From Halopedia, the Halo wiki
Unlike the multi-role warships used by the Covenant, older, single-purpose vessels such as the Carrack have become important assets in Covenant remnant factions, as many of the warships of the Covenant have since been destroyed. Regardless, contemporary Sangheili fleetmasters have found Carracks to be capable and resilient troop and materiel transports, using them as both carriers and cruisers. Carracks can reinforce naval battle groups and transport entire armies. As in the days of the Covenant's foundation, their reactors burn with the fury of caged stars. By the time the Blooding Years began, Carracks had been upgraded to modern specifications.
Halo: Fleet Battles
Carracks were armed, three-masted ships developed by the medieval Genoese, and heavily used by the Spanish and Portuguese empires, to carry cargoes to and from their imperial territories in the Atlantic, Indian and Pacific oceans. It was a predecessor to the more well-known Galleon.
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