Sean Kery MS PE DE has 30 years experience in a wide range of specialties related to Ocean Engineering, Mechanical Engineering, Buoy Engineering, Naval Architecture and Marine Forensic Studies with more than 50 scientific and technical publications. He is co-chair of the SNAME Marine Forensics Committee. His career has spanned Academia, defense contractors, commercial companies and currently works in the ship concept design group at CSRA Advanced marine center in Washington DC. He has ongoing research projects on a number of historic ships. In 2015 he published 4 papers including 2 that show how to create a physics based model for the sinking of vessels with the creation of debris fields, and the subsequent taphonomy.
The Union ironclad warship USS Monitor foundered in heavy seas off Cape Hatteras, North Carolina,... more The Union ironclad warship USS Monitor foundered in heavy seas off Cape Hatteras, North Carolina, on December 31, 1862. This paper focuses on the development and validation of numerical models of a ship foundering using USS Monitor as a test subject. It begins with a brief account of the vessel’s history and the circumstances leading up to the sinking, then presents the best estimate available for the vessel’s loading condition and hydrostatics. The ingress of water into the ship at a number of locations was described by the survivors, some of whom speculated that the upper and lower hulls began to separate forward due to repeated impact with waves. However, the degraded condition of the wreckage after 149 years on the seafloor prevented an examination of that portion of the hull. Several linear and nonlinear seakeeping models were run on this hull form, including both under tow and after the anchor was dropped just prior to the sinking. The seakeeping models provide time histories of hydrostatic head at each of the down flooding locations along with estimates of the slamming of the overhanging bow in moderate to large waves as reported in survivor testimony. The numerical tools developed to support this analysis will be able to support the analysis of other vessel-foundering events.
When a shipwreck and objects in the associated debris field land on the seabed, they continue to ... more When a shipwreck and objects in the associated debris field land on the seabed, they continue to be acted on by currents and benthic storms that can result in changes to the position, orientations and dispersion. In shallower waters, ocean storm waves and long period swells can cause strong oscillatory water motions to act on the objects. This paper describes a number of cases where the underwater archeological record shows evidence of these changes, and shows how such cases may be modeled using modern COTS software. The technical approach described in this paper shows how the different specialties of naval architecture, oceanography, ocean engineering, sediment transport, hydrodynamics and underwater archaeology can be usefully combined under the umbrella specialty of marine forensics. The phenomenologies associated with freefall in the water column, bottom impact, and then the impact of various post deposition events and processes are modeled for several historic wrecks and the process and results are illustrated. The differential action of storm waves and how to calculate their frequency of occurrence at a specific depth will be described. The sediment transport like action that can re-suspend objects and or tumble them across the seabed will be described and modeled for typical objects. The action of strong oscillating water motions can expedite a wreck's breakup. Scour and erosion corrosion at the water-to-sediment interface have been implicated in specific damage to some historic wrecks. Lastly, the implications to modern search and rescue and to the research of historic wrecks will be discussed.
<jats:p>A dynamic stability event— not to be confused with ordinary or damaged transverse s... more <jats:p>A dynamic stability event— not to be confused with ordinary or damaged transverse stability—is a sudden and seldom occurring event that can result from an unusual dynamic response in some combinations of speed, heading, ship motions phase and wave field. This paper defines several dynamic stability events and describes a process developed to investigate them. The process involves model tests, numerical analyses, and a high speed catamaran test vessel. The strengths and weaknesses of model testing are compared to numerical analyses, and the overall validity of the results are discussed.</jats:p>
An investigation of the capabilities of a suite of seakeeping software to model the interactions ... more An investigation of the capabilities of a suite of seakeeping software to model the interactions of ice floes and icebreaking hull forms was initiated, as part of a wider investigation into arctic operations. The sea keeping behavior of a systematic series of ice floes with variations in area extent and thickness, acting alone and in groups is analyzed and presented. This investigation focuses on developing a methodology that can be used in the preliminary and later stages of ship design for ice infested waters. A number of sensitivity studies were performed that explore the limitations and features of the several software packages available to the authors.
