For cargo transport, the Byzantines usually commandeered ordinary merchantmen as transport ships ("phortēgoi") or supply ships ("skeuophora"). These appear to have been mostly sailing vessels, rather than oared. The Byzantines and Arabs also employed horse-transports ("hippagōga"), which were either sailing ships or galleys, the latter certainly modified to accommodate the horses. Given that the "chelandia" appear originally to have been oared horse-transports, this would imply differences in construction between the "chelandion" and the "dromōn" proper, terms which otherwise are often used indiscriminately in literary sources. While the "dromōn" was developed exclusively as a war galley, the "chelandion" would have had to have a special compartment amidships to accommodate a row of horses, increasing its beam and hold depth.