An opening is useful only when the equipment can reach the deposit and loosened material has a controlled route below. Vessel volume alone does not answer either question.
A roof hatch can appear useful while leaving a large shadow behind an internal ring. The decision about when remote silo cleaning is appropriate comes from the opening position, internal geometry, deposit and required finish. A drawing exposes the surfaces that the opening may not reach.
A useful opening must face the deposit
Roof access helps only when the equipment can reach the required surface. Rings, probes and baffles may block the line of approach, while loosened material still needs a prepared collection point below. The coverage record names both the reachable area and anything left behind.
Read about remote silo cleaning or use the access planning guide to map the vessel.