Roll cages

[Jac Mac]

Frosty5, you simplificate too much, nothing wrong with HMC 's rules to retain the 15" tires, iron heads of the era... but then to suggest that all those cars should have a ~2013 compliant roll cage ... sounds like you want a foot in each camp, I have a problem with the current cage spec, it virtually requires a Hans device to make it safe, if you dont have the Hans device the chances are you will be KO'ed when your head clouts the longtitudinal bars in any sort of side impact, this is in my mind one of the major problems when fitting a current cage design into an older car, especially the smaller Euro, UK designs which have smaller/narrower interiors. A roll bar should be just that, a structure to prevent the roof collapsing in the event you roll the car, I think this would be enough for most classic type cars, the 'Cage' builds too many variables into the car in terms of stiffening the chassis, adding weight, inhibiting access etc.

PS, I shudder at the thought/vision of a cage designed by a 'legal eagle' [ ever noticed that both words use the same letters? ]

[ERC]

The personal history.

Original cage built in 2006 to MSNZ rules/materials into a steel shelled 1950’s saloon car weighing less than 1150kg, but sadly, cage builder(s)/owner never lodged any official paperwork, though pics and details were submitted prior to painting and provisionally approved November 2006.

End 2012, request engineer’s report as MSNZ wouldn’t pass it, but they stated that as long as the engineer’s report was satisfactory, it could be homologated. No guidance was offered as to the potential for the cage to fail the freeform test requirements, so the question has to be asked “Are/were MSNZ aware of the potential test results using the older spec steel?” Equally, are/were they also aware that even if built to the required steel spec, the cage would still fail their own tests?” If not, why not?

At the risk of repeating what was published previously on another thread – this is the cage as built to the old specs and submitted to the engineer. A basic cage only was required as this is not an out and out race car, but it would be nice to race in the MGCC series for example. Equally, side intrusion bars were deemed unnecessary as access was compromised in what is still a road car and the car is quite narrow and there is insufficient space for side bars without stripping out the heavy, steel, doors, compromising the interior totally.
An extra diagonal to the hoop would also mean moving the driver's seat forward - which is also not possible given that my build and physique is rather more more Angus Fogg than Ray Williams.



After a wait of four weeks, this is what was received:

Fabricator: Finally received engineer’s response and not good news, he wants many bars added, see his e-mail below. Some of the bars (the roof diagonal especially) would be extremely hard if not impossible to 360° weld in situ to also meet the regs.

Engineer: To get the cage to meet the stricter current safety cage rules, we will need to add extra tubes as shown below:
A pillar support, a door bar, x in main hoop, a connection between x and harness bar, a roof cross, and base of rear stays to main hoop.
This is major work, it may be easier to just build a new cage to the current rules?

Engineer's demands to conform to MSNZ requirements for homologation:




After a challenge – Engineer’s response: If you look in the new manual, it has three load cases that the alternative design must meet.

These include a vertical and side load on main hoop, case (i)
a side lateral and rear load on lateral at windscreen joint (ii)
and finally a side load on the main hoop (iii)
These load case also have maximum deflections of 50mm, 50mm, and 100mm.
I think these load cases are more than the standard designs shown on pages 298-303 in the book. Especially load case ii, which will require a pillar support and roof diagonal. That is why I recommend that you build a new one as in the standard designs.

ERC:Apparently, the outer bodywork is not included in the calculations. That means that even if you installed the cage in a Sherman tank, it is only the cage performance as a stand-alone structure that counts.
Like with Dave Silcock's, removing the front cage, suddenly makes the car legal, as you do not need homologation just for a rear hoop and back stays.

Would you want to wreck these door trims to accommodate an unwanted side extrusion bar, having spent so much time and effort in making them? Not to mention that a side intrusion bar would then make the window winder inaccessible and according to T & C (sic) window winding mechanism has to remain standard.

[Dave Silcock]

OK Dave, lets just park it there then as obviously this isnt gonna work. I still dont know what the Fraser report is as all I have seen as a roll protection report for your structure was from the Christchurch company that you paid for. Doesnt really matter though.

