Rescue Operations Bulletin No. 5B - Response to Emergencies in Tunnels Under Construction

DISTRICT OF COLUMBIA FIRE AND EMERGENCY MEDICAL SERVICES DEPARTMENT

Rescue Operations Bulletin No. 5B - September 2015

RESPONSE TO EMERGENCIES IN TUNNELS UNDER CONSTRUCTION
Background

The D.C. Water and Sewer Authority has initiated a sewer tunnel construction project, with a completion target set for the year 2025. This sewer tunnel system includes:

  • A total length of fourteen miles

  • A diameter of 26 feet

  • Features such as branch tunnels intended to alleviate surface flooding

  • Various vertical shafts

  • A dewatering pumping station
    The response to any incident that occurs at the tunnel or surface site mandates the use of proper Personal Protective Equipment (PPE), specialized training, and adherence to Level III accountability protocols.

Section 1: Purpose

The essential objectives of these guidelines are:

  1. To safeguard the health and safety of Fire and Emergency Medical Services (EMS) personnel involved in tunnel rescue operations.

  2. To maximize the chances of survival for any victims trapped or injured in the tunnel.

Section 2: Tunnel Rescue Incident Response

Tunnel Rescue Incidents are defined as emergencies occurring within tunnels during their construction phase, which may include rail, roadway, water, or sewer tunnels. These incidents necessitate the use of specialized breathing apparatus, specifically:

  • Scott open circuit Self-Contained Breathing Apparatus (SCBA)

  • Draeger closed circuit Long Duration Breathing Apparatus (LDBA)

Entry into these tunnels is strictly restricted to personnel who have undergone adequate training in tunnel rescue procedures. In cases where incidents occur above grade, with injuries but no complications regarding rescue or extraction, a standard emergency medical response will be executed. The rescue team for tunnel entry must consist of a minimum of five personnel trained in tunnel rescue techniques. Construction workers equipped with tunnel rescue training can function as auxiliary members of the rescue team under the direction of the Incident Commander.
It is the designated responsibility of Rescue Squad Co. 2 to conduct daily inspections and maintenance of the Tunnel Rescue Support Unit by employing a standardized checklist. This unit must be securely stored indoors while connected to the shoreline for readiness.

Section 3: Classifications of Tunnel Emergencies

Tunnel emergencies are classified into two primary categories:

  1. Immediately Dangerous to Life and Health (IDLH) Emergencies

  2. Non-IDLH Emergencies

IDLH Emergencies

IDLH scenarios pose an imminent threat to all personnel working in the tunnels, including workers and rescuers. They can be further categorized into:

  • Fire Emergencies: Such emergencies produce critical hazards such as:
      - Decreased oxygen levels
      - Release of hazardous gases
      - Reduced visibility
      - Increased heat
    The existence of fire can severely impair the tunnel's safety systems, which include water supply and ventilation mechanisms. Fire emergencies are characterized by long duration, high risk, and a diminished likelihood of victim survival.

  • Atmospheric Emergencies: Involve hazards including low oxygen concentrations, methane leaks, or additional hazardous conditions. Effective ventilation and appropriate breathing apparatuses can generally alleviate these emergencies, leading to positive outcomes.

Non-IDLH Emergencies

These emergencies are acute in nature and typically involve a singular victim. Non-IDLH emergencies can be divided further into:

  • Medical Emergencies: May affect one or several workers; however, they do not necessitate the deployment of additional equipment for patient treatment beyond transport.

  • Technical Rescue: Involves situations where specialized victim packaging or rope systems are required, or instances where workers may be pinned or trapped by equipment or collapsing tunnel segments.

Section 4: Definitions

  • Brass Board: An accountability system designed to track the names and counts of workers within the tunnel, placed near the entrance of the vertical shaft.

  • Confined Space: A designated area that is sufficiently large for personnel to enter and fulfill their work but possesses limited or restricted means of entry or exit, and is not intended for prolonged human occupation.

  • Entry Control Officer: The individual collecting Personal Accountability Tags (PAT) from members entering the tunnel, who must return them upon exit, ensuring Level III accountability at the Brass Board unless otherwise instructed by the Incident Commander.

