Development of Rigid Inflatable Boats for U.S. Navy Shipboard Use

1985 ◽  
Vol 22 (03) ◽  
pp. 211-218
Author(s):  
David W. Amick ◽  
Robert Hamilton ◽  
Curtis E. Shields
Keyword(s):  
High Performance ◽  
Surf Zone ◽  
Single Point ◽  
Development Program ◽  
Feasibility Studies ◽  
Breaking Waves ◽  
Coast Guard ◽  
Superior Performance ◽  
Concept Evaluation ◽  
The U.S

The Rigid Inflatable Boat (RIB) was originally developed as a gasoline outboard powered craft for surf zone rescue use by the Royal National Lifeboat Institution in the United Kingdom. The objectives were to provide a craft with extremely good stability characteristics to operate in steep onshore breaking waves without capsizing, and to improve the safety of operations alongside other vessels. Open ocean rescue and boarding applications were of interest to the U.S. Coast Guard because of the inherent stability and alongside safety of the RIB. Subsequent feasibility studies by the U.S. Navy indicated that the RIB would be superior in performance to the present 26-ft motor whaleboat, and could also reduce topside weight. The Navy opted for diesel inboard power for the RIB's designated to be carried aboard combatant ships. A diesel-powered RIB was procured for concept evaluation by the U.S. Navy, and has undergone a series of trials and tests to establish smooth-and rough-water performance characteristics. The data acquired confirmed the theoretical performance predicted during the feasibility studies. This first RIB was deployed on a U.S. Navy DDG-993 Class ship utilizing an existing single-point davit. During that deployment, the RIB was launched and retrieved successfully at ship's speeds up to 12 knots. Early indications are that this development program will result in a new ship's boat and an accompanying davit system which will provide the Fleet with a safe, high-performance craft which will greatly enhance operational capability and safety, and substantially reduce topside weight. The enthusiasm of test and Fleet personnel who have operated the RIB attests to its superior performance and to a high degree of probability for success of the program.

scholarly journals Status of Marine Gas Turbine Inlet Development Program

1979 ◽  
Author(s):  
C. T. Frazier ◽  
R. E. Ruskin ◽  
E. W. Mihalek
Keyword(s):  
Gas Turbine ◽  
High Performance ◽  
Development Program ◽  
Engine Performance ◽  
Test Procedures ◽  
Inlet System ◽  
Turbine Inlet ◽  
Work Tasks ◽  
The U.S ◽  
Inlet Duct

Over ocean, salt aerosols ingested in the combustion air of a marine gas turbine cause engine compressor fouling and are a primary factor in engine hot section corrosion. To minimize salt ingestion effects on engine performance and life, a high performance salt filtration system is required. The U.S. Navy is currently conducting the Gas Turbine Inlet Development Program. The program consists of work elements including salt filter tests, at-sea salt-in-air measurements, ship aerodynamic studies, inlet duct design, etc. To complete the assigned work tasks, Navy facilities had to develop state-of-the-art instrumentation and test procedures. Based on these work tasks, the U.S. Navy will publish a Gas Turbine Inlet System Design Handbook. The handbook will provide design guidance for the ship builder and inlet duct designer for optimizing shipboard salt filtration perfmance.

Fostering Information Literacy in the Management Education at the U.S. Coast Guard Academy

2019 ◽  
Vol 2 (3) ◽  
pp. 1-17
Author(s):  
Alina M. Zapalska ◽  
Ben Wroblewski
Keyword(s):  
Learning Environment ◽  
Information Literacy ◽  
Management Education ◽  
Management Program ◽  
Coast Guard ◽  
Sequential Approach ◽  
Step Process ◽  
New Knowledge ◽  
The U.S

This paper illustrates the information literacy (IL) strategy in an undergraduate Management program at U.S. Coast Guard Academy. The paper exemplifies a sequential approach that improves students’ capabilities to evaluate and apply information in a specifically designed learning environment while generating new knowledge in undergraduate business coursework. The paper also emphasizes how IL can be developed within management coursework through a six-step process, including defining, locating, selecting, organizing, presenting, and assessing.  This specially designed framework of IL learning can be applied across all relevant courses using specially designed assignments in the Management major.

scholarly journals The Accelerations of a Wave Measurement Buoy Impacted by Breaking Waves in the Surf Zone

2021 ◽  
Vol 9 (2) ◽  
pp. 214
Author(s):  
Adam C. Brown ◽  
Robert K. Paasch
Keyword(s):  
Inertial Measurement Unit ◽  
Surf Zone ◽  
Spherical Wave ◽  
Breaking Waves ◽  
Measurement Unit ◽  
High Fidelity ◽  
Wave Measurement ◽  
Near Shore ◽  
Shoaling Waves ◽  
Multiple Deployments

