Dry Docks Research Articles

Anthropogenic Biotic Interchange in a Coral Reef Ecosystem: A Case Study from Guam

Guam is the administrative and economic hub of Micronesia, hosts one of the largest U.S. military bases in the Pacific, and lies at the crossroads among Pacific islands, the United States, and Asia. Although terrestrial introductions, exemplified by the brown tree snake, have received much attention, marine introductions have been little studied until now. We have documented a diverse assemblage of marine species brought to Guam by human-mediated transport: a few intentionally, most unintentionally. Sessile species dominate the nonindigenous biota. Because of Guam's tourism-based economy, ballast water is not a major source of introductions, but ship's hulls have brought many invaders. A study of the fauna associated with two dry docks demonstrates the large impact of such structures, moved slowly from harbor to harbor after long residence times. The majority of nonindigenous species have remained confined to artificial substrata in the harbor, but some have invaded adjacent coral reef habitats and spread islandwide. Although several nonindigenous species are now well established, major impacts to reefs on Guam remain to be identified. Space on reefs is vastly dominated by indigenous species; in contrast artificial substrata often have an abundance of nonindigenous species.

Tributyltin contamination in two estuaries and adjacent ocean coasts: Puget Sound, Washington, and Narragansett Bay, Rhode Island (USA)

Summary Concentrations of butyltins in the tissues of gastropods and measures of imposex in Nucella spp. and intersex in L. littorea were used to assess the levels of TBT contamination in two estuaries, Puget Sound and Narragansett Bay, both of which are subject to high shipping activity. Concentrations of butyltins in gastropods collected from both areas were low, although higher than those in adjacent coastal waters of open Pacific or Atlantic Ocean sites. Commercial harbours and dry docks were still hot-spots of contamination, but serious impacts were localised to within a few kilometres of the sources. Marinas were formerly highly polluted, but levels of contamination are now low, indicating that regulations prohibiting the use of TBT-based antifoulants on vessels <25m in length have been effective in reducing environmental levels of these compounds.

Degrees Of Physical Adaptation: Current Uses OfHistoric Naval Building Types

Historic naval buildings in dockyards across Europe, now redundant for defence purposes, present particular opportunities and challenges to appropriate reuse. Their specialised shapes and dimensions are important factors to what futures they can expect, as are location, funding policy, the surrounding land uses and the historic value placed on them. Adaptation proposals also need to be measured against various conservation criteria and degrees of intervention. In this paper the outcomes of the interaction between cultural and physical constraints on reuse of generic dockyard building types in different European countries are examined. Their varying fortunes are set out according to their history, characteristics and degrees of permissable adaptation. Roperies, storehouses, sail lofts, boathouses, covered slips and wet docks, dry docks and basins are considered. There are of course difficulties of comparing like with like, buildings of different dates and dimensions, but analysis of adaptation of these typical dockyard types offers some general lessons and examples of different countries' responses to the challenge. In Venice Arsenale, some important monuments have been restored for their own sake, reflecting local political culture, although many others await creative reuse. In Sweden historic naval monuments are excellently restored and kept in good condition, whether they have a current use or not, while Skeppsholmen in Stockholm and Karlskrona offer exemplary reuses of whole historic naval sites. In the UK navy buildings have usually been treated as utilitarian structures, to be radically altered to new uses, left empty or demolished. The advent of conservation in the 1970s perhaps prevented further demolition. Low key uses of storehouses, for example for archives, may mean minimum intervention, while intensive human use exposes them to the full rigour of modern building and safety legislation. A high degree of design skill is needed to conserve robust original structure in combination with clarity of insertions for new services and uses. Transactions on the Built Environment vol 55, © 2001 WIT Press, www.witpress.com, ISSN 1743-3509

