Tested Low Bridge Height

[Neal]

Gassssssp, okay, no I didn't hit a bridge, well, yes I did. Heading from home (Richmond, VA) area on my way Gaffney, SC for my annual FL service (postponed from April 15th) on I-85 they had a few bridges that were interesting one as low as 13'10". GPS is setup, it's on I-85, all is good, I'm 12'10" according to Newmar, I think it's more like 13'2" but I have 13'5" in the GPS for a little margin. I have 2 (had) SureCall Omni antennas up front which are 9.25" tall (per my web search last night for replacements). One is attached to a mount on the roof, it's ABS designed for breakaway, one had broken months ago and I redesigned and attached to the front of a solar panel as it has a nice metal band around which makes things easy to attach to. Again, 3D print design with ABS for breakaway, well, it didn't make it to the CG with me. I had heard something twice while driving that caught my attention, I figured it might be thunder from the nearby storm. Nope. I noticed when walking the dog one of my white omni antennas was missing. On the roof I go (with a bad knee) and yep, nothing but wire left. Fortunately no damage to anything else, panels, AC, etc. Toad is fine, not sure where it ended up or if it disintegrated on impact. So yeah, the math is correct, I was right around 13'10" at the top of that antenna, bridge is validated

Fortunately I have too many antennas so I will likely just remove it's twin on the other side and no longer use that set that once was.

 

[Jabber Jaw]

,WOW! Glad nothing more happened!
Question, had that section of I-85 been recently repaved? Reason I ask, is when done, it decreases the height to the bridge by the thickness of the asphalt; but it is usually as you start under & go back out, as they tend not to pave directly under the bridge structure. You could have clipped the antenna, stating under, or coming out from under the bridge. I did see a warning sign about bridge heights about a year ago, but think it was on I-95. A friend that works for VDOT told me that when compressed, a repave adds about 2 1/2". Kind of scary when you think about it!
According to Newmar, my coach is 12' 11", but to top of the antennas, right at 13'2", & that's why I use 13'6"!
Good Luck on the return trip!

 

[Neal]

I don't know about the repave but I would imagine that would warrant a new measurement. I hope they would grade the old out so that when paved it is the same height. It was interesting watching the 18-wheeler next to me go under that bridge as they have to be really close to that height. I would love to know if Newmar's 12'10" measurement is to the top of the AC's or the roof line? As we all know, measure your roof and use that plus padding.

All is good, my biggest fear is a solar panel coming off and that's what I was concerned about when I heard the noise. Best case is it lands in the driver's seat of the toad, worst case is it kills someone on the highway! I hate that these things are held down only by 3M adhesive. Yes, you can screw them down too but most don't. Moral is, don't drive behind a RV!

 

[stang37]

I measure my 2016 Ventana from the top of the AC unit to the ground aired up a month after purchase. It wasn't load for travel and measured 12' 11". haven't thought about measuring loaded and aired up. Guessing it should be the same?

 

[TJ&LadyDi]

Yikes! That's way too close for comfort, @Neal. When you are at FL, would there be any way to have them do a true, at-travel-height measurement for you? Just a thought.

Safe travels.

TJ

 

[Neal]

Yikes! That's way too close for comfort, @Neal. When you are at FL, would there be any way to have them do a true, at-travel-height measurement for you? Just a thought.

Safe travels.

TJ

Thanks @TJ&LadyDi, arrived Gaffney shortly ago. Not needed, the situation is exactly as it should be. With the 9.25in antenna mounted on the side of the solar panel, which is elevated a few inches I think the tip of the antenna was right near 13'10". I just removed it's twin, just not needed and it was a bit of an eye sore. All is good and as I say, good things come from situations like this. You get better from it.

 

[sheridany]

i am thankful I can participate on this forum..and this is a great reason why...I have mine set at 13' thinking that should do it. NOT obviously. I learn something everyday.

 

[AbdRahim]

I thought all interstates were required to be 13'6", minimum.

 

[TJ&LadyDi]

Since 1960, the minimum height on interstate highways has been 16 feet. Prior to that, it had been 14 feet. But, there's a rub...or hit...to this requirement!

The height requirement change in 1960 did not require immediate correction of non-complying overpasses, bridges, etc. to 16 feet. When those structures were eventually replaced or rehabbed, the 16-foot height requirement was supposed to be met.

Any non-complying structures on interstate highways (less than 16' clearance) are required to be marked prominently with the actual clearance height and those signs must be placed far enough ahead for a driver to exit the highway safely and avoid the clearance problem.

As with all rules, they cannot be totally relied upon. Repaving the road surface can reduce the o/h clearance by a few inches each time it is done. That's why I set my GPS height to 14 feet. That gives me a theoretical clearance of at least 10" for my 13'2" coach and makes me feel a bit better.

TJ

 

[Buly]

Letting the air out of the air bags, gives you extra 4” of clearance. “Just in case “ you have no other option.

 

[NWIP]

Newmar states that Dutch Star is 13’. Mine was checked when coach was weighed at Escapees with height at 12’ 10” so am comfortable with Newmar spec. I set GPS at 13’6”, which I believe is standard on semi trailers. When I first got the newer high clearance coaches I had nightmares about becoming a convertible ?

 

[Neal]

Letting the air out of the air bags, gives you extra 4” of clearance. “Just in case “ you have no other option.

And I always forget that with HWH Active Air I can change the ride height on the fly so I can lower the suspension if needed. I'd never find it in time if not prepared for an upcoming bridge. But of course, there shouldn't be an issue regardless.

The other thing is it could have been a bird strike as I'm very good at hunting birds in my RV. I need to put 7 bird silhouettes below my driver's side window.

 

[AbdRahim]

@TJ&LadyDi: Very good info. Thanks. I will change the setting in my gps as well.