The Crumple that Saves

in #stemng6 years ago

I hate travelling in a public transport via road in Nigeria. I know hate may be a strong word. But a tour of any of my nation's major roads may convince you that I may be right for using such a strong language- the carcasses of once upon a time vehicles that litter the roadside is a macabre grim reminder that road is not as safe as it ought to be.



A crash. Image credits: By ThuePublic Domain from Wikipedia Commons, Link]

According to the first quarter report of the Nigeria Federal Road Safety Corps (FRSC) for 2018, we have 8672 victims of road traffic accident that was injured in the first quarter of 2017, and 8466 wounded in the first quarter of 2018 out of the 18230 and 18116 accidents that occurred in the first quarters of 2017 and 2018. These are the lucky ones as the number of fatalities are more than 10% of the injured; 1466 and 1292 for the first quarter of 2017 and 2018 respectively. That means we have an average daily fatality of about 15 per day for both year's first quarter. That is an incredible amount of people dying.

Part of the problem why we have this unusually may be due to bad roads and most importantly the vehicle of choice for most of our public transport sector. The transporters seem to favour Mitsubishi L300 buses and likes which has poor safety features. The Australian New Car Assessment Program (ANCAP), an independent safety information provider rated the bus 8.49 out of 37, a one-star rating for the poor performance in safety.

You may not have to take their word for it, but this collision test video shows you what will happen in the event of a crash. The vehicle, upon lacking seat belt has a terrible crumple zone.

Before we delve into what a crumple zone is, it is imperative that we check the history of it. The name Béla Barényi may not ring a bell like that of fellow inventors like Wright Brothers; the aeroplane inventors or Thomas Edison famous for his works in inventing the electric bulb and other fantastic invention. Barényi, the Austro-Hungarian Mechanical and Electrical Engineer who later worked for Mercedes Benz who has up to 2000 patents which is twice that of Edison may be the guy to make the difference between walking out of a crash or having a loved one ID you in a morgue.



Barényi Béla with a Mercedes Benz model in 1939. Image credits: By MercedesPublic Domain from Wikipedia Commons, Link]

In 1951 Béla Barényi walked out of the patent office with registered patent DBP 854.157 generally referred to as the crumple zone patent.

The crumple zone technology makes a car crumple as it cushions/absorbs the impact created when a car suddenly decelerates due to a collision. You can better understand how this works if you imagine while running and you unintentionally ran into a brick wall versus when you ran into a wall padded with a mattress at the same speed. You will feel more of the impact in the former than the latter due to the time difference between deceleration.

This behaviour occurs thanks to the fundamental laws of physics which is beautifully expressed by Newton Second Law of motion where Force F is equal to the product of mass and, i.e. F= ma.

We may already know that acceleration (a) gauges the change of velocity (∆v) which has a relationship with the mass of the object known as momentum which is expressed as m∆v. If an object has momentum, it means it will be difficult to stop it. The difficulty increases with the increase of momentum. From the formula, you can already relate that the more the mass of the object, the bigger it's momentum.

Since F= ma

and a = ∆v/t

Therefore F= m∆v/t or F∆t= m∆v

The product Ft is known as the impulse. Impulse, on the other hand, gives the relationship between the change that occurs in the momentum of an object. Looking at its formula, ft, it shows the importance of time (t) on the force that acts on an object as its momentum changes. The shorter the time of a crash, as witnessed by a sprinting crashing into a wall, the higher the damage to the body. But a sprinter that crashed into a wall padded with a mattress experiences more time between the time of impact and body coming to rest.



This Saab vehicle shows the crumple zone in yellow with the rigid passenger compartment in red. Image credits: By MarcusrooPublic Domain from Wikipedia Commons, Link]

The crumple zone was designed to reduce the severity of injury by distributing the force of collision to the vehicle through decreasing the stopping time of the car hence lessening its impulse which reduces the impact force of the crash. The passenger compartment of the car is rigid, while the crumple zone "buys more time" via a lengthening of stoppage time thereby reducing the g-force felt due to the very fast deceleration due to the force of inertia-the tendency to continue in the direction of motion.

The bumpers positioned in the front and rear of the vehicle serves the same protection, with some cars having reinforced steek sides which comes in useful in the event of a side-on collision.

Though absorption of impact through the redirection of it is a great feature, some vehicles like the Mitshibusi L300 series crumple up the point of passengers and drivers sitting in the front if there was a frontal collision.

The bulk of the commercial passenger transportation in Nigeria uses Mitsibushi Mini Bus with inferior safety features or the Toyota Hiace buses, a bus currently banned in the USA after crash testing find it unable to yield the much-needed crumple zone for the safety of passengers.


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Pretty good article. I would explain it shortly like:
The faster the deceleration the harder the hit.
If you decelerate from v= 27.78m/s roughly 60 miles/h to 0 in s= 1 metre (3.3 feet): s = 0.5*∆v/t *t² leads to t = 0.072s deceleration time. Which equals in this case 385.8 m/s² which are 39G. Normal roler coasters have up to 3G which equals experiencing 3 times the own body weight.
Now if we decellerate in 0.5 metres (1.6 feet) the G number doubles to 79G what makes it less likely to survive the impact. If the car had no crumpling zone the G-number rises extremely and that extremely loweres the chance to survive because of the high loads effecting the body.

