<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
    <description></description>
    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
    </image>
    <item>
      <title>A kinematic study on three dimensional tandem active chordwise deforming oscillating foils for a hydrofoil-propelled boat</title>
      <link>https://trid.trb.org/View/2693646</link>
      <description><![CDATA[Hydrofoil-propelled boats play crucial roles in ocean engineering, with their propulsion systems serving as core components for maneuvering and control. Existing research predominantly focuses on two dimensional single hydrofoils or examines the influence of various geometric and hydrodynamic parameters. Few studies have adopted tandem three-dimensional chordwise deforming hydrofoil models or analyzed kinematic deformation parameters. To address this problem, based on an active control strategy, this study establishes kinematic equations integrating pitching, heaving, and deformation to investigate tandem chordwise deforming oscillating foils. Numerical simulations are conducted using a computational fluid dynamics approach with dynamic overset grid techniques. Results show that thrust generation primarily stems from positive and negative vortex formation and intervening jets during upstroke and downstroke phases, combined with periodic surface pressure differences. Key deformation parameters significantly affect propulsion: increasing deformation frequency from 1.5 Hz to 2.0 Hz improves propulsion efficiency from 34.9% to 46.7%, a 33.8% growth rate. Raising deformation amplitude from 0.15L to 0.20L and bending coefficient from 3 to 4 enhances the average thrust coefficient by 90.7% and 18.6%, respectively. These findings offer valuable insights into tandem three-dimensional chordwise deforming oscillating foils propulsion mechanisms and provide a theoretical basis for optimizing hydrofoil-based marine vehicle systems.]]></description>
      <pubDate>Tue, 21 Apr 2026 14:31:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/2693646</guid>
    </item>
    <item>
      <title>Sweden Launches World's First All-Electric Hydrofoil Ferry</title>
      <link>https://trid.trb.org/View/2556752</link>
      <description><![CDATA[Now in its second year of commuter service in Stockholm, Candela's P-12 hydrofoil ferry is part of a global trend toward electrifying ferries to improve public transportation capacity and efficiency. The vessels cruise at 25 knots (30 miles per hour), roughly double the speed of conventional ferries, while consuming 80 percent less energy. Less water resistance also enables the use of smaller batteries, freeing up space for up to 30 passengers, as well as bicycles and seating for wheelchair users. Currently, E-ferries are also in use in Europe, Southeast Asia, and Australia. In the United States, tourists can reach Alcatraz—the notorious prison that is now part of Golden Gate National Recreation Area in California—on all-electric ferries. If all goes according to schedule, in 2026 P-12 e-ferries will begin ferrying passengers plus their bikes or ski gear across Lake Tahoe, on the California–Nevada border, cutting the typical one-hour drive in half while reducing congestion and pollution.]]></description>
      <pubDate>Wed, 16 Jul 2025 08:47:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/2556752</guid>
    </item>
    <item>
      <title>Dynamic analysis of hydrofoil flexibility in wave-powered boat propulsion performance</title>
      <link>https://trid.trb.org/View/2551870</link>
      <description><![CDATA[The wave-powered boat constitutes an unmanned surface vehicle that utilizes wave energy to drive hydrofoil rotation and generate propulsion, thus obviating the necessity for external power sources. The hydrofoil system, a critical component of wave-powered boats, plays a pivotal role in determining propulsion performance through its wave energy conversion efficiency. In the present investigation, the hydrodynamic characteristics of flexible hydrofoils in wave-powered boat propulsion systems were systematically examined. A multibody-fluid coupled model of the propulsion mechanism considering the hydrofoil flexibility was developed to investigate the relationship between the hydrofoil flexibility and propulsion parameters such as propulsive force, propulsive velocity and the phase trajectory. The results demonstrate that, when compared to rigid hydrofoil configurations, the number of propulsive force-velocity limit circles can be reduced from 4 to 2 cycles in the appropriately flexibility, resulting in significant enhancement of propulsion stability. Furthermore, within the optimal flexibility range of E = 0.12 GPa, a maximum improvement of 0.37 in the propulsion coefficient (Cx) was achieved, highlighting the advantages of flexible hydrofoils in improving the propulsion performance of wave-powered boat.]]></description>
      <pubDate>Mon, 09 Jun 2025 14:49:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/2551870</guid>
    </item>
    <item>
      <title>High-Speed Jetfoil Ferry Service Tested by Washington DOT in Puget Sound</title>
      <link>https://trid.trb.org/View/2539833</link>
      <description><![CDATA[A $7 million, 242-passenger hydrofoil boat was subjected to a trial program after its authorization by Washington's State Transportation Commission in June. The test program, which was aimed at examining the feasibility and potential of high-speed passenger-only service, was carried out by the State Ferry Service of the Washington State Department of Transportation. This article describes this trial program and gives a brief history of hydrofoil boats. The boat tested was the Jetfoil, manufactured by Boeing Marine Systems in Seattle. It is the latest in hydrofoil craft, which combine the best features of airplane and ship to give maximum passenger comfort at high speeds.]]></description>
      <pubDate>Tue, 22 Apr 2025 11:29:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/2539833</guid>
