How long can you hold your breath underwater? | ERGT
11 September 2019
How long can you hold your breath underwater?
CA-EBS and Offshore Helicopters: An Introduction
Safety has always been top of the agenda for all industries, including those that heavily rely on helicopter transportation. A lot of consultations and policy work has happened in the UK/Europe to bring in advanced safety devices for such risky commutes. One such introduction has been the Compressed Air Emergency Breathing System (CA-EBS). This system greatly improves the chances of survival compared to the air pocket re-breather, also known as an Emergency Breathing System (EBS). Historically offshore helicopter travel in Australia has relied on the passenger’s ability to deploy their air pocket re-breather system before submersion or purely holding their breath. The CA-EBS can be deployed quickly, easily with one hand-purge, breathing off the unit while stationary and moving underwater.
Improving Survival Rates
Impact injury is the main primary cause of fatality in uncontrolled water impact accidents, whereas it is drowning in the instance of potentially survivable water impact. The book ‘Handbook of Offshore Helicopter Transport Safety’ reports on the accident near Cormorant Alpha platform in the North Sea. The book comments on the ability of the occupants to take a breath of air before head submersion when water ingress was rapid. Occupants who were at the front didn’t survive, and those at the rear had a chance to take a deep breath (AAIB, p.28). It highlights the fact that an EBS could minimize fatalities. The impact of low water temperature in reducing breath-hold time considerably is also an important factor.
CA-EBS is believed to improve survival rates. During a submersion, a helicopter can go straight down from 100mph to 0mph in a matter of seconds. Research shows that provision of an underwater breathing device gives adequate time to act appropriately (Ryack et al.,1986, p.608).
It is safe to assume even if the re-surfacing happens from depth with a CA-EBS, survivability factor increases vs. not having a suitable breathing device to survive underwater.
The CA-EBS is also believed to reduce the sense of urgency vs., breath-holding and re-breather, which in turn minimizes the difficulty and less cognitive loading. These findings are recorded in research (The effect of emergency breathing systems during helicopter underwater escape training for land force troops) conducted with Canadian troops in a simulated HUET training. Out of the participants 58% successfully escaped to the surface and 100% managed with a CA- EBS. (McCabe et al.,2009).
Importance of Training
Proper training is essential as it facilitates understanding the nuances of the gear. The potential risks of deploying CA-EBS underwaters, such as decompression sickness and lung inflation should be considered.
These risks can be mitigated through robust and in-water training, allowing the user to deploy with ease and with speed. OPITO recognises the importance of practical hands-on training. In the interest of helicopter safety they’ve recently introduced practical CA-EBS in water activities. These activites are now an option throughout the FOET, TFOET, BOSIET and TBOSIET courses. The CA-EBS in-water activities now allow the user to deploy with both hands, purge and breathe off the CA-EBS system while underwater.
Improvements For a Safer Future
This introduction of the in-water CA-EBS exercises could be seen as nothing but a positive step in the right direction for improving the safety of men and women who travel by helicopter to work every day. Since 2009, six helicopter accidents have occurred that resulted in 33 deaths and needed 65 others rescued. We all should work together to keep striving for best in class safety for those who put their lives in great danger.