This paper describes investigations by Flotation Technologies and Mooring Systems Inc. to develop... more This paper describes investigations by Flotation Technologies and Mooring Systems Inc. to develop a low drag subsurface mooring apex buoy that contains an RD Instruments Acoustic Doppler Current Profiler current meter. Five different candidate mooring apex buoy systems are compared with regard to their drag, inclination and stability in current and effect on the performance of a typical mooring. The Drag Coefficients of cylindrical and spherical buoy candidates are Reynolds number sensitive in the velocity range of 1 to 3 knots. This leads to calculated and observed hydrodynamic instability due to minute variations in current velocity. An airship shaped streamlined body was found to have the lowest drag, best inclination response and little or no Reynolds number sensitivity in the current regime of interest.
When a vessel leaves the surface and plunges to the seabed, a lot of things can happen that will ... more When a vessel leaves the surface and plunges to the seabed, a lot of things can happen that will affect its orientation and position on the seabed and the creation and distribution of the debris field. Crushing and catastrophic implosion due to the rapidly increasing hydrostatic pressure has been noted on portions of many wrecks. Extensive damage due to bottom impact and subsequent motions have also been observed and documented. This paper describes the successful numerical modeling of the sinking of several historic vessels. One was in deep water and another in shallow water. In both cases it was possible for the simulation to replicate important details of the debris field. Further work is planned to help explain some of the taphonomy observed as the wreck decays over time as it is acted on by bottom currents, benthic storms and in the shallow case storm waves.
A satellite antenna was to be fielded at a number of locations in the North Pacific Ocean aboard ... more A satellite antenna was to be fielded at a number of locations in the North Pacific Ocean aboard a vessel. The antenna has a motion compensating pedestal, but the capabilities of the motion compensating system were unknown at the time that the ship selection was required. An objective level of ±5 degrees maximum ship motion, (combined pitch and roll), and
This paper discusses research conducted by The Very Low Frequency (VLF) Group at Stanford Univers... more This paper discusses research conducted by The Very Low Frequency (VLF) Group at Stanford University introducing them and a project called the High Frequency Active Auroral Research Program (HAARP). This project utilizes the latest oceanographic and ocean-engineering technologies for exciting applications to space physics and radio science research. Sponsors consist of the Air Force Research Laboratory (AFRL), the Naval Research
This paper briefly describes the characteristics of 4 different types of bottom mounted instrumen... more This paper briefly describes the characteristics of 4 different types of bottom mounted instrumentation systems developed by the authors and associated others at WHOI. A summary of field experience obtained will be presented for each as applicable. One system that included a gimbal mounted 300Khz RD Instruments ADCP, along with a bottom pressure recording instrument was freefall deployed, twice, in 75 meters of water on Georges Bank as part of the GLOBEC Project. A larger more trawl resistant mount was developed to house a gimbaled 75 KHZ RDI ADCP. Two units of this device were delivered to the US Naval Oceanographic Office, Stennis Space Center, MS and were immediately deployed as part of an ongoing field program. A prototype trawl resistant bottom mount containing a profiling winch is undergoing testing at the time this paper is written. The winch will profile a Video Plankton recording instrument over 70 meters of the water column and is intended for deployment on Georges Bank la...
Under the sponsorship of the Office of Naval Research, the Ocean Systems and Moorings Laboratory ... more Under the sponsorship of the Office of Naval Research, the Ocean Systems and Moorings Laboratory (OS and M Lab) of the Woods Hole Oceanographic Institution developed (1990) and deployed (1991) a fully instrumented subsurface buoy in high current waters close to Woods Hole, MA. The purpose of this engineering experiment, named DYNAMOOR, was to obtain long term, high frequency measurements of the buoy 3D position and of the tension in its mooring line, as a function of prevailing currents and variable, adjustable buoyancy. This paper first describes the main components and the method of deployment of the DYNAMOOR complex experimental setup. It then reviews the mechanical and electrical designs of the entire system. Finally, a review of the data analysis and a summary of the results are presented.
