The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform
F. D. Messina - One of the best experts on this subject based on the ideXlab platform.
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The economic advantages of jet-assisted plowing
MTS IEEE Oceans 2001. An Ocean Odyssey. Conference Proceedings (IEEE Cat. No.01CH37295), 2001Co-Authors: F. D. Messina, J.b. Machin, J.a. HillAbstract:Jet-assisted plowing is rapidly becoming recognized as the intelligent and cost effective technique for deeper, low-tension Cable burial with standard Cable Ships and conventional handling equipment. The development of this approach was motivated by the economic advantages associated with its potential to achieve enhanced Cable protection at increased speed and reduced tow force. While the standard passive plowing technique has been generally effective and reliable, the resulting depth of burial has been limited by the amount of tow force the towing ship can impart to the plow in a given soil condition. In some soils (fine sand and stiff clay), achieving even the standard one-meter burial depth requirement of most Cable burial projects within the bollard-pull capabilities of typical commercial Cable Ships is difficult with conventional passive plowing. Jet-assisted plows, on the other hand, provide deeper burial at reduced tow tension in a greater range of sea floor soils. Recognizing the need for deeper Cable burial to counter the increased threat of larger fishing vessels and heavier trawling gear, the trend with Cable owners is to bury much deeper than the one-meter standard, particularly in soft clay and sand-dominated soils (such as those commonly found in the Far East). TyCom have successfully buried more than 2000 kilometers of fiber optic Cable at an average depth ranging from 1.2 to 1.6 meters with corresponding tow tensions of about 20 metric tons using their new jet-assisted plows developed by Perry Slingsby Systems, Inc. Indications are that deeper burial to 3 meters in this same range of soils is also possible while keeping within the 50 metric-ton tow limit of most commercial Cable Ships. This paper addresses the results from field testing and actual burial projects to discuss in detail the benefits and potential economic advantages of jet-assisted plowing.
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New advances in jet-assisted plowing for the undersea Cable construction industry
OCEANS 2000 MTS/IEEE Conference and Exhibition, 2000Co-Authors: J. H. Kober, F. D. Messina, David DeanAbstract:Cable burial by plowing, using large sled-type Cable plows towed by large powerful Cable Ships is the standard and most widely used commercial method of protecting submarine telephone Cables from fishing activity, large ship anchors and other ocean hazards. With the world's transoceanic Cable systems now rapidly expanding into a global undersea network for the new millennium-and transoceanic Cables connected to regional systems, which are then connected to domestic systems-there is a market trend towards an increased percentage of short-haul and non-repeatered systems. Many of these Cable segments are less than 300 kilometers in length, will be deployed in shallow water (less than 1500 meters) and will require a more cost-effective burial approach. Hence, even though the “brute force” passive trenching method has become established as relatively reliable, there is a growing need for a more versatile, efficient and economical Cable plowing system. Jet-assisted plows are similar to passive plowing tools and have demonstrated their ability to achieve adequate burial depth at reduced tow tension and increased forward speed. These plows utilize nozzles that introduce water at the soil interface to assist the trenching tool, reducing the stresses due to localized changes in soil conditions and possibly reducing pore water effect in cohesionless sands. Caldwell Cable Ventures, Inc. (a General Dynamics Company) has been applying this technology for more than 20 years, burying power and telecommunications Cables in riverbeds, lakes and marshes to depths of up to 14 meters. More recently, General Dynamics-ATS (GD-ATS) and Tyco Submarine Systems, Ltd. (TSSL) have developed new high performance Cable plows based on a novel Swept Flow Jetter (SFJ) approach. Additionally, The GD-ATS plow has an on-board Cable engine to provide both Cable tension and slack management, and a single combination tow/umbilical Cable to reduce the number of Cable winches and overall number of Cables in the water column. The TSSL plow has a novel, more responsive “rudder type” steering arrangement. These new features have been successfully tested, providing a new level of Cable plow performance and an economical burial alternative for the undersea Cable construction industry
David Dean - One of the best experts on this subject based on the ideXlab platform.
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New advances in jet-assisted plowing for the undersea Cable construction industry
OCEANS 2000 MTS/IEEE Conference and Exhibition, 2000Co-Authors: J. H. Kober, F. D. Messina, David DeanAbstract:Cable burial by plowing, using large sled-type Cable plows towed by large powerful Cable Ships is the standard and most widely used commercial method of protecting submarine telephone Cables from fishing activity, large ship anchors and other ocean hazards. With the world's transoceanic Cable systems now rapidly expanding into a global undersea network for the new millennium-and transoceanic Cables connected to regional systems, which are then connected to domestic systems-there is a market trend towards an increased percentage of short-haul and non-repeatered systems. Many of these Cable segments are less than 300 kilometers in length, will be deployed in shallow water (less than 1500 meters) and will require a more cost-effective burial approach. Hence, even though the “brute force” passive trenching method has become established as relatively reliable, there is a growing need for a more versatile, efficient and economical Cable plowing system. Jet-assisted plows are similar to passive plowing tools and have demonstrated their ability to achieve adequate burial depth at reduced tow tension and increased forward speed. These plows utilize nozzles that introduce water at the soil interface to assist the trenching tool, reducing the stresses due to localized changes in soil conditions and possibly reducing pore water effect in cohesionless sands. Caldwell Cable Ventures, Inc. (a General Dynamics Company) has been applying this technology for more than 20 years, burying power and telecommunications Cables in riverbeds, lakes and marshes to depths of up to 14 meters. More recently, General Dynamics-ATS (GD-ATS) and Tyco Submarine Systems, Ltd. (TSSL) have developed new high performance Cable plows based on a novel Swept Flow Jetter (SFJ) approach. Additionally, The GD-ATS plow has an on-board Cable engine to provide both Cable tension and slack management, and a single combination tow/umbilical Cable to reduce the number of Cable winches and overall number of Cables in the water column. The TSSL plow has a novel, more responsive “rudder type” steering arrangement. These new features have been successfully tested, providing a new level of Cable plow performance and an economical burial alternative for the undersea Cable construction industry
J.a. Hill - One of the best experts on this subject based on the ideXlab platform.
