Roll over bar

[alan.gilbert_6384]

Hi all, hope everyone is safe and well.

As our cars were designed a rather long time ago when safety was an after thought, just thought 64 years later,  I would explore the idea of a roll over bar for a Spitfire 1500.  The current design method is to use rather exotic metals in the windscreen frame to provide roll over protection, but this is not an option for the spitfire, does anyone have any thoughts, good or bad, about them and maybe where to get one from?

[Graham C]

Well Alan you have now opened the tin of worms, the question that should not be asked. Just like "should I fit this pipe that feeds extra oil to the rockers".

Everyone has an opinion and the value of commercial roll bars against race tracks ones.

I will now wait for JohnD to answer the question, as actually he does raise some good points.

Over to you JohnD.

Graham

[JohnD]

Your wish is, Graham, my command!

Alan, you are indeed rght to be concerned.    And it was barely a month ago that a GT6 owner in America - no need to use the open Spitfire as an example! - was killed.   While waiting at traffic lights, an 'SUV' failed to notice that they were red and ran into the back of his car, mounting it, and running over the driver's side.   His wife on the passenger side was OK, but he was fatally injured as the SUV crushed the roof down upon him.   See https://www.msn.com/en-us/news/crime/man-killed-in-crash-at-muncie-bypass-mcgalliard-road/ar-BB19rTiq?fbclid=IwAR1yUBmMcWLzzftoygQ1JuI1nu_P8FNAUW4TWoqgeVyadjhl-_TnYAqdOfM#image=BB19rTAw|22

Today's cars are bigger and heavier than they were when Triumphs were made.  Look at this picture of two Range Rovers, one 1970, the other 2020:

Or, a classic Mini and a MINI

THeavier moderns have more inertia and so impact with their elders is more severe, while they are much stiffer in the body shell than their old cousins and protect the occupants.    Again that is without even considering the strength, or lack of it, of the windscreen surround of a Spitfire, the only component to keep your head and shoulders off the ground in case of an inversion.    That is a rare ocurrence, but Risk Analysis has to balance probability with the injury likely.      A trivial injury may be very common, and acceptable, but even a very rare one that kills the occupants should not.

Many consider that a roll over bar - the modern term is a Roll Over Protection System, ROPS - 'spoils the appearance' of a classic car, especially an open one.    That is their priviledge, just as it is for those who skydive, bungee jump or mountaineer.   But those sportsmen do so with the benefit  of a well-packed parachute, elastic or climbing ropes.      The few who 'free climb' are, to put it politely, considered mavericks by their peers, while those who jump naked make it to the ground all too quickly.     A ROPS for your Spitfire is readily available and easily fitted, in a way that will allow you to open or close the roof, from the usual suspects ( Rimmers, Safety Devices)     I encourage you to consider fitting ot having one fitted.

I also have to point out, as I always do, that a Roll Over Bar without a diagonal is little more than decoration.     LIke a carboard box without any ends, it will fold up under stress.     In the unlikely event that you want to enter competion, a diagonal-less ROPS will get you disqualified.    They are available with detachable diagonals, presuambly so that you can seat a passenger in the back.    Of a SPITFIRE??     I urge you to get one with a permanant diagonal, else it will never be there when you need it!

Sorry, long post, but as Graham implied I feel strongly about this!

John

 

[JohnD]

PS  I don't why I sought out and posted the pictures of much bigger moderns.     If yu go to the Piston Heads thread "Classics dwarfed by moderns " there are many, many more example!

 https://www.pistonheads.com/gassing/topic.asp?h=0&f=140&t=1218324

[Clive]

I have rolled a spitfire, and got away with it. I count myself very lucky (in most aspects of my life, not just walking away with cuts to my hand from the incident)

Anyway, the next/current spitfire has a rollbar on the orders of the boss. And it came without a diagonal, but I have added one made from CDS tube, welded into place. Usefully, I have attached a sheet of polycarbonate to act as a windbreak thingy, vert effective too. I did not use the more common/cheaper acrylic sheet (perspex) as that shatters with impacts, polycarbonate is softer but much tougher.

