How safe is safe? Child seat question

[sigtauenus]

I was working on my motorhome for some friends to borrow, and while I had it apart to do some work on the freshwater water pump, which is located under a seat, I noticed that the seat belts were attached to a metal bracket which was about 3/8" diameter and that that bracket was screwed to the wood frame of the seat.

How cow Batman, seatbelts attached to wood in a vehicle?

This issue comes up again because in the past I've asked and read several discussions regarding seatbelts and child seats in the back of our cars. Most discussions involve welding or bolting heavy duty brackets to attach the seat belts and/or straps.

Do we as a group over engineer safety? (as if that's possible)

I'm not a mechanical engineer, so I'm wondering how you go about determining what size bracket would work ok for a child seat strap (like for using the newer LATCH system), or what means would be sufficient (bolt/washer sizes - welding) to attach that bracket to the floor/frame of the car.

 

[daveSanborn]

determining what size bracket would work ok for a child seat strap

If the bracket is ONLY going to be used to secure a child seat/strap, it would be considerably smaller as the weight of the seat occupant is the driving factor. The bracket needs to be strong enough to exceed the greatest amount of momentum. Momentum = mass X velocity. Velocity would be the same regardless of the weight of the occupant.


Or something like that.


I'm not sure that your motorhome is considered a passenger vehicle. Non-passenger vehicle seat belt requirements differ from passenger vehicles.

 

[AtlantaSteve]

http://www.carseat.org/Legal/FMVSS225.pdf

There are the LATCH regulations, if you're curious. Section S9 is the technical stuff.

 

[AtlantaSteve]

I was rushed last time I posted, and just wanted to get that bit of info out...

I'm surprised nobody else has expounded on this subject, but I'm gonna go ahead and try.

I was working on my motorhome for some friends to borrow, and while I had it apart to do some work on the freshwater water pump, which is located under a seat, I noticed that the seat belts were attached to a metal bracket which was about 3/8" diameter and that that bracket was screwed to the wood frame of the seat.

How cow Batman, seatbelts attached to wood in a vehicle?

As Dave pointed out, the laws regarding RVs are remarkably less stringent. I am willing to put forward the theory that people are reluctant to buy a vehicle they'll put their family members (especially kids) if said vehicle doesn't have seat belts. Despite not really being required to have any safety restraints, from a marketing perspective, having no belts make it look unsafe. So they need to put seat belts in to close the sale...but lacking any regulation or requirement, they most likely have no idea if those seatbelts will stay anchored in a severe crash. Indeed, one can argue those belts aren't there for a crash, they're there for comfort, for not being flung about the vehicle while it is en route.

This issue comes up again because in the past I've asked and read several discussions regarding seatbelts and child seats in the back of our cars. Most discussions involve welding or bolting heavy duty brackets to attach the seat belts and/or straps.

Do we as a group over engineer safety? (as if that's possible)

I think we try...here's why:
Most of us aren't mechanical/structural engineers. Fewer still have a specialty in automotive safety systems. Therefore we cannot accurately engineer a safety system so we're stuck with 2 choices: Go stronger than we think necessary, or risk going too weak.

Furthermore, unlike those engineers that specialize in automotive safety systems, we are HOPEFULLY unable to test our systems. We don't know if they'll work or not, because we're not going to strap a dummy into our cars and do an offset head-on accident with a modern vehicle. So without this test data, our only option is to err on the side of safety.

As has been said before, and I'll continue repeating it:

We drive these cars at the peril of the lives of ourselves and the occupants.

To a certain extent, this is true of all cars...but this is even moreso the case with a 45 year old tin-can-car.

Some people jump out of airplanes. Some people climb mountains. We choose (among other things) to drive old cars. The risk they bring is worth it for the joy they bring.

So my opinion is that the owner/builder of the car makes the choice on what he thinks is an acceptable level of risk, and he builds the car in accordance with that, and while we all should point out when we think someone's making a dangerous choice (like, say, Nick's Rollbar) but at the end of the day, it's your car, and you make the choices you're comfortable living with.

I'm not a mechanical engineer, so I'm wondering how you go about determining what size bracket would work ok for a child seat strap (like for using the newer LATCH system), or what means would be sufficient (bolt/washer sizes - welding) to attach that bracket to the floor/frame of the car.

For these, I would look at the technical Regs for LATCH, and at the requirements put out by auto-racing sanctioning bodies regarding bolts/washers/welding to follow their regulations. They're usually pretty detailed, and unfortunately, a lot of their rules are the results of people making dangerous or fatal mistakes in their designs.

