Underride protection bar

[spitzair]

Hi everyone,
I’ve looked all over and can’t find this anywhere... how high can a trailer be before it needs rear underride protection? Thanks.

 

[Truck Shop]

That depends on tire size. According to Utility the bottom edge to ground for under-ride
dot bar is 21" with LP 22.5 tires.

 

[spitzair]

Thanks Truck Shop. This would be on a deckover flatbed trailer with 235/80r16 tires on 7k lb axles...

 

[Coaldust]

In the future, those specs can be found under CFR 49 - 393.86.

(3) Guard height. The vertical distance between the bottom edge of the horizontal member of the guard and the ground shall not exceed 560 mm (22 inches) at any point across the full width of the member. Guards with rounded corners may curve upward within 255 mm (10 inches) of the longitudinal vertical planes that are tangent to the side extremities of the vehicle.

 

[spitzair]

In the future, those specs can be found under CFR 49 - 393.86.

(3) Guard height. The vertical distance between the bottom edge of the horizontal member of the guard and the ground shall not exceed 560 mm (22 inches) at any point across the full width of the member. Guards with rounded corners may curve upward within 255 mm (10 inches) of the longitudinal vertical planes that are tangent to the side extremities of the vehicle.

Ok so is it safe to assume then that if the underside of the deck is more than 22" above ground a guard is required? The intent of my original question is how high can the back of the trailer be before I need to install one of these guards.

 

[Truck Shop]

Pie are Square-No Jethro pie are round.

If the deck is higher than CFR 49 -396.86-22Z-----22" from bottom of deck to ground, then you will have
to add a under ride that is no less than Utility's 21"or 22".

 

[spitzair]

Perfect, thanks! That clears up my confusion! I appreciate the help!

 

[skyking1]

I have thought of retrofitting the company's older tilt with one. It was built well before 98 and is exempt. It would have to articulate.