Section 4
Mine Exploration
Barefaced exploration
Exploration is a broad topic. We’ll be talking about preparations for explorations, team briefings and debriefings, standard procedures for advancing inside the mine, and the equipment you’ll be using during exploration.
II. Examination of mine openings- Before anyone goes underground, it's important to examine the mine openings to determine the safest route for entering the mine. Tests should be made for the presence of gases, and someone should make ventilation checks.
Whenever possible, it's best to enter the mine by way of the safest intake airway.
In a shaft mine, check the cage to make sure it’s operating properly. To test an automatic elevator, run it up and down the shaft manually several times.
Tests should also be made for the presence of gases, smoke, or water in the shaft
.If a mine has had an explosion, the cage, signaling devices, and head-frame may be damaged. You may have to use a mucking bucket or other improvised means to make your descent provided all 5 team members will fit. However, a cage should be made available as soon as possible.
III. Barefaced exploration- In some disaster situations, conditions may make it possible to conduct an initial exploration without self-contained breathing apparatus. This is known as "barefaced" exploration.
Often, barefaced exploration is conducted with apparatus on team members, "ready" to function. This allows the team to quickly put on their facepieces and get under oxygen if conditions make it necessary.
Barefaced exploration should be conducted only when the ventilation system is operating properly and frequent gas tests indicate that there is sufficient oxygen and no buildup of carbon monoxide or other dangerous gases.
A backup crew with apparatus should be stationed outside the area, ready to go in immediately to rescue the others if necessary.
The purpose of such exploration is to quickly establish the extent of damage and to progress to the point where apparatus teams can continue the exploration.
Locomotives can be used during barefaced exploration as long as there is no smoke and no evidence of explosive gases. Usually, two locomotives are used in case one breaks down.
During barefaced exploration, the crew uses the mine’s communication system to report their progress and findings to the surface. This lets the backup team know where the barefaced team is located and whether it’s necessary to go in after them.
Barefaced exploration should stop at any point where disruptions in ventilation are found, or when gas tests indicate the presence of any carbon monoxide or other noxious gases, elevated readings of explosive gases, or an oxygen deficiency. A barefaced crew should also stop exploration when they encounter smoke or damage.
A fresh air base is usually established at the point where conditions no longer permit barefaced exploration. Because . the area has already been explored, rescue team members and backup personnel are then free to travel to and from the fresh air base without apparatus. Teams equipped with apparatus and under oxygen continue exploration from the fresh air base.
IV. The fresh air base- The fresh air base is the base of operations from which rescue and recovery work advances into irrespirable atmospheres. This is where apparatus crews begin their exploration of the affected area.
The fresh air base also functions as a base of communications for the operation linking the team, the command center, and all support personnel.a. Establishing a Fresh Air Base- Often, the operation’s initial fresh air base will be established somewhere underground. But in some mines, especially shaft mines, it may be necessary to establish the initial fresh air base on the surface. And sometimes the fresh air base will remain on the surface throughout the entire operation.
Whether you put it underground or on the surface, the fresh air base should be located as close as possible to the affected area of the mine, but situated where it’s assured a supply of good air.
Underground, existing refuge chambers are sometimes used as fresh air bases. Or, a fresh air base can be set up in a drift, entry (for single-level, room-and-pillar mines), or crosscut close to the affected area. In these cases, an air lock must be built to isolate the fresh air base from the unexplored area beyond it. The air lock allows teams to enter and exit the unexplored area without contaminating the air in the fresh air base.
Here are some specific factors to take into consideration when you select a site for a fresh air base:
1. Be sure the fresh air base is located where it’s assured positive ventilation and fresh air.
2. If the fresh air base is underground, it should be located where it’s assured a fresh air travelway to the surface. This travelway will be used to safely move people and supplies to and from the fresh air base. If possible, there should also be transportation available.
3. The site should be situated where it can be linked to the command center by means of a communication system.
4. There should also be a communication system to link the team and the fresh air base.
These four are probably the most important factors that help determine where to establish a fresh air base, but there are also some other elements to take into consideration. For example, the area should be free of oil and grease.
Also, the fresh air base should be large enough to accommodate all the people who will be using it and allow enough space for them to work efficiently.
It is often recommended that all possible electrical conductors (track, pipe, wires, etc.) be severed so that the affected area beyond the fresh air base is isolated from any possible stray or direct current.
The fresh air base is normally outfitted with supplies and other equipment to be used during the operation. For example, a typical fresh air base will probably be equipped with gas testing devices, equipment for detecting oxygen deficiency, and perhaps firefighting equipment.
There may also be first aid supplies and oxygen therapy equipment at the fresh air base, as well as tools and replacement parts for self-contained breathing apparatus. And, there should be a map of the affected area at the fresh air base.
