rams/catapults

Anyone used'em till now? I'd like some quick info on how to use, who can use, restrictions and so on about them.
Thanks :) .

PS:i dont need to know how to make em, thats easy.

Military Engineers can use them. You are not allowed to have pets spawned when you wanna spawn rams/catapults, not even pick pet.
They have around 500k hp and you can move at decent speed with them.

You can make them every 1 or 2 hours, forgot...

Anything else?

I hope you're right.