Roll over bar

[Clive]

27 minutes ago, Colin Lindsay said:

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?

A rollbar on "our" cars is always going to look a modification. And an obvious one. 

My take is if fitting one for safety (Have you seen the "show cages" sold for all sorts of hot hatches, even proper minis? slot together aluminium. Why? just why?) you may as well get one with a diagonal as it makes little difference to practicality, but will if the roll bar is being put to use. And like all things, YMMV and indeed your use. I did consider a full cage, but decided a simple rollbar would cover the more likely scenarios while still being practical for normal or even trackday use.

I see John has chipped in. I didn't realise there had been 2 incidents. I got away with it once, and unlike a cat I doubt I have nine lives. Hence my view on safety.

The safety view covers all sorts of stuff besides roolbars, especially tyres and brakes. The number of people in classic cars driving around on 10year+ tyres, saying the tread is OK, they don't go fast etc. Doesn't matter, as with most things on a car, you can get away with it 99% of the time. But it is the 1% that we should be worried about.

[Colin Lindsay]

2 hours ago, clive said:

The safety view covers all sorts of stuff besides roolbars, especially tyres and brakes. The number of people in classic cars driving around on 10year+ tyres, saying the tread is OK, they don't go fast etc. Doesn't matter, as with most things on a car, you can get away with it 99% of the time. But it is the 1% that we should be worried about.

Again, I don't want to feel like I'm 'getting away with anything' but it can always be argued that our cars, being less safe than moderns, are dangerous. Brakes are less efficient. There are no airbags or crumple zones. If I decide to stick with an original car in original spec, no matter how well maintained, no matter how well I drive or how carefully, someone somewhere will be able to come up with a well-reasoned argument about how much I'm risking my life and how many more times I'm likely to be killed or seriously injured than in a modern or an armoured / uprated / heavily strengthened and protected equivalent of a 1960s Triumph. Someone, somewhere, will always nod their head sagely and tell me: 'Well, it's your life.'

It's an argument that I simply cannot win. If I try to argue: 'someday it may happen, someday it may not', I'll be made to feel that's an irresponsible attitude. No, I can't guarantee that I won't be in accident, and I can't vouch for all the idiots out there in oncoming cars. All I can do is try to be responsible, try to be careful, and try to finish every journey that I start in one piece. I'll keep good tyres, good uprated brakes, improved lighting and well fitted seatbelts, and trust that these are adequate. But: I don't want to fit a roll bar.

[JohnD]

Car design has improved enormously in the last 70 years - the manufacturers and our legislastors would be culpable idiots if not!    

When over a similar period there are more than five times as many vehicles on the road:

, That is not because there are better drivers about, but the cars survive crashes better, plus the seat belts, which our cars have, and airbags, crumple zones, boron steel-supported survival pods that they don't.  Let alone electronic skid control, ABS etc.etc. The one thing that you can add to your car that will make it more survivable is a roll bar!   But, Colin, it is a personal choice, except in the same sense as a  mountaineer, of whom , if they are properly equipped and trained but overtaken by unexpected bad weather, no one will say anything but, "Bad Luck!".      If they go out in pumps and t-shirts, they are irresponsible, and I fear that even in the first case, no one will say of the dead motorist, "They died doing what they loved".

Lastly, "our cars, being less safe than moderns, are dangerous. Brakes are less efficient. "   Yes to the first, a loud NO! to the second!        Old, worn, badly maintained? Possibly, but in good condition, and excepting ABS in the most extreme circumstances, our brakes are no less 'efficient' than any modern.

John

[Colin Lindsay]

2 hours ago, JohnD said:

But, Colin, it is a personal choice, except in the same sense as a  mountaineer, of whom , if they are properly equipped and trained but overtaken by unexpected bad weather, no one will say anything but, "Bad Luck!".      If they go out in pumps and t-shirts, they are irresponsible, and I fear that even in the first case, no one will say of the dead motorist, "They died doing what they loved".

