Of Car Fires and Explosions

WHILE I am not an expert on car fires and explosions, I will do my best to explain why cars catch fire after an accident. I have been getting emails from readers asking me to explain what could have happened to Genius Kadungure’s Rolls Royce Wraith.

Andrew Muzamhindo

Analyst

This has become a topical issue in Zimbabwe after the death of four individuals from the tragic accident that included socialite and businessman Genius Kadungure, popularly known as Ginimbi.

Rolls Royce Wraith is a coupe launched in 2013 at Geneva Motor Show. It is a sleek luxury machine. It has a long bonnet, 8-speed gearbox and 623 bhp horsepower. The Wraith, powered by a 6,6-litre turbocharged V-12 engine, goes from 0 to 100 km/h in 4,4 seconds. It is targeted at those in their 40s. About 70% of Wraith buyers are conquests.

The Wraith is a fastback coupe with a shorter wheelbase and wider track than the Ghost. Because of the Wraith’s more dynamic handling and appearance, the manufacturer said, “it will be a significant vehicle for us,” but would not give a projected sales split between the Wraith and the Ghost.

The brand was usually for old money and the mature — people with liquid assets of at least US$30 million. While it does some limited print ads, it primarily reaches them through dinner parties, personally signed letters from the CEO and custom-car features. Rolls Royce’s target market is part of a very elite niche.

As such, Rolls Royce does not take the contemporary approach to marketing that many car manufacturers have been known to take such as social media marketing. Usually there is a process where it is decided if the person wishing to buy it is fit or not to be its owner and, money is not the criterion.

It is now appealing to those in their 40s who are entrepreneurs and conquerors. Generally, it is not a brand for speed merchants. Those who drive a RR cruise in it or are actually chauffeur driven. They do not have to be behind the wheel for you to know that it is their car.

I will leave you to decide whether Ginimbi is the target market for RR.

Suffice to say cars do not usually explode even after accidents. To have an explosion, you have to produce a lot of hot gas in a confined space so that the gas can then go rocketing outwards.

Your best bet for that to happen is in the car’s fuel tank, since you have got petrol in an enclosed space, but it is hard to make that happen. For one, petrol by itself is not explosive. We explode it in car engines; but to make that happen the engine vaporises the petrol turning it into gas and mixes that with air before introducing the spark of flame to create the explosion. If you light a cup of liquid petrol, it will burn, but it will not explode.

On this particular accident, I have tried to get a comment from Rolls Royce head Office without success.

However, as Zimbabweans we must interrogate ourselves internally before we point our fingers to outsiders. We need to know if Ginimbi was speeding, ie, driving above the 60km/h limit required along Borrowdale road? Was Ginimbi drunk? Was Ginimbi on his mobile phone? Was Ginimbi under any form of distraction? Was Ginimbi tired from partying? If we answer “yes” to any of the above, we then are compromised. We also need to know how he managed to open his night club well after the 10pm curfew and party into the wee hours of the morning as is evident from the videos available.

We have been in touch with their South African dealership without success. We have been waiting for their responses for the past two weeks. My take is they will not get themselves involved in this accident at all. To them Zimbabwe does not matter. The market is insignificant. After all there is no RR dealership in Zimbabwe so brand damage is insignificant. As much as Ginimbi might have been popular in Zimbabwe, some countries in southern Africa and the Zimbabwean community abroad that uses social media, he was not a world figure for RR to worry about.

“There is no vehicle that is fireproof. The materials that make up any vehicle such as the rubber on the tyres, the plastics, interior carpets etc are combustible if subjected to intense heat. Cars carry fuel, (petrol or diesel) which is highly combustible. Any accident that ruptures the fuel tank may result in a fire. Transmission and other oils also burn when subjected to intense heat. All vehicle manufacturers make a conscious effort to minimise fire risk in their car designs. This includes putting heat resistant shields around components that reach high temperatures, for example, exhaust manifold, turbochargers so that they do not make contact with combustible materials,” William Sibanda, a highly qualified diesel mechanic who has worked on most leading brands, explained. He is currently in charge of aftersales at a leading auto giant in Zimbabwe

One lesson from this debacle is: our local celebrities, leaders and opinion makers need to buy cars from local dealerships. That brings some accountability whenever there is a mishap. You cannot run away from the fact that some of these cars need constant servicing. How do you justify towing a car to South Africa for service?