    </item>
    <item>
      <title>A resistance model for hydrofoil fast ferries with fully submerged foil systems</title>
      <link>https://trid.trb.org/View/2354246</link>
      <description><![CDATA[This paper introduces an algorithmic method for the design and resistance prediction of hydrofoil vessels for fast ferry applications, using only design speed and mass as input parameters. A database of resistance estimates has been created and shared online. Furthermore, a simple model is introduced for the extension of the results to off-design speeds.The efficacy of the models is demonstrated through three case studies. Firstly, the importance of accounting for the power requirement during take-off is investigated, concluding that a simple assumption of constant speed yields accurate energy estimates for routes exceeding approximately six nautical miles.Case study number two entails a comparative analysis of hydrofoil vessel resistance to that of slender catamarans across a wide range of vessel sizes and speeds. The results reveal a potential for reducing the energy requirement of passenger fast ferries by 30% to 50% through the use of hydrofoils.The paper concludes with an investigation into the influence of surface roughness on hydrofoil resistance, indicating significant deteriorating effects even at moderate roughness levels.]]></description>
      <pubDate>Fri, 29 Mar 2024 10:16:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2354246</guid>
    </item>
    <item>
      <title>Study on dynamic performance of wave-powered boat under the action of ocean current</title>
      <link>https://trid.trb.org/View/2218915</link>
      <description><![CDATA[Wave-powered boat will be affected by the ocean current when moving forward. In order to study the impact of the ocean current on the dynamic performance of wave-powered boat, the fluid-multibody coupled model of the hydrofoil was established in FLUENT through the dynamic mesh method. The hydrodynamic force and moment of the hydrofoil were introduced into the rigid body dynamic equation of the boat, the motion parameters at that time can be calculated by numerical integration to achieve coupling process. The results shows that, with the increase of counter-current velocity, the propulsion velocity of the wave-powered boat and hydrofoil rotation angle both decrease. The results in co-current conditions are more complicated and the rear hydrofoil will be affected by the superposition of the current and the wake vortex falling off from front hydrofoil, causing fluctuations in its rotation process. Beside, the restoring stiffness has an important influence on the propulsion performance of wave-powered boat, so it is necessary to select the appropriate restoring stiffness to improve the propulsion performance of the device under different current velocities.]]></description>
      <pubDate>Mon, 28 Aug 2023 09:19:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/2218915</guid>
    </item>
    <item>
      <title>A probabilistic method to evaluate bow foils for realistic seas and shipping routes</title>
      <link>https://trid.trb.org/View/2052759</link>
      <description><![CDATA[To improve ship efficiency and reduce CO2 emissions, the use of renewable based energy saving devices is an emerging field. By harnessing the ambient wave energy, ship bow mounted foils can serve as an energy saving device (ESD), reducing the added resistance in waves and generating an additional thrust. This paper presents a methodology to predict the efficiency of bow foils over various regions, seasons and ship routes. The results show that ship length significantly influences the effectiveness of bow foils with respect to differing regions worldwide. The percentage foil retraction is also shown to be a significant factor in operating bow foils with a large variation depending on ship heading and encountered sea state. The presented method, which could be implemented for the assessment of future bow foil designs, provides a holistic approach to evaluate bow foils for route and ship specific energy savings.]]></description>
      <pubDate>Tue, 24 Jan 2023 09:29:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/2052759</guid>
    </item>
    <item>
      <title>Electric Fast Foil Ferry: Re-imagining the Mosquito Fleet for Accelerating Passenger Ferry Innovation</title>
      <link>https://trid.trb.org/View/2062441</link>
      <description><![CDATA[Kitsap Transit, across the Puget Sound from Seattle, will receive funding to design a model for a high-speed passenger ferry powered by battery-electric, low-emission technology. The state-of-the-art hydrofoil design will rely on lightweight carbon fiber construction and batteries to speed up travel between urban centers and suburban and rural communities and significantly reduce fuel use compared to conventional fast ferries.]]></description>
      <pubDate>Tue, 15 Nov 2022 16:17:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2062441</guid>
    </item>
    <item>
      <title>Typhoon: A vortex-lattice code for assessing dynamic stability characteristics of hydrofoil crafts</title>
      <link>https://trid.trb.org/View/1889006</link>
      <description><![CDATA[In this paper an open-source implementation of the vortex-lattice method to perform a dynamic stability analysis for hydrofoil crafts is discussed. The difference with existing vortex-lattice codes is the addition of a free-surface boundary condition which is needed to analyse surface piercing foils. This code, called Typhoon, can be used to perform a dynamic stability analysis (DSA) on hydrofoil vessels. The goal of this code is to have an easy-to-use and cheap alternative to compare different designs in early design stages. This paper gives a brief background to all the concepts used, followed by a short theoretical explanation of the vortex-lattice method. The second part of this paper focuses on a practical example of how this code can be used on an example.]]></description>
