The Office of Naval Research has sponsored a collaborative effort between the Naval Surface Warfare Center Carderock Division, Advanced Technology and Research Corporation, Newport News Shipbuilders, the National Institute of Standards and Technology (NIST). Phase I of this effort is nearing completion to autonomously weld double-hull ship sections together. In order to accomplish the delivery ...

The increase in global trade is driving growth in both the size and number of ships. However, this increased demand is leading to greater contributions from shipping to air pollution. This is leading designers and operators to propose and adopt novel powering and propulsion systems. However, there is a challenge with assessing the actual benefit from using a certain retrofit technology or chang...

DC faults may cause severe disruptions in continuity of service to vital loads in a shipboard integrated power system, hence detection, isolation and protection against dc faults must be incorporated in both medium-voltage dc and low-voltage dc systems. A standard z-source breaker can identify and de-energize a faulty dc load on both buses quickly. However, until now, provisions for re-energizi...

We report about a hierarchical design for extracting ship features and recognizing ships from SAR images, and which will eventually feed a multisensor data fusion system for airborne surveillance. The target is segmented from the image background using directional thresholding and region merging processes. Ship end-points are then identified through a ship centerline detection performed with a ...

All-electric ships are now a standard offering for energy/propulsion systems in boats. In this context, integrating fuel cells (FCs) as power sources in hybrid energy systems can be an interesting solution because of their high efficiency and low emission. The energy management strategy for different power sources has a great influence on the fuel consumption, dynamic performance and service li...

The power of main engine must be determined in such a way to let the seagoing ship reaches the predicted, in the agreement with the ship owner, service speed. Significant influence on the main engine power, apart from the ship’s speed, has a geometry shape and the dimensions of the ship’s hull. Begins from the general form of Admiralition’s equation, it is essential to establish the specific qu...

This paper addresses the resonance phenomena that can occur in an isolated distribution system during transient events such as repeated energizations or power converter switching. In particular, the aim of this study is to analyze the energization of an onboard radial distribution system installed on an electric ship and to determine how the various leakage parameters that can cause resonance p...

Since 1965, the Naval Ship Engineering Center (NA VSEC) and the Naval Ship Research and Development Center (NSRDC), sponsored by the Naval Ship Systems Command, have been actively involved in developing and using computer facilities for the design and construction of naval ships. The overall goals of this effort, known as the Computer-Aided Ship Design and Construction (CASDAC) project, have be...