includes a drilling rig, mobile crane and a concrete truck. I want to know the safe distances that each of these plant have working between each other?

Here is my illustration of the process:



Could the drilling rig, the mobile crane and the concrete truck be closer, of should they be further apart? What is the safe pratise for this kind of operation? Ive searched and searched but cannot find a difinitive answer.

Many thanks