The newshot Isle project

The economic events of the late 1950s and early 1960s precipitated a crisis of major proportions for British shipbuilding, hitherto one of this country's most important and prestigious industries. Severe competition from new and reconstructed economies in the Far East and Western Europe would terminally challenge outmoded management and labour relations in an industry which had led the world for a century. Although there would be no respite for British shipbuilders, the industry endeavoured to meet the challenge from abroad by embarking upon yard modernisation schemes, as if these alone were the panacea for righting the industry's deep‐seated problems. However, this agonising period was accompanied by the dramatic increase in the size of crude oil carriers, soon to be given the acronym VLCC (Very Large Crude Carriers), which added a twist of their own and give rise to the Newshot Isle Project. These vessels, at that time approaching 250,000‐dwt, had prompted a number of foreign yards to construct large dry docks in which to build them. As dry docks appeared to be a highly efficient way to build such large vessels, several of the larger British shipyards pondered how they might reorganise their productive resources by constructing large dry docks within the physically restricted areas their yards occupied. For world renowned shipbuilders, John Brown & Co. Ltd of Clydebank, the extraordinary proposal was made, biblical in scale, to divert the River Clyde into a new channel and build three giant dry docks in the redundant riverbed. However, such a massive scheme would require public money, as the estimated £25 million it would consume was well beyond the means of beleaguered John Brown & Co. At the same time, the Labour Government of the day, alarmed at the crisis facing British shipbuilders, established a Committee of Inquiry to report in 1966 on restructuring and financing the industry in a hoped for return to profitability. This article looks at the imaginative but unfulfilled John Brown proposal, and charts its progress in the face of the Government's own proposals for shipbuilding on the River Clyde.

Biological treatment of mineral oil in a salty environment

Mineral oil may be spilled into the marine or coastal environment through the discharges of ballast and bilge water, dry docking activities and tanker and non-tanker accidents to contaminate both of the seawater and coastline, especially in harbors. The unsuitable storage and disposal of wasted mineral oil may also contaminate saltified soil or brackish groundwater that have been polluted by salty wastes or intruded by seawater in coastal areas. In order to clean those contaminated sites, the mineral oil must be removed from the salty environment. In this study, a lab-scale aerobic biofilter-biotrickling tower system packed with particulate plastic media (1.5 cm, hexagon in shape) was used to treat the salty artificial wastewater polluted by mineral oil (diesel fuel) mixed with chemical dispersant (CPC OD-10) and inorganic nutrients. The volatile organic compounds (VOCs) escaped from the biofilter due to aeration was then treated by the biotrickling tower of the treatment system. According to the experimental results, the optimal removal efficiencies of the emulsified diesel in this salty water was found to be 95% controlled under concentrations as high as 1000 mg TOC/L of diesel in the influent and volumetric loading rate of 1.5 kg TOC/m3-day. The biodegradation rate constant (k) was measured to be 0.169 hr–1 for a first-order reaction assumed. As to the removal efficiency for VOCs, a low percentage of 68.2% was measured due to short hydraulic retention time (10 seconds) applied to the tower. However, only a small fraction (7.9%) of total amounts of diesel was measured as VOCs. The chemical dispersant used in this study was biodegradable, which could be used as a surfactant to emulsify the mineral oil into seawater for biological treatment. Due to short HRT applied to this aerobic biofilter-biotrickling tower treatment system, both the surface area and reactor volume required to build this treatment equipment are thus decreased to make it more easily set up in a mobile ship or truck. Thus, we may treat the mineral oil in marine or any other salty environment more conveniently.

The use of imposex to assess tributyltin contamination in coastal waters and open seas

Imposex in muricid gastropods has been used to monitor tributyltin (TBT) contamination worldwide. Pollution was severe during the 1980s but regulations prohibiting the use of TBT-based antifoulants on vessels <25 m in length have been highly effective in reducing TBT levels in coastal waters. Large vessels are still sources of TBT and major ports, especially those with dry docking and repair facilities, continue to be hot-spots of contamination. Measures of imposex suggest that severe pollution is normally localised to within a few kilometres of them. Mild imposex, possibly as a result of TBT pollution (although other causes have not been ruled out), has been described in whelks Buccinum undatum from offshore waters of the southern and central North Sea. However, the species is still abundant there and the occurrence of imposex does not seem to have affected its breeding performance. Imposex was mild or absent in populations of dogwhelks from open oceanic sites around the north Atlantic Ocean, suggesting that the oceans are free of contamination at biologically significant levels.

