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  • Graeme Warnell

EV Fire Suppression & Environmental Risk Management Considerations for Coach and Bus Terminals

Updated: Aug 3, 2023

As I travel around the UK, I always stop to look at how we are transitioning from diesel and petrol to electric vehicles. As a keen environmentalist I always try and use public transport whenever I can. I have seen many of the UK’s bus and coach terminals transform over time, often becoming cleaner and more customer friendly.

However, when I look at the change in vehicle type from diesel to electric or hybrid, I do not see the type of infrastructure, fire suppression, environmental or public safety changes I would have expected.

I often remember the strong smell of diesel in these sites as I travelled around them by bus and coach as a student back in the 90’s. As an engineer I remember visiting these sites and sometimes almost not be able to stand up due to the diesel and oil that was underfoot in the bus and coach repair bays.

But as we have moved away from the flammable, slippery, polluting diesel did we really think its electric replacement was risk free?

In 2021 there were at least 3 recorded bus depots fires all of which caused significant or sometimes total destruction of the facility. The failure of the battery whilst under charging is thought to have caused each of the fires.

As the UK rolls out more and more electric busses and coaches the risk of these fires will inevitably increase. Vehicles and charging infrastructure will get older, our demand for faster charging puts more strain on the batteries, small bumps, potholes, speed ramps, small innocuous road traffic accidents may all be impacting the integrity of the battery.

At this point it is important to note an electric or lithium-ion battery fire is very different to a fire in a petrol or diesel vehicle:

1. Explosive gasses are released

2. An explosion typically precedes a fire

3. The fire can easily burn at up to 2000 degrees

4. The battery emits highly toxic fumes

5. The fires are notoriously difficult to extinguish

6. Thousands of litres of toxic firewater are generated

What is even more important to remember is that when an electric or hybrid vehicle is parked next to traditional diesel-powered vehicles the end result is a very complex multi class fire.

The following events are rare but as we continue with the electrification of busses incidents like this will become more common.

United Kingdom – Potters Bar 2021

An eyewitness said he heard an "unbelievable noise that sounded like a jet" and he saw a bus had "exploded into a ball of flames". The fire was believed to have been caused by a battery exploding in one of the electric buses while it was charging.

People reported that the toxic smoke cloud could be seen 18km away with local residents being told to avoid the area and keep windows closed.

A total of six buses were on fire – two electric-hybrid, and four diesel-powered.

Transport for London had to remove 108 London buses from service following the blaze, with a knock-on effect disrupting nine local bus routes.

Stuttgart – Germany 2021

A large fire event occurred in Stuttgart Straßenbahnen (SBB)’s bus depot which destroyed 25 buses on Thursday 30th September. An assessment by the police, reported that the fire completely destroyed 25 buses and 6 SSB employees received medical attention. The fire was probably caused by an electric bus during the charging procedure.

Guangxi Zhuang - China 2021

A blaze from one electric bus spread to four other buses on a university campus in southern China’s Guangxi Zhuang Autonomous Region. After just a few seconds, smoke was seen billowing out from one of the buses. Almost instantly, it exploded in a ball of fire. This caused a second bus to catch fire. The inferno then spreads to a third electric bus and before long, a fourth is engulfed in flames as well.

In the event of a fire your only current form of defence will be to call the fire and rescue services who will use well in excess of 10,000 litres of firewater to try and suppress the fire. This firewater will be highly toxic and should never be allowed to enter storm drains, sewers or the environment. If it, does you can be prosecuted. Guidance on the management of firewater is well documented so there is no excuse for not following it. The emergency services are there to fight the fire not protect the environment - that is your legal responsibility.

In addition, if your new charging points have not been included in your fire and risk assessment for the site and they impede previously determined emergency exit routes, or access to firefighting equipment the Health and Safety Executive will definitely be interested as to why.

When I visit any bus or coach depot, whether they are operated privately or by local authorities I ask myself if the owners / operators have considered the following:

1. Have I adjusted my fire safety plan in line with a lithium-ion battery fire?

2. Have I engaged with the local fire and rescue authorities for their opinion?

3. Do I need to re-assess my evacuation procedures?

4. Can the structural integrity of the depot survive this type of fire?

5. What additional structures may now be at risk due to explosion or excessive heat?

6. How do I control fire water on my site, can I isolate my drains and what retention capacity is there?

7. Is my current drainage system fit for purpose?

8. What if I cannot contain firewater on my site – where will it run to?

The list is not exhaustive, and each location will have its own unique risks and challenges. These issues give everyone a clear decision to make. Are they going to be proactive in managing risk or will they be reactive, and possibly looking back after a serious fire at all the things we could have done.

At EV-EXBOX we can help EV charging locations mitigate these risks through our pollution control and fire suppression systems. We are also here to help in the surveying of existing EV installations and to input into the development of future sites. Our solutions are designed to help the emergency services suppress fires more effectively and to reduce the risks of environmental pollution.

Most importantly however, we hope our blogs help educate the EV charging community into considering more than just getting the chargers into the ground and switched on as part of the design and construction of charging facilities.

If you would like to discuss electrical charging safety at any of your facilities, please contact: Graeme Warnell email: or call us directly on Mobile +44(0)7766107088 WWW.EV-EXBOX.COM

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