Just got an announcement from NASA.


"No new logbooks will be issued after 4/30/03 to any race car
that has a cage made from ERW tubing. Cars with cages
certified before then will be grand fathered in."

For those of you who have been running HPDE with a ERW cage & planning on racing later in the year, just go out & get the logbook now. You don't have to race to have it. The car just must meet the minimum safety requirements per the CCR.

It also goes on to say that the SCCA has a similar ruling taking place 1/1/03 (or 4/30/03 - unclear to me) per a conversation with their National Tech. Dept.

 

What has to be done to have a certified Cage?

Inspection after it put in?
Or does a certified welder have to put the cage ine?

 

To get a 'logbook', the car must be inspected after all the safety equipment is in place. It is in section 16.0 of the NASA CCR.

http://www.nasaproracing.com.

 

Hey Mike, someone asked me this the other day and I couldn't answer. How do you tell if it's ERW or DOM once its installed?

 

so it doesn't matter who put the cage in as long as it has bars in the correct places, passes inspection, and its DOM and not ERW..

Is that correct

 

These are all 'I think' things. If it unpainted, you can see a 'seam' on ERW. ERW seems to have less surface hardness. Any cage buiders or tech people care to offer an opinion? I am going to email Ken @ IO Port to get more info. He is a local tech/safety czar (or **** - depending on who ask).

 

Yes....sort of. Doesn't have to be DOM until after 4/30/03. Doesn't have to be DOM, even after 4/30/03, if you had/have a log book issued prior to that. As far as weld quality, if you go that route, that is covered in the CCR too. I have a welder but I wouldn't do my cage!

 

ERW has a seam. Those who know what they're looking at can spot it rather easily.

 

wouldn't the DOM still have the seam since its ERW tubing to begin with since itts welded and not drawn tubing.

 

DOM = Drawn Over Mandrel

Thus no seam.

 

I checked the left over piece of DOM in the garage. Didn't see a seam especially when compared to the ERW stuff used for the back brace.

BTW, Ken didn't have time to go into it with me right now.


[Modified by civicrr, 2:57 PM 1/9/2003]

 

DOM starts life as ERW. Then it is drawn. Whether or not the seam is still visible, I have no idea.

 

Can you measure the thickness of the tubing to determine DOM vs ERW?

 

Here's a description of the process:

http://www.webcoindustries.com/tubin...om_process.asp

Seems like the point is to work the material enough to remove the discontinuity caused by the welded seam.

 

Again, I am no expert but.... No. Both are available in various common diameters & wall thicknesses.

 

I have a message into the SCCA tech department regarding this rule. When I hear back, I'll post.

 

it sounds like the erw version is sort of out of date or they would not be getting ri of it. I think for my own piece of mind I will probably buy the newest version rather than what is deemed out of date.

 

I'm going to answer the debate from a book published by the National Tube Company (now a part of USX. THis book contains all of the processes used for making tubing commonly manufactured after 1938.
DOM is tubing made without ANY welding whatsoever. The ingot is drawn over a lance and thru a rollset/die to form the tube. This is a hot metal process or can be formed cold depending on the type and size of the tube. At no time is DOM manufactured from welded stock according to the literature I have. For those interested in more on this subject-take a look at Shelby Seamless Mechanical Tubing from USX.

The proof of what your cage is made from rests with you and the source of the cage (KIRK, Autopower, Art Morrison). You need to have a certificate from the builder showing the materials used to be on the safe side of the rules.
True you can "grandfather" your existing cage in. It is also true that upon close inspection there will be a visible seam in the case of ERW. (BTW: there are several varieties of welded tubing too)

I have no convenient way to put the pages of the book online. Contact USX or a metals supply house for literature.


[Modified by jc836, 9:55 AM 1/13/2003]

 

Both John and I were pursuing the SCCA tech department, I guess I was a bit more vigilant and finally got through before 6am Pacific time.

I spoke with both Jeremy, the technical director for club racing and with Doug Gill, the technical director for Solo. The reason for my conversation with both of them will become evident if you keep reading.

My first conversation was with Jeremy and centered around the change from ERW to DOM. Yes, the change is official as of 1/1/03, to be issued a new logbook you are required to have a cage made of DOM. The comments in the January Fasttracks are for the discussion that was taking place at the meeting. They discussed moving enforcement of the rule to 1/1/04 and tabled the decision until "comments from the stewards" could be made. From my discussion with Jeremy the comments are in and they are not delaying implementation of the rule. So if you wish to go door to door with SCCA and do not yet have a logbook I hope your cage is DOM.

My situation is a touch different, I don't plan on going door to door racing, my goals are more modest at this time... I want to participate in Solo I events. Thus my conversation with Doug Gill. The rules for Solo I are not changing. The 03 GCR (appendix k) will remain as it is was written in 01 and 02. For cars under 3500# the tubing must be 1.75" and .120" in thickness. So therefore my 4pt autopower bolt in will work - phew!

The folks at the SCCA were a pleasure to talk with and I must thank them heartily for taking the time to answer my questions and persistant calls

Nash - who realizes the crack pipe is now in his hands, the question is "what will he do with it?"

 

Thanks Nash. Anyone want to buy a boat anchor?

 

Besides the seam, the tube will probably be visibly ovalled at the bends.

 

jc, there can be multiple ways to produce DOM tubing. starting from a solid ingot may be one method, whereas starting from a previous ERW tubing may be another with different cost/strength benefits. just a thought.

 

Tyson-thank you for your input. As I noted, USX does NOT have a rerolling method in their standards. DOM is drawn into shape. I only wish I could figure out how to post the pictures I have of this process versus the 2 welded (ERW) processes that are in this handbook. I am not a metallurgist (my father was) but do know that there are standards that are published for the types of tubing we are talking about. I might add that it is my understanding that "Shelby" tubing is the norm for roll cages.

 

so i did a quick google search "dom tubing". there are of course many manufacturers for steel and DOM tubing. many (most, all?) of them do describe DOM as specifically starting from ERW.

http://www.copperweld.com/pdfs/LTV_DOM%20Insert_FI.pdf
http://www.summosteel.com/products/
http://www.plymouth.com/PDFs/DOM_Broch.pdf
http://www.lonestarsteel.com/aboutus/business.asp

also, it seems (haha i kill me ) that shelby seamless tubing is a specific type of DOM tubing, but most DOM tubing is in fact drawn from ERW. second to last page kinda mentions that.
http://www.copperweld.com/pdfs/MechPocket.pdf




[Modified by Tyson, 11:38 AM 1/14/2003]

 

Tyson: I see where you are coming from. I do know that several cage builders spec the "Shelby" tubing as it is in fact seamless. You may also want to take a look at the 2 types of ERW that are generally available (depending on diameter and wall thickness. Then decide which type you want from a strength and performance point of view.
Happy racing
Update-I just spoke with someone at USS Tubular Products department. He informs me that indeed the current state of the industry is to take ERW and cold draw it over a mandrel. This does produce DOM tubing. Thanks for your insight. I stand corrected.



[Modified by jc836, 3:26 PM 1/14/2003]