Involving hundreds of vehicles containing tens of thousands of litres of hydrocarbon fuel (say 80GJ worth) and perhaps 250 tonnes of combustible plastics (say 2TB)?
Yes plenty ofenergy there.
Let's disregard the politics and the lobbying and look at the bare objective scientific facts.
We have a precedent in the Liverpool ECHO Arena Fire of 31 Dec 2017. We have the Fire Brigade Report into that matter. This gives us a point of comparison.
In the Liverpool car park fire, the culprit was a diesel-only Range Rover.
16:29 first signs of smoke on CCTV
16:42 first call to Fire Brigade
16:43 first fire alarm activated x 2 extinguishers applied
16:45 Event (horse show) fire-fighting team arrive
16:56 external fire-fighting begins
17:08 first BA team fire fight from stairwell 2 into level 3
17:40 BA crew reports up to 30 vehicles running rows of burning fuel between two rows of cars
17:52 CCTV shows first sign of flames from level 4 above intial level 3 fire
18:07 first BA team committed from stairwell level 1 to level 3. ‘Fire confined to two rows of vehicles, away from ramps’.
18:20 All BA crews withdrawn from stairwells 2 and 3 due to ‘untenable fire conditions’.
18:38 Emergency evacuation of all teams due to firefight safety issues.
Time taken for the Liverpool car park to develop into a major fire:
Two hours nineteen minutes from when smoke first noticed to fire teams having to withdraw. Alternatively, one hour 56 mins from when first call made to Fire Brigade (999).
Let’s call it two hours for simplicity. 1,150 vehicles lost car park full due to equestrian event. The car park had to be demolished. Structure unsafe and collapsing from the centre - safe enough for firemen to stand around the outside of each level.
Ultimate cause of Liverpool car park spread:
“CCTV footage shows that the fire started in a vehicle on level 3. Attending fire crews reported rapid lateral fire spread, running fuel fires, vertical fire spread from level of origin and a “waterfall” of fire from the ceiling of level 3. It was initially thought that fire spread was via the central ramps, but upon further investigation it is considered that the drainage system was the likely cause of vertical fire spread.” Merseyside-FRF-Car-Park-Report.pdf
From a fire safety research paper of 1968:
Running fuel fires, due to failure of plastic fuel tanks, in early stages of vehicle fires can be expected. It is estimated 85% of European vehicles have plastic fuel tanks.
Sprinklers are effective in both controlling a developing and fully developed fire. Without sprinklers fire is likely to spread from car to car and dangerous levels of smoke are likely for long periods (BD2552 p.46). Designers should seriously consider sprinkler provision to avoid multiple vehicle fires, resulting in huge insurable losses and the possible loss of life. Fire may spread beyond floor of origin. In the case of Kings Dock evidence would suggest that this was initially through the failure of the drainage system. Designers should give serious consideration to the implications of drainage design that could aid fire spread between levels
1968 research shows ““The experimental work carried out…..confirms the fact that an outbreak of fire, within a single parked car, is unlikely to result in uncontrollable fire spread in the car park or in serious damage to the structure of the building.”
So
nota bene that the Liverpool car park fire was due to a fuel leak which due to an electric fault caused burning and this burning fuel spread from car to car along two rows, initially, but owing to the sloping floor designed for drainage, the burning fuel seeped into other floors.
So conclusion: fuel leak, burning fuel spreading to other cars then onto other floors. Firefighters able to work from the stairwells for at least two hours trying to extinguish it.
Fast forward to the Luton Fire:
First call to the Fire Brigade 999 was at 20:47
21:38 Major incident declared.
Firefighters tackling the intense blaze from
outside the building, unlike at Liverpool.
'Major incident' within 51 minutes - half the time of the Liverpool fire.
As can be seen in the video posted earlier, a lithium car battery fire explodes outwards at high temperature and its contents flare out as projectiles for several metres, thus no fuel line leak required. Concrete floors collapsed quickly.
On the other hand, Luton had no sprinklers as was recommended and was made of uncoated steel that become ductible at circa 500°C, when Liverpool car park was made of concrete.
Conclusion suggests this may not be an ordinary ICE car fire involving the usual fuel leak and electrical fault.
AA technical expert Greg Carter said the most common cause of car fires is an electrical fault with the 12-volt battery system.
He added that diesel is “much less flammable” than petrol, and in a car it takes “intense pressure or sustained flame” to ignite diesel.
https://www.itv.com/news/anglia/2023-10-11/fire-service-chief-cause-of-luton-airport-car-park-fire
This is why it is not possible at this stage to 'confirm' that the fire was definitely caused by a diesel-only powered car because it doesn't explain the super rapid spread and intensity of heat that kept the fire brigade external to the building.
