Emergency situations in subsurface structures hold specific challenges, particularly in the case of highly dissected underground structures (several levels, winding, high penetration depths). Successful mission accomplishment is primarily linked to the existence of a functioning ventilation system, which must be understood and controlled by the emergency forces. This paper presents the development of a physical separation of the zone transitions to enable interventions in the air flow conditions by means of ventilation elements which can be quickly deployed and relocated. Besides the availability of specialized units capable of setting up the necessary ventilation sections, expert knowledge in the SubSurface Operations Cell (SSOC) and a suitable ventilation simulation is needed to define these sections. The interdisciplinary development of a customized mobile ventilation door is an essential building block for managing complex underground operations. The establishment of zone crossings even in large cross-sections allows effective ventilation interventions in two-lane underground traffic structures with a large longitudinal extension.