I consider a rollbar an essential bit of kit. No matter how you drive (my accident was down to diesel/oil on a corner, no excessive speed involved. Police agreed when they attended, and we all saw another car skid on the same patch and hit an oncoming vehicle. )

[Bfg]

 

4 hours ago, alan.gilbert_6384 said:

Hi all, hope everyone is safe and well.

As our cars were designed a rather long time ago when safety was an after thought, just thought 64 years later,  I would explore the idea of a roll over bar for a Spitfire 1500.  The current design method is to use rather exotic metals in the windscreen frame to provide roll over protection, but this is not an option for the spitfire, does anyone have any thoughts, good or bad, about them and maybe where to get one from?

Thank you, yes safe and well.

My own thoughts regarding a roll-over bar or roll-cage are somewhat bias because since a child I've ridden a bicycle (..and still do), and then from the age of 16 I've ridden motorcycles (..and still do). Thereafter I built, drove and sold kit-cars made from wood, steel and fibreglass ..and inbetween times I've had a number of open cars including an early Spitfire, a TR3 (without a windscreen) and a TR4 (..and am about to buy another).  And then I've also owned and extensively driven a number of lightweight (in particular a Triumph Herald and a number of Citroen A-series cars) that would crumple if sneezed at, let alone when driven over by a Chevrolet pickup truck (ref. the accident cited by John D.).  If I recall I first had a license in 1974 and so I am no youngster, and still my two remaining best friends each ride bicycles on a daily basis.  Having a roll cage around me or my dearest friends has not protected us for the past 50+ years 

40+ years ago as I pulled up at traffic lights in my little white MkII Spitfire, alongside a lorry - I did (very consciously) realised how HUGE their tyres were and how monstrously heavy their vehicle was compared to the car I was driving ..with my exquisitely beautiful loved one in the passenger seat.  Modern cars getting bigger haven't changed that one iota.!  Even then though, I knew the greater risk was always in my making a mistake in going around a country lane corner too fast and ending up upside down in a ditch or a field (..that being aside from hitting a steadfast tree ).  Again, those risks have not changed (either on motorcycle or in open-top car) and my being astutely aware of that - hasn't lured me into a false sense of security that a roll cage might suggest ..so I both ride and drive accordingly. 

As a retired Design Engineer I'd also have to advise that any roll-cage bolted to the body tub &/or wheel arches, rather than the chassis, is a waste of space. 

I'm about to buy another TR4 and have been seriously considering my fitting a roll cage ..versus the airiness and real life convenience of having somewhere to throw a camera bag, a coat &/or other touring necessities versus loosing the space to a steel cage, that may or may not protect you, depending very much on the type of accident.  After all Construction and Use regulations say you must use e-marked light bulbs but say nothing to the effect that a motorcycle or car should have roll-over protection.  Surely if it were a statistical imperative then they would insist that we protect ourselves ! 

As I'm exceptionally tall., the realities of having a full roll cage built-in would negate me from comfortably fitting in almost any sports car.  My greater fear though is that I would crack my scull on the roll-cage during an accident.!  A driver of a race car, wearing a helmet is far less at risk from such an injury but what about you and or your loved ones, either if the car is hit from behind or is it turned over.?  

This photo convinced me. . .

 

^ even without diagonal bracing of the roll cage, a car so configured would be totally useless to me when touring.  I don't expect four seats in a sports car but in this example there's not even enough space to fit a man-bag, a camera case, nor barely a lady's purse.

Might I also suggest you also take the petrol tank out of the car's interior (..such a terrible risk !) ..or otherwise fill it to the brim with high-grade petrol and invert it ..and see if it leaks all over the place.?   

That said, I do accept John's arguments and very much understand his earnest desire to offer good and sensible advice.  I wouldn't even contradict him but I do ask ; has the risk actually changed so very much over the past 64 years ? ..  I knew the risks then as I do now.  Bigger cars driven by persons believing sat-nav are only a small percentage of the real risk - v - your making your own mistake !

