Rollover Safety: Fiberglass hightop vs Poptop

[BrianW]

If you get a high top van that used to be a paratransit, school bus, or even ambulance I think those high tops are usually reinforced with a sort of metal skeleton for extra rollover safety. Your standard Fiberine top is not.

[GunniLuv]

Hypothetical; if you had the crush data you are looking for, what margin are you willing accept? Assuming there is a decrease in the crush strength, what is your go/no-go number? I’m only asking because it seems by your posts you might be unwilling to accept any decrease in strength, which is likely for any modified van roof.

[N147JK]

Originally Posted by GunniLuv

Hypothetical; if you had the crush data you are looking for, what margin are you willing accept? Assuming there is a decrease in the crush strength, what is your go/no-go number? I’m only asking because it seems by your posts you might be unwilling to accept any decrease in strength, which is likely for any modified van roof.

A good and rational observation.

1. I'm going to guess that no one, not even the manufacturer, knows if the crashworthiness of the modified structure is greater than, less than, or equal to the unmodified structure.
2. Most owners assume it's less crashworthy.
3. Most owners simply accept the extra risk and don't dwell on it.

There are no risk-free activities, not even getting out of bed in the morning. If you want to participate, you have to agree to accept an unknown degree of extra risk. Of course, irrationality and fear start to factor in. As an example, most people would never participate in skydiving, even though skydiving is actually a very safe activity.

[simplesez]

+1 or Like or thumbs up to that post

[motovan_mn]

Originally Posted by N147JK

Yours are good questions. They have me wondering.. who are the folks that design these tops and how they attach to the body? Are they professional engineers who perform the load and structural analysis that is called for, and are able to certify the results? Or are they more like mechanics who just take their best guess at what "seems adequate" without really knowing how safe the structure actually is? Hopefully it's the former and not the latter!

Exactly what I'm getting after! If I owned a van upfitter business, it would seem insane from a liability standpoint to sell a product or cut a hole in the roof of a customer's van, unless I had the analysis or test results to prove it was "safe."

Originally Posted by GunniLuv

Hypothetical; if you had the crush data you are looking for, what margin are you willing accept? Assuming there is a decrease in the crush strength, what is your go/no-go number? I’m only asking because it seems by your posts you might be unwilling to accept any decrease in strength, which is likely for any modified van roof.

That's a great question, which I don't have a clear answer to. I think the best case scenario is that there is a federally mandated requirement. Maybe the OEM van body passes with a 20% margin, and the modified van body passes with a 10% margin, but at least it still passes. I agree a modified van roof is likely to have lower strength than the OEM body.

Originally Posted by N147JK

A good and rational observation.

1. I'm going to guess that no one, not even the manufacturer, knows if the crashworthiness of the modified structure is greater than, less than, or equal to the unmodified structure.
2. Most owners assume it's less crashworthy.
3. Most owners simply accept the extra risk and don't dwell on it.

There are no risk-free activities, not even getting out of bed in the morning. If you want to participate, you have to agree to accept an unknown degree of extra risk. Of course, irrationality and fear start to factor in. As an example, most people would never participate in skydiving, even though skydiving is actually a very safe activity.

Totally understand your risk management perspective. I ride motorcycles, both street and dirt, which is all about risk management, NOT elimination. Perhaps my judgement is a bit clouded by the fact that I now have to transport my 2-year old in the van. The same risk management principles should apply, but that stakes certainly seem higher.

[motovan_mn]

I forgot to mention in my previous posts that I had reached out to both Fiberine and CCV to ask them whether they were aware of or met any federal regulations.

Just got a response back from CCV stating that they remove less material than is allowed by the Ford upfitter guide, and that they install a structural frame (I assume similar to SMB's solution previously described in this thread). They also said there are no federal regulations specifically in regards to installation of pop tops.

It sounds like there is clear documentation from Ford dictating what kinds of roof modifications are allowed, so that is good enough for me

[86Scotty]

Originally Posted by N147JK

I wonder if lack of seat belts isn't behind this statistic. Typically, is everyone in a 15-passenger van secured by a full set of lap belt and shoulder harness, or is it more akin to riding in the city bus. ie, most occupants are not secured in any way? A rolling van with multiple unsecured passengers is bound to end badly.

I have thought about this a lot.
I grew up riding in church buses and vans even through college and into adulthood with various youth groups and summer camp kind of things. I don’t remember a driver one time asking anyone in the back to buckle up.

There are two other major players in those statistics though. One is tires and the other is inexperienced drivers.

Think about it. Church and school vans sit in the back corner of the parking lot 350 days a year unmaintained with the tires dry rotting. Then they put someone who has likely never driven a van likely behind the wheel with everyone’s kids. They don’t check tire pressure, they just load up heavy and light off a few hundred miles to their destination without a clue.

This is not speculation. I’ve seen it many times. Sadly, I’ve been on both sides and im lucky I never put anyone’s children in jeopardy.

We often broke down on trips even with newer vans due to them sitting and never being maintained. Usually it was tire failures.

[Lilnuts2]

Lots of info on the subject.
https://crashstats.nhtsa.dot.gov › ...PDF
Web results
Analysis of Crashes Involving 15-Passenger Vans - CrashStats ...

[jamesc]

Because of their insurance, my kid's preschool would not let parents give other students rides to school events in 15 passenger Vans.

[Pntyrmvr]

When you take apart a 1982 Sportsmobile and then cut into a 1984 virgin sheet metal roof of a host van to swap it over many things cross your mind:

1- unbelievable how thin the virgin roof is

2- unbelievable how thin the roof ribs are that are completely removed by Sportsmobile

3- unbelievable how many wall ribs are cut to allow for windows in an originally factory cargo van. Both donor and intended receiver.

4- unbelievable how heavy the frame is that Sportsmobile installs around the opening you just cut in a virgin van roof

5- unbelievable how few bolts go through such thin factory sheetmetal to hold that frame in place

6- unbelievable how heavy the fiberglass and canvas top assembly is

7- unbelievable how few times ambulance chasing whores-in-suits lawyers have had a chance to show this as a negligent design in any way given the number of these machines on the roads

8- especially unbelievable when Sportsmobile put many of these units on the road well over GVWR and didn't get sued out of business. My 3/4 ton top donor had 4 tanks: water, sewage, propane, and gasoline. Plus a full camper with cabinets and lounge interior, and a 400 lb pop top with bed. All supposedly under a GVWR of 6600 lbs. Again unbelievable as that doesn't include occupants of 4 seats and their gear in an extended van.

So if that went on for years I think there is little to worry about.

Oh, I did call Sportsmobile about the GVWR years ago. Nancy at SMB east seemed puzzled by my question as to how so much weight never broke any rules.

Onward!