. ▁It ▁was ▁on ▁this ▁route ▁that ▁the ▁fast est , ▁largest ▁and ▁most ▁advanced ▁lin ers ▁travel led , ▁though ▁most ▁ocean ▁lin ers ▁histor ically ▁were ▁mid - s ized ▁vessels ▁which ▁served ▁as ▁the ▁common ▁carri ers ▁of ▁passengers ▁and ▁fre ight ▁between ▁nations ▁and ▁among ▁mother ▁countries ▁and ▁their ▁colon ies ▁and ▁dependencies ▁in ▁the ▁pre - jet ▁age . ▁Such ▁routes ▁included ▁Europe ▁to ▁African ▁and ▁Asian ▁colon ies , ▁Europe ▁to ▁South ▁America , ▁and ▁migr ant ▁traffic ▁from ▁Europe ▁to ▁North ▁America ▁in ▁the ▁ 1 9 th ▁and ▁first ▁two ▁dec ades ▁of ▁the ▁ 2 0 th ▁centuries , ▁and ▁to ▁Canada ▁and ▁Australia ▁after ▁the ▁Second ▁World ▁War . ▁ ▁Sh ipping ▁lines ▁are ▁companies ▁engaged ▁in ▁sh ipping ▁passengers ▁and ▁cargo , ▁often ▁on ▁established ▁routes ▁and ▁sched ules . ▁Reg ular ▁scheduled ▁voy ages ▁on ▁a ▁set ▁route ▁are ▁called ▁" line ▁voy ages " ▁and ▁vessels ▁( pass enger ▁or ▁cargo ) ▁trad ing ▁on ▁these ▁routes ▁to ▁a ▁tim et able ▁are ▁called ▁lin ers . ▁The ▁alternative ▁to ▁l iner ▁trade ▁is ▁" tr amp ing " ▁where by ▁vessels ▁are ▁not ified ▁on ▁an ▁ad - h oc ▁basis ▁as ▁to ▁the ▁avail ability ▁of ▁a ▁cargo ▁to ▁be ▁transport ed . ▁( In ▁older ▁usage , ▁" lin er " ▁also ▁referred ▁to ▁ships ▁of ▁the ▁line , ▁that ▁is , ▁line - of - b attle ▁ships , ▁but ▁that ▁usage ▁is ▁now ▁rare .)