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    <title>Transport Research International Documentation (TRID)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <title>RECENT DEVELOPMENTS IN ANTIFOULINGS</title>
      <link>https://trid.trb.org/View/72305</link>
      <description><![CDATA[Largely as a result of increasing fuel costs, detailed investigation has recently been carried out on the problem of controlling the growth of fouling on the underwater hulls of ships.  The biology of fouling organisms has been extensively studied and there is now a much better understanding, particularly of algal fouling.  Fouling is an extreme aspect of the general problem of hull roughness which develops as a consequence of the traditional approaches to underwater hull maintenance.  It is suggested that the practice of cleaning and repainting at frequent intervals, using traditional materials, does not provide the ideal answer either in terms of fouling control or long-term control of roughness.  The more recent approaches of diffusion control by hydrophilic varnishes, the introduction of scrubbable coatings, and self-polishing copolymer antifouling systems give an indication of the effort that the marine coatings industry has made towards providing improved ship performance.  Order from: BSRA as No. 47,359.]]></description>
      <pubDate>Sat, 12 Apr 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/72305</guid>
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    <item>
      <title>A TECHNO-ECONOMIC APPROACH TO THE COMPARISON OF UNDERWATER COATINGS FOR NEW SHIPS</title>
      <link>https://trid.trb.org/View/467276</link>
      <description><![CDATA[The ship designer has to select an engine power to meet the specified trial speed, as well as the service speed requirements.  The size of the service power margin should reflect not only the average weather conditions over a typical route, but also deterioration in hull surface condition increasing resistance.  The choice of underwater coating, particularly anti-fouling, is important in terms of minimising speed loss, being affected by drydocking intervals and cost.  A spreadsheet model has been developed to permit a techno-economic comparison of alternative underwater coatings.  Unscheduled ships like VLCCs with 'better' coatings have the benefit of higher speed at constant fuel consumption.  An example shows a smaller power margin needed for a self-polishing type anti-fouling compared with a 'conventional' one.]]></description>
      <pubDate>Mon, 04 Nov 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/467276</guid>
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      <title>HULL ROUGHNESS AND FUEL CONSUMPTION</title>
      <link>https://trid.trb.org/View/456130</link>
      <description><![CDATA[Shipowners are only too aware of the direct relationship between the roughness of a ship's hull and the cost of sailing the vessel at her designed economic speed.  This article discusses the development of highly successful self-polishing antifoulings, the best of which can keep a hull smooth and free of fouling for up to five years.]]></description>
      <pubDate>Mon, 04 Mar 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/456130</guid>
    </item>
    <item>
      <title>WIND TUNNEL TESTS ON AN ARTIFICIALLY ROUGHNESS SHIP-HULL MODEL</title>
      <link>https://trid.trb.org/View/431332</link>
      <description><![CDATA[Wind tunnel tests on an artificially roughened model of a slender ship-hull were carried out.  The rough surface was made up of irregular, tightly packed, sand grains and the corresponding roughness function was determined by the Liverpool pipe flow technique.  A special three-hole Preston tube, suitable for the ship model, was constructed and calibrated to measure the wall friction on both rough and smooth surfaces.  The results obtained were compared with those predicted by an integral method of calculation of boundary layer on rough ship hulls.  In order to perceive the roughness effects on the hull surface pressure distribution, the latter was measured on the model fitted with special roughness strips distributed girthwise from the fore to the after peak.  The results are compared with potential flow calculations by the Hess and Smith method.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/431332</guid>
    </item>
    <item>
      <title>EFFICIENT UNDERWATER SURFACES</title>
      <link>https://trid.trb.org/View/431516</link>
      <description><![CDATA[It is now understood that a rough underwater surface gives rise to a fuel penalty and adequate procedures exist to assess the economic consequences.  Over the last 10 years about 250 hull roughness surveys have been carried out but wider adoption of the practice of routine hull roughness measurement is required. However, the choice of which roughness parameters to measure is a contentious issue, although over the last 35 years the average hull roughness Rt(50) originally proposed by BSRA has been accepted.  This is adequate for quality control purposes but to improve the correlation between surface finish and drag a more detailed description of the surface may be required.  A prototype instrument has been developed at the University of Newcastle upon Tyne and Teesside Polytechnic, which allows digital recording of hull surfaces for preliminary on-site analysis by its own microprocessor and more detailed statistical analysis later on a main-frame computer.  This paper also discusses the present state-of-the-art in relating roughness-induced additional drag to statistical descriptions of hull surfaces and the problem of propeller roughness measurement.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/431516</guid>
    </item>
    <item>
      <title>THE INCREASE IN SHIP RESISTANCE DUE TO FOULING AND THE EFFECTIVENESS OF METAL CLADDING IN PREVENTING GROWTH OF MARINE LIFE</title>
      <link>https://trid.trb.org/View/432761</link>
      <description><![CDATA[The effectiveness of a cladding system involving cupronickel sheets and a strong adhesive was confirmed by test plates submerged in the sea for four months.  The resistance increase due to barnacles, shells and plate overlapping were carried out using replicas.  The increase in resistance for fishing boats of about 10 tonnes displacement and for yachts of about 5.5m was estimated from these experiments.  The increase in resistance due to the overlapping of the adhesive metal plates was slight.  The resistance increases due to biofouling were about 7% for the fishing boat and 30% for the yacht.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/432761</guid>
