RI 9686 

REPORT OF INVESTIGATIONS/2011 

SUPPLEMENT 

Radio 101: 

Operating Two-Way Radios 

Every Day and in Emergencies 

Student Handbook 

Department of Health and Human Services 

Centers for Disease Control and Prevention 

National Institute for Occupational Safety and Health 
 

 

 

 

 

 

 

 

Student Handbook 

Radio 101: Operating Two-Way Radios Every 

Day and in Emergencies 

Catherine Y. Kingsley Westerman, Michael J. Brnich, Jr., 

Carin Kosmoski 

DEPARTMENT OF HEALTH AND HUMAN SERVICES
 Centers for Disease Control and Prevention
 

National Institute for Occupational Safety and Health
 

Office of Mine Safety and Health Research
 

Pittsburgh, PA • Spokane, WA 

August 2011 
This document is in the public domain and may be freely 

copied or reprinted. 

Disclaimer 

Mention of any company or product does not constitute endorsement by 

the National Institute for Occupational Safety and Health (NIOSH). In 

addition, citations to Web sites external to NIOSH do not constitute 

NIOSH endorsement of the sponsoring organizations or their programs 

or products. Furthermore, NIOSH is not responsible for the content of 

these Web sites. 

The findings and conclusions in this report are those of the authors and 

do not necessarily represent the views of the National Institute for 

Occupational Safety and Health. 

Ordering Information 

These materials and other mining safety materials can be downloaded 

from the NIOSH website at www.cdc.gov/niosh/mining. 

To receive documents or other information about occupational safety and 

health topics, contact NIOSH at 

Telephone: 1–800–CDC–INFO (1–800–232–4636) 

TTY: 1–888–232–6348 

e-mail: cdcinfo@cdc.gov 

or visit the NIOSH Web site at www.cdc.gov/niosh. 

For a monthly update on news at NIOSH, subscribe to NIOSH eNews by 

visiting www.cdc.gov/niosh/eNews. 

DHHS (NIOSH) Publication No. 2011-203 

Included as Supplement to RI 9686. 

August 2011 

SAFER • HEALTHIER • PEOPLETM 
Contents 

Types of Radio Traffic ....................................................................... 1
 

Routine Traffic ............................................................................... 2
 

Issues with Basic Use of Mine Communications Systems....... 2
 

How to Use the Radio............................................................... 4
 

What to Say .............................................................................. 4
 

How to Say It ............................................................................ 4
 

Tips for Using Your Radio on a Daily Basis ............................ 5
 

Emergency and Mayday Traffic .................................................... 7
 

Issues with Emergency Use of Two-Way Radios .................... 7
 

What to Say .............................................................................. 8
 

How to Say It ............................................................................ 9
 

Tips for Using Your Radio in an Emergency .......................... 10
 

Wireless Communications Systems ....................................... 11
 

References ...................................................................................... 13
 
1

Student Handbook
 

Radio 101: Operating Two-Way Radios Every 

Day and in Emergencies 

Types of Radio Traffic 

When learning how to use the radio, it is important to know that 

there are three types of radio traffic. These include: 

Routine traffic – the regular, daily radio traffic one would 

hear on the mine radio including basic emergencies such as 

an injured employee, but whose injuries are not life 

threatening. 

Emergency traffic – radio traffic about an emergency 

situation (e.g., a miner with a fractured arm or the loss of 

ventilation on a working section). In these situations, a 

miner would call out that they have emergency radio 

traffic. Then the dispatcher or communications person 

would clear the airways for this person to state the problem. 

Mayday traffic– describes radio traffic when a major mine 

emergency occurs (e.g., explosion, fire) or someone is in 

danger of death (e.g., heart attack, pinned by machinery or 

roof fall). The term ―Mayday‖ is repeated three times, 

―Mayday, Mayday, Mayday‖. In this case the dispatcher 

should respond by asking all other traffic to cease, except 

for the Mayday traffic. 

