It's Not A Picnic, So Who Invited The Ants?
Communication, Emergency Rescue Equipment, And Supplies
After appropriately trained personnel are onsite, the project is ready to begin. While work is progressing, at least one responsible, on duty person must be designated for purposes of maintaining an accurate below ground head count and to summon help in an emergency. Consequently, voice communication must be maintained between the surface and underground crew. If out of earshot then some form of powered communication must be present and working. One or more five-person rescue teams must be onsite or within a thirty minute response time for every 25 underground personnel. These teams may be trained employees or consist of local rescue service personnel. In either case, rescue teams members must be trained in appropriate underground emergency response procedures such as fire-fighting equipment and self contained breathing apparatus.
Equipment, tools, and supplies allowed underground also create challenges. Gasoline in any form is prohibited, as are internal combustion engines other than diesel. Diesel fuel and other petroleum products such as greases and oils require storage in sealed containers located in designated fire-resistant areas, clear of vertical shafts and steep passageways. Hydraulic fluids must be rated fire resistant, unless the equipment in use is protected by adequate fire suppression systems or extinguishers. Welding gases and oxygen are only permitted in quantities that provide enough supply for a 24 hour period. A portable hand lamp or cap lamp must be provided for every employee, unless adequate lighting is provided for escape during a power outage or other emergency. In areas that may trap personnel by the presence of smoke, gas, or other air quality concerns, NIOSH approved self-rescuers must be provided. And so on. Needless to say, supplying a substantial underground project can create more than a few logistical headaches.