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Plus Test (English)

Vti

An invitation to visit Vti in Sweden is a dream come true for everyone with an interest in childrens´ safety in cars. Vti performs the world´s toughest crash test to measure loads in the head and neck in child car seats – the so-called Plus Test. Vti also performs compnonent testing as well as the ECE R 44 compliance testing.

Plus test and the T-Standard Test

An invitation to visit Vti also means meeting one of the world´s leading experts in the field of child safety in cars: Tommy Pettersson. Tommy developed the Plus Test as well as its´ predecessor – the T-Standard Test, which also measured the loads in the head and neck starting in 1975. That´s about 8 years prior to the introduction of the ECE R 44 approval testing which was introduced in 1983. The basis of the T-Standard and the Plus Test is VVFS 2003:29  Bilaga 2 . In other words, the Swedes performed crash tests on car seats since 1975 and thereby long before everyone else did. The T-Standard Test became a supplement to the ECE R compliance testing in 1983 as head and neck loads were not and is still not meassured in this test. The first rearfacing car seat ws introduced in Sweden in 1967.

The T-Standard Test was altered a bit and renamed Plus Test in 2008, as the T-Standard Test was found to be very disortive by the EU and had to be dismissed. The T-Standard was mandatory and no forward facing car seat could pass. They still can´t.

Plus Test is divided into two groups: 18 kg/40 lbs and 25 kg/55 lbs. and is voluentary. This way the Swedes can keep the double marking on child car seats.

Plus Test is carried out at 56 km/h.

Plus Test maximum loading in the neck

18 kg (Q3 test dummy 14½ kg): 1220 Kg newton = 122 kg pull load.

25 kg (Q6 test dummy 22,9 kg) 1640 Kg newton = 164 kg pull load.

The limits used in the Plus Test have been found via reconstructing thouands of real road accidents throughout the years – all carried out by Volvo.

Installation of the seats happen according to the user guides made by the manufactorers. However, sometimes the manufactorers will ask to have their seats tested in an alternative way that might not be in the user guides. This is granted for as long as the installation methods do not deviate from the ECE R 44 child seat regulations.

 

This way a child seat can be tested not using the footprop and installed leaning on the steel tube on the test rig, which represents the dash board in a car or a frontseat. 

 

Test results cannot be transferred directly to a car, because the dashboard and the front seats are softer than the steel tube on the test rig. But the results are still very trustworthy and usuable in real life accidents as the testing methods are  constructed completely according to findings in the reconstructions of real car crashes.

 

Plus Test is carried out with a very advanced test dummy series: The Q-dummy series. The frontal collision in the ECE R compliance test is carried out at 50 km/h (35 mph) with a somewhat less advanced dummy series: The P-dummy series.

Neck loads are not measured in the ECE R testing.

Why measure neckloads?

Everything in the car moves towards the point of impact with the speed the car was travelling at prior to the impact – particulary in frontal impacts. It is the isofix system or the car seat belt that stops the child seat. The child seat´s restraining system, which will be a 5-point harness or an impact shield, stops the child´s body after that. Then the head is stopped by the neck. Last but not least, the brain is stopped by the skull.

The neck consists of 7 neck vertebraes. The nerves gradually merge into the spinal cord, which is protected by the spine itself. In other words the higher, the more nerves in the spinal cord. All the nerves connect to the brain in the C1 neck vertebrae(upper part of the neck). The lower neck region is between C4-C7 neck vertebraes. The spine itself is connected to the skull and not the brain. The brain floats in cerebral fluid, which offers protection to the brain in case you hit your head – keeping it away from the skull.

The neck, spine, spinal cord and the nerves are all elastic. All of it can stretch up to 5 inches. But it only takes ¼ of an inch for it to break and injure the spinal cord as well as the nerves in it.

In a forward facing car seat it is the neck that stops the head. In a rearfacing car seat it is the shell of the car seat that stops the whole upperbody at once and in alignment. The loads in the internal restraining system is much less that way in rearfacing seats than forward facing seats. This shows clearly below.

Seats with with impact shield:

VTI have tested the first seat with impact cushion.

The seat was tested with the Q3 dummy and the resulting neckloads mounted to 1974 Kg/Newton = 197,4 kg = 434,5 LBS. The maximum neckloads for the Q3 dummy in the Plus Test are: 1220 Kg/Newton = 122 kg = 268.4 LBS. The resulting neckloads in this seat are much too high, and the seat DID NOT pass the Plus Test.

 

The manufactorer has complained about this test stating that it was not correctly carried out. THAT it was indeed; The Plus Test carried out on this seat was somewhat milder than would have been the case with a rearfacing seat. What this means in terms of loads on the neck, is that this number would have been somewhat higher if the test had been carried out like it normally would have been.

