Have had 2 timing light sensors hit by spinning cars at the finish at the last 2 events.

Wondering what folks are using to protect the sensors from damage from being hit by cars?

Lindsay - Colorado Springs, CO

This has been a topic of concern for our region in the past. At one time, we used solid sided milk crates. These provided some environmental protection for the lights, but were easily damaged if they were hit by cars. Wind could also be a problem, so we had some bricks in them to keep them stable, until we realized that the bricks became projectiles when hit by the cars.

These were replaced with very stable and solid custom build metal housings on an adjustable tripod stand. These worked great, and allowed the lights to survive in an impact. But the trade-off is that these were strong enough to actually do some damage to the cars that hit them. In some way, this served as a deterrent to them being hit, but accidents can still happen.

Some of the best designs that I've seen use the lights mounted in PVC tubes on tripods that provide weather protection and some accident survivability without being too dangerous to cars or spectators. The key is to use lights that can be placed far enough back from the course to keep them out of the way. Course design near the finish is also important. We almost always use a finish that allows the cars to finish under power and in balance. But accidents can still be an issue.

George M

Change the finish of your courses and it should not be an issue.

All the clubs in our area charge $75 (or more) if a competitor hits the timing lights. Even if there was no damage done to the lights, they have to pay. Problem solved. (been doing it this way for 4-5 years now)

Putting anything that could damage a car in the line of fire is not a good idea. (been there, done that....wasn't a good situation)

In San Francisco Region, we have our timing lights inside a light plastic milk crate.

Make sure you move the timing lights far enough away from the finish cones to allow for spinning finishes.

I can't tell you how many times I've walked a course and had to ask the safety steward to move the finish lights back farther. Course designers apparently don't seem to drive high hp rwd cars that spin without a moments notice....

I don't see how this could not have been the easy answer? Move the finish lights back away from the course more. Or make the finish more straight.

Some clubs don't have this luxury. Running on smaller lots creates certain challenges. But yes, we always move the lights back as far as possible to prevent someone from hitting them. But some people drive WAY over their abilities, so our $75 fine motivates them to dial it back a notch at the finish.

THere's a local region here that puts them inside 5 gal buckets that are closed up and weighted.

A guy went thru the finish kinda tail-happy and met one along side his mustang. You could hear the "thud" from 200 ft away. Think it left an impression on him that he won't soon forget.

That's not a legal thing to do. You can't put heavy objects on course. It's the same reason we have to stay 75 feet from light poles. I'd be pissed if I was the driver of the Mustang.

We have our lights in lightweight milk crates (no ballast), and they seem to work pretty good. Ours have been hit more than one would like, but the lights have been unharmed in any of those cases. Our theory is that in a big impact the milk crate would be sacrificial and the lights would be unharmed - but truth be told, the milk crates are light enough they just slide across the pavement after the impact unharmed.

I've seen some of the more significant light mounts out there, and they scare me with regards to karts and open wheelers. Having a 25# (or more) weight attached to the timing lights may be a 'deterrent' to having them be hit, but what if a kart still gets it wrong - something like that could kill a kart driver if they hit it just right. Autocross is meant to be a 'lower risk' motorsport, not one where messing up a corner is likely to cause serious injury or death (or even significant vehicle damage).

My suggestion would be just to mount the lights in something cheap and light that would be sacrificial if hit. The idea isn't to make the lights impervious to an impact, but to make the lights be protected in an impact and maybe have to replace the stand afterwards. If your stands take $5 to make and hits are still too common (and the course or light position can't be changed), maybe implement a $5 fee for hitting the lights.

I would think you might want to reconsider your course design or your site choices. Our local club runs a site about the size of a postage stamp that has curbs on all sides, and we still manage to run a legal, safe event, and in the 8+ years at that site, as far as I know, have never had a issue with the timing lights being hit. I agree that people need to not go nuts and drive within reason. I assume if people are getting out of control at the finish, there is likely a turn going into it. Maybe consider putting the lights after a straight or making it a tight corner (tight as in cones close together). before the lights. If you still have issues with your drivers, I would consider talking with them and their future at events.

I am not at all saying your $75 rule is bad. I like it. I'm just saying there are so many ways to design so that it isn't likely to happen. Careless drivers need to be dealt with separately.

