VESSEL REVIEW | Guardian – Optionally-crewed daughtercraft prototype for sea rescue duties

Edinburgh, UK-based search and rescue (SAR) technology company Zelim has introduced a new fast daughtercraft with unmanned operation capability. Designed by local naval architecture firm Chartwell Marine, Guardian is the first unit in a new similarly named series of unmanned surface vehicles (USVs) that will undertake SAR duties under a range of weather conditions, including those that are deemed too hazardous for traditionally crewed vessels.

Fitted with sophisticated casualty detection and recovery systems

The new fast rescue craft has an aluminium hull, an LOA of 8.4 metres (28 feet), a beam of 2.55 metres (8.37 feet), a draught of only 0.6 metre (two feet), a displacement of 3.8 tonnes, an AI-based detection system that can spot and track multiple casualties in the water (as well as distinguish casualties from floating objects such as buoys and debris), and a specialised bow-mounted rescue conveyor that can be lowered into the water to retrieve two people simultaneously. The latter two systems were developed in-house by Zelim.

The USV is designed to be capable of quick recovery of up to 11 accident survivors, or nine survivors if the craft has two embarked personnel when operating in crewed configuration. The craft can undertake rescue operations even under Sea State six conditions (characterised by significant wave heights of up to four metres) to minimise the risk of their exposure to the elements.

Because the craft can operate without an embarked crew, SAR operations can be performed without risk of impeding factors such as crew fatigue.

The craft also boasts remote command and control (C&C) and autonomous operating capabilities, thanks to the installation of a C&C system from Sea Machines Robotics. The design is aimed at providing an enhanced capability to respond to person overboard incidents and provide close standby cover for offshore operations.

Deploying from a larger vessel offshore via a LARS davit (whether single or four-point lift), the USV will be first to arrive on scene to recover casualties and bring them back to the safety of the parent vessel.

The USV also has protected onboard space for immediate treatment of injured survivors.

Compatible with existing systems in other marine sectors

Power for the craft is provided by a Bukh diesel inboard engine driving an Alamarin AJ285 waterjet to deliver speeds in excess of 30 knots and a range of 15 nautical miles. The USV also has self-righting ability to ensure continued operation following an accidental capsize, while a maximum endurance of six hours will permit sustained SAR operations especially at night or in bad weather.

The electronics suite also includes a Furuno radar and a Teledyne FLIR rotating thermal camera. The latter will be used in conjunction with Zelim’s AI-enabled casualty detection technology.

The USV has already garnered initial interest from the offshore energy sector and also shows potential for adoption by other sectors across the maritime industry such as the cruise ship segment. This is partly because the craft is compatible with currently available LARS equipment, thus requiring no further modifications to existing vessels.

Guardian was developed with input from the UK Maritime and Coastguard Agency (MCA) and the US Coast Guard. Design work on the craft was completed in compliance with Lloyd’s Register requirements and the MCA Workboat Code.