I am running a little personal survey.  How many of you run where there are lasers that are used to set the barrels?  It would probably only be in an indoor arena.  Also do you know what color the lasers are?  Give color.  Just curious.  Are there any indoor arenas that do not have the lasers?  

Several indoors around me use them, pretty sure they are all red colored.

Thanks

I have ran at several arenas that have them and they  shine a red light down to mark the stake.  It's so much better than restaking the arena ever time the tractor rips up a stake.

Not really your initial question, but this amazed me. These big arena MOVE throughout the day---they chase the sun and can move up to a foot. Ran into this recently and I could not believe it but I guess it is pretty normal. So if the lasers are set---the pattern can move up to a foot.

How is this possible ? I don't see how position of the sun  in a covered arena would alter a laser beam ?

I don't see how it could move that much either. Moving a foot back and forth over a 24 hour period would cause metal to loose in walls and your welds to lose integrity. I have never heard of arenas getting safety inspected because they move. 

Yes, of course they do expand, minutely, but it would take 1,000 degrees to expand 9" per 100'. 

https://www.fireengineering.com/fire-prevention-protection/construction-concerns-expansion-of-metals/#gref

It happens---was at the pole bending finals and they said it happens all the time. Poles were on lasers and they moved throughout the day so they were constantly checking it with a tape measure.

Was telling a buddy of mine about it that builds big buildings---he said, oh yeah, they move all over the place. He will be building one that he has to put an overhead crane in and the engineers will be there and shoot measurements and by the time they go to set the cranes it will have moved.

Also---the building that this happened with is 580' by 360'---not all clear span but a huge part of it is.

Hmmm. I asked my hubby who has worked in construction all his life. Doesn't sound right. For an enclosed, insulated, "normal" indoor arena facilty, you won't have movement like that. Maybe really slight fluctuations if you have large temperature swings throughout the day ... but not a FOOT.

I get that ClearSpan is going to move some in the wind, but I guess I don't think of that when I think of an indoor arena. But still, a whole FOOT? That much constant movement and you'll have a building that isn't going to last.

So new question - at least where I have been where they have used lasers for barrels, they've also had lasers for the timers. (which usually don't get moved for drags)  If a building is going to move that much, you'd see timers getting moved around too. Which I haven't seen.

I'm sorry but your comment on the timer made me laugh!!!  Those buildings can't possibly move a foot. The vertical walls for the various rooms like offices, restrooms, concession stand would buckle. I mentioned before that the welds would be compromised. When I was a kid and we didn't have wire cutters, we would bend the wire back and fort until it broke. Same concept. Ask your husband, bet he has done that too!!  

I guess I was mistaken then, I was one of the ones setting the poles.

I mean bridges do have the gaps for expansion but they are like a max of 4 inches apart so that wouldn't cause a huge difference in the pattern size. I would think that if the building was moving a foot there would be ground level evidence of the shift at each weight bearing pole but who knows.