保险公司要求明确船舶船龄

为防止部分船级社在签发证书时减少船舶船龄的情况出现．货物保险商表示，明确船舶的船龄非常重要。保险商要求明确船舶的船龄正是因为某些船级社签发证书时出现了减少船舶船龄的情况。“修改船龄“对货物保险商来说是一个非常重要的问题．因为他们主张对老旧船舶支付额外的保险费，     

世界船队的船龄分析

船队的船龄,是进行技术进步、船队更新、航运安全等决策的重要的背景材料。本文分析了世界船队的船龄构成与平均船龄的演变,以及船龄与报废率、灭失率的关系等。从中发现了船龄层次波动的规律,可以提高对世界船队增长,船龄结构与船舶更新数量的预测精度,为我国航运业与造船业参与国际市场竞争,制订相应的技术,提供必要的依据。     

数字

18年 据统计，截至2005年底，中国远洋油轮平均船龄为18年，比全球运输船队的平均船龄大6年。     

老旧河船分类及改建管理

老旧河船分为以下类型： （一）船龄在10年以上的高速客船，为一类老旧河船； （二）船龄在10年以上的客滚船、客货船、客渡船、客货渡船（包括旅客列车轮渡）、旅游船、客船，为二类老旧河船；     

油轮平均拆解船龄降至21年

疲软的运费市场正在加速船东拆解船舶的船龄年轻化。BIMCO日前表示,油轮拆解的平均船龄已从26年降至21年。2010年,平均拆船船龄曾降至19．6年,创下19年新低的纪录,当然这一记录与IMO当时发布淘汰单壳油轮密不可分。同时．逐渐降低的油轮拆解船龄从另一方面反映了油轮市场的低迷。     

“MSCChitra”号事故促印度推出一系列新安全措施

印度航运部长Vasan日前就印度最近发生的事故以及印度国会通过的大量新的安全措施给公众带来压力等一系列问题作出回应。Vasan以30年船龄，2314TEU的MSCChitra事故船舶以及28年船龄，4．2万DWT的事故散货船 Khalijia3为例，来阐释船舶到港的通知必须提前48小时到达港口这一新规。印度政府承认目前还有大约95艘船龄超过25年的老旧船舶。同时这些船舶都加入了印度船级社（RS）的船级．RS已于去年成为了IACS的正式成员。     

集装箱船拆解船龄创新低

日前，建于1999年的”Ocean Producer”号1500标箱集装箱船被拆解．船龄仅为13年，创造集装箱船在无损状态下拆解的船龄最低纪录。”OceanProducer”号．是Norasia公司10艘s级船中的1艘，该批船均建于1998年至2000年间。这些船最初就存在技术和实际方面的缺陷以至于难以达到设计指标。尽管大部分问题随后得到了解决，但并未达到预期目标。这些存在缺陷的集装箱船或面临高额的维修费用，其中包括一些低于20年船龄的船也存在被拆解的可能。     

PARIS MOU将重点检查高危船舶

从7月22日起,在Paris MOU覆盖区域工作的港口国控制检查人员将开始实行更严厉的检查.根据去年通过的和近日在克罗地亚Paris MOU委员会会议上讨论的新的检查要求,3000总吨以上和15年船龄以上的油轮、10年船龄以上的化学品和天然气运输船、12年船龄以上的散货船、15年船龄以上的客船(不包括滚装渡船和高速艇)将接受强制检查.以上船舶还要接受每年一次的扩大检查.作为一项新措施,Paris MOU还引入了一个目标因素体制(target factor).     

船东考虑通过拆船应对航运市场“大屠杀”

日前，欧共体船东协会主席Philippe Louis-Dreyfus提出了通过拆卸老龄船恢复航运市场供求关系平衡的方案，并希望该方案能获得欧盟的支持。Louis-Dreyfus先生并未透露将提议的具体船龄上限，只把范围圈定在22年到25年的老龄船。但他同时指出，仅基于船龄来考虑的拆船计划并不完善，因为众所周之，一艘到了拆卸年龄的老船，包括气体运输船，如果他们一直被保养得很好，     

船龄对旧油轮改造FPSO工程影响研究

为了评估船龄对旧油轮改造FPSO工程影响,以船龄为5年和15年的VLCC型油轮为研究对象,分析不同船龄油轮规范要求的差异性。基于S-N曲线和Miner线性累计损伤理论,按照全球海域航行环境条件,采用MARS软件对不同船龄油轮的纵向连接构件进行二维疲劳寿命分析,并显示出横舱壁上的各纵向加强筋的疲劳寿命。计算结果表明,针对改造FPSO在相对温和海域服役12年要求,5年船龄油轮油舱可不需要结构加强,而15年船龄油轮油舱必须加强结构才能满足设计需求。     

不同龄期混凝土抗氯离子渗透性试验

针对水运工程中混凝土抗氯离子渗透性试验龄期的不同选择，从普通及泵送混凝土两方面着手，分别进行28d与90d龄期的抗氯离子渗透性的测试，比较不同龄期的混凝土抗氯离子渗透性的结果有何不同，结合实际施工情况，从而提出评定混凝土抗氯离子渗透性的试验龄期。     

水泥加固海相淤泥室内配比试验与现场工艺试桩

针对软弱海相淤泥问题土的加固问题,依托香港机场扩建工程,首次在该地区开展深层水泥搅拌法(湿法)的室内配比试验和现场工艺试桩,着重研究淤泥的土性参数、水泥掺量和养生龄期等因素对室内和现场水泥土强度的影响,得出其强度随水泥掺量和养护龄期增加而显著增长的规律,以及不同龄期室内水泥土的强度比例关系。本研究为香港地区滨海软土地基推广应用DCM工法加固,提供了很好的工程借鉴和技术参考。     

