Is this 70 ton Flexible or not ...?

The difference is that on a west coast trailer the axles are on a beam that pivots at the back of the trailer (Walking beam or coffin box)

The booster attaches to the axle beam but not the trailer body

on an east coast The axles are attached to the trailer and the booster is pinned to the back of the main trailer frame.

 

Interesting. That east coast trailer looks very similar to what we use out here in western Canada.

 

the hydraulic accumulator or nitro ones are east coast

 

We have a handful of these that get a lot of use. They are tough and can stand up to heavy use. These require a ton of shims as well. Lol

 

Now one needs a nice stack of dunnage to make that work