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The economic advantages of jet-assisted plowing
MTS IEEE Oceans 2001. An Ocean Odyssey. Conference Proceedings (IEEE Cat. No.01CH37295), 2001Co-Authors: F. D. Messina, J.b. Machin, J.a. HillAbstract:Jet-assisted plowing is rapidly becoming recognized as the intelligent and cost effective technique for deeper, low-tension Cable burial with standard Cable Ships and conventional handling equipment. The development of this approach was motivated by the economic advantages associated with its potential to achieve enhanced Cable protection at increased speed and reduced tow force. While the standard passive plowing technique has been generally effective and reliable, the resulting depth of burial has been limited by the amount of tow force the towing ship can impart to the plow in a given soil condition. In some soils (fine sand and stiff clay), achieving even the standard one-meter burial depth requirement of most Cable burial projects within the bollard-pull capabilities of typical commercial Cable Ships is difficult with conventional passive plowing. Jet-assisted plows, on the other hand, provide deeper burial at reduced tow tension in a greater range of sea floor soils. Recognizing the need for deeper Cable burial to counter the increased threat of larger fishing vessels and heavier trawling gear, the trend with Cable owners is to bury much deeper than the one-meter standard, particularly in soft clay and sand-dominated soils (such as those commonly found in the Far East). TyCom have successfully buried more than 2000 kilometers of fiber optic Cable at an average depth ranging from 1.2 to 1.6 meters with corresponding tow tensions of about 20 metric tons using their new jet-assisted plows developed by Perry Slingsby Systems, Inc. Indications are that deeper burial to 3 meters in this same range of soils is also possible while keeping within the 50 metric-ton tow limit of most commercial Cable Ships. This paper addresses the results from field testing and actual burial projects to discuss in detail the benefits and potential economic advantages of jet-assisted plowing.
J. H. Kober - One of the best experts on this subject based on the ideXlab platform.
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New advances in jet-assisted plowing for the undersea Cable construction industry
OCEANS 2000 MTS/IEEE Conference and Exhibition, 2000Co-Authors: J. H. Kober, F. D. Messina, David DeanAbstract:Cable burial by plowing, using large sled-type Cable plows towed by large powerful Cable Ships is the standard and most widely used commercial method of protecting submarine telephone Cables from fishing activity, large ship anchors and other ocean hazards. With the world's transoceanic Cable systems now rapidly expanding into a global undersea network for the new millennium-and transoceanic Cables connected to regional systems, which are then connected to domestic systems-there is a market trend towards an increased percentage of short-haul and non-repeatered systems. Many of these Cable segments are less than 300 kilometers in length, will be deployed in shallow water (less than 1500 meters) and will require a more cost-effective burial approach. Hence, even though the “brute force” passive trenching method has become established as relatively reliable, there is a growing need for a more versatile, efficient and economical Cable plowing system. Jet-assisted plows are similar to passive plowing tools and have demonstrated their ability to achieve adequate burial depth at reduced tow tension and increased forward speed. These plows utilize nozzles that introduce water at the soil interface to assist the trenching tool, reducing the stresses due to localized changes in soil conditions and possibly reducing pore water effect in cohesionless sands. Caldwell Cable Ventures, Inc. (a General Dynamics Company) has been applying this technology for more than 20 years, burying power and telecommunications Cables in riverbeds, lakes and marshes to depths of up to 14 meters. More recently, General Dynamics-ATS (GD-ATS) and Tyco Submarine Systems, Ltd. (TSSL) have developed new high performance Cable plows based on a novel Swept Flow Jetter (SFJ) approach. Additionally, The GD-ATS plow has an on-board Cable engine to provide both Cable tension and slack management, and a single combination tow/umbilical Cable to reduce the number of Cable winches and overall number of Cables in the water column. The TSSL plow has a novel, more responsive “rudder type” steering arrangement. These new features have been successfully tested, providing a new level of Cable plow performance and an economical burial alternative for the undersea Cable construction industry
Jerzy Herdzik - One of the best experts on this subject based on the ideXlab platform.
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Application possibilities of electric driven propulsion of multi-mode Ships
Journal of KONES, 2020Co-Authors: Jerzy HerdzikAbstract:The ship propulsion solution based on unconventional thrusters driven by electric motors is most often applied for the multi-mode Ships. These Ships ought to have dynamic positioning system. It forces an application of a few thrusters (most often four, seldom more up to eight). Records from a number of multi-mode Ships show a mean load of less than 40% of maximum load on the propulsion system. In other side the demand for electric energy of ship industrial part is large, more often than for the propulsion part. In that case the diesel-electric propulsion system application may be economical, because the electric energy generation for all ship’s purposes makes possible the main engines work on the optimum loads on lowest specific fuel consumption and allows them a long-term work on heavy fuels. For multi-mode Ships like Cable Ships, suppliers, drilling vessels are convenient an application of unconventional thrusters with direct electric propulsion as well, especially for dynamic positioning systems. The efficiency of the thrusters is a predominant factor for the successful and economical operation. Forecasted development and rise of quantity of diesel-electric propulsion (it means with electrical transmission) would cause increased interest of unconventional thrusters. Ultimately they may revolutionize ship propulsion systems.