If possible, the fresh air base should be supplied with benches, canvas, or brattice cloth for the backup team to set their apparatus on.b. The Fresh Air Base Coordinator- Stationed at the fresh air base, there will be a person who is responsible for establishing and maintaining orderly operations. This is the "fresh air base coordinator."
There will also probably be an advisory committee at the fresh air base to help the coordinator. This committee is usually composed of Federal and state officials, and union representatives, if involved.
And, sometimes "runners" are stationed at the fresh air base to carry messages from the fresh air base to the command center in the event of a communication breakdown. The runners may also be responsible for other chores, such as taking gas samples to the surface or monitoring the communication system cable.
The main responsibilities of the fresh air base coordinator are:
1. Maintaining communications with the working rescue team and the command center;
2. Following the team’s progress on the mine map and marking findings on the map as the team reports them; and
3. Coordinating and overseeing the activities of all personnel who are at the fresh air base, including the advisory committee.
Fulfilling these three basic responsibilities involves performing a number of duties. The coordinator carries out many of these duties. Some of the tasks may be delegated to other individuals, but it’s the coordinator’s responsibility to see that they’re carried out.
Let’s take a look at the fresh air base coordinator’s responsibilities during a typical operation.
An incoming coordinator who is replacing another coordinator should get all necessary information from the outgoing coordinator to ensure that the changeover goes smoothly.
It’s also the incoming coordinator’s duty to check communications between the fresh air base and the command center to make sure the system is operating properly. The coordinator also usually reports his or her arrival at the fresh air base, and logs the arrival time.
In addition to this, the coordinator’s duties typically include checking the name or number of the team going into the affected area to work, checking the condition of the backup team, and checking and logging equipment and materials. The coordinator should also make sure there is a map of the affected area at the fresh air base.
A fresh air base coordinator is normally responsible for logging the times that all personnel enter and leave the fresh air base, and for logging the time and nature of all telephone calls.
As work progresses, the fresh air base coordinator monitors communications from the working team, relays instructions from the command center to the team, and provides information to the backup team based on reports received.
It’s also usually the coordinator’s responsibility to make sure someone is stationed at the fresh air base to monitor the team’s communication cable if this type of communication system is being used. This person should help to unroll the cable as the team advances and roll it back up as the team retreats.
The coordinator should also make sure the requirements for a fresh air base are constantly maintained. It is typically the coordinator’s responsibility to make sure that no unauthorized personnel are permitted to go forward of the fresh air base.
As you can see, the fresh air base coordinator plays a key role in ensuring that the entire operation runs smoothly and efficiently. The coordinator maintains crucial communication links with the command center and the working rescue team. In addition, the coordinator is responsible for just about everything that goes on at the fresh air base.
Because the coordinator’s job is such an important one, it is absolutely essential that everyone at the fresh air base respect the coordinator’s authority and do whatever they can do to help out. In order to make the fresh air base coordinator’s job a little easier, it’s also essential that only those people necessary to the operation be permitted at the fresh air base.c. Advancing the Fresh Air Base- In single level mines using the room-and-pillar system, the fresh air base is usually advanced closer to the affected area of the mine as soon as areas forward of the base are explored and reventilated. This assures that the apparatus crews will begin their explorations as close as possible to the affected area of the mine.
To advance the fresh air base, the team will have to build a new air-lock at the site of the new fresh air base, and put up any additional temporary bulkheads in parallel entries that are needed to seal off the area at that point so that fresh air can be advanced.
Also, the team will have to repair any damaged ventilation controls in the area between the old fresh air base and the new one. However, be sure to make the necessary adjustments for directing air to an exhaust airway. This ensures that the area can be properly flushed out and ventilated.
Next, return to the old fresh air base and remove or open that air lock and any bulkheads in parallel entries. This permits air to enter and flush out the area up to the new fresh air base.
Before everyone is moved up to the new fresh air base, the area between the old and the new base should be explored by a team. Using appropriate gas testing devices, the team should check all dead ends, intersections, and high places in the area to make sure it’s adequately ventilated.
Once the entire area is explored, all appropriate checks have been made, and the area is declared safe, the team and other fresh air base personnel can move up to the new fresh air base.V. Apparatus teams- Once the fresh air base is established, apparatus teams will begin to explore the affected area.
This exploration may require only one or two trips, or it may continue through many team rotations. How many oh trips will be needed to complete the exploration (and how long it will take) will depend on the extent of the area involved and the conditions within the affected area.a. Team’s Role in Exploration- During exploration, the rescue team travels in potentially hazardous atmospheres.
As the team progresses through the mine, team members make gas tests and assess conditions. The team also searches for clues as to where survivors may be located, and locates fires. All these findings are mapped and reported to the fresh air base as the team proceeds.
As you explore, keep in mind that your first priority is team safety. The rescue of survivors comes second. Your third priority is the recovery of the mine.
