A liner service generally fulfills the schedule unless in cases where a call at one of the ports has been unduly delayed due to natural or man-mad causes.Liner carriers are referred to as common carriers.
A common carrier holds itself out to provide service to the general public without discrimination (to meet the needs of the toward the public's interest) for the "public convenience and necessity".A common carrier must further demonstrate to the regulator that it is "fit, willing, and able" to provide those services for which it is granted authority.
Common carriers typically transport persons or goods according to defined and published routes, time schedules, and rate tables upon the approval of regulatorsLiner vessels do not include ferries or other vessels engaged in short-sea trading, nor dedicated cruise ships where the voyage itself, and not transportation, is the prime purpose of the trip. Nor does it include tramp steamers, even those equipped to handle limited numbers of passengers.
Some shipping companies refer to themselves as "lines" and their container ships, which often operate over set routes according to established schedules, as "liners".
Ocean liners are usually strongly built with a high freeboard to withstand rough seas and adverse conditions encountered in the open ocean.
Additionally, they are often designed with thicker hull plating than is found on cruise ships, and have large capacities for fuel, food and other consumables on long voyages.
Example : The UK/NWC continent service of MSC which has a fixed weekly schedule calling the South African ports of Durban, Cape Town and Port Elizabeth and carrying cargo to the UK/NWC ports of Felixstowe, Antwerp, Hamburg, Le Havre and Rotterdam..Summary of major characteristics of liners / liner companies
- They are common carriers- Operate under fixed schedule / timetables
- Call advertised ports- Freight rates are somehow identical for all shippers
- Liner companies are bigger establishments- They issue bill of lading as evidence for the contract
- Carry general cargo consisting of finished productsA Tramp Service or tramper on the other hand is a ship that has no fixed routing or itinerary or schedule and is available at short notice (or fixture) to load any cargo from any port to any port..
Example : A ship that arrives at Durban from Korea to discharge cargo might carry some other cargo from Durban to the Oakland in the West Coast of USA which in an entirely different direction.. From Oakland say for example it could carry some cargo and go to Bremerhaven..