What structures are typically used to house bulky items such as large transformers and network protective devices?

Vaults are structures specifically designed to accommodate bulky items like large transformers and network protective devices. They provide a secure and spacious environment that can withstand various environmental factors, enabling the safe storage and protection of critical electrical equipment.

In contrast, manholes, while useful for access to underground utilities, are generally not designed to house large items; they primarily serve as inspection points or access points for cables and pipes. Conduit pipes serve to protect and route electrical wiring but do not provide the necessary space for bulky equipment. Ducts are typically used for airflow and cable management and are not designed to support heavy or large items either. Thus, vaults are the optimal choice for the safe housing of substantial electrical equipment.