  • Hazardous Atmosphere: Defined as any atmosphere that presents dangers of death, incapacitation, injury, acute illness, or impairment of self-rescue ability, determined by one or more characteristics:
      1. Presence of flammable gas, vapor, or mist at levels exceeding 10% of the Lower Flammable Limit (LFL).
      2. Airborne combustible dust at concentrations meeting or exceeding its LFL.
      3. Atmospheric oxygen levels below 19.5% or exceeding 23.5%.
      4. Atmospheric concentration of hazardous substances that could expose personnel beyond the Permissible Exposure Limit (PEL).

  • LDBA: Long Duration Breathing Apparatus, specifically the Draeger BG 4, which is a four-hour closed circuit breathing apparatus.

  • Loci: Refers to a diesel-powered locomotive utilized on small gauge tracks within tunnels for transporting personnel and equipment.

  • Rescue Entrant: A team member designated to enter a tunnel who meets the necessary training qualifications.

  • Mine Phone: A low-voltage communication system employed throughout job sites, serving as the primary communication method within tunnels.

  • Rescue Group Supervisor: Oversees all phases of entry, patient extrication, and the removal of both patients and entry personnel.

Section 5: Tunnel Rescue Dispatch and Responsibilities

In response to calls indicating a rescue or recovery in progress within a tunnel, a Tunnel Rescue Task Force will be mobilized. Responsibilities are delineated based on unit types as follows:

  • Closest Engine Company:
      - Position apparatus at a designated hydrant.
      - Place crew at the Brass Board.
      - Implement Level III accountability.
      - Document the positioning of brass tags on the Brass Board.
      - Establish an exclusion zone surrounding the vertical shaft entrance.
      - Ascertain the location, number, and condition of victims.
      - Investigate the activities of workers prior to the emergency call.

  • Closest Truck Company:
      - Locate the Foreman and Safety Manager.
      - Coordinate with Haz-Mat to confirm that vent systems are functional.
      - Ascertain the direction of air flow.
      - Evaluate the status of utilities, including power, lighting, water, and compressed air, and carry out Lock-Out Tag-Out procedures if feasible.
      - Verify atmospheric monitoring conducted by the contractor.
      - Relay relevant information to the Special Ops Chief via radio.

  • Rescue Squad Co. 2:
      - Respond with the Tunnel Rescue Support Unit and the Tunnel Rescue Trailer.
      - Operate as teams of five Fire Department members, with additional contractors potentially included in the Fire Department team.
      - Get ready to enter with necessary PPE and equipment aligned with the information gathered.
      - Await the establishment of a backup team before entering the tunnel.

  • 2nd Rescue Squad:
      - Operate as teams of five Fire Department members, with provisions for added contractor personnel.
      - Prepare for deployment as a secondary entry team or as a Rapid Intervention Team for the initial rescue squad.
      - Once utilized, the second rescue squad must be substituted with another rescue squad.

  • Haz-Mat Unit:
      - Calibrate all monitoring devices set to be utilized during the incident (this calibration must not delay rescue operations).
      - PlaceAtmospheric monitoring equipment, such as Area RAE steel, at the base of vertical shafts to remotely monitor conditions prior to deploying entry teams.
      - Record initial meter readings and subsequent readings every 10 minutes or whenever conditions change, documenting Tunnel Ring numbers with associated meter readings.
      - Aid in testing and preparing equipment, such as BG-4s, for operational readiness.

  • Closest Battalion Fire Chief:
      - Immediately report to the Command Post for an operational update.

  • Special Ops Battalion Chief:
      - Supervises the entire incident.
      - May decide to set up the Command Post in a conference room or "Nerve Center" that already has established communications and atmosphere monitoring in place by the contractor.

  • Air Unit:
      - Stage at a locale determined by the Incident Commander.

  • Safety Officer:
      - Position at a site designated by the Incident Commander.

  • EMS Units and EMS 7:
      - Assemble at the situation location directed by the Incident Commander.

Section 6: Special Considerations

  • Ensure that all apparatus is positioned as per the directions of the Incident Commander.

  • All vehicles must be arranged to facilitate access and exit for transport units and additional specialized units.

  • Consider the possibility of requesting extra EMS units or Mass Casualty support based on the information received on-site.

  • Hyperbaric emergencies may necessitate air transportation to hospitals with dedicated hyperbaric chambers.

Section 7: Safety

When addressing tunnel emergencies, the following safety protocols are mandatory:

  1. Tunnels present unique hazards requiring specialized equipment and training. Given the high risks involved, decisions taken by emergency personnel must prioritize safety above all.

