Aged Ships Research Articles

A Study on Life Assessment of Ships and Offshore Structures

In order to extend a life of ageing ship, it is necessary to make a study on feasibility for extending her planned life. Such feasibility study consists of life assessment with a condition survey/assessment, life prediction technique and availability assessment. Nippon Kaiji Kyokai (NK) has made a basic study for developing life assessment system of ships and offshore structures. The logic of procedures for the life assessment is shown diagrammatically in the paper. On the life assessment, special attention shall be paid to fatigue strength as well as protection of corrosion. In the paper, studies on fatigue strength of hull structures and maintenance procedures for well protection of corrosion are briefly reviewed. A discussion is made on several technical aspects of the assessment of aging ships.

Fundamental Study on Ship Life

Ship life depends on many factors. The factors will be divided into three groups, the law of nature, performance and economy. The laws of nature are mainly fatigue and corrosion which reduce the retained structural toughness in aged ships. The performance factors of social impact will sometimes act key point. For example, marine pollution has a great influence on types of ships. In economy factors, investment and its recovery are basic ones that should be analyzed, and cost sensitivity of each of the factors should be analyzed on the point of effect on life. And some investigations show low finantial merit in ship life extention. The authors investigated the factors for proper ship life in basic and fundamental aspect, and confirmed that it should be taken heads to link the factors together. The points to be cleared in engineering point of view are the properties of corroded plates, and some results show very low fatigue strength and fracture toughness that warn low strength redundancy of aged ships.

Bronze Age ship's cargo of copper and tin

A report on finds from an underwater excavation off the northern coast of israel: a copper ingot, 5 tin ingots, and 4 stone anchors, evidence of a possible bronze age shipwreck. Incisions on the ingots suggest a cypro-minoan inscription. Neutron activation analysis was used to determine the trace elements. The presence of copper and tin ingots in the same cargo may mean that bronze was produced by the crew. References.

On the Bronze Age ship model from Flores, Indonesia

Presentation d'un modele reduit de bateau decouvert a Kampong Dobo. Il fournit des indications sur la navigation, l'armement et le vetement. Epoque de Dong Son

A Study of the Old Aged Ships in Japan

The Author has written down this paper with a view to stimulate the replacement of Superannuated ships with new and better ones, for the sound development of the shipping and shipbuilding industries in Japan.In the first half of the paper there is given a full description about the fact that the development of Japanese shipping is mainly attributed to the importation of old ships from abroad since Japan started the modern shipping, but as a matter of course Japan was ever and is still a remarkable old-ship-owning country in the world. The Author compares the percentages of old aged tonnage of each of the shipping countries in the world and gives precise statistics about the old aged ships in Japan. He also gives a warning about the coming crisis of the rapid increase of old aged tonnage in Japan after about fifteen years, the most of the old aged ships at that time being the so called war-made vessels which are more or less peculiar and inferior in design, construction and performance. Turning to the importation of old ships, the Author describes about the tonnage, age, country where built &c. of the ships imported into Japan during last about thirty years. He also discusses about what has been the effect of the Registry-Ordinance in Kwantung Province (Kwanto-shyu) upon the old ship-owning in Japan. The reasons why Japanese shipowners buy old ships are explained and some hints are given concerning the policy to prevent the shipowners from buying old ships and to encourage them to turn towards new ships.In the latter half of the paper the Author describes about what are the relations of the age or date of built of vessels to the dead weight capacity, boiler pressure, market price, laid-up tonnage, scope of active service and sea casualty of vessels, and draws attention to the inferiority of old aged ships.There is a further field of investigation on the present subject and the Author has much to say from technical-, economical-, administrative-, &c. points of view, which was left out this time. Therefore there is not shown a concrete conclusion in this paper, it being left to the readers for the time being. But the Author believes that throughout the paper there will be some indications which one might easily find out.