I don't disagree with you. I don't think our lights have the greatest range, so that may be a big part of the problem as well. What lights are you guys using?

4" schedule 40 pipe filled with concrete would probably be adequate to protect the lights.

Using heavy pieces of metal as a deterrent is not in keeping with being "friendly".

At an FLR event a few years ago, the timing lights were about 60' beyond the last cones of a slalom. I hit the steel block and one of the trailing arms on my car was bent into a 90 degree angle. What was impressive about this is that the trailing arm looked like a soft piece of steel that could be bent back into shape but each person who picked it up couldn't budge it at all. That showed how much mass the protector has.

Was it my fault that I let the car understeer into a tank trap. Sure. But the penalty of a bent suspension piece wasn't appropriate. Laying a piece of heavy steel on an autocross course is not recommended. The only way to appropriately and adequately protect the timing lights is through course design.

http://www.flickr.com/photos/fudosh...hotostream

We had a similar incident. We had trouble with wind blowing the finish lights out of alignment. So someone's "solution" was to put spare tires on each of the lights. A driver who was taking a fun run in his buddies car, spun out and slid into the finish lights creating major damage to the bodywork. The driver was VERY upset. He pointed out that the tires weren't there when he walked the course. He said, if he would have known about the tires, he never would have drove on course. I think our club ended up paying for a large portion of the body work.

We learned an important lesson. :(

We use small sections of steel pipe flattened into a box just larger than the beams to protect them. Another local club built wooden ramps. Between the two, it offers a lot of protection to the timing equipment without being a huge risk of damage. The wireless equipment is another story...

Regardless of your site, you should never have a finish where the car is at risk of spinning, though. That's just poor course design. You can never design a course that protects every possible course a driver comes up with on their own if they get behind in a slalom or whatever, but you can (and should) design the course to end in a forgiving element with no hard cornering involved anywhere near the finish beams.

JA Circuits photoheads are usually mounted in milk crates, and get punted pretty easily if a car hits them. They are not as immune to wind as one would expect from a mesh-walled crate, but a few spare cones placed around them will usually keep them planted in less than tropical storm force winds without greatly increasing the vehicle damage risk.

Farmtek wireless photoheads mount on tripods. I really don't have experience with them to say if they cause vehicle damage upon collision.

RaceAmerica (and AXware) wired photoheads don't usually come with mounting hardware, but Vitek has a few different options pictured on the AXware web site. I think that he sells bent lexan, and has photos of large PVC electrical conduit elbows being used to house the emitters and receivers.

What I did with New York Region's RaceAmerica photoheads was to put them into a short piece of 4" PVC pipe, using a block of ethafoam to hold the sensors snugly inside the pipe. I originally made a set of wooden 2x4 T's and tie-wrapped the pipe on top of one, trying to get a 4" lift off the pavement. My wife found a bunch of tiny stackable 6" milk crates at our local dollar store, and they made even better stands for getting the lights/pipe off the pavement with minimal weight to cause damage.

If I had to do it again, I would go with a modified JA Circuits milk crate solution. I would take a full-size milk crate, and mount a piece of rectangular PVC house gutter downspout pipe on the inside of one of the sidewalls. Lay the crate on it's side so that the gutter pipe is on the highest sidewall, slip in the RaceAmerica photohead with some foam, and call it done.

WARNING! WARNING! WARNING! :-) If you are using the RaceAmerica/AXware photoheads, they do *not* like to be recessed in any type of housing. Whatever mounting system you devise, make sure that the lenses of the photoheads are flush with the ends of the housings. Even a 1" recess will cause all kinds of false trips in my experience, and I think that Vitek was the person who told me about this. Don't say that I didn't warn you. :-)

If anybody remembers the old McKamey/Evo school photoheads, they were mounted inside bent sheet metal and held down with two cones. The sheet metal offered no real protection, but did leave the first paint gouge in the submarine back in the day when a nameless Evo instructor hit the finish lights and somehow managed to throw the photohead and metal up behind the car where it impacted above the bumper skin. I have hit plenty of cones in my lifetime, but never had to remove a cone scuff from the rear bumper of the car when I hit it driving forward. Guess that's why he has/had lap records at Sebring, and I only have a National Tour trophy on my shelf..... :-)