Marine Link
Friday, October 20, 2017

Prismatic Coefficient

What Hull Shape Is Best?

Back at the dawn of maritime history, a coastal dweller first took a log and ventured out on the water. Over time his craft evolved from a rough log to one that had shape at the ends and was hollowed out. These changes to the basic log shape were the first example of modifying a hull form to increase carrying capacity, improve ride comfort, and to reduce resistance. Since then, shipbuilders, naval architects, and ship owners have experimented with hull shapes and the number of hulls to find the "best" design. Let's look at some of those variations to understand the challenges of choosing a hull shape. Monohull Design The basic monohull can be defined by six key numbers: length, beam, depth of hull at midships, design draft, prismatic coefficient, and displacement. Length, beam, and draft are familiar to everyone. Depth of hull at midships gives an idea of the freeboard as well as an indication of the hull strength in bending. The prismatic coefficient is a measure of how much shape there is in the ends of a hull. A high prismatic coefficient means that the ends are full such as a tanker bow. A low prismatic means that the ends are fine, with little volume, such as a tugboat stern. The choice of what dimensions to use depends on the intended use of the vessel. For a passenger vessel, there are considerations of carrying capacity, operating environment, and type of operation

BMT’s Fleet Management System to Debut at Nor-Shipping

Photo: BMT SMART

BMT SMART Ltd., the specialist fleet and vessel performance management company of BMT Group, will launch its new SMARTFLEET Management system at Nor-Shipping in Oslo next month. Technical experts will be on hand to showcase the system and its capabilities whilst discussing with delegates their specific challenges and needs.    Peter Mantel, Managing Director of BMT SMART commented, “Whilst there are cost savings to be made through on-board optimization

Safety: Slip and Fall Accidents in the Marine Environment

Because the exposure to the marine environment and motions of a vessel, slips and falls are a significant source of personal injuries in floating equipment, probably substantially greater than most industry groups. Although there are a good number of publications, books and articles written regarding the subject of slip and falls, there are almost none addressing the conditions found in a marine environment, which influence slips and falls. Consensus

RoPax Propulsion Concept Proves Efficient

Wärtsilä, in conjunction with the Finnish research project SEATECH 2000+, has been developing some new machinery solutions for RoPax vessels. A promising concept is a semi-diesel electric machinery, where mechanical propulsion is combined with a diesel electric power plant. This new RoPax concept was presented for the first time at the Europort 2001 exhibition. The RoPax vessel has a semi-diesel electric machinery featuring a diesel mechanical part driving a conventional CP propeller and a

MHI LNG-FPSO Approval for Two Tank Types

Mitsubishi Heavy Industries, Ltd. (MHI) completed development related to floating production, storage and offloading units for liquefied natural gas (LNG-FPSO), and has obtained two kinds of approval in principle (AIP) from major international ship classification societies. In tandem with intensified activity in medium- and small-scale offshore gas field development, demand for LNG-FPSOs, a new method of gas production offering movable capability, has been increasing globally

NASSCO Licenses LNG Containment Tech to Braemar

Image: Braemar

General Dynamics NASSCO and Braemar LNG BV announce LNG containment technology licensing agreement   General Dynamics NASSCO and Braemar LNG BV, a wholly owned subsidiary of Braemar Shipping Services PLC, have signed a technology licensing agreement for Braemar to use NASSCO’s intellectual property in its design and construction of Flat-Panel, Semi-Membrane, Prismatic-Shaped (FSP) LNG containment systems.   

DSME's New LNG Tank Technology Approved by LR

ACTIB ((Aluminium Cargo Tank Independent Type B) tanks - prismatic, large, independent cargo tanks -  reduce sloshing, suitable for LNG containment The ACTIB tanks, constructed of insulated aluminium 5083, will have the world’s largest storage capacity in an independent, insulated LNG tank system. The volume capacity in the initial design will be nearly three times larger than comparable types currently in operation.

MOL Ink Deal to Build, Charter 300m LNG Carrier

New LNG carrier rendering courtesy of MOL

Mitsui O.S.K. Lines (MOL) inform it has signed a Head of Agreement on joint ownership and 20-year charter contract for a newbuilding LNG carrier with Tokyo LNG Tanker Co., Ltd. At the same time, MOL signed a contract with Japan Marine United Corporation to build the new vessel. The ship is slated for completion in 2017. MOL will manage the new carrier, which will transport LNG mainly from the Cove Point LNG Project in the United States to Tokyo Gas facilities.

