Child crash test dummies & car seat weight limits

[Gena]

This is probably a question for one of our resident techs.

Lately I've been wondering about the child crash test dummies used to test carseats. I found this website (http://www.ftss.com/crash-test-dummies/children) vey interesting, but I haven't really aborbed all the details. My understanding of the information there is that the 3 year old models weigh 33-35 lbs, the 6 year old models weigh 47-51 lbs, and the 10 year old model weighs 77 lbs. Am I reading that correctly?

If these are the weights of the crash test dummies available, how do car seats get certified to other weights? We have a Nautilus, which has a 65 lbs harness limit, as do several other seats on the market. How do all these seats get tested and certified to 65 lbs when there is no 65 lbs crash test dummy? Do the car seat manufactures have different dummies? Do they add weight to the existing dummies? Is it based on some mathematical formula I cannot hope to understand?

Help me understand this.

[Joolsplus2]

Right, a mathematical formula that computers figure out (and maybe the geniuses who program the computers... lol). Seats with weight limits 50 and above actually don't have to pass the usual testing (head excursion, knee excursion, a couple other measures, in a 30mph crash into a rigid barrier), they just have to stay intact. At least that's all the government demands of them. We know that Sunshine Kids actually puts that 10 yo dummy in it's seats and makes sure the head excursion is well within the government limits, but other car seat makers aren't so loose-lipped with their data, so we at least HOPE they do extensive testing with heavier dummies (they probably do, it would cost them 19 fortunes to pay for a lawsuit for an injured kid, and they know it).

[Gena]

Right, a mathematical formula that computers figure out (and maybe the geniuses who program the computers... lol). Seats with weight limits 50 and above actually don't have to pass the usual testing (head excursion, knee excursion, a couple other measures, in a 30mph crash into a rigid barrier), they just have to stay intact...

Thanks, Jools. Somehow that fails to inspire my complete confidence.

[bubbaray]

I think that is part of the reason that some (not all) techs feel more comfortable with children in boosters, as opposed to high-weight harnessed seats after they are around 5 years of age. We know that (most) seatbelts can hold a few hundred pounds of adult weight. The semi-recent Transport Canada testing throws into doubt how some harnessed seats perform (in certain vehicles) with higher-weight dummies.

Interestingly, in places were extended harnessing is practiced like Sweden, they go directly from a rear-facing harnessed seat to a booster -- they don't use high-weight harnessed seats FFg. The benefits of the harnessing in that situation are due to the seat being RFg, KWIM? If you poke around on car-seat.org and look for posts from AdventureDad, you'll some "colorful" exchanges about whether people should be using high-weight harnessed seats FFg at all (he is in Sweden and opposed to it).

[Joolsplus2]

Yeah, the pendulum has really swung back lately, we used to be all about harnessing for a long long time, and the Kyle David Miller tragedy really inspired a lot of extended harnessing. There's not a lot of data to prove that it's actually safer, though, and Sweden has proved for years that a good booster is very safe for kids about age 5 and older (younger than that, they mostly rearface, though I read a safety advocate lament once that so many parents turn their kids FF at age 3, it was a tragedy...well, it probably is when they are going into a booster...but it was interesting the difference because we lament people turning kids FF before a year or at a year..at least they are in harnessed seats still, usually).

[Gena]

Yeah, I've been reading the stuff there (car-seat.org) for years and looking at it again recently, which is what made me start thinking about the dummy weights vs. seat limits.

DS (5.5 years) is 46 unclothed, which means that he is pretty much at the LATCH limit for our vehicle and seat (48 lbs). If it were still summer, I could probably stretch that out a little longer, but layered winter clothes weigh more than summer shorts and tee shirts. we are not thrilled with the seat-belt installation in our vehicle, so DH and I have been discussing the options. This of course raised the issue of whether to keep DS harnessed or move him full-time to a booster.

DS has been booster training in DH's car for the past 4-5 months in a Tubro Booster and does surpringly well. He understands the "car rules" and has been following them diligently. (This is one area where the rigid thinking that is part of his autism seems to play in our favor.) So maybe he is ready to go to a booster full time?

Last week, after DH and I had a discussion about this, I was at Target and they had a red Monterey on clearance for $80. Red is DS's favorite color and he has been telling us he wants a red car seat for months (after we bought the blue Turbo Booster). So I grabbed it. DS loves sitting in the seat in the living room and it seems to fit him great, but he hasn't tried it in the car yet. I'm still not sure it it's what I want to do.

So I'm driving myself a little nuts over the all the factors involved in harness vs booster and Nautilus vs Monterey. Jools's answer about the crash test dummies moves me closer to putting him in a booster.

[bubbaray]

It sounds like he's ready to at least try the Monterey. FWIW, I :heartbeat: our Monterey. DD#1 says its the most comfortable seat she's been in and it fits her REALLY well.

I vote for give it a try and see how it goes. GL!