This morning I have asked 7 experts in motorsport fabrication from NZ and around the world regarding if the formula/figures that MSNZ currently use are wrong. All the FIA ASN's (country representatives) use the same formula/s and the NZ constructors are very comfortable with the current system.

As for Ray's scenario, that is more demanding to find a solution.

Perhaps in your previous career as a civil servant you could dictate to people when a discussion was over but those rules don't apply here. I think that what this discussion hinges on is the integrity of the participants. And in regards to this matter, and given your seeming inability to make meaningful responses to matters raised, I'll make it easy for you. Did you or did you not, on the 1st of Oct 2012 at 11.32am, send me an E mail thanking me for a report I had forwarded you from M C Fraser Ltd., Consulting Engineer Wanaka ? And in that same E mail did you not CC to Brian and Julian at motorsport. org nz? A simple yes or no would be best.
It may interest you to know, seeing you seek to cast doubt on this report, as it is only an opinion in your view,I have checked with an engineer who graduated with a masters degree from Canterbury University, and he informs me that in matters of strength analysis of steel there is no room for opinion and any discrepancy will be the result of faulty calculations.
If you are so confident that your approved roll cages meet your own standards, perhaps instead of phoning the world for support, you could pick some of the designs from the year book at random and subject them to the same Finite Element Analysis [FEA] that my structure was.
But, apart from establishing what actually happened in this sorry saga, it does not matter as I have decided I will waste no more of my life on an activity administered by an organization so bereft of integrity and common sense.
So to those of you who have expressed a desire to see my car in action, I'm sorry but you will not hear the 7000rpm howl of the most highly developed and powerful XK engine in the world or hear the three 55mm Webers gobbling up the air it comes toward you, or see the three eared knock off's spinning against the polished Dunlop wheels.

But what the hell, someone in Wellington thinks a bit of procedure is more important than that!

[ERC]

So sad... I am fed up of being force fed a diet of Falcodores in various guises whilst potentially interesting cars are sidelined.

People will genuinely go "Wow!" when they see and hear the Jag on full song. Are our leaders so fixated on the boring stuff that they can't see or won't see what they are doing to the sport? Don't they recognise the NZ Heritage of building and racing interesting cars? Are they intent on everyone driving or racing blandmobiles in the future?

When I had an interview in the UK in 1982 for what was then a top NZ manufacturing company, I was told by the interviewer, "You will find that we are over administrated and under managed." I think he could well have been talking about other organisations.

[crunch]

Perhaps in your previous career as a civil servant you could dictate to people when a discussion was over but those rules don't apply here. I think that what this discussion hinges on is the integrity of the participants. And in regards to this matter, and given your seeming inability to make meaningful responses to matters raised, I'll make it easy for you. Did you or did you not, on the 1st of Oct 2012 at 11.32am, send me an E mail thanking me for a report I had forwarded you from M C Fraser Ltd., Consulting Engineer Wanaka ? And in that same E mail did you not CC to Brian and Julian at motorsport. org nz? A simple yes or no would be best.
It may interest you to know, seeing you seek to cast doubt on this report, as it is only an opinion in your view,I have checked with an engineer who graduated with a masters degree from Canterbury University, and he informs me that in matters of strength analysis of steel there is no room for opinion and any discrepancy will be the result of faulty calculations.
If you are so confident that your approved roll cages meet your own standards, perhaps instead of phoning the world for support, you could pick some of the designs from the year book at random and subject them to the same Finite Element Analysis [FEA] that my structure was.
But, apart from establishing what actually happened in this sorry saga, it does not matter as I have decided I will waste no more of my life on an activity administered by an organization so bereft of integrity and common sense.
So to those of you who have expressed a desire to see my car in action, I'm sorry but you will not hear the 7000rpm howl of the most highly developed and powerful XK engine in the world or hear the three 55mm Webers gobbling up the air it comes toward you, or see the three eared knock off's spinning against the polished Dunlop wheels.

But what the hell, someone in Wellington thinks a bit of procedure is more important than that!