The seat got a high score in the big child seat consumer test issued each year, where the neckloads were deemed low.

Tommy Pettersson interview about the impact shield seat test (in Swedish)

Plus Test af kollisionspudestol/Shield seat

 Plus test af kollisionspudestolen – Svensk Artikel

VTI installation of the seats

Installation of the seats happen according to the user guides made by the manufactorers. However, sometimes the manufactorers will ask to have their seats tested in an alternative way that might not be in the user guides. This is granted for as long as the installation methods do not deviate from the ECE R 44 child seat regulations.

 

This way a child seat can be tested not using the footprop and installed leaning on the steel tube on the test rig, which represents the dash board in a car or a frontseat

 

Test results cannot be transferred directly to a car, because the dashboard and the front seats are softer than the steel tube on the test rig. But the results are still very trustworthy and usuable in real life accidents as the testing methods are  constructed completely according to findings in the reconstructions of real car crashes.

Link to the list of seats that have been tested and meet the T-Plus Standard.

Plus-tested stole/seats

My visit at Vti

So I´m one of those who have had that dream for a long time despite having spoken with Tommy Pettersson on the phone about a year ago. Suddenly I received a phone call and an email from Besafe Denmark asking me if I wanted to join them on a visit to Vti in Sweden in only 5 days! It was Besafe Norway that contacted Besafe Denmark a while ago (a massive thank you to Victoria once again). Furthermore, Besafe Denmark have followed Sikkerautostol.dk for some time. Another blogger Kristian Konne – owner of Autostol.dk had kindly forwarded my phone number to them (secret due to a lot of commercial calls). It appears that my email spam filter is a little overactive having sent several mails from them straight to the spam folder.

The journey started with a long bus ride at about 11.30 am to app. 6.30pm with just one 45 min. long break at Godisflyget. Staff from babygear shop chain Ønskebørn were with us.

We stayed at a very decent hotel in an idllyic area of Sweden just about 1 hour drive from Vti in Linkjöping.

VTI besøg

 

Our only complaint was that the neighbor was a church and not a pub. BUUT we forgot that quickly being busy talking about car seats and private talk.

VTI Kirken

 

Swedish scenary

VTI svensk natur

 

Swedish sunset

Svensk solnedgang

 

The delegation:  Besafe,  Autostol.dk, Ønskebørn and Sikkerautostol.dk (behind the camera)

VTI Delegationen

 

The evening was spent eating very tastefull homemade Swedish food. After that it was time for a lecture by Besafe. Subjects that were touched were: ECE R 44 regulations and compliance testing, ADAC, I-Size regulations and Plus Test . This explains the reason that the entry about Forbrugertests has not been changed one bit. The different types of car seats was also touched. O the blog entry about Impact shield vs. rearfacing has not been changed one bit either.

 

After that it was time for some fun The Danish way. Most of us slipped at around 12.30am. We had to get out of bed early the next day and leave for Vti.

The first thing that we saw was the test track at Vti. This is the track and sled where all the car seat tests are carried out. It is not easy to see, but the test rig weighs app 1200-1300 kg (2400-2600 lbs)

VTI Slæde

 

VTI testbane

 

My knowledge about car seats is very extensive. However, it is bleak in comparison with the knowledge og this man:Tommy Pettersson (the one in the suit)

Tommy Pettersson

 

Rudolph was there too

VTI Rudolf

 

This overdimensional helmet is supposed to be the haed that small children have. It is there for people to try in order to find out just what it feels like to have a head that is overdimensional in relation to the rest of the body and weighs app. 25% of the total bodymass. The head on small children is very big and it´s weight comprises 25% of the total weight of the child. I don´t how much the helmet weighs for sure, but Vti used to sell heads (Yes, really!!) Manaquin heads, which I happen to own. The weight and size of the big head equals the average size of  adult person weighing 75 kg (165 lbs).

The full table from Vti. The weight indications are average and may vary a bit from one person to the next. However, the percentages are not average.

Newborn

Bodyweight: 3,4 kg. (7½lbs)

Weight of head: 0,7 kg. (1½lbs)

Weight of head in %:  20,6 % 

9 months

Bodyweight: 9,0 kg.(20lbs)

Weight of head: 2,2 kg.(4,4lbs)

Weight of head in %: 24,4 %

18 months

Bodyweight: 11,0 kg.(24,2lbs)

Weight of head: 2,7 kg.(6lbs)

Weight of head in %: 24,5 %

3 years

Bodyweight: 15,0 kg.(33lbs)

Weight of head:  2,7 kg.(6lbs)

Weight of head in %: 18,0 %

6 years

Bodyweight: 22,0 kg.(48,2lbs)

Weight of head: 3,5 kg.(7,7lbs)

Weight og head in %: 15,9 %

10 years

Bodyweight: 32,0 kg.(70,4lbs)