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    <item>
      <title>ESTIMATION OF THE INCREASE IN RESISTANCE DUE TO HULL ROUGHNESS</title>
      <link>https://trid.trb.org/View/437152</link>
      <description><![CDATA[After a brief discussion of scientific and empirical approaches to the problem the present situation is analysed. The formula proposed by the International Towing Tank Conference for determination of increase in the coefficient of the total resistance of a vessel, attributable to hull roughness, is examined. The paper examines the reasons for discrepancies found and a new formula proposed.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/437152</guid>
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    <item>
      <title>THE ITTC CORRELATION ALLOWANCE: THE EVIDENCE RE-EXAMINED AND SUPPLEMENTED</title>
      <link>https://trid.trb.org/View/438283</link>
      <description><![CDATA[The original data leading to the present International Towing Tank Conference (ITTC) correlation allowance has been supplemented by data from the model tests and trials of eight sister tankers, some of which were undertaken in-service over a period of 4 years. The supplementation generally supports the ITTC correlation allowance but the roughness surveys of all the data are shown to be unreliable.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/438283</guid>
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    <item>
      <title>TOWARDS RELIABLE ESTIMATES OF FULL-SCALE VISCOUS DRAG</title>
      <link>https://trid.trb.org/View/438284</link>
      <description><![CDATA[No abstract provided.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/438284</guid>
    </item>
    <item>
      <title>TURBULENCE MEASUREMENTS IN A SHEAR-LAYER ASSOCIATED WITH A SHIP-HULL ROUGHNESS</title>
      <link>https://trid.trb.org/View/438285</link>
      <description><![CDATA[The need for high quality turbulence measurements associated with shear flow over a ship hull roughness is examined in relation to an increasing interest in computational fluid dynamics. Previously unpublished turbulence measurements for such flows are presented. These data demonstrate that surface roughness affects not only the Reynolds stresses, but also their spectral composition. Present turbulence models take no account of this phenomenon.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/438285</guid>
    </item>
    <item>
      <title>INVESTIGATION OF THE EFFECT OF A PAINT COAT ON THE TURBULENCE NEAR A ROUGH FLAT PLATE</title>
      <link>https://trid.trb.org/View/438341</link>
      <description><![CDATA[Paint coating of marine (ship-hull) surfaces is known to alter the original substrate roughness topography of the base surface. The effect of coating on the frictional resistance of such painted surfaces so far has not been investigated thoroughly as regards the flow wall turbulence, although a few useful and relevant papers have so far been published Musker & Sarabchi (1980) and Walderhaug (1986). None of the work done so far has concentrated on gathering of detailed data on the mean flow or on the accompanying turbulence structure along with an appropriate roughness topography survey. The present experiment was set up to fill this gap.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/438341</guid>
    </item>
    <item>
      <title>A DIGITAL HULL ROUGHNESS ANALYSER</title>
      <link>https://trid.trb.org/View/438342</link>
      <description><![CDATA[It is over three decades since BSRA (British Ship Research Association) carried out a series of full scale ship trial experiments on LUCY ASHTON with different hull conditions. The results of those experiments clearly demonstrated the sensitivity of ship performance to changes of hull surface conditions. In order to throw more light on the ship trial results, BSRA specifically built a Wall Roughness Gauge to record the undulations of hull surfaces. The method of analysis of hull roughness profiles recorded by the Wall Gauge was tedious and very time consuming. BSRA subsequently developed an on-the-spot measuring instrument called the BSRA Hull Roughness Analyser. The Rt(50) parameter which the Hull Roughness Analyser produces has been generally accepted as a standard measure of hull roughness.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/438342</guid>
    </item>
    <item>
      <title>A TWO-PARAMETER ROUGHNESS ANALYSER AND PERFORMANCE MONITORING SOFTWARE</title>
      <link>https://trid.trb.org/View/438343</link>
      <description><![CDATA[For four decades BSRA/BMT has been involved in research and development activities in relation to hull and propeller roughness. Interest in the topic arose initially in response to the effect of hull surface condition on the performance of ships during acceptance trials. In the aftermath of the oil crisis in the seventies, the emphasis moved away from the base level of hull roughness arising from shipyard production practices to the degrees of propeller and hull surface deterioration due to conditions in-service. Finally, as periods have increased between mandatory drydockings, the focus of attention has again moved and has included the economics of trading-off partial or full underwater cleaning (afloat), drydocking, partial or full painting of the hull and polishing or refurbishing the propeller. Throughout this period the simple, but robust BSRA hull (and propeller) roughness gauge has played a central role in providing objective, quantitative data on which to base analysis and research in order to improve the quality in shipyard production processes.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/438343</guid>
    </item>
    <item>
      <title>THE HULL ROUGHNESS PROBLEM</title>
      <link>https://trid.trb.org/View/440017</link>
      <description><![CDATA[Large amounts of fuel are wasted by ships with rough hulls. Whilst methods do exist to estimate the resistance penalty, they are crude and often very inaccurate.  The problem is described against a background of renewed interest in limiting the consumption of fossil fuels.  A new approach to predicting the additional resistance is suggested and its link with modern developments in surface metrology is outlined.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/440017</guid>
    </item>
    <item>
      <title>DRAG LOSSES OF NEW SHIPS CAUSED BY HULL FINISH</title>
      <link>https://trid.trb.org/View/441365</link>
      <description><![CDATA[No abstract provided.]]></description>
      <pubDate>Mon, 14 Aug 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/441365</guid>
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