FSP LNG Containment System Construction To Begin Soon

Chairman Zhang Mi

  The joint venture group FSP LNG BV stated that it is taking the FSP LNG Flat Panel Semi-membrane Prismatic Type B containment system through General Design Approval (GDA) with the American Bureau of Shipping in Houston, and is projecting that construction of the first tank will begin at the end of this year.   Formed earlier this year to take the FSP LNG containment system through the general approval process, the group comprises Braemar Engineering

FinMin Says to Stick to Oil Duty Cuts Plans in 2017

Russia's Finance Ministry will go ahead with plans to lower oil export duties next year if prices do not increase significantly, Deputy Finance Minister Ilya Trunin told reporters on Monday.   Russia had scrapped plans to cut the duty for this year due to lower prices of oil, the country's main exporting commodity. Oil producers had expressed concern that the government would increase the tax burden as it tries to make up the shortfall in state coffers.  

US LNG Going Global

© Anatoly Kolodey / Adobe Stock photo

The U.S. liquified natural gas (LNG) market is ripe with opportunity, according to American Action Forum (AAF).   "When coupled with the tension surrounding Qatar (the largest exporter of natural gas in the world), this makes U.S. LNG production a very attractive option," said Kimberly VanWyhe is the Director of Energy Policy at the AAF.   In 2016, LNG exports from the U.S. totaled 184,141 million cubic feet with a value of roughly $564 million.  

US Built Refrigerated Liquefied Gas Carrier Launched

Photo: Vigor

New ATB tank barge will transport up to 22,000 tons of American-made anhydrous ammonia (NH3), a key ingredient in fertilizer   U.S. shipbuilder Vigor has launched The Harvest, the first complex liquefied ammonia transport barge built in the U.S. for Jones Act trade since 1982. The vessel was constructed to support the operations of The Mosaic Company, an integrated producer and marketer of concentrated phosphate and potash

Moving Ahead Powerfully

(Photo: MAN Diesel & Turbo)

MAN Diesel & Turbo optimizes the efficiency of ship propellers using cutting-edge CFD simulation methods   The layout of ship propellers is a balancing act between optimal power conversion and the avoidance of unwanted cavitation effects, which can result in damage to the propeller structure and higher noise levels. MAN Diesel & Turbo in Frederikshavn, Denmark, is using the computational fluid dynamics (CFD) simulation solution STAR-CCM+ from Siemens PLM Software to model

BV Approves Braemar’s LNG Containment System

(Image: Braemar Technical Services)

Braemar Technical Services announced that Bureau Veritas (BV) has issued a General Design Approval for the FSP Type B LNG Containment System (FSP).   Starting with the General Dynamics NASSCO-patented tank design, for which the American Bureau of Shipping (ABS) and Lloyd’s Register had issued Approval in Principle (AiP) several years prior, Braemar engineered a new and improved containment system that meets the demands of LNG storage in marine, offshore and onshore applications

Hard Problems Demand Soft(ware) Solutions

ABB

Make no mistake, the commercial maritime industry will always revolve around heavy duty machinery and mega-machines designed to weather some of the toughest operating conditions on earth. But in recent years a proliferation of Software Solutions has evolved to help the machines operate more efficiently and cost effectively. MR editors report on latest developments in maritime specific Software Solutions. Design Kværner Verdal AS selected AVEVA Bocad Steel and AVEVA Bocad Offshore for

Conflicting Objectives in Ship Design

Figure 1: Detailed geometry for STAR-CCM+ simulation of ship self-propulsion

Enviro, Safety Regulations Conspire to Complicate  the Marine Classification Business “ABS is first and foremost a safety company,” says Richard Korpus, “but safety can arise on many different fronts. It can refer to the safety of a high-valued asset, for the people who work on that asset, for the environment where the asset operates, or even for the financial security of the owners and operators of that asset.”