养护龄期和矿物掺合料对砂浆氯离子结合能力的影响

为研究养护龄期和矿物掺合料对砂浆氯离子结合能力的影响规律,通过比较不同氯离子浓度检测方法的准确度和重现性,确定自动电位滴定法为最佳检测方法。采用自动电位滴定法,对不同养护龄期和掺入不同矿物掺合料的砂浆试样进行水溶性氯离子和酸溶性氯离子研究。结果表明,砂浆中水溶性氯离子含量随龄期延长而逐渐降低,而酸溶性氯离子含量与龄期无关;矿物掺合料中活性SiO_2和活性Al_2O_3含量,决定着固化氯离子能力;在中长龄期(180d)下,粉煤灰对氯离子的固化能力要大于矿粉的。     

信息化战争下的通信要求及技术研究

现代战争已经进入信息战争时代。信息已成为战争的关键要素之一,夺取信息优势是赢得战争的前提。因此,信息战争对通信提出了更高的要求。在研究国内外通信现状的基础上,结合军事需求提出了信息化战争下的通信要求,并讨论了几种先进的通信技术。     

A note on the age of radioactive tracers

The age of a water mass is often estimated experimentally using the radio-age computed from the distribution of a radioactive tracer (radiocarbon, helium–tritium). Deleersnijder et al. [J. Mar. Syst. 28 (2001) 229.] have shown that the radio-age underestimates the age of the water and is larger than the age of the radioactive tracer used for its evaluation. This result is generalized here to radio-ages computed from the ratio of two radioactive tracers. The differences between the different ages are also studied analytically and numerically as functions of the decay rate of the radioactive tracers.For small decay rates, the difference between the age of the water mass and the radio-age is shown to be proportional to the decay rate. It depends also on the level of mixing in the system; even radioactive tracers with small decay rates can provide poor estimates of the age of the water mass in a strongly diffusive flow. For small half lives, both the radio-age and the age of radioactive tracers decrease as the inverse of the square root of the decay rate.The same analysis applies to some extent to the estimates of the age of a water mass from stable tracers with known time dependent sources (e.g. chloroflurocarbons).     

An investigation into the existence of a two-tier spot freight market for crude oil carriers

Developments in environmental legislation have exercised increased pressure on the tanker sector to improve its quality. To date, the most influential and, indisputably, the most controversial piece of legislation against oil pollution is the U.S. Oil Pollution Act that was introduced in 1990. This paper attempts an empirical examination of the effects of these developments in the spot freight market. Using a database of Worldscale fixtures over a period of four and a half years, a series of statistical tests was performed with the aim of detecting the existence of any premium paid for vessels of lower age, double hull construction, or trading to the U.S.A. The results were mixed, indicating in several cases some form of premia for US.-bound vessels, but less evidence of premia for lower age and better hull construction.     

基于ABAQUS的载人潜水器观察窗结构蠕变行为分析

[目的]观察窗作为载人潜水器(HOV)人员和结构安全的核心部件,准确计算其长周期载荷作用下的结构蠕变性能极其重要.[方法]首先,基于观察窗树脂玻璃材料(丙烯酸塑料材料)拉伸试件蠕变测试数据结果,通过多参数比较优化方法确定时效硬化蠕变模型的基本参数;然后,通过ABAQUS进行观察窗结构建模,耦合时效硬化模型和结构接触,以...     

Changes in size at maturity of European hake Atlantic populations in relation with stock structure and environmental regimes

European hake (Merluccius merluccius) female size at maturity is estimated on an annual basis for Bay of Biscay and Galician coast, which are parts of the distribution of the Northern and Southern stocks, respectively. Clear trends in this reproductive parameter are observed along the time series and the potential factors affecting these trends have been investigated. Total biomass, different indexes of SSB, age diversity index, fishing mortality at age, NAO winter index, upwelling index and temperature were included in multiple regressions models to assess the relative importance of each of them on shifts in size at maturity.Bay of Biscay and Galician coast hake have followed different evolution in patterns of changes in size at maturity. In Bay of Biscay, a steadily decline of 15 cm has been observed from 1987 to 2004, which is well predicted by fishing mortality and age diversity, but also the environment may have played an important role. However, on the Galician coast a drastic decline of 16 cm from 1980 to 1988 was followed by a rapid increase in size at maturity during the next 10 years to original values and a stable period in the last 6 years. Decreasing biomass may explain the decline in size at maturity in the first period. However, total biomass and spawning biomass declined even during the period when size at maturity increased, which is contrary to compensatory theory. Shifts in environmental regime, NAO and upwelling, may have contributed to a decelerated growth during this period that might explain the later maturation.     

An econometric analysis of deficiencies noted in port state control inspections

The factors to consider in selecting which vessels to board for port state control (PSC) inspections are crucial. This paper tries to identify these factors using 4080 reported PSC inspections from the Swedish Maritime Administration for the period 1996-2001. It relies on count data models and compares results from the Poisson, negative binomial, random effect and random parameters models. The results suggest that three factors are the main determinants of the number of reported deficiencies: the age at inspection, the flag of registry and the type of ships. Conversely, the year when the inspection occurs does not seem to be a significant factor. Estimations also stress that the relationship between the age at inspection and the number of deficiencies detected is not similar for different vessel types. For instance, the number of deficiencies detected decreases for chemical carriers and Ro-Ro passenger vessels older than 25 and 22 years old, while for instance the effect is rather small for tanker and bulk carriers and only occurs when vessels are older than 35 years.