1. Yes Dave; I do have that email. Thanks for giving me the exact reference.
2. Dave; I was never a civil servant as you imply. I was an Electron Microscopist who worked for the Govt and private industry simultaneously. Not an office body faceless entity beaurocrat as you are trying to imply.
3. I have given you the easiest option, out of this that will get you your roll protection. Maybe you should have been more on the ball a year beforehand so we didnt have to find a "backdoor way" of getting you a solution. That can still be used if you wish.
4. Sitting on file in the MSNZ office are FEA reports that do test the structures. I am informed they are correct. This was confirmed by local and overseas sources.
4. Frankly; it's your choice what you do, to say I dont really care would be a bit harsh, but I'm over it.

[crunch]

[QUOTE=ERC;23128]
Are our leaders so fixated on the boring stuff that they can't see or won't see what they are doing to the sport?
NO
Don't they recognise the NZ Heritage of building and racing interesting cars?
YES
Are they intent on everyone driving or racing blandmobiles in the future?
NO

Answers as we discussed on Saturday Ray

[Frosty5]

Hi again guys, well we have got ourselves into a right mess here to coin an old phrase. I have read and re-read the threads here several times and have changed my views somewhat to my previous comments. Like I said I don't have an axe to grind but there seems to be a level of bloody mindedness on this subject be it MSNZ or the participants (not sure which at this stage). I said previously "the rules are the rules" however, surely if the period cars raced previously with then certified roll cages and I certainly don't recollect anyone being seriously injured or god forbid, killed in a roll over back then, why shouldn't that designed roll cage be able to be certified today. Why is the "current" approved design needed anyway. Old story, "if it ain't broke dont fix it". I dont think the pointing of fingers and some of the language used on this subject is particularly helpful, it alienates people and before we know it the whole show turns to custard. How many other cars are in the same situation as Dave Silcocks? Can we/you or a body have these cars classed as heritage cars similar to the structure that is in place for old houses/buildings. Perhaps that would give the owners some protection from modern rules applying to classics - just a thought. Just try modernising a heritage home! All of us need to to compromise here somewhat I think, because if we don't we are going to lose some very interesting race cars and the history that goes with them - heaven forbid. These are just the thoughts of a simple country boy from the Waikato who has a passion for motorsport history. Cheers guys.

[Russ Cunningham]

Not being a helpful chap but hey! we can't all be.............An oldie but relevant.........A very wealthy man asks his ten year old son what he'd like for his birthday and the son says a "mickey mouse outfit" so Dad bought him MSNZ.

[Frosty5]

Not being a helpful chap but hey! we can't all be.............An oldie but relevant.........A very wealthy man asks his ten year old son what he'd like for his birthday and the son says a "mickey mouse outfit" so Dad bought him MSNZ.

WTF does that mean!!!!!!!

[jamie]

Russ you are Naughty BOY KEEP up the good work Jamie A

[Russ Cunningham]

WTF does that mean!!!!!!!

What does WTF mean???????????????????????????????????????????????????????????????????????????????????????????????????

I've come up with a few possibilities but I'm wary to make these public.

[ERC]

WTF = Wot the flippin 'eck (Unless you are very much tongue in cheek...)
I still can't use the fingers of my left hand, so as I was contemplating what jobs I can still do on the car, I was wondering if I have permanently lost the use of that hand, whether or not I then have a claim against the MSNZ technical Department, as the "disability" was caused when dealing to the cage?

Russ, I am with you. The price on my head is also about a buck, as:

a) I have finished producing offspring
b) I have seen my grandchild
c) There is no F1 drive ahead
d) I have travelled the world
e) The mortgage is paid
f) There is little or no consultancy work anymore so obviously my expertise is no longer required

Personal safety is my choice and my choice alone, which is why I choose to wear gloves (optional) and a neck brace (optional), a two layer race suit rather than single layer (optional), and race cars with roofs rather than open wheelers (optional), on a circuit with barriers rather than gravel roads bounded by trees (optional), four wheels rather than two (optional), so I don't see why the thickness of just one piece of steel tube is of any importance whatever and certainly nothing to do with anyone else.

[Carlo]

b) I have seen my grandchild


Personal safety is my choice and my choice alone,

so I don't see why the thickness of just one piece of steel tube is of any importance whatever and certainly nothing to do with anyone else.