Lastly, "our cars, being less safe than moderns, are dangerous. Brakes are less efficient. "   Yes to the first, a loud NO! to the second!        Old, worn, badly maintained? Possibly, but in good condition, and excepting ABS in the most extreme circumstances, our brakes are no less 'efficient' than any modern.

John

Difficult analogy for my point, John - modern mountaineers don't go out in 60 year old equipment, and those idiots who go hill walking in t-shirts and shorts would probably drive with bald tyres and dodgy brakes, and then blame the weather for a crash...  

But: if you take any other hobby - for example, firearms - anyone who loves old weapons will tell you modern guns are more accurate and potentially safer for the user, yet you don't add telescopic sights to an old musket, or a modern rubberised butt, or gas tubes to reduce recoil; you can, and people will argue that it's safer and more comfortable, less likely to cause injury etc but it's not the original experience and you might as well just buy a modern weapon.

Same with cars - why don't I just drive a modern everywhere? Safer, more comfortable, better mpg... so I have to sacrifice something if I want to drive an old car. It's striking a balance between originality and safety and there has to be a point a which I'm prepared to say: that's it, and come what may.

As for brakes... a car with front and rear discs and a servo has to have some advantage over a four-drum Herald!

[Clive]

But Colin, remember a rollbar would have been available "back in the day" so is a period accessory. Far more useful than an SAH rocker cover or whatever too, as it has a real, practical use. 

[mark powell]

I had this mandrel bent out of correct tubing, Floor mounted at the front with strengthening plates under. The rear hoop bolts through the wheel arches with plates behind also. After reading this thread, I feel I ought to install a diagonal. However, because of the seat positions, it would have to run from the top of the front hoop to the base of the rear hoop.       Thoughts please.  (The hoops are welded together at the top in two places with 4mm steel plates) 

 The car has been completely rebuilt and has no corrosion. 

 

[JohnD]

Colin, ah!  Four drums on my Herald!   Touche!  You have the advantage, in argument if not on the road!

And yes, analogy is never precise.  A musket with telescopic or laser sighting?  It'll never catch on!

Mark, two diagonals?   Both top corners down to the transmission tunnel?  I think that is MSUK Section K acceptable - I'll check if you like!

John

[PeteH]

Whilst I can well see from from a H&S Point of View, the desire for a Roll bar/cage. Surely that detracts from the reason one wanted the Car in the first place? Nostalgia!. Properly engineered/restored, Brakes, in good condition. Good quality tyres. For the rest, its back in the "lap of the gods". If the bullet has your name on it?

P.s. Mark?. Are they MX5 "tombstone" seats?.

Pete

[Peter Truman]

OH&S wise where your head rests on the seat relative to the roll bar tube I'd think of fitting the foam noodle tubing for head protection. 

I agree with Peter H why did you go for the convertible initially, lets face it the Heralds saloon roof isn't that strong anyway it'll crush very easily.

[Bfg]

On 30/12/2020 at 17:17, Colin Lindsay said:

why don't I just drive a modern everywhere? Safer, more comfortable, better mpg... so I have to sacrifice something if I want to drive an old car. It's striking a balance between originality and safety and there has to be a point a which I'm prepared to say: that's it, and come what may.

 

As a compromise might I suggest ..

• 

When driving something like that - the tables are turned ..and everyone in a modern will be scampering away to buy a bigger, stronger, military grade (MdUK) Section M roll bar (which as you can see is double braced to the transmission tunnel)  

 

[Clive]

13 hours ago, mark powell said:

I had this mandrel bent out of correct tubing, Floor mounted at the front with strengthening plates under. The rear hoop bolts through the wheel arches with plates behind also. After reading this thread, I feel I ought to install a diagonal. However, because of the seat positions, it would have to run from the top of the front hoop to the base of the rear hoop.       Thoughts please.  (The hoops are welded together at the top in two places with 4mm steel plates) 

 The car has been completely rebuilt and has no corrosion. 