The Union ironclad warship USS Monitor foundered in heavy seas off Cape Hatteras, North Carolina,... more The Union ironclad warship USS Monitor foundered in heavy seas off Cape Hatteras, North Carolina, on December 31, 1862. This paper focuses on the development and validation of numerical models of a ship foundering using USS Monitor as a test subject. It begins with a brief account of the vessel’s history and the circumstances leading up to the sinking, then presents the best estimate available for the vessel’s loading condition and hydrostatics. The ingress of water into the ship at a number of locations was described by the survivors, some of whom speculated that the upper and lower hulls began to separate forward due to repeated impact with waves. However, the degraded condition of the wreckage after 149 years on the seafloor prevented an examination of that portion of the hull. Several linear and nonlinear seakeeping models were run on this hull form, including both under tow and after the anchor was dropped just prior to the sinking. The seakeeping models provide time histories of hydrostatic head at each of the down flooding locations along with estimates of the slamming of the overhanging bow in moderate to large waves as reported in survivor testimony. The numerical tools developed to support this analysis will be able to support the analysis of other vessel-foundering events.
When a shipwreck and objects in the associated debris field land on the seabed, they continue to ... more When a shipwreck and objects in the associated debris field land on the seabed, they continue to be acted on by currents and benthic storms that can result in changes to the position, orientations and dispersion. In shallower waters, ocean storm waves and long period swells can cause strong oscillatory water motions to act on the objects. This paper describes a number of cases where the underwater archeological record shows evidence of these changes, and shows how such cases may be modeled using modern COTS software. The technical approach described in this paper shows how the different specialties of naval architecture, oceanography, ocean engineering, sediment transport, hydrodynamics and underwater archaeology can be usefully combined under the umbrella specialty of marine forensics. The phenomenologies associated with freefall in the water column, bottom impact, and then the impact of various post deposition events and processes are modeled for several historic wrecks and the process and results are illustrated. The differential action of storm waves and how to calculate their frequency of occurrence at a specific depth will be described. The sediment transport like action that can re-suspend objects and or tumble them across the seabed will be described and modeled for typical objects. The action of strong oscillating water motions can expedite a wreck's breakup. Scour and erosion corrosion at the water-to-sediment interface have been implicated in specific damage to some historic wrecks. Lastly, the implications to modern search and rescue and to the research of historic wrecks will be discussed.
<jats:p>A dynamic stability event— not to be confused with ordinary or damaged transverse s... more <jats:p>A dynamic stability event— not to be confused with ordinary or damaged transverse stability—is a sudden and seldom occurring event that can result from an unusual dynamic response in some combinations of speed, heading, ship motions phase and wave field. This paper defines several dynamic stability events and describes a process developed to investigate them. The process involves model tests, numerical analyses, and a high speed catamaran test vessel. The strengths and weaknesses of model testing are compared to numerical analyses, and the overall validity of the results are discussed.</jats:p>
An investigation of the capabilities of a suite of seakeeping software to model the interactions ... more An investigation of the capabilities of a suite of seakeeping software to model the interactions of ice floes and icebreaking hull forms was initiated, as part of a wider investigation into arctic operations. The sea keeping behavior of a systematic series of ice floes with variations in area extent and thickness, acting alone and in groups is analyzed and presented. This investigation focuses on developing a methodology that can be used in the preliminary and later stages of ship design for ice infested waters. A number of sensitivity studies were performed that explore the limitations and features of the several software packages available to the authors.