Sea Hawk Debuts VMG Hard & Fast Racing Finish

Fresh Water Boaters Hard, Fast Racing Finish Sea Hawk

Sea Hawk today  announced the introduction of VMG Hard & Fast Racing Finish, a revolutionary new bottom coating geared specifically for fresh water sail boaters and power boaters looking to enhance the performance of their vessels. VMG, earning its designation from the yacht racing acronym for Velocity Made Good, is specifically formulated and crafted to provide fresh water boaters with an added edge in maximizing velocity while protecting their vessels hulls

McClain Appointed MD of Braemar Engineering

Sheila McClain

Braemar Shipping Services Group PLC is pleased to announce that Sheila McClain, Executive Vice President of Braemar Engineering, has been appointed Braemar Engineering's new Managing Director.  Sheila will continue to be based in Houston, Texas and will assume management responsibility for global operations with effect from 8 June 2016.  In conjunction with her management team, Sheila will continue to develop and promote Braemar Engineering’s expertise specialising in marine

DNV GL Okays New Floating Power Generation Concept

A 3D model of the FLPS concept. Note: “FLPS” is the registered trademark of IHI Corporation in Japan. Image: DNV GL

 DNV GL has given IHI Corporation Approval in Principle (AiP) for its FLPS (Floating LNG Power Station) concept.   The formal handover of the Approval in Principle took place in Tokyo on July 5. The design has been found to comply with DNV GL class standards and other relevant industry standards.    The FLPS concept is a combination of a Floating Storage and Regasification Unit (FSRU) and a power plant

Electric Motors for Marine Applications

A waterproof motor with stainless steel exterior (Photo: Empire Magnetics)

Empire Magnetics President Richard Halstead discusses the critical considerations necessary for engines operating in Arctic waters.    A large number of vessels sail in more than one ocean, from warmer seas to arctic waters, so motors for marine applications must be versatile enough to operate in a variety of conditions. While the greater majority of my experience involves building motors for use in fin controls on mini submarines

Overcoming the Propeller Supply Bottleneck

Image: Hydrocomp

Hydrocomp’s ProCad facilitates in-house Process Control of Propeller Design and Manufacture.   Maritime Tactical Systems Inc. (MARTAC) is a Florida-based company building next-generation unmanned vessels for military applications. In preparation for the “Rim of the Pacific” (RIMPAC) military exercises in Pearl Harbor this last July, MARTAC needed a new propeller design for their MANTAS series high-speed vessels

Op/Ed: Shiphandlers Beware

Chemical tanker Carla Maersk and bulk carrier Conti Peridot off Morgans Point, Texas, March 10, 2015, after being involved in a collision March 9, 2015. (U.S. Coast Guard photo by Dustin R. Williams)

Was the closing of the Houston Ship Channel for over three days in March 2015 due to the use of Ultra Low Sulphur Fuel Oil (ULSFO)? After reviewing the testimony, and evidentiary material presented by the National Transportation Safety Board (NTSB) regarding the 2015 Conti Peridot’s collision with the Carla Maersk, it is the authors' opinion the report fails to address significant contributing factors. The NTSB has overlooked a serious threat to vessel operations throughout the world

Fast Small Ship Simulator

Photo: MARIN

Bouncing over the waves at a speed of 43 knots, the director of the Defense Materiel Organization (DMO) Vice Admiral Arie Jan de Waard, and MARIN’s director Bas Buchner, made the first test voyage on the moving ‘Fast Small Ship Simulator.’ This FSSS is built by MARIN and SME partners, Cruden and TreeC, as part of a CODEMO project to stimulate the development of a prototype. Vice Admiral De Waard felt the test was very realistic and said: “You feel as if you are involved

The Digital Future of Exhaust Gas Temperature Sensors

(Image: CMR Group)

CMR Group’s chief technical officer, Patrice Flot, considers the current approach to sensing exhaust gas temperature (EGT) on high horsepower engine platforms and the capabilities provided by new digital technology.    An EGT sensor measures the temperature of the engine exhaust gas to prevent damage to critical components such as the after treatment system, turbines and cylinder head exhaust valves. It can also be used inside the combustion chambers where hot gases are

Tech File: HydroComp NavCad for Optimized Design

Schematic and implemented bulb geometry

HydroComp NavCad, internationally recognized for resistance and propulsion prediction for naval architects, can also leverage analysis capabilities with features that support optimized hull form and propulsion system design.   NavCad may be most well-known for its library of parametric-statistical hull form and propulsion system models (often called “1D” models). The recent introduction of the Premium Edition now brings a higher-order distributed-analytical

Maritime Reporter Magazine Cover Oct 2017 - The Marine Design Annual

Maritime Reporter and Engineering News’ first edition was published in New York City in 1883 and became our flagship publication in 1939. It is the world’s largest audited circulation magazine serving the global maritime industry, delivering more insightful editorial and news to more industry decision makers than any other source.

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