Safety and safety planning - Tunnel Engineering: Basics and Additional Services for Design and Construction - page 329

8.7.2.1 Hazard analyses
The contractor produces and hands over hazard analyses for all potentially dangerous
construction measures and processes, updates them and produces concepts to reduce risk.
8.7.2.2 Fire protection, escape and rescue concept
Contractors undertake hazard analyses in accordance with this concept, and produce an
overall concept and a plan of measures including an evacuation programme for all persons
who could be affected on site. This applies to underground and overground works. Meas-
ures are also given for precautionary fire protection.
Contractors have to consider the following points in their concepts:
- An escape and rescue plan is to be produced for each construction section and displayed
at suitable locations. These plans must be adapted to suit the state of construction pro-
gress.
- The escape and rescue routes are to be kept in proper condition at all times.
- Precautions for the vertical transport of patients on stretchers also have to be consid-
ered; in particular, all construction excavations with a depth of more than 7.50 m are to
be provided with a passenger hoist ( l min = 2.10 m).
- Access for rescue vehicles must be ensured at all times. This applies both to the rescue
of construction workers and to the rescue of inhabitants in the area affected by con-
struction.
- In order to ensure access for rescue vehicles, the size of open construction excavations
is to be limited to a maximum length of 12.50 m at locations where there is no adequate
vehicle access at the side.
- The necessary sickness containers are to be determined and their locations are to be
planned considering any nearby hospitals.
- The possibility of rescue by helicopter is to be investigated and included.
- An emergency call system for all construction states, and an alarm plan including con-
sideration of any working times (shift operation) are to be produced.
- Rescue gathering places and their signage are to be identified and included.
- It is a requirement that all employed trades personnel are trained in first aid, independ-
ent of the “A2 Gelbe Seiten”.
- In the course of the tunnel advance, the following additional measures are to be con-
sidered:
Fixed extinguishing equipment. Fixed extinguishers are to be provided in shield tunnel-
ling machines and their backups at potentially dangerous locations like transformers or
grease injection points. An automatic activation system is to be provided. The backup is
to be fitted with a water mist system toward the tunnel mouth designed to prevent smoke
penetrating the tunnel and thus into the rescue and fire fighting access. Extinguishing
systems are to be provided with a supply pipe from outside if water is a component of the
extinguishing agent. A water tank of 10 m³ must be installed on the backup.
Fire alarm system. A warning (optical and acoustic) must be given in the shield tunnel-
ling machine. A backup alarm button is to be installed in the construction supervision
location outside the tunnel.