This paper describes investigations by Flotation Technologies and Mooring Systems Inc. to develop... more This paper describes investigations by Flotation Technologies and Mooring Systems Inc. to develop a low drag subsurface mooring apex buoy that contains an RD Instruments Acoustic Doppler Current Profiler current meter. Five different candidate mooring apex buoy systems are compared with regard to their drag, inclination and stability in current and effect on the performance of a typical mooring. The Drag Coefficients of cylindrical and spherical buoy candidates are Reynolds number sensitive in the velocity range of 1 to 3 knots. This leads to calculated and observed hydrodynamic instability due to minute variations in current velocity. An airship shaped streamlined body was found to have the lowest drag, best inclination response and little or no Reynolds number sensitivity in the current regime of interest.
When a vessel leaves the surface and plunges to the seabed, a lot of things can happen that will ... more When a vessel leaves the surface and plunges to the seabed, a lot of things can happen that will affect its orientation and position on the seabed and the creation and distribution of the debris field. Crushing and catastrophic implosion due to the rapidly increasing hydrostatic pressure has been noted on portions of many wrecks. Extensive damage due to bottom impact and subsequent motions have also been observed and documented. This paper describes the successful numerical modeling of the sinking of several historic vessels. One was in deep water and another in shallow water. In both cases it was possible for the simulation to replicate important details of the debris field. Further work is planned to help explain some of the taphonomy observed as the wreck decays over time as it is acted on by bottom currents, benthic storms and in the shallow case storm waves.
A satellite antenna was to be fielded at a number of locations in the North Pacific Ocean aboard ... more A satellite antenna was to be fielded at a number of locations in the North Pacific Ocean aboard a vessel. The antenna has a motion compensating pedestal, but the capabilities of the motion compensating system were unknown at the time that the ship selection was required. An objective level of ±5 degrees maximum ship motion, (combined pitch and roll), and
This paper discusses research conducted by The Very Low Frequency (VLF) Group at Stanford Univers... more This paper discusses research conducted by The Very Low Frequency (VLF) Group at Stanford University introducing them and a project called the High Frequency Active Auroral Research Program (HAARP). This project utilizes the latest oceanographic and ocean-engineering technologies for exciting applications to space physics and radio science research. Sponsors consist of the Air Force Research Laboratory (AFRL), the Naval Research
This paper briefly describes the characteristics of 4 different types of bottom mounted instrumen... more This paper briefly describes the characteristics of 4 different types of bottom mounted instrumentation systems developed by the authors and associated others at WHOI. A summary of field experience obtained will be presented for each as applicable. One system that included a gimbal mounted 300Khz RD Instruments ADCP, along with a bottom pressure recording instrument was freefall deployed, twice, in 75 meters of water on Georges Bank as part of the GLOBEC Project. A larger more trawl resistant mount was developed to house a gimbaled 75 KHZ RDI ADCP. Two units of this device were delivered to the US Naval Oceanographic Office, Stennis Space Center, MS and were immediately deployed as part of an ongoing field program. A prototype trawl resistant bottom mount containing a profiling winch is undergoing testing at the time this paper is written. The winch will profile a Video Plankton recording instrument over 70 meters of the water column and is intended for deployment on Georges Bank la...
Under the sponsorship of the Office of Naval Research, the Ocean Systems and Moorings Laboratory ... more Under the sponsorship of the Office of Naval Research, the Ocean Systems and Moorings Laboratory (OS and M Lab) of the Woods Hole Oceanographic Institution developed (1990) and deployed (1991) a fully instrumented subsurface buoy in high current waters close to Woods Hole, MA. The purpose of this engineering experiment, named DYNAMOOR, was to obtain long term, high frequency measurements of the buoy 3D position and of the tension in its mooring line, as a function of prevailing currents and variable, adjustable buoyancy. This paper first describes the main components and the method of deployment of the DYNAMOOR complex experimental setup. It then reviews the mechanical and electrical designs of the entire system. Finally, a review of the data analysis and a summary of the results are presented.
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Papers by Sean Kery