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-   -   Thar Hard Top, how safe in a roll over? (https://www.team-bhp.com/forum/road-safety/145162-thar-hard-top-how-safe-roll-over.html)

Dear Members,

In an accident or a rollover with or without a roll cage, how important a role does a 'Hard Top' play in saving the driver/ passengers of the vehicle from minor to severe injuries, as compared to a soft top Thar?

Would a FRP hard top survive a roll over and what would be its general condition after?

Your valuable inputs could help in saving lives by improving the design.
Regards,

Sir this is a very improtant point you have raised. I have already sent my Thar to Bimbra for a Hard Top fittment. For next phase of mods I was planning on getting an external roll cage. Now, my usage of the vehicle is very limited as I have another vehicle which is my primary vehicle.

However, there are a large number of enthusiasts who use the Thar as their primary vehicle and hence have put a Hard Top as well. Here comes the issue of whether an external roll cage vs. internall roll cage vs. only the B pillar (manufacturer provided) is the safer in event of a Roll Over, be it Off-road or On-road. In off road scenarios usually the vehicle is at very slow speeds and the terrain may also be soft so likelyhood of major damage is low. The issue is with on-raod performance where a vehicle with 100+ bhp and no safety features is a big danger to all occupants (family, friends, kids, etc..). How do we best safeguard against this hazard. What are out options?

Very valid concern. The rear passengers are at maximum risk, since if the side facing seats are retained alongwith hardtop, there is no provision of seat belts.

Is it possible to fit a rollover bar inside a hardtop? Or if front facing seats are installed, where are seat belts mounted?

Definitely not in my opinion.

Discussed briefly here also:

http://www.jeepforum.com/forum/f12/d...ction-1332559/



A roll cage or at least a proper roll bar below the FRP should be there. The B pillar if not modified MAY offer a BIT of added protection.

@Go Slow: a hill climb gone wrong or a side incline can also cause catastrophic crashes at slow speeds of offroading.

A MM 540 weighs minimum 1500 Kgs , Cj 3 weighs 1300 Kgs (as far as I remember) all others weigh more than that .

Now consider a hammer of even 500 Kg, how much havoc it will wreak . Calculate with whatever lesser momentum you want .

As Tejas has rightly said it " catastrophic crash ", never under estimate it.

Now more the speed + distance it covers greater the impact .

The answer to the opening post is critical , but for safety purpose not to be relied on anything other than a properly made six point roll cage with adequate seat belts .

Sudarshan

Fazal bhai...I remember how you had started a thread on HHT development. So was a little perplexed when you started this one. Nonetheless sharing my experience and views here. I have a HHT and I decided to get one mostly on the feedback on your thread. My reason for getting one was that it was mandatory to get one for participation in RDH. However I was not satisfied with the structural safety of the vehicle with HT, more so considering the topography of the rally route, so I decided to get an external roll cage. I don't know how safe this roll cage is ( and I hope I never get to test it :) ), but I think it does a better job than a HT alone. My HT has developed some cracks where it meets the rear gate - so if it cannot stand the impact of a door slamming hard, I doubt it will be able to withstand a roll over.

here's a link to my roll cage fitted Thar - post #89. This has been done by Prabhu himself. Do let me know if you think this one works.

http://www.team-bhp.com/forum/4x4-ve...rde-4wd-6.html

Red Herring,
The reason for starting this thread dawned upon me after a very recent incident of a Thar roll over.

Reg. the RC, I personally would want it to be bolted to horizontally than lateral as on your Thar.
Sudarshan,
As rightly pointed out, there is no alternative to a six point roll cage, HT or ST.

Tejas,
An HT definitely offers more protection than a ST, though maybe not life saving.

Yes, an off road roll over can go unimaginably wrong and fatal too.

Dodge Viper,
Yes, it is definitely possible to have an RC inside the HT, many have done it.
The rear seat belt can be fixed on the vertical pipe of the RC as on the Lynx, but make sure the pipe for the RC is a thick guage (4mm in my case) and so is the bracket with solid weld and not a cosmetic RC.