Pete 

[Clive]

While I can tolerate the opinion that a roll bar bolted to a spitfire shell is useless, I totally disagree. The fixing points are such that in a roll the bar would provide a great deal of protection to the occupants. With me, the flimsy fibreglass hardtop did the job, so that was a test to destruction. Had we rolled again, it would have been a very different outcome as the roof structure had crumpled somewhat, and the screenframe was pretty flat to the body (the body was rusfree and in excellent unmolested condition, something I am eternally grateful for. A rustier or restored one would not have faired as well. And for clarity, the fuel tank was entirely undamaged and leak-free. In fact it is n a very safe position, well away from all impact areas.

To me the slight inconvenience of the bar (I can still access the rear area, but the polycarbonate screen makes it a little awkward, especially when the roof is up. Roof down, I can fully load the area with tent/sleeping bag/foldup chairs etc) is FAR outweighed by me having a much greater chance of walking away should the car roll again. And doubly important as my daughter has, and will again, drive the car on trackdays. 

Your car, your choice. Risk is small, consequences can be as high as they get.

[Anglefire]

I have no roll over bar and no plans to get one either. I absolutely know the risks and all the arguments for them and (Very few) against.  My mileage in the car is extremely low (Need to drive it more actually) in comparison to my daily - though pandemic as well as changes to the way my industry is changing with remote access is reducing my business mileage significantly (6-8k less this year). The actual accident risk is higher in my daily - though significantly higher chance of survival than the Spitfire. Funnily enough I was talking to my kids only yesterday (Or day before, time is very much an illusion) about how many miles I've done since I've been driving and its something like 3/4Million and in that time have written off 1 car (With 2 weeks of passing my test - Mum was pleased 🤣) and been rear ended once and have run into a Land Crab in my Beetle when I was about 19 - he had a towbar on and had no damage - I had to panel beat the bonnet back into shape and repaint it (With no filler and was perfect when done) as well a couple of minor scrapes.

What I'm saying is that the risk for me is acceptable. 

[PeteH]

The minute, you make a decision to purchase a vehicle without any structural "roof", or even any vehicle of older vintage you have accepted, even if you don`t think it, the fact that it has more potential danger in it`s use. By all means if you feel it necessary fit roll protection, but if so I suggest you fit the best. (not the 2" scafolding we used in the early day grass track cars!!). I have considered fitting one to the Herald, but TBF. I was looking at its use as an aid to entry and exit!, as my godson did with his MX5, as much as for the protection factor.

Pete

[Pete Lewis]

was there not some discussion way back that a roll cage  had a uplift on insurance as it was  deemed to be 

used for racing ???   or was that a  covid  dream   is this also something to add to the good/ bad/ indifference

Pete

[alan.gilbert_6384]

Blooming heck, talk about light the blue touch paper and run  I feel like a dentist that's touched a nerve 

@JohnD great pictures, the new Range Rover L405 used on the right is in fact the stretch version we designed especially for the Chinese market (because the Chinese are much bigger people than Europeans or even Americans )  interestingly the classic RR weighed in at over 2.6 tons, the new stretch one, despite its size is only 500 kg more, with the help of some fancy aerospace grade aluminium and cutting edge rivet bonding technology.

 

Any way back to the safe area of roll bars, a Roll Over Bar without a diagonal it is then.

And Oh yes I did know what I was buying, I have added DRL's to help with the blind people out there who should not be on the road, and I drive it like a professional motor bike rider, having been a police out rider in a previous life.

[Graham C]

Sorry was there a question in the message.

A roll over without diagonal?

I would follow JohnD advice and have a bar without diagonal.

If I was to go for a roll over bar that is what I have, however theses seem to be hard to find.

Graham

Ps like with your first post light the blue touch paper and stand back.

Graham

[JohnD]

Alan referred to a blue touch paper, but notably there were no fireworks!   Just a vigorous discussion and difference of opinion.   That, gentlemen, is Sideways at its best!   Many other boards would be at each others throats by now!

