船舶营运经济性

运输成本The principal parameters to be considered in any marine transport system are:1. Cargo payload 11. Other daily running costs2. Ship cost 12. Bunkering pattern3. Speed 13. Fuel price4. Fuel consumption at sea and in ports 14. Port charges5. Round trip distance 15. Freight rate6. Cargo handling rate 16. Cargo handling charges7. Number of ports of call 17. Discount rate8. Service days per year 18. Depreciation policies9. Ship's life 19. Credit facilities10. Crew costs 20. Subsidies21. Escalation of costs and freights.Although the list of parameters to be established for alternative designs apparently only shows a few directly related to technical characteristics, in practice, a full process of naval architecture design is required to establish them, for example, calculation of cargo payload or fuel consumption requires as a minimum the establishment of basic data such as length, breadth, draft, depth, speed, hull form coefficients, power and type of machinery, dead weight and capacity.折旧DepreciationThe depreciation is not an actual cost or expenditure of cash, but a book transaction used for both tax and for accounting purposes. It is used to assess the profit available for shareholders after applying a rate on fixed assets that maintains capital intact in money terms at the end of economic lifeTypes of Depreciation:1. Straight Line Depreciation: In which the capital is divided into equal parts according to the number of years assigned for the project life (N).Annual Depreciation = (P – S) / NP is the capital; S is the disposal value or resale value2. Declining Balance Depreciation: In which the annual allowance is made equal to a Percentage (R) of the residual value of the capital each year.1st Year allowance = R x P2nd Year allowance = R (1- R) PNth Year allowance = R (1- R) N-1 x PResidual Value (S) after N years = (1 – R) N x PThe Declining Balance R = 1 – (S/P) 1/N3. Sum of the Years Digit Depreciation: In which the capital is allowed to be consumed in a progressively dec reased percentage depending on the remaining years of project’s life:Annual allowance = [(Remaining Years + 1) / Sum of the years] (P-S)4. Free Depreciation: In which the capital is allowed to be consumed as much as the return permits, in other words , writing the project off as fast as the difference between revenues and expenses permits and extinguishing all liability for tax until the full consumption of the capital .船速的选择The ship operation is managed according to speed decision which is dependent on whether the freight rate is known or not.The operation speeds may be classified as follows:1. Optimum Profitable SpeedIs the speed which the best to be decided, it is the speed which gives the highest profit at a known market freight rate.2. Zero Profit SpeedIs the speed at which the freight rate will be the minimum RFR and there will be no profit?3. Economical Speed:Is the speed at which the least cost per ton mile will be paid , this speed is not dependent on freight rate , it may be with profit or with loss , it is best used if there are no boom freights and in depressed market conditions .经济指标，NPV及RFR等Net Present Value (NPV)The net present value of income and expenses is a good measure of economic success of any project.NPV = PW (Annual Cargo x Freight Rate) - PW (Annual Operating Costs) - PThis is for the life span of the ship.B. Criteria for Unpredictable Future Income.1. Average Annual Cost (AAC).The most economical ship is that which produce the service at the lowest average annual cost, this is in case if the alternatives have the same revenues annually.2. Required Freight Rate.If revenues vary between alternatives, and the choice is done between different ships, the required freight rate may be a suitable criterion; it forms the least income per ton of cargo.RFR = AAC / Cargo TransportedOrRFR = (CR. P + Annual operating expenses) / Annual Cargo Transport3. The Specific Cost (Sc).It is the most suitable criterion in many ship design problems, it can be considered as a suitable measure of the economical utility of the ship, it does not use the future income which is mostly unpredicted, this criterion is defined as the cost of transporting one ton of cargo through a distance of one sea mile or the cost of unit energy of ship's transportation.The specific cost has to be the minimum between alternatives.Sc = PW (Overall Costs through the Life Span)Total Cargo Transported x Distance Traveled in Sea MilesElements of Operating Costs of the ShipA well-established economic criterion must be based on proper and accurate evaluation of costs elements of the ship, the costs elements of any ship may be as follows:A. Capital or First Cost,B. Operation Fixed Costs (speed independent)1. Manning (Crew),2. Victualing (Provision),3. Stores and Supplies,4. Maintenance and Repair,5. Insurance,6. Administrations and overheads.C. V oyage Costs (Speed dependent)1. Bunkering at Sea and in Ports,2. Port Dues and Canal Dues,3. Ancillary Voyage Expenses which may include Commissions.。