SUONO - Safe Underwater Operations iN Oceans
Project executive summary
Modern society sustainability is closely connected to energy from fossil fuels and renewable sources. Energy retrieval processes are increasingly challenging due to the continuous increase in energy demand from human civilization (currently about 18TW), and because of the inevitable depletion/saturation of hydrocarbon deposits and sites suitable for renewable energy extraction.
In this context, the search for energy sources has set its sights on the sea, specifically on hydrocarbon extraction from subsea deposits and installation of offshore wind farms. As can be seen from the programmatic documents "New National Energy Strategy" (October 2012) and "The European offshore wind industry key trends and statistics 2012", the accelerated development of offshore energy activities in the next 20 years will establish new markets worth hundreds of billions of Euro. Beyond energy issues, it should be considered that commercial diving in the civil sector is required to open new perspectives to the sustainable use of natural marine resources, as well as to protect and enhance the underwater cultural heritage.
Marine technologies and, in particular, commercial offshore diving technologies/techniques play therefore a fundamental role and belong to the so-called "enabling" technologies in sustainable economies; firstly, with regard to urban and industrial energy demand and, secondly, for energy transport and distribution.
Commercial offshore diving (up to 300 m) involves not only robots, which can be designed for specific working environments, but also human operators, obviously born to live in quite different environmental conditions. The involvement of human beings leads to an unavoidable and sizable increase in commercial diving safety while ensuring its effectiveness, improving efficiency and life quality for all people involved. This objective can be pursued on the one hand by a) resorting primarily to ever more advanced and autonomous robots and, on the other one, b) by improving the working conditions and life quality of human operators - still required - while minimizing their risks.
Project SUONO, fully endorsing this double approach, pursues increased safety in commercial diving through research, development and innovation regarding both human operator lifes and robotic technologies.
The recent, enormous interest of the business, industrial and scientific world in commercial diving, as mentioned above, is mainly related to oil and gas sector and, therefore, to research and management of offshore energy sources, as evidenced by the document of the Italian Ministry of Economic Development "New National Energy Strategy" (October 2012). By no means of lesser importance are the applications and implications for scientific research, renewable energy (e.g., offshore wind farms and tidal power generation systems), environmental protection (including pollution in port areas or sea areas at large), geophysics, aquaculture and underwater archaeology.
Diving operations for monitoring or intervention, such as pipeline welding, cable laying, structure assembly and/or disassembly, object/artefact recovery, etc. are typically carried out by highly specialised divers and/or robots depending on risk level, depth and mission type. The first are the so-called Certified Commercial Divers (CCD) while the latter generally fall under the Remotely Operated Vehicle (ROV) category - i.e. robots operated by pilots positioned on a support vessel or on a platform - and, more rarely, under the Autonomous Underwater Vehicles (AUV) category.
In practice, the use of CCDs and robots is not mutually exclusive and, for example, an observation ROV is always used to monitor CCDs during operation, sending images to the mission supervisor located in the control room aboard the support vessel or platform. Furthermore, CCDs and ROVs can take turns in the execution of certain operations depending on the skill level or strength required, naturally favouring CCDs for highly specialised missions and ROVs otherwise. CCDs operate in deep water down to 300 m (but typically in the 150-200 m range), breathing high-pressure mixtures of helium and oxygen. This activity involves the use of:
- diving bells for transporting CCDs from the support vessel/platform to working depth and vice versa at the end of each working day;
- deck-based hyperbaric chambers (saturation systems) placed on the support ship/platform for the rest periods and for pressurization and decompression stages required at the beginning/end of each saturation work period (usually 4 weeks);
- hyperbaric evacuation systems (HES) in the case of severe damage to the support vessel/platform.
Needless to say, CCDs operate under heavy working conditions in extreme environments: 1) environmental temperatures often below 5 °C, 2) 8-hour shifts at depth; 3) CCD stay for the remaining 16 hours in a hyperbaric environment, identical to that of the prior working depth, generated by deck-based hyperbaric chambers aboard the support vessel/platform. These chambers provide a service area and living quarters fitted with resting bunks. Life in such environments provides for extended stays under highly pressurized conditions (up to 30 atm) with a helium-oxygen breathable mixture during shifts of 4 consecutive weeks; extended stay times necessarily cause tissue saturation with the breathed inert gas. In addition, helium mixtures, a gas required to minimise decompression problems, present a thermal conductivity that is an order of magnitude above that of air (0.152 W / (m K) against approximately 0.026 ); accordingly, CCDs are likely to experience sweltering heat or intense cold if an accurate control of environmental conditions is not provided. Such operating conditions require the design of technologically advanced, saturation hyperbaric chambers to maximize the crew's safety and life quality.
