boolean.. thanks for pointing out the size/body shape effects on encumbrance!
That makes it easier to find something that could lug it around.. MavrickWeirdo's suggestion of an elephant was good.
I made my calculations on being able to carry it as a heavy load, not just dragging it.
To be able to drag it, you need 27 str if medium biped.. if assuming we have a large quadruped (a horse), it needs a str of 17 to be able to drag it on the ground if favorable conditions (factor x2).. A heavy horse have 16 str. Two of them should do fine... if slow.
I cant find anything on the loading ability of a vehicle, like a cart/wagon - how much can you load on it, and how many/strong horses do you need to pull it? The PHB only lists how fast you can travel per day with a wagon..
Dannyalcatraz had some good suggestions also, on spells making it easier.. I can add one more suggestion, albit for short time spans.. the psionic power skate has a secundary benefit - you can manifest it on an object, reducing its weight 10x for dragging it along on the ground.
I guess there are some epic/near-epic PC's with these strength levels.. I can imagine a metamorphosed, expanded (huge), psywarrior myself..
Overall, this thread is kinda interesting, and shows that some logistical problems can be hard to solve, even by high-level parties, without resorting to lots of horses..