The handbook is presented in two sections: 

routine traffic (or basic use) 

emergency and Mayday traffic 

Note: Your mine may have different designated terms for each type 

of radio traffic; if this is the case, then you should use those 

designated terms. 
Routine Traffic 

Issues with Basic Use of Mine Communications Systems 

According to a group of miners who were asked about using radios 

in a mine, the radio is easy to use—―you just push the button and 

talk.‖ However, in the past there have been some difficulties 

associated with using radios to communicate. When we asked 

miners, they noted the following problems that can occur when 

using the communications systems in mines on an everyday basis: 

Miners underground do not always call out when there is a 

problem, such as when the carbon monoxide (CO) alarms 

go off. 

Finding radio units with dead batteries, which then cannot 

be used. 

People not answering the phone on the sections. ―They can 

hear it; they just ignore it. In fact, the dispatcher will page 

them again and say  ̳there‘s not work involved, answer it!‘‖ 

o	 One story shared was about someone‘s child who was 

injured in a car accident. No one inside the mine would 

answer the phone because they thought there was work 

to do. They had to announce the message about the 

accident over the airwaves to get the father‘s attention 

to answer the phone. 

The lack of good maintenance on the system. For example, 

if someone is loading supplies and hits a communications 

cable, it needs to be fixed. 

People chattering on the line so when it is really needed it 

is not available. 

People inadvertently or unknowingly holding down the mic 

button so the line is busy, such as when the radio is in 

someone‘s pocket. 

People not knowing what signals mean. 

2
 
o	 For example, at a mine that has a pager system that 

flashes different lights for different messages, miners 

did not know the meaning of each different light signal. 

People not remembering to keep portable radio units with 

them as they move around the mine and forgetting to bring 

them back. 

o	 One miner reported his mine had lost 50 units in the 

mine within a six-month period. 

Maybe you can think of similar problems at your own mine! The 

goal of this training is to teach you some ―rules of the radio‖ that 

can improve the efficiency and effectiveness of the radio in a mine. 

3
 
How to Use the Radio 

Push and hold the transmit button before starting to talk. 

Wait a few seconds before you start talking. 

Hold the radio 3–4 inches away from your mouth. 

Do not yell into the radio. 

Speak slowly and clearly. 

Remember only one person can talk at a time. 

o	 Simultaneous communication will cancel each talker 

out, and both talkers will be unaware that their 

messages did not go through. 

What to Say 

Message Content 

o	 Communicate where you are and your request/problem. 

o	 Use location identifiers (e.g., Crosscut 23). 

o	 Know what you want to say before you press the 

transmit button. 

How to Say It 

4
 

Be brief and efficient: 

Reduce the use of air time as much as possible. 

o	 Keep the length of the transmission to a minimum. 

o Communicate essential information only. 

Use this standard protocol for speaking: 

o	 Sender: ―Hey Fred, it‘s me George.‖ (receiver‘s name 

first, then yours) 
o	 Receiver: ―Go ahead, George.‖ 

o	 Sender: State the message (only pertinent, specific 

information). 

o	 Receiver: Repeat the information back. 

o	 Sender: Correct or confirm the information. 

o	 Receiver: Simply states what will be done (e.g., ―We‘re 

sending Engine 1, estimated time of arrival 4 minutes‖). 

For example: 

o	 Section mechanic: ―Hey, Fred, this is Mike on F20 

Panel.‖ 

o	 Maintenance foreman: ―Go ahead, Mike.‖ 

o	 Section mechanic: ―Fred, I need five water spray 

nozzles for the continuous miner and three shuttle car 

cable splice kits.‖ 

o	 Maintenance foreman: ―Okay, that‘s five water spray 

nozzles for the miner and three shuttle car cable splice 

kits, correct?‖ 

o	 Section mechanic: ―Yes, that‘s correct.‖ 

o	 Maintenance foreman: ―Okay, Mike, I will bring them 

when I come to F20 Panel in about an hour.‖ 

Tips for Using Your Radio on a Daily Basis 

Politeness does not matter; efficiency is more important. 

o	 You do not have to say ―please‖ and ―thank you.‖ 

Avoid jargon and codes. 