 

Mark, I am not sure if a diagonal to the upper/rear mount complies with MSUK regs, but it would definitely give a great deal of protection against folding up. 

 

13 hours ago, PeteH said:

Whilst I can well see from from a H&S Point of View, the desire for a Roll bar/cage. Surely that detracts from the reason one wanted the Car in the first place?

I don't understand why additional safety features detract. Nobody blinks at people fitting set belts to a pre64 car (no requirement to do so in law)  I want a Spitfire because I have plenty of "history" with them, and socially a good chunk of my life involves Triumph owning friends. My spitfire has become what I want it to be. And that includes sensible/reasonable safety add-ons. So yes, many turn their noses up or sneer. But the real hard-core Triumph owners, the ones who can replace a clutch at the side of the road in the Alps, or change a stag driveshaft in the motorway service area, that sort of thing, have no issue apart from gentle, good natured ribbing.

Honestly, not having a rollbar is daft. Another analogy. It is a bit like and RCD in your consumer unit at home. People regard them as a nuisance. They trip sometimes (99.99% of the time with good justification) but the user doesn't understand why. And sometimes object when they are told they HAVE to have one fitted. But that one time when it saves their life, they may actually appreciate it.

[mark powell]

Right, one diagonal is on the cards.  Two would be really awkward to install...  The whole idea was for a degree for safety / peace of mind.  It will not be used in any form of competition.

Yes, tombstone MX5 seats, £40 the pair.

[JohnD]

Mark,

A diagonal that goes from a top corner down to the footplate of the opposite back stay is acceptable according to Section K (drawing No.5)       That may clear your seats better, if that was a problem.

You may ignore the front hoop of the full cage.

[Colin Lindsay]

3 hours ago, clive said:

Honestly, not having a rollbar is daft. 

My argument in a nutshell. Why on Earth would I want to risk my life in a basic, dangerous, life-threatening car at all is beyond me, but if I want to - why do others have to make me feel inferior, or that I'm some kind of careless idiot who will throw my life away whilst others nod sagely? Your analogy of RCDs can be used in the same fashion - they're there for safety. How would you view someone who puts on rubber gloves everytime they want to turn on something electrical? It may save their lives, it may look strange to others, but then they can turn round and say that those of us who don't are risking our lives unnecessarily and if we die, it's our own fault. I guess I'm just daft, then.

[Chris A]

18 minutes ago, Colin Lindsay said:

 I guess I'm just daft, then.

We've all known that for a long time, it's what we love about you 🥳

[PeteH]

I think, (maybe I should`nt?), That the sight of a roll bar/cage on an open top car, is IMV a visual detraction. It`s OK when the hood is in place (Visually). But in that case why not buy the saloon in the first place?. Putting aside the "safety" aspect(s), When seat belts where first introduced, there was a school thought which actually surmised that they where dangerous, (in an open car) the standpoint being that rather than having 1/2 a ton of car on top of you, possibly even in a water filled ditch!, you could be better off thrown clear?. Of course even F1 cars only have the tiny "hoop" behind the driver?.

What would be interesting, would be to see the stat`s ref the No of open top cars on the road and fatalities caused as direct result of not having "roll" protection?.

In the final analysis, it is down to how individual feels, no one should feel pressurised in either way?.

Anyway, heres to a MUCH better 2021!. Keep it upright guys (and gals)

Pete

[Clive]

31 minutes ago, Colin Lindsay said:

 Your analogy of RCDs can be used in the same fashion - they're there for safety. How would you view someone who puts on rubber gloves everytime they want to turn on something electrical? It may save their lives, it may look strange to others, but then they can turn round and say that those of us who don't are risking our lives unnecessarily and if we die, it's our own fault. I guess I'm just daft, then.

I would say the rubber-glove wearer was either an oddball fetishist or complete c**k. All they need to do is fit an RCD and all is safe. For them and everybody else who steps foot in, or around, the house.

