Slave vessels dispatched from Northwest Europe were larger and more heavily armed than their Iberian and American counterparts. The barricado, a heavy wooden barrier located midship, separating off men-slaves, was a central feature not found among slavers in the South Atlantic. The Portuguese operated vessels in which many crew were Black, including some enslaved. These were able to talk to captives in their own language and provide some assurance that they would not be eaten on arrival and would have some familiarity with their new environmrnt. Rebellions of slaves on Portuguese vessels were unusual. The Portuguese/Brazilians also did very little ship trading. Instead, they used bulking centers on land to hold slaves prior to their embarkation en masse. This reduced the time a captive would spend on board, which was already shorter than those of their Northwestern European rivals because of the shorter voyage times to Brazil from most parts of Africa. The Portuguese were thus the most efficient of all national slave traders. The bulking centers in Upper Guinea and Angola were connected to trade routes through to the interior and manned by lançados, usually half-African and half-European. The shipping part of their system was adopted by all slave traders in the nineteenth century.