Use established protocols for identification, 

communication, and signoff.
 

o	 Repeat back what you heard to ensure you have 

understood the message being sent. 

5
 
Be brief, listen, speak slowly and clearly, acknowledge 

receipt of information. 

o	 Brevity is important, but messages must be relayed 

verbatim. 

Only transmit relevant information.
 

Keep the radio with you at all times as you move around
 

the mine.
 

Be aware that, in addition to the intended audience, other 

people may overhear your message. 

Limit your talking to essential communication to avoid 

―clogging‖ the line or ―overtalking.‖ 

o	 Do not have personal or casual conversations on the 

radio. 

o Do not talk too much.
 

Do not swear or shout.
 

Many wireless systems are line-of-sight. If possible, move
 

to transmit line-of-sight to the next radio.
 

Antennas can be easily damaged; protect them as much as 

possible.
 

6
 
Emergency and Mayday Traffic 

Issues with Emergency Use of Two-Way Radios 

Miners and mine rescue experts were asked about using radios in 

emergency situations. These individuals shared their thoughts and 

ideas on emergency radio use including problems they have 

encountered. Here are some of the topics that were discussed: 

There tend to be different interpretations of the term 

―emergency‖. Though the miners said there are true 

emergencies, such as life-threatening injuries, fires, and so 

forth, they also said there can be production emergencies. 

While miners contend they do not have a problem using 

radios during true emergencies, they find operators tend to 

treat production emergencies with the same urgency. 

When an emergency occurs at a mine, there can be an 

inundation of radio traffic over the airways. Personnel 

outside in the communications or command center are 

trying to get information about what is happening. 

Likewise, miners are trying to find out as much as they can 

about the situation. 

When there is an emergency, people sometimes talk over 

each other. This occurs when someone is talking on the 

radio and another person on the line will try to talk at the 

same time. When this happens, neither message gets 

through. 

Some radio communications systems may not be reliable. 

Therefore, some miners do not have confidence that the 

radio communications system in place at their mine will 

work when they need it. 

Depending on the type of radio system in place, there can 

be problems with limited transmission distance. Depending 

on the system and how it is set up, there can be ―dead 

spots‖ (where communications are unavailable) in certain 

7
 
locations in the mine. There can even be problems 

transmitting from one entry to the next. 

What to Say 

It is important to know how your radio works and how to 

physically use it. This was covered in the section ―How to use the 

radio.‖ In addition to this knowledge, it is equally important to 

know what information to communicate during an emergency. 

Most messages will consist of: 

Orders and instructions to perform tasks for controlling the 

situation. 

Reports about the conditions and progress encountered. 

Requests for additional resources to fulfill assigned tasks. 

8
 
Here is what to say during an emergency. 

Ask for radio waves by saying ―Emergency traffic‖ or 

―Mayday, Mayday, Mayday‖ (or the codes designated by 

your mine). 

Tell the receiver of your call WHO you are. 

Tell the receiver of your call exactly WHERE the problem 

is located. 

Tell the receiver of your call WHAT is happening at the 

scene of the problem. 

After this, give the details of the situation including: 

o	 MINERS: details about the miners involved (e.g., ―Two 

miners are hurt.‖) 

o	 EVENT: details about the event (e.g., ―The miners are 

pinned under a roof fall.‖) 

o	 RESPONSE: details about the response that is 

occurring (e.g., ―We‘re trying to get the rock off of 

them.‖), how many people are there, what equipment is 

there and/or needed. 

If you will be bringing someone out of the mine, ask the 

dispatcher or communications person to clear all vehicle 

traffic to allow you to exit the mine quickly. 

Note that these instructions on what to communicate 

correspond to the NIOSH Emergency Communication 

Triangle [NIOSH, 1999]. 