Widening of the Great Lakes Bulk Carrier MV Algoville

The Senneville was built in 1967. She was managed from 1973 to 1990 by Scott Misener Steamships (later Misener Transportation) and from 1990 to 1994 by Great Lakes Bulk Carriers (GLBC). With the demise of Great Lakes Bulk Carriers (GLBC) in 1994, the ship was purchased by Algoma Central Marine and the name was changed to Algoville. This paper gives a brief outline of the history of the ship, including ownership and events leading up to the need for major structural modifications and also discusses some of the design aspects leading to the decision to widen the hull from 75 ft-3 in. to 78 ft-0 in. (22.8 to 23.7 m) beam. A brief description of the widening project by Port Weller Dry Docks is presented, followed by some thoughts on the results of the widening and the successful operation of the vessel since returning to service.

A Study on the Dry Docks built up in the Meiji period in Japan

The first dry dock in Japan is No.I Dock of Yokosuka Dock Yard and was built up in 1871 by French civil engineers. After that more than thirty dry docks had been built in Japan until the end of Meiji period. Now one of them is designated as a cultural asset, and another one is registered as a cultural asset by Japanese Government. So we need systematize a history and building technology of them. For that purpose, this paper tries to understand over the general state of them by following three steps. Firstly it makes a list of dry docks built up in the Meiji period, secondly we collect each material of them, thirdly, we visit to see existent dry docks.This paper indicates the characteistics of all the dry docks built in Meiji period from the folowing three view points:1) original technology for building dry docks was introduced by French engineers, 2) most of them were built of stone, 3) some of them are located in specified area, Kanagawa, Nagasaki, and the Inlands Sea.

The asian decapodHemigrapsus penicillatus (de Haan, 1835) (Grapsidae, Decapoda) introduced in European waters: status quo and future perspective

The Asian decapodHemigrapsus penicillatus (de Haan, 1835) was first recorded in European waters in 1994. The first specimens were collected in the estuary of Charente Maritime on the west coast of France close to La Rochelle. The current range in Europe covers Spanish shallow water habitats of the Bay of Biscay to areas north of La Rochelle (France). Densities of up to 20 specimens per square metre occur. This species has a high temperature and salinity tolerace and will expand its distribution in European waters. It is not clear whether this crab was introduced by shipping in ballast water or as a fouling organism. Based on a study of ship hull fouling in German dry docks this account provides evidence that hull fouling is a likely vector for the introduction of this crab. In August 1993, six juvenile specimens ofH. penicillatus were removed from the hull of a car-carrier. After its journey from Japan into European waters this vessel docked in the port of Bremerhaven (Germany) for a routine inspection and coating with antifouling paint.

Metals Pollution in Marine Sediments of the United Arab Emirates Creeks Along the Arabian Gulf Shoreline

The study of trace metals in the marine environment of the United Arab Emirates is very important since coastal regions are presently experiencing a phenomenal rate of growth in terms of industrial and urban development. Special emphasis is given to enclosed areas and creeks due to the vastness of these parts of the country’s waters, their richness in marine life. and the difficulty of combating pollution that may reach these areas. These creeks are used as harbors for hundreds of fishers and cargo boats. They receive intermittent and variable amounts of municipal wastewaters from many outlets in addition to various pollutants from many other wooden huts. dry docking companies, petrol filling stations, repair and storage yeards. The primary objective of this paper was to identify pollution levels and distributions of several trace metals in five different creeks sediments of the United Arab Emirates along the Arabian Gulf. MATERIALS AND METHODS Sediment samples were collected from five different creeks along the Arabian Gulf Coast of the United Arab Emirates using a Hydro-Bios grap sampler (Fig. 1). Grain size distributions were done using a standard set of stainless steel sieves and electric shaker. Trace metals analyses were done by treating the sample with hydrogen peroxide and diluted hydrochloric acid (Agemian. Chau 1976; Van Valian , Morse 1982). Measurements were carried out in duplicate by direct aspiration into the appropriate flame of a GBC model 906 atomic absorption spectrophotometr equipped with a simultaneous background corrector. autosampler and recorder. Duplicates, spikes and blanks were treated identically using the same reagents to test for precision, accuracy, and reagent’s purity in the analytical procedure. respectively. Percentage recovery for spiked samples ranged from 96 to 105 %. while precision agreed within 5 %.

