As the education of maritime college has a characteristics of seafaring professional institutions, the potential benefit following from the employment of seafarers would put substantial impact on it. The socio-economic position of seafaring occupations has been deteriorated considerably with changes of ship's auto-mation, specialisation and low cost operation management of shipping companies through severe internatio-nal competitions. The quality and number of applicants for the maritime college has declined and most students have no hopes for the study of seafaring subjects which followed bewildering in their college days. However, the demands for seafarers are fairly large from the viewpoint of national maritime industry. The maritime institutions should not only meet these demands but also revitalise students by reforming the educational contents. The contents should be influenced by the social approach to educational needs in particular maritime shore-oriented subjects. The maritime education is no more restricted to the sea, it covers the land based world of the maritime industry as well. The new contents will lead the maritime educated students to the shore-based occupa-tions after finishing their seafaring if they want to. This may not only make ways to the maritime educa-tion fruitable, but also the students have a zeal and hope for the subjects taught.

A lot of studies of ship's economy are on the traditional fields such asreducing propulsion resistance, raising cargo handling rates and lessening building consts, but there are few researches on the merchant ship's economy concerning their deadweights and speeds according to shipping companies managerial cercumstances. Contrary to the contemporary trend that "the bigger, the better, if the cargo handling rate could increased sufficiently to hold down port time to that rate of smmaler vessels", this paper demonstrates the existence of certain limits in ship's size and speed according to the coditions of the freight rates, voyage distances, cargo handing rates, prices of fuel oil, interst rates etc. Fom the curves of criteria contour for various ship's deadweights and speeds which are depicted from the gird search method, one can get the costs and the yearly profit rates under the conditiions of large volume with long term contracts for the transportation of bulk cargoes. In estimating ship's transportation economy, the auther takes the position that the profit rate method is properer than the cost method, and introduces the calculation table of the voyage profit rate index. The use of the criteria contours will be of help to ship owners in determining the size and speed of the ship which will be built or purchased and serve in a certain trade route.

There may be a lor of studies on the economic design of ship for the most favorable combination of design basis on the owner's request. However, there are few on the economical ship's size and speed for the ship owner's stand point. This paper describes on the optimal ship's size and speed to the given marine commercial environments for the owner's requirement to the shipyard. As the result of the paper, the criterion curve of bulk carrier will also be used to assess existing ships for their profitability.

Presently, there are some means of voyage estimations such as Hire base, Charter base, and Anticpated income and expenditure statement of voyage. The former two are the means of estimation for profit of a ship's voyage per a deadweight tonnage adn a month, and it is well used in the case of chartered ships. But it is somewhat meaningless for the shpowner who runs his ships for himself. The latter means for estimation is mainly used in western shipping, and do not set forth simpler way of comparing profit with another voyage or with another ship's employing in other route. And this paper has yielded an index of ship's voyage profit evaluation by building a model of ship's voyage evaluation formula, and the index may be used in evaluation of the new investigation of shipping as well as setting out a shiop in a voyage. The model has yielded a break even curve which may be used for deciding the amount of demurrage and the period of ship's port time for a specific voyage contraction.

As far as transportation problems are concerned, the minimization of transportation cost is the most prevailing object. But in some cases, the cargo delivery time is the utter problem rather than the cost. For instance, we may imagine the case that the delivery of the construction materials is delayed behind the schedule and this makes the construction cost increased because of idle time of other materials and man power, in addition to the indemnity. Therefore the allocation of ships, in marine transportation which is now the main route of overseas trade, to the needed area on the required time is to be appropriately performed. However, there are several restrictions for cargo delivery to meet the demand, such as ship's size, number to be employed and cargo handling capacity of the ports, etc. And there are some other factors to be considered, that is, the degree of necessities of commodities, on their kinds, amount, and the time of arrival, etc. This paper deals with the problem of optimum allocation of ships emphasizing the cargo delivery time adopting Linear Programming technique with those cargo delivery restrictions and factors transformed by introducing the multi-speed conception, the conversion of multi-commodity to a single commodity, allowable delivery time, weight penalty number and nominating priority. This paper presents a case of optimum allocation of ships in the light of cargo delivery time for a construction company which has two different construction places and analyzes the result. This study will give a planner a good tool for optimum planning of maring transportation and be used for decision of schemes.

A liner ship has its own freight rates on cargoes carried in the trade. This study is on the optimum combination of high and low paying cargoes to deduce the maximum freight revenue in various freight rates at the comparison of low paying freight rate with high paying freight rate in a liner trade. The solution is under the assumption that the probabilities of being booked of high paying cargoes are either a uniform distributiion or a normal distribution. A numerical solution is also used for deriving out the maximum freight revenue which will not have general solution, and also a numerical method is applied for the further-practical results of the clearer relations between high and low freight rates. From the result, we can expect a higher revenue by appropriate combination of high and low freight cargoes according to their freight rates comparison.