Table of Contents
- What is an avalanche transceiver?
- Types of avalanche transceivers
- Elements of an avalanche transceiver
- How does a transceiver work?
- Can different avalanche transceiver brands be used together?
- How to use your transceiver to conduct a search?
- How to use a transceiver in multiple burial situations?
- How should a transceiver be worn?
- Some safety equipment to carry along with a transceiver
- What is a RECCO Reflector?
- Handy tips
In North America alone, of all the people caught up in avalanches, 42 die annually. 3 out of every four deaths related to avalanches are caused by asphyxiation when buried under compact layers of snow while the rest die of trauma and this is perhaps the highest statistics ever recorded. Avalanches can sweep away anyone including expert backcountry sportsmen and hikers. This is why an avalanche transceiver, also known as an avalanche beacon, is one of the most essential equipment needed for backcountry snow travel. This device can, in fact, be a lifesaver in a life or death avalanche situation.
What is an avalanche transceiver?
An avalanche transceiver is a device used to locate a victim buried under snow when an avalanche takes place. It is usually tied to the body under a layer of clothes using a harness. This device, when turned on, usually emits pulsed radio signals on 457 kHz frequency which is the international standard frequency set for avalanche beacons. In the event that an avalanche occurs, the carrier of this device sets it on a receive mode for its signal to locate that of the transceiver worn by a buried victim.
Types of avalanche transceivers
There are two main types of avalanche transceivers, the traditional analog transceivers which were used in the past and the technologically advanced digital transceivers commonly used today.
As we have already seen, these were the first transceivers ever used on an avalanche rescue mission. They feature a single antenna which when put on receive mode will locate a buried transceiver by emitting signals produced as beeps that get louder as you draw closer to the buried victim.
Within the past decade, technology has seen to the evolution of these handy devices to the digital ones that are today popular in the market. The digital transceivers, considered to be more efficient and to emit stronger signals, feature two or three antennas transmitting signals in an X and Y axis or X, Y and Z axis. This makes it much easier for them to locate a buried victim and ultimately the safest option for backcountry travelers.
They also have several microprocessors which they use to convert transmitted information into an audible and visual signal. They typically show the direction and the location of the located transceiver.
On the con, however, they usually come at a higher price tag.
Elements of an avalanche transceiver
An avalanche transceiver features the following elements:
The function of the display is to show the distance (usually in meters) and the direction of the buried victim.
The range represents the maximum distance within which a transceiver receives a signal from a buried victim and is usually stipulated by the manufacturer. While a greater range will mean that a transceiver can receive a signal from a far-off distance, this is still determined by how well it is oriented to the transmitting transceiver.
Search strip width
This refers to the diameter of the circle within your transceiver will locate the signal of a buried victim despite the orientation of the paired transceivers.
This is a scenario in which there are more than one victims buried under snow. Many manufacturers today produce transceivers which can detect more than one signals with the strongest signal being one that is closest to the receiving transceiver. These then give you the option of flagging off the signal of the victim you have already located in order to continue with your search for the remaining victims.
Most if not all transceivers are designed to be powered by alkaline batteries.
Some extra elements that you may find in specific transceiver brands include:
You may come across several transceiver brands that have been designed with an acoustic sound that will guide you to locate the transmitting device alongside the display function.
The Smart Antenna Technology allows the transceiver to analyze and adjust its signal automatically to the antenna with the best transmission. This technology is very helpful in a multiple burial situations. This technology is advantageous because it increases a transceiver range and efficiency will still significantly lowering its power requirements.
In addition to the basic distance and direction details that other transceivers display, W-Link enables additional details such as micromovements to be detected by the transceiver. This technology is found in Mammut transceivers.
This technology optimizes the transition potential of each antenna to allow the receiving transceiver to locate a buried victim much faster.
How does a transceiver work?
- Assuming that an avalanche has just occurred and all transceivers were set to transmit mode, individuals who suspect that others have been buried in the snow will switch their transceivers to receiving mode while the buried devices will continue emitting signals.
- As the buried transceiver continues to emit signals from under the snow, the receiving transceivers will detect if they are both located within the same range and are well oriented. The range of most transceivers will fall between the 30 m and 80 m bracket.
- The receiving transceiver will then translate the signal being received into an audible and visual display. The visual display gives distance and direction towards the buried transceiver, while the audible display produces sounds that adapt as the transceiver draws nearer to the buried transceiver. A good transceiver will display such data real-time thereby enhancing the efficiency and facilitating the speed with which the buried victim will be located.
- In the case of multiple burials after a victim has been located, the signal from his transceiver will be flagged off in the receiving transceiver or turned off in his transceiver to allow the receiving device to pick up other signals or direct the search party to the next buried victim.
Can different avalanche transceiver brands be used together?
Older transceivers were designed to use 2.275 kHz frequency which is no longer used today. Current transceivers have been designed to use the 457 kHz frequency which is the sole reason why they should work with each other. It is also important to note that some current transceivers, as earlier mentioned, come with an extra W-Link frequency which enhances their data transmission. However, this does not make them incompatible with the rest as they would still bear the standard frequency.