BTW, New year, so folks, go and press the test button on your RCD's. Best to warn everybody in the house first. If you don't have an RCD, do yourself a favour and get one fitted. If you have one fitted and the test button doesn't flick it off, get a new one fitted. There, a bit of useful advise that nobody in their right mind could disagree with 🙂

[JohnD]

Whatever makes you think that a Triumph roof is any protection at all?   The roof of the GT6 that I referred to in the OP was crushed down onto the unfortuate driver, killing him, by an SUV driving over it.  The bolt-on roof of te Herald/Vitesse is probably even wekaer than the integral roof of the GT6.   

And the "tiny" hoop behind the drver in an F1 car?   Clearly, you haven't noticed the "Halo" device first used this year and already credited with saving more than one from injury or death.    But the whole point of the original "tiny hoop" was that it would keep the driver's head off the tarmac, even upside down.

As to pressure, I'll take the opportunity to persude anyone to fit a roll bar - we need live Triumpheroes, not dead ones that are not "visually detracted"!

 

 

[Colin Lindsay]

1 hour ago, clive said:

I would say the rubber-glove wearer was either an oddball fetishist or complete c**k.

Love it. 

Actually it's a great debate, I love a good discussion - not much opportunity recently with all these lockdowns - so keep it going.

[Anglefire]

I am in the “not fitting a roll bar camp”. Don’t get me wrong, they are a life saver if ever needed. 
And yes I do have a Rcd fitted - was a regulation requirement when I rewired the house - or if not legal then a good idea. 

In the last 26/27 years it’s been fitted it has never tripped because someone in the house has done something daft.  And yes it does work. 

And a roll bar is a good idea- no doubt about it. But still won’t be fitting one.  

[mark powell]

2 hours ago, JohnD said:

Mark,

A diagonal that goes from a top corner down to the footplate of the opposite back stay is acceptable according to Section K (drawing No.5)       That may clear your seats better, if that was a problem.

You may ignore the front hoop of the full cage.

Yep, that will do it!  Thanks John.

[Chris A]

1 hour ago, Anglefire said:

I am in the “not fitting a roll bar camp”. Don’t get me wrong, they are a life saver if ever needed. 
And yes I do have a Rcd fitted - was a regulation requirement when I rewired the house - or if not legal then a good idea. 

In the last 26/27 years it’s been fitted it has never tripped because someone in the house has done something daft.  And yes it does work. 

And a roll bar is a good idea- no doubt about it. But still won’t be fitting one.  

Ditto and hopefully 2021 will be more normal and everyone will get more use out of their Triumphs.

Meilleurs vœux, bon santé et bon route

[JohnD]

21 hours ago, Peter Truman said:

OH&S wise where your head rests on the seat relative to the roll bar tube I'd think of fitting the foam noodle tubing for head protection. 

I agree with Peter H why did you go for the convertible initially, lets face it the Heralds saloon roof isn't that strong anyway it'll crush very easily.

Many people cover cage tubes where they might get in the way, with pipe lagging foam.   Very convenient, easy to fit, and if you buy right non-inflammable.   But it's far too soft!     FIA approved "foam" is hard, hard, hard! It works by having a larger radius than the cage tubing, so spreading the impact.   See https://www.merlinmotorsport.co.uk/knowledge_base_articles/view/roll-cage-padding-comparisons-301

[thescrapman]

The FIA one does not even look like foam. More like a solid rubber product.

 

[Bfg]

Ok., aside from the debate around aesthetics, the so called 'originality' of a classic car, and/or the intrusion of roll-over protection into the limited amount of space behind seats and clear of a folding hood (or within a hardtop) - let me offer a few (hopefully useful) pointers in road-car roll-over bar design. 