If I may continue my arguement?  BFG considers a roll cage based on the floor pan to be useless.    If I weren't on my phone until after Xmas, I would show pics of the End of the Silverback.   They have appeared here before, so a little search might find them.

The Sb crashed and rolled on the Nurburgring, the GRP roof was ripped off, as were both doors and nearly the bonnet.    The front roll hoop was bent, when it landed on the front left corner of the roof.   There wasn't a straight panel on the car.   But NONE of the footings on the floor pan gave way, and I was unhurt.   

So, BFG, the evidence is that you are wrong.

Alan, I hope that you miswrote when you said you would choose one without a diagonal.      Such are little more than decoration, and 'proper' bars are easy to find.     Rimmer's, or Safety Devices sell them.

John

 

[Bfg]

 

I concur, by ancient definition a forum is "for the discussion of questions of public interest".  It wouldn't be much of a conversation if everyone thought the same. 

John and I may disagree on certain points and to me that's constructive because I am glad to learn from another man's experience. I also happen to respect John's opinion.

In this particular instance I didn't disagree with John's advice to fit a roll bar with diagonal bracing.  I was simply presenting various counter arguments for Alan to appraise for himself the benefit versus the inconvenience and cost. He did after all ask for "any thoughts, good or bad" 

I do however believe that many commercially supplied cut-price rollbars for d.i.y. fitting to a car's body panel and wheel arches - that were never designed to take such dynamic loads ..let alone after a car's 40 years of everyday road use and abuse, concealed corrosion and budget home repairs ..which are unknown to the current owner. In such a scenario it is possible that having a roll cage is potentially more dangerous than having no roll-bar at all. 

As a retired design engineer - I did at one time professionally design roll-over protection for agricultural, commercial, and airport use.  We used an independent test facility to assess our designs on a dedicated rig which used hydraulic rams to loads from the front, back, top, and sides ..or any combination of those. The loadings and deflections ..and also any failures of welds were duly recorded, and where necessary we made improvements.  There was and most likely still exists a paper trail of the designs we manufactured at that time.  

So if I might - I'll simply pose a few simple question.. When you buy a roll bar to fit to your car ; was the man who designed it professionally qualified and/or capable to do so ?  Was it properly, and independently, tested ?  What quality assurance checks are made in material stock and manufacturing.?  Are the mountings universal rather than specific to a model of car, and were they tested.?  And like seat-belt mountings - have load paths been thought through and the adjacent structure suitably reinforced ?  Was the design ever approved by the vehicle's manufacturer ?  I ask these points after reading on the TR forum of owners cutting the feet off brand-new roll bars "from the usual suspects"  and having to alter them - because they didn't fit the shape of the car.  And I have seen so many cases of thoroughly rotten B-posts and sill & floors on cars that until stripped-out were thought to be structurally roadworthy. 

Personally, I feel that a roll bar offers a false sense of security and worse still - that a badly designed one, made of the wrong material and/or inadequately mounted might rip out in an accident ..and actually cause injury. Or else they may crumple under the load and be a steel bar that folds forward onto the occupant rather than saves them.  JohnD also expressed "a Roll Over Bar without a diagonal is little more than decoration.  LIke a cardboard box without any ends, it will fold up under stress."  I believe he was referring to a cross diagonal brace (seen in the first photo below), but there are also roll bars being sold for the Triumph Spitfire that have no diagonal bracing back, so in the event of an accident they might simply rotate forward into the heads of occupants.   

Further to John's comments regarding Silverback, a very much modified Vitesse, I note he says "The front roll hoop was bent" in the crash.  If you are unfamiliar with exactly what he's saying here's a photo of said car where you can see the front hoop just inside either windscreen post.  Clearly that's not something usual in a road car's roll bar. 

And below is a 3/4 rear view showing, through the side window, the diagonal bracing into the back of the car.  John's was at a good angle to prevent the roll bar folding forward.  In most any 2-seater sports cars - and the length and that angle of those is very much less useful . .

And here is the same after his crash . . .