I've considered installing a LATCH-style system in my car, but as my son ages and my car continues to sit, I suspect this is less and less worth investigation.

Stay safe,

Steve

 

[sigtauenus]

I've considered installing a LATCH-style system in my car, but as my son ages and my car continues to sit, I suspect this is less and less worth investigation.

I think that will likely apply here too.

 

[apollard]

I've considered installing a LATCH-style system in my car, but as my son ages and my car continues to sit, I suspect this is less and less worth investigation.

I think that will likely apply here too.

I'm so sure it will apply in my case, I've switched to planning projects we can both work on in the future.

My son is two. :ep

Andre

 

[AtlantaSteve]

I'm so sure it will apply in my case, I've switched to planning projects we can both work on in the future.

I hear ya...I'm getting excited though. Everytime I paint something my son HAS to help. So I usually lay some washers down on the paper and let him paint those. He has a nice little collection in his bedroom. I have to help him a little as his little hands are too small and too weak to press the nozzle on the rattlecans, but I'm letting him do as much as he can. Hopefully he'll start figuring out how nuts and bolts go together, and then finally how to use a wrench on them. At that point he'll be more knowledgeable about working on cars than I am

 

[AzPete]

There used to be a snap on handle for the rattle cans. If you can find one, it might be easier for the little guy to operate, giving him more satisfaction in painting daddy's Mustang.

 

[sigtauenus]

I hear ya...I'm getting excited though. Everytime I paint something my son HAS to help. So I usually lay some washers down on the paper and let him paint those. He has a nice little collection in his bedroom. I have to help him a little as his little hands are too small and too weak to press the nozzle on the rattlecans, but I'm letting him do as much as he can. Hopefully he'll start figuring out how nuts and bolts go together, and then finally how to use a wrench on them. At that point he'll be more knowledgeable about working on cars than I am

That is a great idea. The only problem I have is that I would insist that he only paint them outside in the back yard by the shop, ie, no-where near the cars in the garage.

 

[daveSanborn]

That is a great idea. The only problem I have is that I would insist that he only paint them outside in the back yard by the shop, ie, no-where near the cars in the garage.

I'll never forget the beautiful Saturday morning back in 1999 when I was out in the driveway wet sanding a fresh from the booth 1970 Mustang that I'd painted a week or so earlier. My at the time 4 year son was playing out in the yard and unbeknownst to me decided to start "helping daddy" on the opposite side of the car from where I was working. When I didn't see him for a minute I started looking around for him and found him "hard at work" on the side of the passenger front fender with an old piece of 400 grit paper he'd found laying in the driveway.

:ep


Be careful having little ones "help" you. Not all of the memories are pleasant ones.

 

[apollard]

I'll never forget the beautiful Saturday morning back in 1999 when I was out in the driveway wet sanding a fresh from the booth 1970 Mustang that I'd painted a week or so earlier. My at the time 4 year son was playing out in the yard and unbeknownst to me decided to start "helping daddy" on the opposite side of the car from where I was working. When I didn't see him for a minute I started looking around for him and found him "hard at work" on the side of the passenger front fender with an old piece of 400 grit paper he'd found laying in the driveway.

:ep


Be careful having little ones "help" you. Not all of the memories are pleasant ones.

You'll laugh about it one day with him. I'd think that will be when you both can have a few beers

 

[buening]

Something that many people don't think about is that in a normal vehicle you should put the carseat in the middle seat. This puts the child the furthest away from any side impacts. Our cars have a hump at the middle of the backseat and am not sure if a carseat will work there. The LATCH isn't necessary, as not all cars on the road have these anchor points. The good ol seatbelt will hold the carseat in just fine.

As already stated, the anchor plates are dictated by the design passenger weight as well as the distance between supporting anchors. Wood anchor plates scare me, but not surprising given that it's a motorhome

I'd love to have my car done in time to bring our little baby girl home from the hospital in. The seatbelt/carseat thing isn't something I'm worried about, its the side impact that scares me.

 

[blue65coupe]

Being that my wife is a certified car seat instructor, I have some SECONDHAND knowledge of this subject. Some of it is not gonna make sense as the "rules" were written by gov't agencies. If the car is not equipped with a LATCH system, do not install one. (Yeah, I know) What I did in the rear of the stang was install seat belts that came with anchor bolts and washers. They were pretty much front seat belts that I anchored to the rear by drilling through the floor. They are attached the same way as the fronts. I mounted the belts in a male/female/male/female pattern vs. a male/female/female/male pattern so I could put one seat in the middle and secure it. My "anal retentive about car seats" wife has no problem with me hauling the kids around.