18-wheeler height?

[MSHappyCampers]

Thanks for all your comments!

[TandW]

How much do they shrink down when fully loaded by weight?

[Isaac-1]

Some trucking companies operate 14'0" trucks in the western states and 13'6" trucks in the eastern states. About 15 years ago we ended up storing one of these 14'0" trailers a the family business in western Louisiana 15 miles from Texas, for one of our suppliers for about 3-4 months due to it being a 14'0" trailer that failed to clear the 13'6" railroad underpass about 10 miles north of our warehouse (peeled nearly the entire roof off the trailer). We were the last stop for the truck and he was heading home to I think Minnesota, and someone apparently forgot that Louisiana is one of the few states west of the Mississippi with 13'6" standard height limit. It was an independent truck driver pulling a company trailer, I guess the driver knew he was not getting paid after the accident, so dumped the trailer in an abandoned grocery store parking lot and took off, we got a call a week or two later when the police tracked down the company asking if we could transport it over to our warehouse and store it until they could get a truck down to pick it up.

[BillJinOR]

We had a few older 14’ trailers in Oregon and Washington that were legal without permits , but they were phased out. All the current trailers are 13’6 which is the standard height. The 14’s were all marked everywhere as 14 in big letters as there are a few overpasses that you had to watch for.

[Glenn and Kathy]

Originally Posted by Theunz

I drove trucks in the LTL (less than trailer load) for about 40 years. We covered all of the lower 48 states and any one of our trailers, which were marked 13’6”, could end up in any state. All of the major players in the freight industry are the same. The only exception was trailers used specifically for city use. I would venture to guess that at least 90% of the semi trailers you see are 13’6”.
Here’s something to think about though, if the bridge signage says you have an inch of clearance and you run over a 2X4 board under the bridge your suspension may not compress enough to prevent you from scraping the top��

Reminds me of when I worked in a distribution center, we had a inside Dock and it required crossing a curb to enter. There was a heavy beam in the ceiling and a 13'6" trailer would just clear it. One day a guy came in with a trailer with the adjustable axle location set for shorter wheelbase. He was ok until his Wheels hit the curb and raised his rear by several inches. He smacked the beam hard enough he had to go get repairs done before he could open the doors. His delivery was a couple days late.

Glenn

[glwinger]

Originally Posted by jimcumminsw

Another point to think about is one side of the bridge may say 13'-6" (going north bound) and the other side could say 14' (going south bound) on the same roadway. I have seen this many of times when passing under a railroad bridge. Also, if in question of the bridge height travel in the left lane on a four-lane highway or over to the center if possible. Since the 13'-6" is measured from the lowest point of the road surface.

But, do they ever measure the height after repaving? Also, the left lane gong in either direction normally as more clearance. You'll often see signs that say "trucks, left lane only' when approaching some overhead roadways.

[koda59]

Many trucks today run low profile tires.

[Joebcf]

Drove truck 40 years 13’ 6 east of miss river 14’ 2 out west

[Larvettman]

13' 6"

[Bedlam]

13.5' is the interstate norm although some states are 13' or 14'. I am pretty close to that:

[Bedlam]

Originally Posted by Glenn and Kathy

Reminds me of when I worked in a distribution center, we had a inside Dock and it required crossing a curb to enter. There was a heavy beam in the ceiling and a 13'6" trailer would just clear it. One day a guy came in with a trailer with the adjustable axle location set for shorter wheelbase. He was ok until his Wheels hit the curb and raised his rear by several inches. He smacked the beam hard enough he had to go get repairs done before he could open the doors. His delivery was a couple days late.

Glenn

Same thing happened to friend in a parking garage with a full sized passenger van. It cleared fine until running over the recently installed speed bumps. The garage paid for damage and then changed signage.

[nehog]

Originally Posted by MSHappyCampers

Yesterday we were driving behind an 18-wheeler that looked really tall, but we saw him go under a 12'6" train trestle! I thought he was gonna scrape for sure!

Many years ago, I was following a car hauler in rural MA. I drove the route many times and knew there was a low rail bridge a mile up the road. Got near the bridge and said to myself, "He's not going to make that one," and hit the brakes and slowed down for the show.

He didn't slow down one bit--but I can tell you I saw no space between the top of those vans on the upper level of his hauler and that bridge. Bet he cleared with about 2 inches to spare, if that.

[jellison76]

As to repaving might raise the net clearance - in California look at the pavement under freeway undercrossings. 9 out of ten are the original concrete. That keeps the height the same. Otherwise, new paving will agree with the old signs or new signs are needed. bje

[dbrink153]

Originally Posted by MSHappyCampers

Is there a standard height for 18-wheeler trailers?

As a general rule, 13' 3", but it depends on size of tire's, etc.