オンボード・メンテナンスと入渠作業の日程管理の研究

In this paper, drydocking operations are scheduled in order to cope with the increasing number of on board maintenance (OBM) tasks. The critical path method (CPM) was applied to the dry docking schedule of a training ship. The following results were obtained: 1) the project scheduling techniques including PERT and CPM methods can be successfully applied to reduce the duration and manpower of docking operations; 2) spare and/or repair parts should be supplied according to the OBM schedule since increasingly, more jobs are going to be carried out on board; and 3) the life-cycle cost concept has to be established in order to keep the ship cost-effective within the constraints specified by operational and maintenance requirements.

Environmental Pollution Control: Regulatory Considerations and a Case in Point

During recent years, the United States has paid increasing attention to controlling and minimizing environmental pollution. One result of this attention is the development of new laws and regulations, enforced by the Environmental Protection Agency (EPA) and by state and local agencies. These new environmental laws and regulations are considerably more stringent than those of past years and they directly impact how shipyards must conduct their operations. This paper discusses these laws and regulations at the national, state (including California, Virginia, and Connecticut), and local levels. With the environmental regulatory background in focus, the paper proceeds to explore the effects of the regulatory trend on one particular segment of the shipbuilding and ship repair industry: floating dry docks. Floating dry docks provide an illuminating example, because of the environmentally sensitive industrial activities carried out on board, such as grit blasting and painting with antifouling paints. The operational norms of floating dry dock pollution control are discussed, starting with present day commercial and Navy facilities, and culminating with the Navy's newest floating dry dock design, the AFDB 10.

Occurrence and fate of tributyl‐ and triphenyltin compounds in western mediterranean coastal enclosures

AbstractTributyltin (TBT) and its degradation products, mono‐ (MBT) and dibutyltin (DBT) have been determined in the dissolved and particulate phases of seawater, sediments, and biota collected in some representative open and enclosed coastal areas of the western Mediterranean Sea. The highest levels were found in sediments and seawater of dry docks and marinas, closely related with boating activity and clearly decreasing according to the distance from the point sources. Triphenyl‐ (TPhT) and diphenyltin (DPhT) were also identified for the first time in seawater and sediments collected in marinas, exhibiting concentrations similar to TBT. Concentration ratios between TBT/DBT and TPhT/DPhT in each environmental compartment as well as the field partition coefficients (Kd, K′d, and Kb) of the different tin species point out the complexity of organotin speciation, because accumulation and degradation processes occur at different rates, depending on the environmental compartment.

Organotin compounds in the Mediterranean: A continuing cause for concern

Abstract Extensive survey data for butyltins are reported for Mediterranean coastal waters together with the first phenyltin concentrations from the region. Elevated levels of tributyltin (TBT) are reported for most marina/harbour waters. In the great majority of cases, the ‘no observable effect’ aqueous concentration of 20ng litre−1 is exceeded. The TBT concentrations encountered are comparable to those reported in a previous MEDPOL pilot survey. This questions the efficacy of current legislation in the Mediterranean. The movement of foreign vessels painted outside of the scope of legislation offers an explanation for this observation and endorses the need for region-wide control measures and enforcement. The Contracting Parties to the Barcelona Convention have recently agreed to adopt such control measures to protect the Mediterranean; these are described and discussed. Concerning triphenyltin, concentrations of 21–94 ng litre−1 are reported, with most of the compound associated with the particulate phase. The distribution in samples collected from marinas and in proximity to dry docks attributes the origin of the compound to antifouling paint leachates.

Inputs of tbt to the marine environment from shipping activity in the U.K.

