 Before any troop transportation could be undertaken , all of the ships had to be hastily refitted . Of the fourteen ships , four , including El Occidente , were designated to carry animals and cargo ; the other ten were designated to carry human passengers . The four ships designated to carry animals had to have ramps and stalls built . All the ships had to have gun platforms installed , before each ship docked at the Brooklyn Navy Yard to have the guns themselves installed . All the ships were manned by merchant officers and crews but carried two U.S. Navy officers , Navy gun crews , quartermasters , signalmen , and wireless operators . The senior Navy officer on board would take control if a ship came under attack . 