      <pubDate>Sun, 31 Oct 2021 19:06:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1889006</guid>
    </item>
    <item>
      <title>Passenger Mobility in a Discontinuous Space: Modelling Access/Egress to Maritime Barrier in a Case Study</title>
      <link>https://trid.trb.org/View/1592785</link>
      <description><![CDATA[The present study analyses a transport system in a discontinuous space. Classical specifications of transport models cannot be applied directly when evaluating the influence of territorial discontinuity and related barriers on user behavior. Adjustments are required for this specific case because studies relative to discontinuous spaces are limited. The influence concerns the different travel components (access, barrier, on board, and egress) and could impact travel choices (departure time, destination, mode, and path). In this paper, the models refer to access and egress components with a focus on the mode of travel choice level. The paper focuses on the influence of discontinuity, introducing some adjustments to the classical demand models used to simulate discontinuity crossing. The main variables influencing the user’s choice, and their relative weight in discontinuous space, are investigated. These elements are fundamental for any planning and design procedures to improve the quality of mobility. In the paper, the case study of the Strait of Messina in southern Italy is analyzed. In this case, the barrier is constituted by the sea that physically separates the two shores. In this work, only strait crossings via hydrofoil, from Reggio Calabria to Messina, are considered in random sample interviews.]]></description>
      <pubDate>Thu, 25 Apr 2019 11:19:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/1592785</guid>
    </item>
    <item>
      <title>Toward the development of a hydrofoil tailored to passively reduce its lift response to fluid load</title>
      <link>https://trid.trb.org/View/1549341</link>
      <description><![CDATA[The objective of this research is to explore the possibility of using Passive Adaptive Composite (PAC) on structures to help control the lift generated by hydrofoils on boats such as the International Moth. Introducing composite fibres oriented at off-principal axis angles, allow a foil to passively control its pitch angle to reduce the lift generated at higher boat speeds helping to achieve a stable flight in a wide range of weather conditions. PAC utilises the inherent flexibility of a composite structure to induce a twist response under bending load which could be used to minimise the use of active control systems, or even improve the dynamic response of foils in waves. However, to design flexible foils requires numerical and experimental tools to assess the complex fluid structure interactions involved. This paper evaluates a simplified hydrofoil geometry designed to reduce its lift coefficient with increased flow speed. A coupled Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) methodology is presented to predict flexible foil performance. Validation of these numerical tools is achieved through the use of wind tunnel experiments including full field deformation measurements. Twist deformations resulted in a reduction in the effective angle of attack by approximately 30% at higher flow speeds reducing the foil lift and drag significantly.]]></description>
      <pubDate>Mon, 01 Oct 2018 09:26:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1549341</guid>
    </item>
    <item>
      <title>Seabubbles prototype : electric hydrofoil water taxi launched on Lake Geneva</title>
      <link>https://trid.trb.org/View/1522330</link>
      <description><![CDATA[]]></description>
      <pubDate>Thu, 05 Jul 2018 12:22:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/1522330</guid>
    </item>
    <item>
      <title>Water flying : aviation technology powers the USA racing yacht</title>
      <link>https://trid.trb.org/View/1473390</link>
      <description><![CDATA[]]></description>
      <pubDate>Wed, 05 Jul 2017 14:13:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/1473390</guid>
    </item>
    <item>
      <title>Plane sailing : Airbus engineers and top racing sailors team up to try and produce the world's fastest yacht</title>
      <link>https://trid.trb.org/View/1468935</link>
      <description><![CDATA[]]></description>
      <pubDate>Thu, 01 Jun 2017 10:14:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/1468935</guid>
    </item>
    <item>
      <title>Numerical analysis of base-ventilated intercepted supercavitating hydrofoil sections</title>
      <link>https://trid.trb.org/View/1362741</link>
      <description><![CDATA[A numerical analysis of the inviscid flow over a family of base-ventilated intercepted hydrofoils is presented using a low-order, non-linear boundary element formulation. The blunt-based section geometry used is based on the NACA 4-digit modified thickness distribution with the addition of a trailing edge fence (or interceptor) for lift production. An optimum section shape, in terms of stable cavity behaviour, was found to be a trade-off between the leading edge minimum pressure and the trailing edge slope. The former affecting the potential for leading edge cavitation and the latter flow separation from the trailing edge. The maximum hydrodynamic efficiency was obtained with a thin section, a small trailing edge slope and operation at a low cavitation number. For a profile with 15% thickness to chord, at zero incidence and an interceptor height of 1% of the chord length, a maximum lift/drag ratio of around 12 was achieved. The practical realization of this value is likely to be affected by structural limitations, cavity dynamics and serviceability constraints.]]></description>
      <pubDate>Thu, 30 Jul 2015 09:03:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/1362741</guid>
    </item>
  </channel>
</rss>