ROVs are unmanned underwater vehicles, used both for surveillance/monitoring and work operations, which are connected to the support vessel by a tether carrying power, ROV-sensor data, video camera information, and control signals. The ROV operator uses information from cameras and sensors to control the ROV and perform required operations. In this field, important innovations are connected to operability, sensors, and control interfaces necessary for using these devices at depths unsuitable for CCDs, and in any case, under conditions deemed hazardous for humans and for the environment (for example, consider a well-head clamping necessary in case of accidents from underwater mining operations).
The modular saturation system, HES, ROVs, and the support vessel/platform represent the living and support/technical aid structures for an intelligent community comprising men with different skills: CCDs, ROV operators, and the entire crew of the support vessel/platform. Interplay between technological and human aspects becomes essential to increase the efficiency of this micro-community, whose performance ensures the proper operation of the macro-community, for example, metropolis, etc.
On this basis, the general objective described above consists in improving health and safety at work, work efficiency, and the life quality of Certified Commercial Divers (CCDs), as well as increasing the performance of ROV operators. This general objective shall be accomplished through a multidisciplinary approach whereby the biomedical and engineering component will be integrated at several levels: from robotics to domotics to more holistic aspects connected to the psychology of small social groups, with a strong research component tied to an immediate industrial application.
Project SUONO (hereinafter SUONO for brevity) aims to produce
(A) a new HES type;
(B) a new ROV type, or rather a new HUV (Hybrid Underwater Vehicle) type.
In addition to the engineering objectives, SUONO aims to identify vulnerability indicators (biomarkers) for "environmental" stress or abnormal emotional behaviour to propose and introduce preventive (domotics) or personalised corrective measures. Under this aspect, SUONO also considers various work and stress-related issues.
Thus, the project addresses issues connected to health and safety at work for CCDs, as well as innovative HUVs to cover the entire operational chain of Commercial Diving (Figure 1). Accordingly, project SUONO will be divided into two subprojects: one devoted to the development and testing of HES, and the other dedicated to HUV development.
SUBPROJECT 1: A modular hyperbaric facility (SAT-Diving System) (Hyperbaric Modular System - MHS) containing also the (Hyperbaric Evacuation System - HES) module to evacuate CCDs upon accident of the support vessel/platform. Until now, HES were produced by a few foreign (non italian) companies disregarding the ergonomic and operational safety criteria necessary for an "autonomous hyperbaric lifeboat". The MHS will be equipped with devices for remote monitoring of biomedical data of the CCD, allowing remote - online and offline - medical and psychological consultation. Furthermore, this subproject also addresses various technical aspects of the HES architecture and, in particular, those of naval-mechanical nature (including the propulsion system), biomedical sensors onboard, and environmental enrichment measures (sounds, colours, etc.) as stress relievers.
SUBPROJECT 2: (a) a HUV with innovative features regarding actuators and the use of control interfaces -including those of haptic nature- essential for effective operability in delicate unmanned operations for system and environmental safety and (b) an immersive control station equipped with virtual reality technology to mimic the operating environment and advanced human-machine interaction interfaces for remote control.
This subproject aims to provide a hybrid, modular, and remotely operated underwater vehicle (ROV), i.e. a HUV, also equipped with an autonomous power supply system (which makes it hybrid), which is able to operate in observation mode albeit capable of switching to a work mode, by adding a submarine robotic handling system (this particular feature requires to implement a modular system). An innovative HUV of this sort offers a platform able to accommodate a large variety of measurement and work tools required to carry out various underwater operations. In particular, this HUV will be able to perform both observation operations alongside CCDs and underwater missions at higher depths, typically attributed to heavier ROVs of work class type. The HUV will be designed to be more modern, versatile, economic and of easier maintenance than those machines on the market today. In particular, it will be equipped with "friendly" control systems that ensure maximum effectiveness and efficiency in human-machine interaction, the crucial parameter and potential ROV usage limitation nowadays. The project addresses various technical aspects of the vehicle architecture and, in particular, naval-mechanical (including the propulsion system), on-board sensor and user interface elements.
From an organizational and structural point of view, the outcome of the project, beyond instrumentation and operating models, is the implementation of a safe, integrated system for extreme environments, which represents a unique achievement by itself. In this regard, what sets Project SUONO apart from other initiatives is precisely the study of human-environment interaction and human responses to extreme conditions, considering also the social structure wherein individuals must live for extended periods. This part subsumes the project under a new "technological humanism", whereby the contribution of partners apparently unrelated to each other can be summarized in a project focused on men and their life quality, understood primarily as harmonious integration with the physical, architectural and social environment.
On this basis, the project philosophy can become a technological/scientific/ social reference for all operators in hostile environments (e.g., fire brigade, civil protection, military, etc.), who may benefit from a real and innovative know-how where men and their health and safety (work-related stress and occupational diseases) lie at the centre of industrial development and basic research.
Thus, the natural evolution of SUONO lies in extending the use of methods and systems produced in commercial diving to "surface" operations, again with the ultimate goal of improving health and safety at work, optimizing work performance through robotic technologies, and identifying preventive strategies aimed at reducing the person's psycho-physical vulnerability to stress while safeguarding his/her well-being.