STL Presentation at Oceanology International 2022, London
As development of our Remote Sensing System (RSS) nears completion, we are pleased to share some of the details in a presentation titled ‘A Motion Compensated Robotic Arm for Use …
Developed by Submarine Technology Limited, the Neptune offshore access system is designed to reduce maintenance costs and increase the
availability of normally unmanned offshore installations by providing safe and timely access for
maintenance personnel and engineers.
Motion-compensated personnel-access system and light crane.
The Neptune 20M+ system enables transfer of personnel or cargo from a vessel to a fixed offshore structure with full motion-compensation so that all wave-induced motions are removed and the payload arrives at the target structure with no relative movement between them.
Six degree of freedom (6DOF) Motion Platform.
A variant of the classic ‘Stewart Table’ or ‘Hexapod’ and is similar to those found in flight simulators. It is commercially available for use for third party work.
Ship-Based Robotic Arm for Autonomous Operations.
The arm will form part of a new Autonomous Synchronised Stabilised Platform (ASSP) to enable ASV’s to execute intervention tasks. It will also find applications on-board on manned vessels.
STL Research is a consultancy, design, development and ‘one-off’ project implementation group, specialising in the sub-sea and offshore industries.
Initially operating from Aberdeen, STL Research has been involved in many leading edge projects within the sub-sea and offshore arena – including diving systems, ROV/diving bell launch and recovery systems, hyperbaric lifeboats, HP/HT valves, ship-borne space stabilised crew transfer solutions, well head control & monitoring systems, automated ultrasonic NDT and much more!
STL Research is committed to taking innovative technological concepts, developing them to a practical and economically viable state, and to create commercially successful ventures using the technologies.
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Here we are committed to taking innovative technological concepts, developing them into a practical and economically viable state, and creating commercially successful ventures using the technologies.
With particular specialisations in control & automation and sub-sea & offshore engineering, STL is ideally placed to take innovative & cutting-edge sub-sea and offshore technology IP from its infancy, to eventual IPO or trade sale.
If you would like further information or are interested in our services, please contact us here.
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To transfer personnel and equipment between an offshore support vessel and a fixed structure (wind turbine or hydrocarbons production facility) quickly and safely. The design is based on a 56 metre DP Support vessel and is intended to be able to operate in up to at least a significant wave height (Hs) of 2.5 metres (which may contain a wave of 4.65 metres). Larger vessels will have a greater operational range depending on the particular vessels’ response to wave actions.
The system is space stabilised in 6 degrees of freedom (DoF – roll, pitch, yaw, heave, surge, sway) and will allow safe transfers from a vessel to and from a fixed structure in marginal sea states.Neptune is designed to reach at least 28 metres above lowest astronomical tide and maintain a standoff of at least 15 metres from the vessel to the target structure. It will carry a payload of 500 kg and will have secure seating for 4 persons or 3 including a stretchered medical evacuation. With the personnel carrier removed Neptune will have a lift capacity of at least 1,000 kg. The system is fully redundant and has a built in self stowing ability in the event of a complete system failure.To assist in the development of Neptune a 6 DoF vessel motion simulator (a Stewart platform) has been built and is currently being used in conjunction with a scaled model (approximately 6 metres high) to finalise the design and assist in the development of the mechanical/hydraulic/control systems, and also carry out failure mode test investigations.
The Neptune system is shown below is fitted to the stern quarter of an 56 metre Wind Turbine Support Vessel. It is expected that the support vessel will be equipped with sufficient accommodation facilities to support the marine crew in addition to all additional crew members working 24hours/day involved in the tasks of maintaining the field production equipment. It will be equipped with workshops, instrument shops and storage facilities.
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To create a device capable of simulating vessel motion, in order to test the control system of the Neptune Offshore Access system described in Challenge 1 The device must be capable of achieving a maximum heave of 2.5m and pitch and roll of ± 15°.
Inspiration was sought from existing motion simulators and in particular The Stewart Table which is a 6 degree of freedom hexapod system.
Consultation with ‘H Technologies’ in Littlehampton was sought for the design of the motion table in accordance with the data obtained from the analysis of vessel motions.
The simulator is now fully operational and an image of it is given below, the system is capable of replicating the motions of a relatively small vessel (53 metres long) to a scale of one eighth full size in a significant wave height seas (Hs) of 2.5 metres (Hmax = Hs x 1.86).