Target is to achive a constant and low deceleration. To achive that the car companys use struts like on the left side of that picture:

They absorb most of the impact energy of a frontal crash. On the other side the passenger compartment should be very stiff in order to keep the passengers from beeing squished.

Thank you for the inclusion of the G-aspect.

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The situation is not far from the one in my Country Kenya the only bad thing is that 90% of vehicles on our roads are secondhand vehicles imported from Japan the vehicles are atleast 7 years old and are mostly low end toyotas and nissans this means they have little in way of protection and this coupled with the rampant corruption at inspection stations means that alot of vehicles on our roads are unroadworthy.
Alot of accidents are attributed to failing mechanical parts on our vehicle are the fact that large trucks share the same road with small speeding vehicles is always a recipe for disaster.
The government recently completed the construction of a standard gauge railway with funding from the ever present chinese, this was meant to ease the strain on the roads and reduce the accidents but the reluctance by the citizens to embrace this new form of transport and rather prefer the road route is really discouraging.

That's the sad reality of most developing nation.

only if we could use techmology to eradicate the scrounge

To be sincere I have never heard the word crumple zone before,

I love the way you used those formulas to illustrate the advantage of crumple zones (impulse)

When I get my car, I ll dm you to know what car has the best crumple zone ..

#safetyfirst

Nice presentation

I know most people may wonder why a car crumples during accident, I see some people say the vehicle is "not hard", without knowing it was part of protection.

Posted using Partiko Android

I must say this the first time I am learning about the term 'crumple zone'. Thought seat belt was the all in all during car crash.

You are so right with the condition of the road over here. Most times traveling is like hell. It is now a routine thing for me after travelling for a long distance through land, I must take pain killer to suppress the headache and pain accompanying it.

Most drivers run as if the vehicle is on air, especially the inexperienced ones.
Though most transport companies now install speed limit devices so as to keep their drivers in Check, peace mass transit, GUO are few of the ones that maintain this standard.

Traveling by land though has it own advantage in terms of survival during accidents, but in the case of travelling by air, you hardly hear of any survival.

I think we need the speed limiters installed in more of these buses as they are mostly made for metropolitan transportation and not all these freeway high speed travelling. It's crumple and not crample :)

If only our commercial buses would have these safety features, the number of death caused by accidents would be reduced (imagine that the majority of the commercial buses here are the L300). It only seem they care less about human lives; and this is too bad. And coupled with our not-too-good roads, it's just awry.

Nice piece again buddy

It's a sad situation. I guess they don't care enough since they don't ride in one.

I really enjoyed reading this..we do have a lot of bad roads in Nigeria but some of them are caused by people who dont make drainages jn front of their homes or buildings which could cause erosion and which could cause the roads to turn bad.
However there are places the government themelves have ignored to fix and also speed limits should really be followed and bumpers as well. Some individuals will never slow down unless they see a bumper and some are so blind they just speed on and only notice it when they hit it. Car accidents happen alot but it shouldn't make you stop travelling by road, no where is completely safe wothout God's protection.
First time I'm hearing crumple zone and am glad to have finally known it, i cant believe i have never heard of Bela Barenyi till now unlike edison and the rest. The world should know this man

That goes to show you that not all heroes wear capes :)

I know you know already but you're very good.

Using the word hate for Nigerian roads wouldn't been a strong word for someone who have seen and rode on it. I keep postponing a journey just because I don't want to get on that road and avoid seeing accident scene which is not uncommon to come by.

I've thought how dangerous it is for vehicles without safer crumple zone couple with the fact that majority don't use seat belts. I never knew there was a real explanation for that. Thumbs up to Barényi, one of the great heroes who have saved many lives yet his name his not so mentioned on the lips of many.

Thanks a lot for contributing to the conversation. Barényi Béla's contribution to a safer road transportation is very important and lifesaving.

Hello @greenrun

Before reading this, I have occasionally wondered why crashes involving the above mentioned businesses would always result into a lot of deaths, to the extent that, for me, it is either a luxurious coaster bus or nothing. And I have been practicing this strict decision since the event of my accident.

I can see the the countries where the leadership values human life have already taken practical steps against all these moving deathtraps in the name of vehicles, while Nigeria leadership are yet to take any concrete step against these vehicles. Such a pity!

The crumple zone was designed to reduce the severity of injury by distributing the force of collision to the vehicle through decreasing the stopping time of the car hence lessening its impulse which reduces the impact force of the crash.

That's noteworthy.

Regards

@eurogee of @euronation and @steemstem communities

The lack of seatbelts in these mini buses increases the risk. Sadly our regulatory bodies do not care enough to insist on compliance.

Posted using Partiko Android

Yes, exactly.

The stats by FRSC is simply heartbreaking. I am lookin at the content of this article, I must confess right now I am scared to the marrow to embark on road trip in the future. God help his children.

@sciencetech
STEM contributor

We can only help ourselves through proactive measures, for instance by using bigger buses for our long distance journeys.