A spherical wave measurement buoy capable of detecting breaking waves has been designed and built. The buoy is 16 inches in diameter and houses a 9 degree of freedom inertial measurement unit (IMU). The orientation and acceleration of the buoy is continuously logged at frequencies up to 200 Hz providing a high fidelity description of the motion of the buoy as it is impacted by breaking waves. The buoy was deployed several times throughout the winter of 2013–2014. Both moored and free-drifting data were acquired in near-shore shoaling waves off the coast of Newport, OR. Almost 200 breaking waves of varying type and intensity were measured over the course of multiple deployments. The characteristic signature of spilling and plunging breakers was identified in the IMU data.

scholarly journals Development and Validation of Quasi-Eulerian Mean Three-Dimensional Equations of Motion Using the Generalized Lagrangian Mean Method

2021 ◽  
Vol 9 (1) ◽  
pp. 76
Author(s):  
Duoc Nguyen ◽  
Niels Jacobsen ◽  
Dano Roelvink
Keyword(s):  
Surface Waves ◽  
Deep Water ◽  
Surf Zone ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Breaking Waves ◽  
Successful Implementation ◽  
Random Waves ◽  
Mean Motion ◽  
Generalized Lagrangian

This study aims at developing a new set of equations of mean motion in the presence of surface waves, which is practically applicable from deep water to the coastal zone, estuaries, and outflow areas. The generalized Lagrangian mean (GLM) method is employed to derive a set of quasi-Eulerian mean three-dimensional equations of motion, where effects of the waves are included through source terms. The obtained equations are expressed to the second-order of wave amplitude. Whereas the classical Eulerian-mean equations of motion are only applicable below the wave trough, the new equations are valid until the mean water surface even in the presence of finite-amplitude surface waves. A two-dimensional numerical model (2DV model) is developed to validate the new set of equations of motion. The 2DV model passes the test of steady monochromatic waves propagating over a slope without dissipation (adiabatic condition). This is a primary test for equations of mean motion with a known analytical solution. In addition to this, experimental data for the interaction between random waves and a mean current in both non-breaking and breaking waves are employed to validate the 2DV model. As shown by this successful implementation and validation, the implementation of these equations in any 3D model code is straightforward and may be expected to provide consistent results from deep water to the surf zone, under both weak and strong ambient currents.

Distributions of void fraction under breaking waves in the surf zone

2005 ◽  
Vol 32 (14-15) ◽  
pp. 1829-1840 ◽  
Author(s):  
Ashabul Hoque ◽  
Shin-ichi Aoki
Keyword(s):  
Void Fraction ◽  
Surf Zone ◽  
Breaking Waves

Low ECD High Performance Invert Emulsion Drilling Fluids: Lab Development and Field Deployment

2021 ◽  
Author(s):  
Vikrant Wagle ◽  
Abdullah Yami ◽  
Michael Onoriode ◽  
Jacques Butcher ◽  
Nivika Gupta
Keyword(s):  
High Performance ◽  
Filter Cake ◽  
Drilling Fluid ◽  
Field Performance ◽  
Superior Performance ◽  
Core Material ◽  
Drilling Fluids ◽  
Invert Emulsion ◽  
Field Deployment ◽  
Permeability Studies

Abstract The present paper describes the results of the formulation of an acid-soluble low ECD organoclay-free invert emulsion drilling fluid formulated with acid soluble manganese tetroxide and a specially designed bridging package. The paper also presents a short summary of field applications to date. The novel, non-damaging fluid has superior rheology resulting in lower ECD, excellent suspension properties for effective hole cleaning and barite-sag resistance while also reducing the risk of stuck pipe in high over balance applications. 95pcf high performance invert emulsion fluid (HPIEF) was formulated using an engineered bridging package comprising of acid-soluble bridging agents and an acid-soluble weighting agent viz. manganese tetroxide. The paper describes the filtration and rheological properties of the HPIEF after hot rolling at 300oF. Different tests such as contamination testing, sag-factor analysis, high temperature-high pressure rheology measurements and filter-cake breaking studies at 300oF were performed on the HPIEF. The 95pcf fluid was also subjected to particle plugging experiments to determine the invasion characteristics and the non-damaging nature of the fluids. The 95pcf HPIEF exhibited optimal filtration properties at high overbalance conditions. The low PV values and rheological profile support low ECDs while drilling. The static aging tests performed on the 95pcf HPIEF resulted in a sag factor of less than 0.53, qualifying the inherent stability for expected downhole conditions. The HPIEF demonstrated resilience to contamination testing with negligible change in properties. Filter-cake breaking experiments performed using a specially designed breaker fluid system gave high filter-cake breaking efficiency. Return permeability studies were performed with the HPIEF against synthetic core material, results of which confirmed the non-damaging design of the fluid. The paper thus demonstrates the superior performance of the HPIEF in achieving the desired lab and field performance.

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