For convenience, to highlight its 'key features', I'll use the following crudely-penned sketch, which illustrates the type I designed * and manufactured for one of my open-top sports cars (.. from '79 through to the mid '90's I was in the car &/or kit-car business). This particular item was for a front-wheel-drive road car, with a chassis but no driveshaft tunnel, but the general principles carry across to RWD where behind the seats is often a transverse, and essentially straight, step over the rear axle . . .

• 

This design of roll-over bar

• was to also to improve side-impact protection.
• had its main loop is leant backwards, well clear of the occupants shoulders and heads.
• that angle (think in terms of vectors) also offered resistance to the roll-bar tilting / rotating forward if the car was inverted and sliding backwards (perhaps after having tripped over tree). 
• was triangulated with rear legs, again so the forces from either sliding forwards or backwards (in an inverted car or on its side) would not tilt the roll bar (rotate it to being flat with the car's deck. The greater the angle, of the rear diagonals, the more stable the mountings (like a tripod with its legs opened wider is more stable).
• those corners had gusset plates (welded flush to their outsides and inside) to a.) dissipate loads away from the localised stress of the welds, and b.) to shorten the free length / span of each segment.  (These being higher than the car's sides, I used the inner gusset on either side for conveniently positioned seat belt mountings)
• the triangulated legs were tied back to main roll bar at their feet, to stop them from bending / splaying.  
• the main structure was bolt through the body tub and directly to the chassis rails.
• the ties to the rear diagonals were through bolted to the body tub (along the length of corner between the inner mudguard and the flat area over the rear axle).
• the length of 'feet' (both the transverse beam and those running back) allowed numerous bolt positions to be picked up. These distribute alongways tearing, twisting and pulling (..shear and tension) loads across a far greater expanse of body tub and chassis. Generally speaking, the more mountings, and the greater they are dispersed around the body &/or along the chassis, the better. (which is, in part, why roll cages work so much better than roll bars). Backing plates were used under all fastening bolts, to minimise the risk of their ripping-out.
• similarly compression loads (ie., the car landing inverted onto them) are better distributed across a far broader expanse of body tub and chassis. (If a 3/4-tonne load of crashing car is hammered into a wheel-arch, via a very neat little 3" x 2" pad - then the 1mm thick metal under that pad will buckle).
• used the car's lower seat-belt mountings to further tie its structure into reinforced / strong points of the car.  (these particular kit-cars also had side-beams, which tied into the windscreen post structure and a traverse beam under the dashboard). Body or suspension mounts and bump stop might likewise be so used, as might sills and the door's frame.
• The top width of the main roll over tube is narrower for a.) folding hood-frame clearance, b.) to encourage an inverted car to roll back over onto its side, thereby enabling the occupants to get out and away quickly, c.)  to minimise the structural beam's span length (short is stiffer than long un-braced lengths).  Of course the inside top width was still clear of the occupant's head.
• The roll bar was made from a suitable grade, thickness and diameter of steel and the tube's bending was smooth (kinks and folds focus high loads and potential failure).  The corners also had a generous radius (which in effect 'cut the corners' between straight lengths - again to minimise each beam's span (straight unsupported length).

I'm sure there are other aspects, but those are what immediately come to mind. 

No, such a design would not be approved for most racing.  It does not have an intrusive diagonal brace, nor does it have a cross beam for a 4-point seat harness. Nor does it have padding. But it was compact and so practical, and visually acceptable for a road car. 

I hope the above helps you (indicates what you might look for) when choosing a roll bar for your own car.

Pete.

 

* My design was a derivative of that designed by (now Professor) Anthony Stevens ..which was used in his Cipher  sports cars. It used a very similar loop with rear-diagonals but was welded directly to its multi-tubular chassis. (I had the great fortune to learn my trade directly from working for, and later with, Tony.  And he has remained a dear friend ever since).  

 

   

^  My own Falcon kit car. c. mid-1980's                                    .. and the Stevens Cipher 1980

In my opinion, the roll bar doesn't detract from either car's style.