Double Stacked Leaf Packs: Craziest thing ever?

My brother in law owns a welding company and I was visiting him at his shop to borrow a tool over the weekend. I was checking out one of his f250s and noticed some very strange with his rear suspension. He has a several aal's in the original leaf pack, then a block stacked on top of that, then an additional leaf pack stacked on top of the block, all bolted down with huge u-bolts. I'd never seen anything like it. He said he needed greater load capacity in that truck and a mechanic added the leafs for him. The truck is heavy; it has a custom steel flatbed on a diesel 4x4. Is this normal? Safe? Insane?

Check out the pictures:

 

that's not double stacking, it's just extra leafs

edit: installed incorrectly too

 

It just throws me off that he has a block in between two sets of leafs. It just looks crazy to me!

That said, it's a work truck and hasn't failed yet.

 

normal, for heavy duty overloads.

 

Pretty common on HD trucks. Most will only have one extra arched leaf above a block, but I've seen some with 3-4 like that one.

 

shows what I know...

He does carry some HEAVY duty stuff back there and pulls a trailer.

 

hey man i've never seen that either if it makes you feel any better

 

x3.