packsaddle
A saddle-like frame placed on a pack animal (horse, ox, etc.) to secure loads. Common in historical or rural contexts.
They loaded a packsaddle onto the horse and carried the goods.
Compound of 荷 (ni, 'load, baggage') and 鞍 (kura, 'saddle'). The reading にぐら is a rendaku form of くら.