Weight of head: 3,6 kg.(8lbs)

Weight og head in %: 11,2 %

Adult male

Bodyweight: 75,0 kg.(165lbs)

Weight of head: 4,5 kg.(9,9lbs)

Weight of head in %: 6,0 %

 

Helmet weight calculation

Head + helmet: 75 kg(165lbs) – 25% = 18,75 kg.(41,2lbs)

The helmet: 18,75 kg(41,2lbs) – 4,5(9,9lbs) = 14,25 kg(31,4lbs)

No wonder that small children walk with their legs spread and the legs are unstable. I think all of us did the same thing. But don´t worry, the helmet is attached so no-one falls anywhere with it.

VTI hjelm

 

Next up was Tommy Petterssons presentation of himself, his work, the main aim of Vti, the tests, the test dummies that are used today and what was going to happen that day.

Q-Test dummy serie

Q3 weight

Head & neck: 3,17 kg.(7lbs)

Torso: 6 kg.(13,2lbs)

Both legs: 3,54 kg.(7,8lbs)

Both arms: 1,48 kg.(3,3lbs)

Clothes: 0,4 kg.(0,88lbs)

Total weight: 14,59 kg.(32lbs)

 

Q3 height:

Sitting height (neck slightly bent) 54,4 cm.(136”)

Shoulderheight: 32,9 cm.(82,3”)

Total height (neck slightly bent): 98,5 cm.(245”)

Depth of torso: 14,6 cm.(36,5”)

Width of shoulders: 25,9 cm.(64,8”)

Width of hips: 20 cm.(50”)

Backside to knees: 30,5 cm(76”)

 

Q6 weight:

Head & neck 3,94 kg.(8,7lbs)

Torso: 9,07 kg.(19,9lbs)

Both legs: 6,90 kg.(15,2lbs)

Both arms: 2,49 kg.(5,5lbs)

Clothes: 0,55 kg.(1,2lbs)

Total weight Q6: 22,95 kg.(50,5lbs)

 

Q6 Height

Sitting height (neck slightly bent) 60,1 cm.(150,3”)

Shoulderheight: 36,2 cm.(90½”)

Total height (neck slightly bent): 114,3 cm.(286”)

Depth of torso: 14,1 cm.(32,3”)

Width of shoulders: 30,5 cm.(76½”)

Width of hips: 22,3 cm.(55,7”)

Backside to knees: 36,6 cm.(91½”)

 

Then came the time for some crash testing at 30 mph (Plus Test: 35 mph). First seat to go was the Besafe Izi Comfort installed with isofix and forward facing. Test dummy used was the Q3 which is on the table right next to it.

VTI Q3 dukke

 

Tommy Pettersson presenting the crash test.

VTI Tommy

 

The Izi Comfort after the crash test. Noticehow loose the harness has become. I was able to get an arm through. The test dummy was properly fastend in the seat, the harness is good quality and so is the car seat. The loose harnes was due to the large strain put on the harness even at a speed of 30 mph.

It is certainly worth mentioning that a crash at 30 mph is the same as a 10 meter free fall – or a fall from the 3rd floor app. And you hit a car, the road or whatever in case you are not fastend in the car. The same goes for small children. The odd thing about this is that some parents think it is okay NOT to properly secure their children in the car or to have the child on the lap in the front seat. This particulary counts for taxi rides. However, the same parents would never ever dream of throwing their children out the window from the 3rd floor on purpose.

IMG_0206

 

IMG_0208

 

IMG_0209

 

The reason that a crashed cars seat should never be used again

The loading on the Izi Comfort is clearly visiable in these pictures. This is NOT a sign that the car seat is poor quality. This happens to be a very good quality forward facing car seat. The marks on the seat shell clearly shows how the seat shell has stretched. All of it helps stop the child in the best and most delicate way possible. The harder – the worse.

IMG_0210

 

IMG_0211

 

IMG_0213

 

IMG_0212

 

IMG_0214

 

Tommy Pettersson reviewed the crash test afterwards showing us the video of it in slowmotion.

Then the time came to crash test the Izi Kid X3 rearfacing with isofix. Test dummy Q3 and 30 mph right into the concrete barrier.

IMG_0199

 

VTI Izi Kid

 

Car seat and test dummy after the crash test. Notice just how much less slack there is in the harness.

VTI Izi Kid skader

 

IMG_0223

 

The car seat was inspected and it did really well.

VTI Izi Kid skader

 

Position of the seatbelt and 5-point harness

This subject was touched right after the crash tests.

Accidents, new regulations (ECE R 129) and stats

Lessons in these subjects took place at the university not far from Vti by Tommy Pettersson among others. Each subject is added to the Misuse, faulty installtions and I-Size respectively

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