Abstract Following legislative measures to ban the use of tributyltin‐based anti‐fouling paints on small boats in the U.K., a programme of investigations has been commissioned to examine inputs from shipping. Shipping activity has been divided into three categories for investigation: (a) commercial harbours; (b) anchorages; and (c) dry docks. Significant concentrations of TBT have been measured in harbours and at anchorages, in some cases exceeding 50 ng 1−1 TBT in the water column in the immediate vicinity of ships. However, the contribution to environmental concentrations of TBT from anti‐fouled yachts caused difficulties in assessment of the inputs from ships alone at many of the sites under investigation. Dry‐docking practices have been shown to result in discharge of hazardous concentrations of TBT and such activities are now subject to a voluntary code of practice.

Shipyard Facilities—New and Old Closures for Dry Docks

Among the many old and new shipyard facilities, this paper depicts three types of closures for dry docks, one old and the other two new, and discusses them from the standpoint of operation, capital investment, life cycle costs, and adaptability to specific sites. The first is a sliding caisson, used in the 40's, the second an innovative double keel caisson, and the third is a seldom-used cantilever-type flap gate, which appears to have great potential. In addition, a recently installed intermediate dock gate is presented.

Comparative study of the design methods for pile foundations with specific reference to the dry docks of Cochin shipyard : Babu, D R; Jose, B T Proc 8th Southeast Asian Geotechnical Conference, Kuala Lumpur, Malaysia, 11–15 March 1985V1, P3/48–P3/57. Publ Kuala Lumpur: Organising Committee, 1986

Comparative study of the design methods for pile foundations with specific reference to the dry docks of Cochin shipyard : Babu, D R; Jose, B T Proc 8th Southeast Asian Geotechnical Conference, Kuala Lumpur, Malaysia, 11–15 March 1985V1, P3/48–P3/57. Publ Kuala Lumpur: Organising Committee, 1986

Technical Challenges Associated with Dry Transportation

Less than twenty years ago the first jack-up drilling rig was transported "piggyback" on a submersible barge. Dry transportation of extremely large and heavy cargoes has developed rapidly ever since. Specialized ships have been designed and built; records (with regard to weight, size or complexity of the transport) have regularly been broken. In this paper, the development of heavy-lift transportation is outlined, followed by a review of present heavy-lift design criteria. Technical challenges associated with several types of heavy-lift cargoes such as jack-up/semisubmersible rigs, dry docks, jackets, tension leg platforms, and modules are discussed. The importance of the transportation engineer's involvement in the preliminary project engineering stage is emphasized.

Expander bodies as ground anchors : Broms, B B; Nord, Ground EngngV18, N7, Oct 1985, P19–23

A new type of ground anchor, the expander body anchor, has been developed by Atlas Copco MCT, Stockholm, Sweden. This new anchor consists of a folded thin steel sheet, the expander body, which is inflated in the ground. The anchor is placed in a predrilled hole. The new anchor can be used to support a sheet pile or slurry wall, to increase the stability of slopes or to resist the high uplift pressures acting on dry docks, subway stations and hangars. The ultimate tensile strength of the new ground anchor can be evaluated from the maximum grout pressure required for the inflation of the expander bodies or from the results of different penetration tests (cpt, spt or wst). The ultimate tensile resistance of the new anchor has been tested in different soils in Sweden and compared with that calculated from the results of penetration tests (weight soundings), the undrained shear strength of the soil as well as from the maximum grout pressure required for the inflation of the expander bodies. The proposed calculation methods were found to give results which in general are conservative and safe.

Criteria for Capacity Certification of Dry Docks and Significance of Classification and U.S. Navy Standards as They Affect Ship Safety

Extremely expensive and sensitive warships as well as valuable merchant ships are being docked in a wide variety of dry docks, many of them not originally built for the modern vessels and often operated by crews with very rudimentary training and experience and with limited engineering backup. Only since 1973 has Lloyd's Register of Shipping had published rules for steel floating dry docks, and the ABS rules were created only very recently. Following the example of the 5th Naval District, NAVSEA in Washington started the MIL-STD-1625 code using very limited personnel and funds to prepare a dry dock certification program to attempt to insure ship safety in all docks. It is a serious mistake to think that certification is a cure-all. Adequate qualification of the docking crew is just as important, including skill in dealing with special problems with special ships.