It might matter to the one mentioned in b) for I would suspect they would like to have you forever

[crunch]

WTF = Wot the flippin 'eck (Unless you are very much tongue in cheek...)
I still can't use the fingers of my left hand, so as I was contemplating what jobs I can still do on the car, I was wondering if I have permanently lost the use of that hand, whether or not I then have a claim against the MSNZ technical Department, as the "disability" was caused when dealing to the cage?

Russ, I am with you. The price on my head is also about a buck, as:

a) I have finished producing offspring
b) I have seen my grandchild
c) There is no F1 drive ahead
d) I have travelled the world
e) The mortgage is paid
f) There is little or no consultancy work anymore so obviously my expertise is no longer required

Personal safety is my choice and my choice alone, which is why I choose to wear gloves (optional) and a neck brace (optional), a two layer race suit rather than single layer (optional), and race cars with roofs rather than open wheelers (optional), on a circuit with barriers rather than gravel roads bounded by trees (optional), four wheels rather than two (optional), so I don't see why the thickness of just one piece of steel tube is of any importance whatever and certainly nothing to do with anyone else.

Go on Ray, you secretly desire the gravel road and trees scenario...I know, it is the ultimate test! BTW, remember the email you were going to send me we discussed last Saturday? Be good to get that asap.

[Dave Silcock]

Go on Ray, you secretly desire the gravel road and trees scenario...I know, it is the ultimate test! BTW, remember the email you were going to send me we discussed last Saturday? Be good to get that asap.

True to form Raymond you fail to address the content of Ray's post. I have never found doing skids on gravel much of a challenge. I wont do rallies as I love my cars too much. If you need an ultimate test why don't you try racing motor cycles.

[crunch]

True to form Raymond you fail to address the content of Ray's post. I have never found doing skids on gravel much of a challenge. I wont do rallies as I love my cars too much. If you need an ultimate test why don't you try racing motor cycles.

I have Dave, it's what my father excelled at in the 50's, however after a few mishaps I decided to still go fast on loose surfaces, but just with some metal around me. I have addressed maybe some of Ray's questions via private conversations. I didnt realise there was actually something for me to address in the content of that post of Rays?

[ERC]

I am putting together an email for the Historic Commission (via Crunch) regarding the test requirements and a request that the approved designs as published in the MSNZ book have test results applied to them and the results pubished. Incidentally, my own cage has a couple of bars over and above the published basic design therefore is stronger and I'll also be requesting that any freeform cage has to achieve or better the same results as the lowest performing MSNZ approved design.`

I suggest that others do the same, but I am realistic enough to realise that this will not exactly over fill Crunch's mailbox and those of us caught in this trap are in the minority, caught up in a transition period. However, there are many existing cages that are deemed legal regardless of the test results, or the metal specs, but builders of freeform cages need to be aware of the requirements.

Dave's case I believe is based on the material used but my case is the performance of a cage built to a previous standard, so the issues are not identical.

[John McKechnie]

Crunch- If you are going to be at Hampton Downs this weekend, can we catch up with each other- blue XA Coupe 083.
I want to talk cages on my Team Cambridge Monaro.

[crunch]

Crunch- If you are going to be at Hampton Downs this weekend, can we catch up with each other- blue XA Coupe 083.
I want to talk cages on my Team Cambridge Monaro.

Sorry John, could only make the one day trip last weekend as it was my daughters first birthday on the Sunday and this weekend the in-laws are moving in for a while. Hell; maybe a good reason to come up!! Email me on crunch1@xtra.co.nz or ring (06) 3564058 (021) 2503055 or even that facebook thingy under Raymond Bennett

[Bruce Sollitt]

... remember I/we dont have to be doing this..

Actually, you do Crunch. Both yourself and the sport have a responsibility to sort issues that affect or prevent members participation. It is only right that you are attempting to do so.

Dave & Ray ... you have gone to some lengths describing issues around engineers reports etc... , however you've been vague on the actual reason your cages did not qualify for standard approval. I'm assuming it's simply down to the use of the 38.1mm tube in the main hoop rather than the newly required 44mm?
Assuming that's the case, can you relay any incidences of communication between yourselves and MSNZ during the 18 month lead time from rule change advance notification to rule change enactment?