Hull Optimization of the Unmanned AGaPaS Rescue Vessel

Abstract

Crew safety is a key parameter for any seagoing mission. Although today’s standards are high, occasionally people go overboard while working on deck. In this case the probability of survival remains low. The joint research project “AGaPaS” [1] aims to significantly increase the chances of survival for a drifting person. Its main objective is to develop a self activating, partially autonomously operating rescue system, able to search, find and rescue people gone overboard. A crucial part of the system is a remotely operated vessel, which is released by free fall from a mother ship. This paper focuses on the hull optimization of this rescue vessel, considering various aspects. The rescue operability has first priority and leads to numerous system specifications such as main dimensions. In addition, adequate seakeeping behaviour is a prerequisite for the successful recovery of a person in distress. This includes small relative motions between the vessel and the drifting person. Moreover, the vessel’s free fall characteristics are to be analyzed. Here, particular interest has been laid on the reduction of the peak acceleration as well as on transferring the vertical velocity into a horizontal motion, in order to minimize the risk of a collision with the mother ship. Various hull geometries have been investigated by means of numerical methods as well as model tests leading to the final hull design of the unmanned AGaPaS rescue vessel.

Investigation of a Cabin Suspended and Articulated Rescue Vessel in Terms of Motion Reduction

“…The front arch is connected to the rescue platform and the suspension system by spherical joints, and the rear arch is connected to the left and right pontoons by articulation joints with rotational degrees of freedom in the horizontal and vertical planes, which constitute the articulated system of the vessel. According to the application and rescue environment of the rescue vessel [24], the specific dimensions of the rescue vessel designed in this research are shown in Table 1. According to the application and rescue environment of the rescue vessel [24], the specific dimensions of the rescue vessel designed in this research are shown in Table 1.…”

“…According to the application and rescue environment of the rescue vessel [24], the specific dimensions of the rescue vessel designed in this research are shown in Table 1. According to the application and rescue environment of the rescue vessel [24], the specific dimensions of the rescue vessel designed in this research are shown in Table 1. The novel idea of the suspension system mainly comes from the automobile industry.…”

A Survey on Unmanned Surface Vehicles for Disaster Robotics: Main Challenges and Directions

“…Kurowski et al [194] developed a satellite-guided SAR system, to be used in special ships and offshore platforms in case a person falls overboard. It consists of three main components: (1) A vest with an Automatic Identification System (AIS), worn by every crew member of a ship or offshore platform; (2) An autonomous twin-hull catamaran USV, referred to as the “rescue vessel” (described in detail in [195,196]); A satellite-aided control station. When a person falls overboard, the AIS vest activates upon contact with the water, and the SAR process starts.…”

AGaPaS: A new approach for search-and-rescue-operations at sea

“…Thus, the ship does not need to stop to lower the rescue boat. 2 After the release, the rescue vessel moves autonomously as fast as possible to the POB and maintains a minimum safety distance to the POB. At this point, an operator on board the parent ship or offshore platform takes over the control of the rescue vessel.…”

“…The retrieval of the POB takes place via a hydraulically operated net basket, which is fixed at its rear edge. The hull speed is about 5.5 knot, and the free fall accelerations from 7.5 m height can be reduced to approximately 6.5 g. 2 The full-scale vehicle is about 4.5 m long and almost 2.3 m wide. Two electrical podded drives move the vehicle, getting its power from 48 V lithium batteries.…”