How to Say It 

After stating ―Emergency traffic‖ or ―Mayday, Mayday, 

Mayday,‖ follow the same protocol for speaking as you 

would on a daily basis. 

9
 
Tips for Using Your Radio in an Emergency 

Every message must be clear, concise, and timely. 

Provide regular status reports or updates about the incident. 

Timing of updates: 

o	 Community emergency responders suggest the first 

progress report be given about 10 minutes after the 

initial report. 

o	 For the next hour of the incident, provide an update 

every 10 to 15 minutes and whenever a significant 

escalation of operations occurs. The transmission of 

additional alarms would be defined as escalation and 

would require the Incident Commander to inform the 

communications center of the reasons for this additional 

response. 

10
 
Wireless Communications Systems 

Following are some simple tips for users of these systems. For 

detailed information on the components of these systems and how 

they work, see NIOSH‘s Tutorial on Wireless Communication and 

Electronic Tracking, which is located at: 

http://www.cdc.gov/niosh/mining/topics/electrical/commtrackingtu 

torial/commtrackingtutorial.htm 

Leaky Feeder 

Leaky feeder communications systems use two-way radios and a 

special antenna cable called a leaky feeder. The cable runs from 

outside the mine (surface) to all working sections (underground). 

The main control, called the ―head end,‖ is located on the surface. 

At predetermined locations along its length, the leaky feeder has 

signal amplifiers (boosters) designed to help maintain signal 

strength. Communication in a leaky feeder system goes through the 

head end. Depending on the individual mine, a leaky feeder system 

may have one or more lines into the mine. 

Assuming there is only one line in and out of the mine, if there is a 

break in the line, miners on the side of the break away from the 

head end will not be able to communicate even with other workers 

on the same side of the break. In other words, if there is a break in 

the line, anyone inby the break will not be able to use the system. 

However, if there is an additional alternate line into the mine, then 

miners inby a break in one line may be able to move to the 

alternate line and communicate through it. 

Handhelds for this system sound a warning tone if two devices are 

keyed at the same time. 

Medium Frequency (MF) 

Compared to other communications systems, medium frequency 

systems depend much more on the environment to work, such as 

through the pager phone wire, water pipes, power lines, etc.). 

There must be metal available in the mine for the signal to travel. 

11
 
Medium frequency has a delay of 1–2 seconds (or more depending 

on how far the signal has to travel). If two radio mics are keyed at 

the same time on an MF system, the message may not go through, 

and there is no way of knowing and no warning that both sides 

tried to communicate at the same time. 

Through-the-Earth (TTE) 

The antenna for this system is a long, looped wire. In general, the 

bigger the circle enclosed by the antenna, the better reception you 

will get. 

TTE is a slower system with less bandwidth—most likely there 

will only be text communication when using this type of system. 

This system is susceptible to interference. TTE would most likely 

be used as an emergency backup system only. 

12
 
References 

NIOSH [1999]. The emergency communication triangle. By 

Mallett LG, Vaught C, Brnich MJ Jr. Pittsburgh, PA: U.S. 

Department Of Health And Human Services, Centers for Disease 

Control and Prevention, National Institute for Occupational Safety 

and Health, DHHS (NIOSH) Publication No. 99–157. 

http://www.cdc.gov/niosh/mining/products/product34.htm. 

13
 
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To receive NIOSH documents or more information about 

occupational safety and health topics, contact NIOSH at 

1–800–CDC–INFO (1–800–232–4636) 

TTY: 1–888–232–6348 

e-mail: cdcinfo@cdc.gov 

or visit the NIOSH Web site at www.cdc.gov/niosh. 

For a monthly update on news at NIOSH, subscribe to 

NIOSH eNews by visiting www.cdc.gov/niosh/eNews. 

DHHS (NIOSH) Publication No. 2011-203 

SAFER • HEALTH IER • PEOPLETM