And while I accept these (plural) roll bars (..or are they linked to form a roll cage ?), along with a racing harness seat belt and crash helmet, may well have saved John's life, please don't be misled - this is unlikely to be the sort of roll-bar structure that you will be fitting into your everyday-use Spitfire.  "So, BFG, the evidence is that you are wrong"  is not supported by John's counter evidence of a purpose-built structure in a specially lightened race car ..with many well spaced mounting points, compared to what may be bought off the shelf.  The comparison is simply not like for like.   

I do however concur that a well designed and quality assured roll bar, properly fitted to well conceived and structurally sound mounting places may be a life saver, in one accident in many million !  And I likewise wholeheartedly agree with John to buy from an engineering company with a solid reputation and a design specific to your model of classic car.  But... again I see the item offered for the 1500 Spitfire, by the companies John recommended, have no diagonals (either transverse or into the back of the car) and also have their mounting plates very close together.  I doubt it would take a huge amount of force (cantilevered by the bar's overall height) to buckle the lightweight bodywork it is bolted to.

Again I offer these points of view just as food for thought. 

Pete.

[JohnD]

I must respect BFGs opinion, from his previous experience, which I lack!  But I would point out that Silverbacks mods did not include any special strengthening to the floorpan.   Except that, to follow good practice and race regs, the feet were reinforced with backing plates underneath to spread the load.   

Yes, it was a roll cage, braced between the front and rear hoops, so even stronger than a "mere" rear hoop.    Is that a criticism!

As for the arguement that a ROPS will encourage reckless driving, that was put forward against seat belts, and their success in reducing injury has thoroughly rubbished that!

Yes, severe accidents are, thank goodness, rare.     You are unlikely to suffer one on the public road.    But if you do, in a flimsy, fifty year old design of car, against the behemoth that is a modern, you need every additional life saving feature you can afford, as that design offers you very little.   Seat belts are compulsory,you have no choice.   It is your choice to fit a ROPS, I hope you will.

[Clive]

And I think  it is worth considering BFG's experience is in industry, not motorsport. A friend who worked on forklifts built cages etc for them, designed to stop all sorts of stuff falling onto the driver. But the requirements are very different. In motorsport (or driving) the job of the rollbar is to protect in the event of a sideways roll, not end-to end so much. And it is to improve (greatly) chances of survival.

Most of these rollbars are either FIA approved, or copies of those designs. And with a diagonal will comply with the MSUK regs (John, please confirm)

So if MSUK are happy, I think we can accept that as meaning the rollbar will do its job.

Of course, if a car is rotten, there are different issues. But I am happy with the design and fitting of mine, and also the quality of my welding in fitting the diagonal.

As to helmets, I don't wear one on the road, but do have PROPER roll bar padding fitted (ie not pipe lagging as used by many) £15 well spent!

[Badwolf]

As a light hearted anecdote based on the discussion of roll bars, safety cages etc. Many years ago, I was called into a bonded warehouse to assess an accident. A stacker truck had apparently taken out the support leg of some high bay dexion shelving and an entire unit had 'unzipped' from floor to ceiling and the lot (assorted wines and spirits) come crashing down. A quick witted member of staff who was next to the stacker truck saw the incident and reacted quickly dragging the driver from the truck into a safety area. The truck was buried and the cocktail covering the floor had a diameter of about 50 metres. When the wreakage was removed for assessment, it was noticed that the truck's safety cage was undamaged as was the driver's seat, so would have saved the driver's life had he not been dragged to the safe area. The atmosphere was a difference matter and I suspect that had I been breathalysed on the way home, would have been well over the limit. The hangover the day after was unreal. Yes, I have actually paddled in an EU (as was) wine lake. Just a few memories for Boxing Day amusement.

[PeteH]

On 26/12/2020 at 13:28, Badwolf said:

A stacker truck had apparently taken out the support leg of some high bay dexion shelving and an entire unit had 'unzipped' from floor to ceiling

My Collegues, from "Lift and Crane" Examination/Testing, back in the 90`s, before I retired, expressed concern over the height of some of these storage units, for "reasons of saftey". The operators where in the process of introducing "unmanned" trucks (computer controlled) to some wharehousing units, for "efficiency" rather than Health and Safety reasons. I never exmined any myself (different discipline) but I could never understand why they did not appear to be "tied" to the  roof sections in any way?, nor apparently even cross connected?.

