Back in the day Eminem lamented to Moby No one listens to riddles answer so let it go

I have many applications, To assist rubber on roads. As a tourniquet temp. Hydraulic helper for loads. Building me can be deadly, Something often explodes. Unless your vessel’s the lesser, Twenty thousand leagues below.

I stand tall, yet hollow inside, A fortress green, where secrets hide. Though wood I seem, a grass I claim, What am I, whispered in nature's name?

I follow you everywhere, I copy your every move. You can’t hold me, But I’m always with you.

I help you wait your turn, stay calm, and not complain. Without me, things get messy what am I you must train?