Go Slow,
As Tejas mentioned, do not underestimate an off road roll over however slow the speed, it is most unpredictable and incalculable depending on the terrain and angle.

Though a HT may take the first blow better than a ST but it is no safety without a RC, the best safeguard is an RC, still lives were lost in spite of RC's.
Regards,

If you ask me, any top is safer than the OEM soft. Just look at the way the A-pillar has cumbled in this jeep. Safety was the primary reason, I had a roll-cage installed in my jeep.

Regarding FRP, I think a well made and well secured top can withstand a roll over. The Hyderbad Hard top looks very rigid. However, the italian copy from Pune is a very flimsy top and cannot even hold it's own wight. If you keep it on the floor the sides will buckle. It is a thin single piece top.

Frankly, in this particular unfortunate mishap, the top did not seem to get its full test.
Most of the shock seems to be taken by the A pillar & the B after it.

Looks like the B Pillar holds the Key here. It does not seem to have collapsed. But how? looks like it did not crumble & saved the top from bucking in.

Also most of the rear is intact, all and all it seems that the A pillar the door frames & the B pillar to some extent has " Soaked " the impact.

I don't see it as a complete test for the top, so predicting anything without having detailed look at the vehicle will be favoring the HT unduly.

Sudarshan

Any idea at what speed this happened?

One thing is for sure that having a HT is better than having a soft top. Ofcourse roll cage is the safest. What type of roll cage would have protected the occupants in case this vehicle was a soft top? How do you measure the effectiveness of a roll cage? Should it be FIA approved (like in rally vehicles) or is there a best practice design, ??

I don't think the vehicle had a triple roll otherwise the B-Pillar and the HT components would have been totally crushed.

Also looks like the roll-over was caused by impact to the Left Fender/Lower Arm/IFS. Maybe an overtaking move gone wrong.

Which lifted the vehicle and dropped it onto the divider crushing the A-Pillar and Deforming the HT.

Had the vehicle rolled across the highway; considering the are driving in their lane

1) A triple roll-over will take at least 6ft+7ft+6ft+7ft+6ft+7ft+6ft+7ft+6ft +7ft+6ft+7ft+6ft = 84ft from start to finish provided the vehicle executes a perfect roll, and does not bounce skewering my calculation.

6ft = Width of the Vehicle
7ft = Height of the vehicle

In that case it will land in the opposing lane.:Shockked:

2) The Glass and Debris will be strewn across the width of the highway.

3) From the pictures it does not look like the HT Roof bore the brunt of the impact

To Say the a HARDTOP has some role in saving lives is purely misleading the general public.

It is looking for a silver lining which can be misinterpreted as Marketing Ploy.

However for the benefit of the off-roading public I hope FMSCI & FIA Approve of the Hyderabad HT as an alternate to the 6pt Roll-Cage:D

Please accept my apologies, in advance if I'm wrong.

Regards,

Arka

Somehow i guessed that some pics like this proving the FRP is strong would come out after this thread was started.

I agree with Arka.

Every crash has different dynamics and people getting saved here could be attributed to pure luck / fate / good karma / etc and not only the FRP.

I haven't seen how the crash happened and nor am i a crash forensic investigator to comment on it.

All i'd like to say is that let this thread not put a wrong notion in people that the FRP is a safe alternative to a roll cage. I know you are not saying that but people should not interpret it as such.

I feel the same

I did not smell it :D

Saar, aap bhee .. kabhi kabhi ..

Translation; please say something.
I know, that you know better.

On a serious note, this is a second Jeep accident on road , similar situation as I mentioned earlier, first one was fatal, this they got lucky.

Sudarshan

I do not think HARD TOP/SOFT TOP has that much impact on safety. That is why, in situations where roll overs are common (eg rally, professional events) Roll bar is compulsary. Even stock hard top SUVs need to be fitted with an Roll bar protection.
So if you are worried about roll over, get the roll cage. The "top" is for protection from the elements.