Once the ship has sailed, the Operations Department who will repeat all these procedures for the discharging operations.In the case of a time charter the procedures will differ slightly from those for a voyage charter described above. The time charterers will be issuing voyage instructions to the vessel so that it is most important to ensure that the Master is advised who those charterers are including the details of any manager or agent who is authorised to issue instructions on their behalf. The Master must also be advised of the length of the period and the intended trade(s) as far as these are known. It is common for owners to prohibit certain (e.g. dangerous/dirty) cargoes and certain politically or geographically repugnant areas. The Master will need to know about these so as to react promptly if he receives contrary orders from the time charterers. The most urgent information will, of course, be 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 owners at the time of that delivery. Most ships today run their main (diesel) engines using intermediate Fuel Oil (IFO) for normal running. The auxiliary machinery (e.g. electricity generators) usually operate independently from the main engine (although some ships can take power from the main engine to turn the generators). Auxiliary machinery also uses IFO although sometimes Marine Diesel Oil (MDO) or a blend of MDO and IFO is used. MDO may also be in older main engines for starting and warm-up or when manoeuvring because the response time to rapid changes of speed or direction of revolutions would be too slow when using IFO. However so far as possible IFO is used because it is very much cheaper than MDO. When the ship is in port the main engines are, of course, shut down so that the consumption of fuel used reduces but most of the auxiliaries have to run all the time so there is still some usage. If the ship is using its on-board winches or cranes to load/discharge there will be a higher consumption to supply the extra electricity required.