  2. Minimum PPE requirements include:
       - Helmet
       - Eye protection
       - Steel-toe boots
       - Leather gloves
       - Reflective safety vests or USAR gear

  3. All city tunnels are regarded as "potentially gassy." The atmosphere within these tunnels must be regarded as IDLH until proven otherwise through calibrated direct-reading instruments assessing the following conditions in this order:
       1. Oxygen levels
       2. Presence of flammable gases
       3. Potential toxicity of the atmosphere
       4. Continuous atmospheric monitoring must take place while personnel occupy the tunnel using instruments such as Area Rae and Multi Rae Lite meters, with records maintained by the Haz-Mat Unit at ten-minute intervals.

  4. Vertical shafts leading down into tunnels may reach depths of 100 feet. Any personnel operating within five feet of the shaft's edge must wear a Class 3 harness secured to an anchor point.

  5. Personnel are prohibited from peering over or into the shaft to evaluate conditions or communicate with individuals located at the bottom.

  6. Responders should anticipate normal construction activity at the surface level, which may include:
       - Heavy machinery operation
       - Fuel and LPG storage areas
       - Risks of falling objects
       - Tripping and falling hazards, etc.

  7. Entry and operations inside tunnels will inherently pose severe challenges, such as:
       - Restricted access and exits
       - Low visibility conditions
       - Limited communication options
       - IDLH atmospheric conditions
       - Risk of entrapment within equipment
       - Confined spaces and elevated noise levels
       - Presence of potential high-voltage sources, flammable liquids, and fire hazards.

Section 8: Communications

Communication among personnel in tunnels is best accomplished using departmental radios exclusively on talk-around channels. Additionally, Mine Phones are installed throughout the construction sites, both underground and above ground, serving as the preferred method for relaying meter readings prior to tunnel entry. A landline located within the Tunnel Boring Machine Operator's compartment is also available for Fire Department use. Consider the deployment of the Tactical Bi-Directional Antenna, available via the DFC-Operations and communications support unit (Radio Cache).

Section 9: Entry Criteria

The Tunnel Rescue Team's primary function is to execute life-saving measures only; entering a tunnel or vertical shaft is subject to stringent safety guidelines. The following checklist delineates the considerations that must be thoroughly assessed before any entry by the rescue team:

  1. No entry into underground areas shall occur until confirmation indicates that a flammable atmosphere is absent.

  2. In the presence of flammable gas, proper ventilation must be established prior to any entry.

  3. Continuous atmospheric monitoring must be sustained throughout the incident duration.

  4. Vigilance must be maintained for any signs of tunnel collapse, cave-ins, or evidence of fire/smoke as paramount safety considerations for rescue personnel.

  5. Establish Level III accountability and take a photograph of the Brass Board.

  6. Designate an exclusion/hot zone around the vertical shaft entry point.

  7. Exclusive entry into tunnels or vertical shafts shall be restricted to:
       - Personnel trained under MSHA standards or Tunnel Rescue protocols.
       - Authorization by the Incident Commander.
       - A minimum team of five individuals.
       - Required support from a backup team.
       - Confirmation of an imminent life hazard.
       - Assurance of halted construction production.
       - Results of atmospheric tests indicating safe conditions or the provision of appropriate breathing apparatus.
       - Validation of functionality for the ventilation system aligned with parameters and flow ascertainable using an anemometer.
       - Locking out and tagging out any electrical systems other than ventilation, elevator, and pump operations.
       - Establishing communication connections via Mine Phone or landline at the TBM operator station. Department radios are only effective in tunnels via talk-around channels.

  8. The D.C. Fire and EMS Tunnel Rescue Team will not be deployed under the following circumstances:
       - Recovery of construction equipment.
       - Prevention of damage to construction materials or equipment.

  9. Deployments of the Tunnel Rescue Team shall be prohibited under these conditions:
       - Water levels exceeding knee depth.
       - Gas levels at or exceeding 10% of the Lower Explosion Limit (LEL).
       - Rising gas levels, regardless of their current LEL.
       - Presence of explosives, misfires, or explosive devices recognized within the confined space.

Rescue Operations Bulletin No.5B reflects critical operational guidelines for the D.C. Fire and EMS Department’s response to emergencies occurring within tunnels, emphasizing safety, training, and strategic response methodologies to ensure the best outcomes for workers and rescuers alike.