How to use your transceiver to conduct a search?
We have already seen how a transceiver works. Here we will show you how to use your transceiver to locate a buried victim. First things first, before embarking on a search you need to be sure that there is no further risk of snow or other debris resulting from an avalanche flowing down, and that you and the rest of the team are safe.
- By this time your transceiver and those of the rest of the team is set on the receive mode. Start by locating the point at which the missing person was last seen. This should be the first step to detecting the signal emitted from their transceiver.
- Move gradually towards the direction of the flow of avalanche debris from this point. Try not to miss any point by going backward and forward over and over at least at a 10-20 m distance from the starting point.
- Once your transceiver detects a signal, it is time to perform a coarse search. Try to orient your transceiver towards the strongest signal then work your way towards the victim. As you move closer, your transceiver will adapt and start producing a different sound. However, keep checking your transceiver to confirm that you are moving in the right direction since it will also indicate direction and distance in its display.
- When your gadget indicates that you are 3 m away from the buried victim, lower it down to the level of the snow as you now perform a fine search. Check your reading along two axes to identify the strongest signal and the nearest reading. At this point, you are now ready to start probing.
- Once you are sure you have got the strongest signal and the nearest distance, probe in a spiral motion marking every 25 cm. When you finally have a circle, it’s time to dig out the snow to find the buried victim. Remember that his transceiver will still be emitting signals.
- Pick up your shovel and start digging. Remember you are digging bottom-up towards your victim and it is recommended that you dig 1.5 x the burial depth dimension as indicated by your probe. This way you will have dug out something like a furrow which increases the success of finding the buried victim.
How to use a transceiver in multiple burial situations?
The process we have outlined above is a situation in which your transceiver has detected only one signal to mean that there is only one victim caught up in the avalanche. In the event that multiple victims have been buried under snow and you have a transceiver that has been outfitted to detect multiple signals and gives you the option of flagging off victims, you have already located.
Use the above process to search, probe, and find your victims although your gadget will now indicate more than one victim symbols on the screen or a specific number. If you are part of a search party, you should be able to save many victims successfully. This is by following the strongest signal on your device, performing the coarse and fine searches, probing and then flagging off this specific victim. As the rest of the team continues to shovel out the snow, you hop on to your next search whose victim should not be far off.
Don’t be mistaken though, multiple searches require more advanced and well-rehearsed search skills as well as thorough knowledge of your transceiver. You need to consider doing a higher level avalanche course.
How should a transceiver be worn?
A transceiver should be worn under one layer of clothing for the following reasons
- This will prevent them from being pulled off your body in the event that you are caught up in an avalanche.
- Wearing them deep in your pocket or putting them in your backpack will affect the efficiency with which they will detect signals.
In addition, most transceivers come with a harness used to secure it under your clothing. Others will come with a strap rather than a harness system. All the same, make sure that the controls are facing your body to make them easily accessible, something that you will find important when doing a search.
Some safety equipment to carry along with a transceiver
A transceiver on its own will not be useful when out in the dangerous backcountry slopes. Its function is merely to identify a buried victim. Beyond this, you need other safety equipment to facilitate your rescue mission in the event of an avalanche. These include:
A shovel is used to dig out snow and debris to in order to extricate a buried victim.
A rod that is stuck into the avalanche debris to find and check how deep an avalanche victim has been buried.
What is a RECCO Reflector?
These are thin gadgets, the size of a card, that are integrated on ski or snowboard gear and equipment to boost the radio signals emitted by RECCO detectors and are quite popular among search teams. They are typically used to complement transceivers in order to speed up the victim search and rescue process. Not that they should not at all replace transceivers.
- Always use alkaline and not rechargeable or lithium-ion batteries and be sure to carry extra batteries.
- Keep practicing using your transceiver. There is no amount of preparation that will equip you for an efficient rescue mission compared to regular practice. Check out for a practice area near you and use this to perfect your skill. Secondly, a transceiver will only be useful to you if you thoroughly understand how to use it.
- Before venturing out backcountry during winter, read and understand the latest report on snow conditions in the area. You will still be exposed to danger even when armed with the latest technology and expert skill. If you sense danger, it is always wise to turn back and postpone your venture for your own safety.
- Transceivers are excellent lifesavers in avalanches. However, there is no assurance that you will save buried victims. Make sure you know how dangerous an avalanche situation is before embarking on a rescue mission.
- If you have never used a transceiver before, consider taking a skills course to learn how to use it. On the other hand, if you intend to use your gadget in a multiple burial situations take a course in this regard with a certified instructor.
- Know how to read and understand an avalanche report. This includes the snow condition, wind direction, moisture, and temperature level of the snow. This should help you decide whether to go out or not. Ultimately, your safety should be the determining factor.
Winter sports are fun but the risk of being caught up in an avalanche makes them overly dangerous sports activities. We hope that this post will equip you with all the necessary information needed for you to enjoy your past time while at the same time remaining safe.