Experience & Improvements
6/5/04


The new wall has held up well after novice school and 7 weeks of racing including the region 2 states race. It has proven itself quite rugged to real world impacts. So far, the UHMW plastic facing has proven indestructible to the rigors of racing. There has been two minor repairs required. A plywood panel cracked when two Jr. Honda cars locked together and hit it in the center of the panel. The plastic facing was intact and racing continued. The plywood was replaced after racing by 2 people in about 20 minutes, reusing the plastic facing. The PVC plastic weather cap on the top of the wall cracked when a car landed on top of the wall. The piece was replaced after racing in about 10 minutes with a spare piece. So far so good.


The large (6"x6") access holes in the top of the tires significantly weakened to top of the wall compared with the bottom. There was concern that the reduced stiffness on the top would promote cars going up and over the wall. The holes were necessary to allow assembly. The holes were effectively closed up by fastening 12" sections of tread onto to the top of the tires to cover the holes. These were fastened to the tires with deck screws. This stiffens the top of the wall and can be removed to permit access. It also keeps trash and rain out and gives a more finished appearance. This has been a good improvement.

So, how does it work?
Quite well. There have been 3 significant hits on the wall, where the cars hit the wall square. Two Jr. Novices locked together and hit the wall in turn 4. Both cars and drivers were uninjured and could continue racing. A couple of weeks later two Jr. Hondas did the same thing. Again both cars and drivers were able to continue racing. A heavy Honda car hit the wall very hard. The driver was very experienced and said the wall was much less traumatic to hit. He was also able to continue racing.

The slippery surface and flush fasteners have proven successful in allowing cars to glance off the wall when hit at a low angle. Cars do still ride up the wall when they hit at a medium angle. The new wall is no different from the old wall in this respect.

So far the soft wall liner has met the design goals:


Turns 3 & 4
2/28/04


Assembling the wall panels. The crew is fastening the plastic facing to the plywood backing. The painted plywood panels are stacked in the foreground.


Tires staged around the outside of the wall, ready for assembly. The wall assembly crew is starting on the wall proper.


Starting to put the panels on the wall.


Assembling the panels to the tires.


"Adjusting" one of the hand holes in the tires.


One group worked on assembling the tires to the wall. The second fastened the panels to the tires.


Assembled panels and tires ready to go. The compressor ran air ratchets that tightened the nuts inside of the tires.


Lots of extension cords running drills and the grinder.


Busy, busy, busy.


The wall taking shape. Click on the picture to see a close up.


The soft portion of the wall starts with a taper.


The white panels let the soft wall blend in with the existing wall. The 5 vertical bolt heads indicate where the wall starts. The 6 bolt heads in a circular patern indicate the joint between the panels.


The soft wall ends with a taper too.


Tire Day 2/7/04

Making the circumferential cuts for the access holes with a circular saw. This job was a bit smokey.

Loading the tire into the cutting fixture.

Making the cross cuts for the access holes with a portable band saw. The tire is pinched with a fixture to make cutting easier.

Drilling the drain holes with a hole saw.

Finished pile of about 130 tires. The tire on the top shows the finished access hole.

Prepared tires loaded and ready to go to the track. The small trash can is full of the cut out tread sections.

Thanks to the following families for helping prepare the tires for the Oaklane Soft Wall:


Oaklane Soft Wall Prototypes

Present Wall at Oaklane Speedway

1/2 Scale prototype soft wall with Polyethylene facing. Two foot long.

Full Scale prototype wall section, 20' long

Closeup of wall with quarter midget tire for scale

Closeup of UHMW facing on full scale prototype

UHMW Polyethylene facing will make this the safest and toughest track wall in the country. The Brand we used was TIVARŪ 1000 UV-stabilised.

A key part of this project was the research. The most important place for the softwall is where the cars hit the wall. To determine where the cars were hitting the present wall I took some data. The Oaklane wall atthe time was 30+ years old and is made from 1/8" steel sheet welded to 2" I-beams on 4' centers. This wall is tough and normally a car hitting the wall just chips the paint. When a car hits the wall very hard it leaves a dent in the wall. I took data by counting the visible dents in the wall at each 4' section then plotting them in a bar chart in relation to track landmarks.
It is clear that the most hits occur in turns 2 and 4. Besides counting dents the wall is visibly bent out in these locations. This is where the softwall needed to be built. Almost no dents were observed along the straights meaning these locations don't need to be protected.

An OLD arial view of the track showing the location of the poles for reference. Most of the hits were right by the poles exiting turns 2 and 4.

See more pictures of Oaklane speedway.