During exploration, teams will work according to a rotation schedule.
One team, for example, will be scheduled to work. A second team will be stationed at the fresh air base as the "backup team," and a third team, known as the "standby," will be ready and waiting on the surface. Other teams may be scheduled to rest.
Because rescue work is strenuous and demanding, it’s important for team members to be well rested. It’s also recommended that you don’t eat within one hour of the time you’ll be wearing your apparatus, and you shouldn’t drink alcoholic beverages for at least 12 to 18 hours before you get under oxygen.
Lack of sleep, a recent meal, or alcoholic beverages can cause you to be sluggish and impair your judgment and reflexes. It’s also a good idea to limit intake of stimulants, such as coffee, colas, etc., because these substances increase heart and respiration rates.b. Equipment-Equipment for exploration work falls into two categories: the equipment each team member has, and the equipment the team uses.1. Team Members Equipment- Rescue team members use some of the same basic equipment that any underground miner uses. For example, each member will be outfitted with a hard hat, a cap lamp, steel-toed shoes or boots, and a metal I.D. tag.
For rescue work, you will also wear a metal ring on your mine belt so you can hook onto a link-line, and it is common practice for everyone to wear a watch. Of course each team member will also wear a self-contained breathing apparatus.2. Team Equipment-What the Law Requires- Some of the equipment your team will use for exploration is required by law. For example, remember that the law requires your rescue station to be equipped with two gas detectors for each type of gas you may encounter and two oxygen indicators.
According to law, the team must also have a portable or sound-powered communication system. The system’s wire or cable must be at least 1,000 feet long, and it must be strong enough to be used as a manual communications system.3. Other Equipment- Beyond what is required by law, the other equipment your team will use depends on the situation.
For example, if you are rescuing survivors, the team will, probably carry a stretcher or stokes basket, and an extra-approved breathing apparatus for the rescued person. But if your task is to build ventilation controls, the team will probably carry tools and other construction equipment.
Some of the material you need to build ventilation controls may already be underground, so you will simply pick up what the team needs as you progress through the mine. This also applies to other team tasks that require the use of materials already inside the mine. The team simply picks up what it needs as it advances.
As you can see, the equipment your team uses beyond what the law requires is determined by what type of work you’ll be doing. Here are some examples of equipment a typical mine rescue team might use:
1. gas detectors (or multi-gas detector)
2. oxygen indicators
3. communication equipment
4. thermal imaging cameras or heat sensing devices
5. link-line- This is a line or rope, usually equipped with rings, that is used to hook team members together in smoke.
6. Map-board and marker- (The map-board may be fitted with a plexiglass cover to protect the map from water damage in wet mines.)
7. scaling bar
8. walking stick- The captain can use a walking stick to probe water depth or to avoid obstructions in heavy smoke.
9. stokes basket or stretcher
10. first aid kit
11. fire extinguisher
12. tools - This usually includes: hammer, nails, axe, shovel, brattice cloth, and possibly a saw, and a wrench to open water line valves.
13. blankets (if missing miners are involved)
14. an extra approved breathing apparatus (if missing miners are involved)
15. carpenter’s apron The captain may use an apron to carry a notebook, pen, and chalk. Other team members may use one for carrying nails, hand tools, and so forth.
VI. Briefing- Before your team goes underground, you will attend a briefing session. This usually takes place at the command center and is conducted by a briefing officer and a briefing committee.
The briefing committee is generally composed of company and Federal officials and, where applicable, state and union representatives.
At the briefing, you should be told as much as possible about what has happened in the mine and what conditions currently exist.
In addition, the briefing officer will give the captain the team’s assignment. This assignment specifies what areas your team will explore and what you will be looking for.
The briefing officer will also issue your team an up-to-date mine map and give you a time limit within which You should be able to complete your work and return to the fresh air base.
During the briefing, the briefing officer will try to give you whatever information is available. However, it is your responsibility as team members to be sure you have all the information you need to do your work. Before you begin exploration, you should have the answers to the following questions:
1. Is the evacuation complete? Are any miners missing? If so, how many and what are their possible locations?
2. What is known about the cause of the disaster?
3. Is your team the first one to explore? (In multi4evel mines, the team would also want to know if there are any other teams working on other levels.)
4. Have the shaft and hoist been checked and, if so, what condition are they in?
5. Have state and Federal officials been notified?
6. Are guards stationed at all mine entrances?
7. Is the ventilation system operating? Is it an intake or exhaust system? Are attendants posted at the surface ventilation controls? Have air samples been taken? If so, what are the results?
