[Helge B.]

How was horse armour especially the bulky sort made of solid plate transported?

Did the warhorse wear it all the time or was it put on cart? I think the first way would be quite uncomfortable for the horse especially on hot and sunny day. The latter would greatly increase the logistic effort for a fully armoured knight.

[Lafayette C Curtis]

The cart. The extra logistical complication probably wouldn't have mattered all that much to a man-at-arms who already had a squire, a page, a bunch of servants, pack animals, and probably a couple other carts to deal with. Also, it's worth noting that medieval tents and pavilions were usually even more cumbersome to carry than horse barding, but they managed to carry them anyway!