Application is for an underground Utility Tunnel, 7Km long.
Tunnel has (or it is suggested to have) 2 compartments, one for wet services (potable & irrigation water, district cooling) & one for dry services (power cables etc.).
Tunnel is to be accessible from O&M personnel.
Minimum Cross Section is 60m2.
Normal & Emergency Ventilation is to be through jet fans.
Which is the suggested engineering approach and NFPA codes to be used as a design basis for fire protection ?