The procedures of a time charter differ slightly from those procedures for a voyage charter. Time charterers will be issuing voyage instructions to the ship so that it is most important to ensure that the captain (master) is advised who charterers are including the details of any manager or agent who is authorized to issue instructions on their behalf. Captain (master) must also be advised of the length of the period and the intended trade or trades. Usually, shipowners to prohibit certain cargoes such as dangerous and dirty cargoes. Shipowners prohibit certain politically or geographically repugnant areas. Captain (master) need to know about voyage instructions so as to react promptly if captain (master) receives contrary orders from the time charterers.
Most urgent information is the place of and arrangements that have been agreed for the delivery of the ship to the time charterers together with the name of the agents who will represent the shipowners at the time of that delivery.
Today, most ships run their main engines using Intermediate Fuel Oil (IFO) at sea. Auxiliary engines operate independently from the main engine. Auxiliary engines either use Intermediate Fuel Oil (IFO) or Marine Diesel Oil (MDO). Marine Diesel Oil (MDO) may also be in older main engines for starting, warm-up or when manoeuvering because the response time to rapid changes of speed or direction of revolutions would be too slow when using Intermediate Fuel Oil (IFO). Many ships use Intermediate Fuel Oil (IFO) because it is very much cheaper than Marine Diesel Oil (MDO). When the ship is in port the main engines are shut down so that the consumption of fuel used reduces but most of the auxiliary engines have to run all the time. Hence, if ship is using on-board cranes to load or discharge the cargo, there will be a higher consumption of Marine Diesel Oil (MDO) to supply the extra electricity required. In order to calculate all the ship consumption and stowage plan, captain (master) need to know about voyage instructions in advance.