Racing Safety with John Fitch
 |
Fitch Calls on Indy Officials to Modify SAFER Barrier Open Letter on the SAFER Barrier Use at the Indianapolis Motor Speedway
From: John Fitch Date: May 15, 2002 Subj.: Indianapolis SAFER Barrier Gentlemen, Congratulations on the courage you have demonstrated in addressing this challenge to the racing community. Tests of the SAFER at angles of impact of 50-60 degrees have now been conducted on the track at Indy, and certain deficiencies have become evident. We now realize that the steel tubes can be damaged and the total barrier does not displace and absorb energy over a sufficient distance. Fortunately, these problems can be resolved. The overriding deficiency of the SAFER is that the total barrier compression of 6 to 7 inches is insufficient to achieve significant energy absorption and G reduction. The factors that follow contribute to this situation and remedies are proposed. The failure mode of large thin-walled boxes, which the SAFER tubes are in section, is buckling. This is evident in the photo of the McGhee practice crash that appeared in the www.indystar.com website dated May 6, 2002. Punctures in the process of repair by welding, gouging for over 20 ft. and buckling of the tubes is evident. Extensive damage such as this could force cancellation of the race. If not, disrupting delays could result from a hit at the tube joint, locking the internal splices and preventing the replacement of the welded four-tube assembly. The remedy could be to plasma cut the locked joint out and have longer internal splice members on hand to bridge the gap in the four tube section. Polystyrene is a rigid polymer, not resilient and self-restoring. When compressed, it crushes, and because replacement of the foam sheets has not been reported, presumably it has not been crushed, and if so, it has not absorbed crash energy. Consequently, it appears to have failed in its two intended functions: it is too rigid to absorb energy or the tube assembly is too rigid to bend, and it would not be self-restoring if it were to be crushed by forces exceeding those that have occurred. However, it is assumed that the intention to provide for timely restoration is to replace the foam sheets during clean-up. In any case, the 21 inch thickness of the foam would be marginal even if its total crush travel were to be available for energy absorption, which would not be the case due to bottoming of crushed foam. Apparently, the only energy absorption to date has been by the deformation, penetration or gashing of the tubes, and that would be limited by the 6" total width of the tubes. The "soft wall" configuration (Click Here for a Diagram) I have been presenting at safety forums for the past 6 years including SAE Motorsport Conferences, (Click Here for More Details) is described in patent No. 6,010,275 issued on Jan 4, 2000. It specifies a steel car/barrier interface dimensioned to be impervious to damage by high angle impact, instead of the heretofore-favored conveyor belting and other non-metallic surfaces that I have maintained would snag and fail, which has proven to be the case. A bastardized version with plastic deflector panels was installed at Indy in 98 and failed. The second, the SAFER, now finally with a steel car/barrier interface, again has been improperly interpreted with the bold requirement for in-race repair by welding, or alternately by the time-consuming replacement of 20-ft. tube sections, as was done overnight following damage during practice. Every friend of motorsport wants safety innovations to succeed but recognizes that failure could inhibit future progress. In this spirit, further modifications during the week before the final qualifying or before the race are proposed. 1. Reinforce the impact surfaces of the tubes with welded overlaps. 2. Alternately, if time allows, replace the SAFER tubes with rails of the Fitch design, which will bend rather than buckle on impact (5"x5"x3/16"). Such rails would bend in the same manner as the similar component in the Box Beam longitudinal barrier, which is in use nationally on US highways. 3. Replace the SAFER foam panels with a different foam or another resilient material that will compress and absorb energy over a useful distance upon typical loading. 4. Replacement of the SAFER foam sheets by the resilient and self-restoring HDPE cylinders of the Fitch Compression design as described on the website, probably cannot be adapted in the short time available, beneficial as they could be. These cylinders have been approved for this purpose by the US Federal Highway Administration and are in service on highways nationally under the name of the REACT 350, for Reusable Energy Absorbing Crash Terminal. It is hoped that these proposals will be accepted in the spirit that they are offered, as logical steps in the process of learning on the job through failure, and their remedy through perseverance. I presume to express my opinions because my energy-absorbing highway barrier has saved untold thousands of lives over the past 34 years, as recognized by the attached government award (Click Here for Information on the Stonex Award). More convincing will be the approval of my racing safety innovations by the more than 20 experienced engineers, race surgeons and respected journalists including an SAE Fellow and three World Champion drivers. (Names available on request.) Having devoted much of my life to road safety and the last seven years to racing safety exclusively, I would be glad to share my findings with all interested parties and would be glad to meet at your convenience. Yours truly, John Fitch *Gary Nelson - NASCAR Safety Research Director Kenin Forbes - Director of Engineering and Construction, Indianapolis Motor Speedway Brian Barnhart - Vice President, Operations, Indy Racing League
|
|
||||||||||
Copyright ©2016 by Race Safety, Inc. Portions copyright John Fitch. All Rights Reserved.