Will you follow the service plan religiously? Some might argue that the car will be driven once in a while, but that alone brings challenges as some fluids and materials need to be regularly changed within the car for they might deteriorate with time and become hazardous.

I shared some of the pictures from the accident with Ian Dawson a renowned Fire Engineer Consultant based in South Africa. He concluded that the RR must have been travelling at high speed and the impact was on the side of the petrol tank, the impact to the tree caused the tank to rupture and explode, not the initial impact with the Honda Fit. His observation tallies with what eye witnesses said.

Dawson said he needed more information to be 100% certain. He wanted to know how many kilometres were on the car when it exploded? How was it running before the explosion? Did the engine really blow up or did a part come flying out of it?

Petrol will not catch fire all by itself until it reaches around 280°C, so a flame must be introduced to get the petrol in the gas tank going. But to do that, you have got to punch a hole in the tank to get the flame in there, as fire will not normally travel up a fuel line to the tank because there is not enough air in the line to keep the flames going. So suffice to say there was a broken fuel line, air was introduced and a spark from impact caused detonation.

Though an explosion is unlikely, a car accident does often result in excessive heat, punctures, holes, leaks and sparks. A small fuel leak ignited by an even smaller spark can quickly claim the dry, flammable materials within a car. Some will argue that the advancements in car design have made the cabins flame retardant. This is true, but that does not mean those materials will not burn, just that they are less likely to catch fire when compared to other fabrics and plastic. A car fire can quickly heat up to extremely high temperatures that catch even the most resistant objects.

A collision propels hot pieces of metal into places they are not meant to go. Fuel lines get sheared, holes get poked in gas tanks, and sparks fly. I can imagine a scenario where a cut fuel line sprays fuel around enough to start the fire, or the seam between the fuel tank and the rest of the fuel system breaks, or metal jams through the fuel tank. It is rare for this to happen in a collision, but it is not unheard of.

The tank on most passenger cars is underneath the rear of the vehicle, with a combination of metal and rubber hoses to get the fuel to the engine — it is easy for one or more of these to become dislodged in a heavy impact, or for the tank itself to be ruptured.

Cars bursting into flames after an accident is a pretty rare event. According to these stats I got from the National Fire Protection Association (NFPA), a global self-funded nonprofit organisation, established in 1896, devoted to eliminating death, injury, property and economic loss due to fire, electrical and related hazards, only 3% of vehicle fires were the result of a collision or rollover. Almost half (49%) were the result of mechanical failure, leaks, or worn out parts. Electrical issues caused 23% of the fires.

Apparently a dirty air filter can cause a fire as well. In extreme cases, a dirty air filter may become so clogged compromising air flow through the filter. This situation poses a serious fire hazard. It becomes important to service our cars.

Foreign objects landing on the exhaust manifold can also cause a fire. Underneath the car is a catalytic converter that runs your exhaust gas through a catalyst to burn off any unburned hydrocarbons. Exhaust catalysts usually operate in the temperature range 150-600°C, but they can experience temperatures of up to 1 000°C. If you land the car on dry grass it can cause a fire.

Cars will burn if you light them up. You have got a lot of plastic and foam inside a car, and while recent standards require cars to include flame-retardant material in the passenger cabin, “flame retardant” does not mean “will not burn”. Once those materials start burning, they will burn hotly and intensely for some time.

The battery can also blow up. This would normally be caused by the battery or charging system being defective. A battery blast could happen if the battery is overcharged. Also, batteries release hydrogen — freed by electrolysis of the water — when they are being charged or discharged. If a spark ignites the hydrogen, the battery could explode.

If the wiring in a vehicle shorts and gets too hot, it can cause a fire as well. You need to be very careful when doing modifications to original wiring like when you modify a car with big stereos and extra lights that are not professionally installed.

We must conclude by noting that a large number of the deaths resulting from car fires happen because an unqualified person tries to fight the flames without the help of the professionals. It is important to mention this because it can be difficult to make decisions in a time of high stress, like this. Get yourself to safety, help the others in harm’s way, but let the car be until help arrives.

email:andrew@muzamhindo.com

Check Also

MDC Implosion Sets Back the Struggle for Change

Zimbabwe is stuck in mud. People of my generation were in their late 20s or …

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

This function has been disabled for Zimbabwe Today.