Report on survey and analysis of differences between U.S. Navy shipbuilding costs at naval and private shipyards; shipbuilding cost study.

The report is preceded by the Bureau of Ships' Analysis of Arthur Andersen and Company shipbuilding cost study (22 L.)

Blue book of American shipping : marine and naval directory of the United States; statistics of shipping and shipbuilding in America.

Mode of access: Internet.

The modern practice of shipbuilding in iron and steel.

1. Text.--2. Plates.

Shipbuilding & shipping record; a journal of shipbuilding, marine engineering, dock, harbours & shipping.

Mode of access: Internet.

Cost/benefit study of National Shipbuilding Research Program. 1971 to present.

Mode of access: Internet.

U.S. shipping and shipbuilding: trends and policy choices.

Mode of access: Internet.

Shipbuilding and conversion program /

Description based on: 1964

Possibilities of advanced MAG-welding processes in shipbuilding

In shipbuilding industry welding of primer coated and tack welded steel products cause different issues. Primer coated steel products are commonly used at shipyards to ensure corrosion free storage of products in outdoor conditions. However usage of primer can cause imperfections to welds. To prevent porosity primed steel products are usually welded with tubular welding wires. Tack welds cause commonly interferences in mechanized welding when over welded, which increases costs related to welding due to increased need of preparing and repairing. The aim of this study is to research possibilities of advanced solid wire MAG-welding processes to deal with these two previously mentioned problems. This study concentrates to examine possibilities of MAG-welding, pulse MAG-welding, double pulse MAG-welding, RapidArc and ForceArc processes. Large amount of experiments were made to find out the produced porosity and the ability to over weld tack welds with each process in different circumstances. In welding of primed steel products porosity is caused mainly by hydrogen, CO, CO2, nitrous gases and zinc fumes. It was found in experiments that porosity of MAG-welding can be greatly decreased by using pulse MAG-welding instead. Also reduction of welding speed, usage of air gap and usage of solid wire product with higher amount of alloying elements reduces porosity. Researched advanced MAG-welding processes did not have an improvement into over welding of tack welds. With studied throat thicknesses and welding positions conventional MAG-welding managed better over welding of tack welds than the four studied advanced MAG-welding processes. Studied solid wire MAG-welding processes would be best suited at shipyard for mechanized welding in welding position PB. In welding positions PD and PG tubular welding wires are clearly more productive.

Exposure to ambient heat and urolithiasis among outdoor workers in Guangzhou, China

Objectives: To assess the impact of exposure to ambient heat on urolithiasis among outdoor workers in a subtropical city of China. Methods: The 2003–2010 health check data of a shipbuilding company in Guangzhou, China were acquired. 190 cases and 760 matched controls were involved in this study. We assessed the relationship between exposure to ambient heat and urolithiasis for different occupations using conditional logistic regression. Results: Spray painters were most likely to develop urolithiasis (OR = 4.4; 95% CI: 1.7, 11.4), followed by smelter workers (OR = 4.0; 95% CI: 1.8, 9.2), welders (OR = 3.7; 95% CI: 1.9, 7.2), production security and quality inspectors (OR = 2.7; 95% CI: 1.4, 3.0), and assemblers (OR = 2.2; 95% CI: 1.1, 4.3). Overall, outdoor workers were more likely to present with urolithiasis compared with indoor employees (p b 0.05). In addition, workers with longer cumulative exposure time (OR = 1.5; 95% CI: 1.2, 1.8) and abnormal blood pressure (OR = 1.6; 95% CI: 1.0, 2.5) had higher risk for urolithiasis. Conclusions: Our findings demonstrate a significant association between exposure to ambient heat and urolithiasis among outdoor working populations. Public health intervention strategies should be developed to specifically target outdoor occupations.

海底管线强度评估中的两个问题

海底管线是海上油气田生产设施的重要组成部分,它一旦发生破坏会在各方面引起重大损失.挖沟和提吊引起应力超标是海底管线两种重要的破坏形式.挖沟和提吊问题的难点是:1)二者都是动边界问题,悬空长度本身就是未知量;2)挖沟问题中应考虑台阶升高处土壤支持的弹性影响(这比刚性处理更准确,但这会使边界条件更复杂);3)提吊是一个几何非线性问题,求解难度较大.本文给出挖沟和提吊作业状态下,海底管线的强度分析方法.在挖沟分析中,采用线性梁理论,将台阶升高处的土壤支持处理为线性弹簧.在提吊问题中,将管线模型化为大位移梁,采用打靶法,将边值问题转变为初值问题求解.文中还给出有关的典型数值计算结果.

跨越水域交通的阿基米德桥

首先介绍一种跨越水域交通的技术概念一水下悬浮隧道（又称阿基米德桥）的形成和发展历史、结构特点以及国际上正在进行概念设计和可行性分析的几个阿基米德桥典型工程概况。然后概括阿基米德桥设计分析中所涉及的几个关键科学技术问题。最后讨论阿基米德桥的设计方法和技术特点,强调现有海洋工程技术如张力腿平台技术等在阿基米德桥中的潜在应用,并对阿基米德桥的发展前景进行展望。

饱和砂土液化引起的变形研究

为了考察饱和砂土液化后的大变形及对海工结构物的影响,着重讨论了振动载荷作用下,荷幅值和频率以及土体渗透性对土体的变形的影响.为进一步分析土体变形和结构物的相互作用打下基础.

Transformaciones económicas en el sector costero guipuzcoano central durante el siglo XVII

[ES]El presente artículo pretende analizar cómo se desarrolló en el sector costero central de Guipúzcoa (Orio, Zarauz y Guetaria) la llamada «crisis del XVII» y qué mecanismos arbitraron sus habitantes para sobreponerse a las dificultades. En realidad, se trata de analizar y descubrir qué mecanismos utilizaron para llevar a cabo la reconversión y transformación de sus actividades. En el mencionado ámbito tres fueron las principales actividades económicas relacionadas con el mar: el comercio, la construcción naval y la pesca. Las tres actividades tuvieron que llevar a cabo una serie de reestructuraciones y amoldarse continuamente a lo cambiante de la realidad económica de la época a fin de perdurar y sobrevivir.