[Badwolf]

I think, and someone with more experience will correct me, that the idea is, that in the case of an accident, the 'bay width' will drop straight down, as it did in my senario, rather than cause linked bays to topple causing a warehouse wide domino effect.

[JohnD]

On 25/12/2020 at 13:07, clive said:

Most of these rollbars are either FIA approved, or copies of those designs. And with a diagonal will comply with the MSUK regs (John, please confirm)

So if MSUK are happy, I think we can accept that as meaning the rollbar will do its job.

Best is to point you to Section 'K' of the Yearbook of MotorsportUK (previously the MSA): https://www.motorsportuk.org/wp-content/uploads/2019/12/155-195-Safety-K.pdf  and to paras 1.3.3 and 1.3.4 that make back stays and a diagnonal compulsory.    None of those offered by Rimmers (for instance) comply with these requirements.

John

 

[Colin Lindsay]

Isn't that just for Racing / Motorsport? I know they'll be heavier and therefore safer than for roadgoing vehicles, but, for a normal roadgoing car, the others are sufficient?

[Clive]

27 minutes ago, Colin Lindsay said:

Isn't that just for Racing / Motorsport? I know they'll be heavier and therefore safer than for roadgoing vehicles, but, for a normal roadgoing car, the others are sufficient?

My thoughts, a simple hoop may well help in a gentle/slow roll, but risks collapse with anything that would happen at higher speeds etc.

And the addition of a diagonal is not expensive, and only makes rear access slightly inconvenient. 

My roll was purely roadgoing, reckon I was doing about 45mph when the car slid on oil/diesel. Luckily most of that speed was rubbed out by some spinning and re=ferns, before hitting a large rock and gently rolling. If teh roll had been sideways at 45mph I may well not be here today.

[thescrapman]

On 28/12/2020 at 12:50, Colin Lindsay said:

Isn't that just for Racing / Motorsport? I know they'll be heavier and therefore safer than for roadgoing vehicles, but, for a normal roadgoing car, the others are sufficient?

The MSUK stuff shows you how and why to make an effective ROPS, so from that you can work out the effectiveness of commercial offerings.

I have a commercial twin hoop one in my TR, bloody nuisance, blocks the rear view mirror, and can't get the hood past it easily.

Got a spare Spitfire one for sale if anyone wants one.

[Colin Lindsay]

12 hours ago, thescrapman said:

I have a commercial twin hoop one in my TR, bloody nuisance, blocks the rear view mirror, and can't get the hood past it easily.

That's the problem. I know it can be argued that the heavier and more securely braced a roll bar is, the safer it will be, and an entire cage will be the ultimate safety barrier, but at what point do you stop with a normal roadgoing car that you want to look original and period, and not like something from Mad Max?

[JohnD]

On 28/12/2020 at 12:50, Colin Lindsay said:

Isn't that just for Racing / Motorsport? I know they'll be heavier and therefore safer than for roadgoing vehicles, but, for a normal roadgoing car, the others are sufficient?

Colin, are you suffering from magical thinking syndrome?    So that you believe that the physics of impacts and roll overs are different on the public road to the race track?   If so, I sympathise, but please don't infect others with your delusions.

As well as identical physics, in competition, all the cars are going in the same direction, whereas on the road they have opposing velocities, which means that the energy of impact is the product of both.   Kinetic energy is proprotional to the SQUARE of velocity, so if both colliding cars have the same speed, their effective velocity is twice their road speed, but their kinetic enegery is FOUR TIMES greater.   So road impacts can be much more serious than on track.

You then ask, as if it were a question of personal taste, about the look of a ROPS.      It is personal taste, do I want to die,. or worse suffer severe, 'life changing' injury?       And a properly installed single hoop is all that is needed to acheive that.      Even I agree, a full cage is a competition thing, but it has saved my life or injury, twice.

JOhn