Final answer:
The 'turn under' in installing patches to protective covers likely refers to the additional material turned under at the edges, but a standard amount isn't specified in the provided process, which includes securing tarps and moving them after using activated CS capsules.
Step-by-step explanation:
When installing a patch to a protective cover, the term 'turn under' typically refers to the amount of additional material beyond the edge of a repair area that is folded or turned under to create a secure edge. Although the original information provided does not specify a standard amount of 'turn under,' it describes the process of securing tarps in soft rock areas using steel nails with rubber washers applied on reinforced eyelets along the edges or using heavy objects like rocks. The steps include securing tarps with nails or elastomer materials, inserting activated CS capsules with Velcro attachments, and after a period, moving covers to untreated patches with refilled capsules. This method aims to improve productivity and safety while reducing complexity compared to previous methods.