ABS not required

Used to be anything above 50 ton wasn't required to have abs, not sure what the current rule is.

 

No abs on my 65 ton

 

My 55 doesn't either but it's an 06 so I was allowing for a change since then. But yours is pretty new. Curious, was abs an option?

 

No it wasn't

 

Abs is exempt on 51 ton or more.

 

The reason why is air reservoir capacity.
The amount of air capacity required by an air brake equipped vehicle is determined by the number of brake chambers on the unit.
The more tonnage carrying capacity you have, naturally requires more axles, which correlates to more brake chambers thus increasing the air reservoir capacity.
ABS systems have the ability to make way more applications and releases than a driver can due to ECM control as opposed to an actual air pressure signal from the brake pedal.
This means the ABS system has the ability to demand more air volume than the reservoir capacity as well as the ability of even a >30CFM twin cylinder compressor can replenish via a 3/8" DOT approved brake supply line can handle.
So to remove the possibility of an ABS system to completely deplete the air system and engage the emergency spring brakes to a total unit lock-up leading to a loss of vehicle control, large tonnage (>50) units are exempt.
So it's actually safer for large capacity unit to NOT have an ABS system.

 

Yep and you don't need maxi brakes either

 

I don't have those on the big trailer either

 

For some reason my 55 has them on the middle axle, this is the only lowboy I ever pulled that had Maxi brakes.