8. Will there be a backup team standing by at the fresh air base, and reserve teams on the surface?
9. What are the team’s objectives and what is their time limit?
10. What conditions are known to exist underground? (Ground conditions, water, gas, etc.)
11. Is the mine’s communication system operating? Is it being monitored?
12. Is power to the affected area on or off
13. Is there diesel or battery-powered equipment or a charging station in the affected area?
14. What type of equipment is in the area? Where is it located?
15. Where are compressed air and/or water lines located? Are they in operation? Are valves known to be open or closed?
16. What type of firefighting equipment is located underground? Where is it?
17. What tools and supplies are available underground? Where are they?
18. Are there storage areas for oil or oxygen, acetylene tanks, or explosives in the area to be explored?
a. Captain’s Responsibilities- Before your team proceeds to the fresh air base, it is the captain’s responsibility to make sure the team, its equipment, and its apparatus are ready to go. In this capacity, the captain should:
1. Check each team member to make sure he or she is physically fit to wear the apparatus and to perform rescue work.
2. Make sure that each team member’s apparatus has been properly prepared and tested.
3. Make sure the team has all necessary tools and equipment (including the captain’s own supplies: notebook, pencil, chalk, and so on).
Once your team arrives at the fresh air base, it’s the captain’s responsibility to make the final preparations and arrangements before the team proceeds beyond the fresh air base. The captain should:
1. Make sure the team members understand the briefing instructions and what their individual jobs will be.
2. Make sure the gas-testing equipment, the communication equipment, signaling equipment, and stokes basket or stretcher have been checked by the designated people.
3. Establish with the fresh air base coordinator what communications will be used.
4. Synchronize watches with the fresh air base coordinator.5. (If not the first team to explore) Get up-to-date information from the last team (or from the coordinator) about how far the last team advanced and what they found.
6. Make sure your team’s mapman gets an updated map from the last team’s mapman or from the fresh air base coordinator.b. Getting Under Oxygen- Once all of these preparations and last-minute checks have been made, you’re ready to put on your apparatus and get under oxygen.
Once the team is under oxygen, the captain checks each team member and breathing apparatus. The co-captain performs the same checks on the team captain.
When the checks are completed, the captain notifies the fresh air base coordinator that the team is ready to proceed, and asks permission to set out.
Before the team leaves the fresh air base to begin the exploration, the captain should be sure to take note of the time of departure. Some teams jot down the time on their map for later reference.
Every exploration is different. Each one is an unknown situation, so each presents its own problems.
Although it’s difficult to tell exactly what you’ll be doing during any exploration, there are some accepted procedures for carrying out basic exploration work. These procedures have developed over the years as mine rescue teams gained experience. They should be thought of as "guidelines" rather than "rules" because they are fairly flexible.
Let’s take a look now at some of the standard techniques and procedures you’ll use during exploration.c. Team Check- One standard procedure you’ll use during an exploration is the "team check." There are three reasons for the team check:
1. To make sure each team member is fit and ready to continue,
2. To make sure each team member’s apparatus is functioning property, and
3. To give the team a chance to rest.
Usually, the captain conducts the team checks by simply halting the team briefly, asking each team member how he or she feels, and checking each apparatus.
It’s recommended that these team checks be conducted every 15 to 20 minutes.
It is also recommended that you make your first stop for a team check as soon as possible after leaving the fresh air base. There is a good reason for stopping close to the fresh air base: If a team member is feeling unfit to travel or an apparatus is malfunctioning, the journey back to the fresh air base is relatively quick and easy at this point.
For teams using a compressed oxygen breathing apparatus, the captain usually notes each team member’s gauge reading at each rest stop, and reports the lowest reading to the fresh air base. The lowest reading may then be used as a reference point to determine when the team should return to the fresh air base.
Keep in mind that in addition to checking each team member and apparatus, these stops allow the team a chance to rest. If your team is searching for survivors, you’ll probably want to advance quickly, but rest stops are still important. Be sure to allow time for them.
How long you stop for each check will be determined by the conditions you encounter and the work you are doing.
Rest stops are also, important(perhaps more so) on the return trip. The team will usually be more tired once they’ve completed their work. Don’t forget to allow time for team checks as you travel back to the fresh air base.d. Communications- As you travel beyond the fresh air base, communication plays an increasingly important role in your exploratory work. It is extremely important that teams develop an effective method of communicating among themselves and with the fresh air base.e. Team Signals- In case of communication failure, the team should use the standard life line signals. It is advisable that if communications fail, the team should immediately return to the fresh air base to determine the problem. The signals most commonly used are:
One pulls: Stop
Two pulls: Advance inby
Three pulls: Retreat outby
Four pulls: Distress or emergencyf. Communication with the Fresh Air Base- As the team advances, it’s important to stay in close contact with the fresh air base to report your team’s progress and to receive further instructions.
To communicate with the fresh air base, you will generally use either sound or battery-powered communication equipment. Usually one team member wears the equipment, and is responsible for sending information to the fresh air base and relaying instructions from the fresh air base to the team.
Existing underground phones, if operational, may also be used to communicate with the fresh air base.