Degree of Freedom | Limit of Actuator | Safe Working Stroke |
Heave | 481.44 (+/-mm) | 419.06 (+/-mm) |
Surge | 1004.72 (+/-mm) | 879.13 (+/-mm) |
Sway | 909.09 (+/-mm) | 801.20 (+/-mm) |
Pitch | 36.560 | 30.860 |
Roll | 33.680 | 29.580 |
Yaw | 45.860 | 38.900 |
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The design of Wellbuoy is the result of a FEED contract placed on STL/Oceantech by a major E&P North sea operator to minimise sub sea step out from a host gas production platform and to provide a method of control, supervision and chemical injection that is simple to construct and install and economic to maintain and supply. No electro/hydraulic/chemical armoured umbilical connecting Wellbuoy to the host facility is required.
The original design was based on a remote gas reserve in 90 metres water depth some 20 kilometres from the host platform. An autonomy of 90 days is required with an expected field life of 4 years.
The system can be easily reused at other locations a number of times.
Focus was on achieving the main functionality of the system whilst providing reduced capital and running costs, as detailed below:
1. Control and monitoring of wellhead functions, chemical injection, valve control, monitoring and sensor monitoring.
2. Remote operation from a distant master station and real-time communications for monitoring and control.
3. Autonomy in responding to locally-detected conditions; for example causing ESD.
4. Reliability to function for long periods without maintenance; fully-flexible, dual- redundant configuration deployed for all critical equipment to ensure availability is maintained in the case of equipment failure.
5. Maintainability to minimise manned intervention requirements in view of the restrictions on boarding likely to occur due to adverse weather conditions.
6. Reuseable to new location on field depletion.
Using proven single point mooring system technology, coupled with a reduced maintenance system, to design a buoy of modular design, as illustrated below:
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To investigate the possibility of developing a system capable of welding small diameter (maximum OD 250mm) pipes together to form a continuous pipeline. The system must be extremely reliable, fast and produce high quality welds. It must be fully automatic, use minimal personnel and incorporate an automated weld inspection process.
Friction welding has been and is still widely used in various industrial applications to form a high strength, high quality joint during a manufacturing process. It has also applications in the civil and subsea offshore engineering industries to form shear stud and bolted structural connections.
Various target markets have been identified including servicing reel type pipeline lay barges where long pipeline assembly sites are unavailable, offshore pipeline assembly/installation using a suitably equipped support vessel.Total costs will be significantly reduced by a reduction in vessel size and anchor handling support, reduced requirement for specialist personnel, faster production rates, etc.
Whilst the term friction welding is generally used to describe the process it is in fact better described as a forging process. No other materials are added and the weld preparation is limited to a clean cut only, with any impurities carried away on initial contact between the two surfaces.
STL have carried out a number of test welds using 200mm OD pipeline donated to the project by a major UK North Sea operation company. Sections taken from these welds have been subjected to a full range of mechanical and metallurgical tests by the mechanical engineering department of a well known university and were found to be extremely satisfactory in terms of quality and repeatability.
Each trial weld was completed in less than 30 seconds although to provide a usable system it will be necessary to develop a method of cleaning the upset material on both the inside and outside of the welded pipe.
Existing industrial machinery can be converted to carry out the weld avoiding the cost of designing and developing a purpose made machine although additional equipment will need to be developed to clean, inspect and protect the weld.
STL’s six degree of freedom (6DOF) Motion Platform is a variant of the Stewart Table or Hexapod and is similar to those found in flight simulators.
It’s commercially available for hire. Please contact us here if you would like to know more.
The Motion Platform may be controlled using the following methods:
In the future, Autonomous Surface Vessels (ASVs) will play an important role in servicing and repair of offshore installations for wind energy generation and hydrocarbon production. ASVs can operate around the clock in all but the most extreme weather conditions and, being unmanned, savings can be made by eliminating accommodation and equipment related to human safety. However, in order to carry out useful intervention tasks, ASVs need autonomous tools and manipulators.
STL are developing a ship-based multi-axis robotic arm with financial support from the Marine Challenge Fund (part of the ERDF’s European and Structural Funds Growth Programme 2014 – 2020) which was set up to boost marine innovation in Cornwall.
The arm will form part of a new Autonomous Synchronised Stabilised Platform (ASSP) to enable ASVs to execute intervention tasks – e.g. equipment transfers, survey and inspection, or launch and recovery operations. Space-stabilisation technology as used in STL’s Neptune personnel access system will be further developed to permit synchronous-stabilisation between two moving platforms, such as an ASV and another vessel, a floating wind-turbine, a wave-energy converter, or other target with wave-induced motion.
A stabilised robotic arm will also find applications on-board manned vessels. For example, launch and recovery of underwater ROVs and AUVs is labour-intensive and potentially hazardous to personnel and the equipment itself. A robotic arm could increase efficiency, safety, availability, and expand the weather window for operations.
Keep an eye on our NEWS page for updates.
In September 2019, Submarine Technology Limited (STL) and the Southwest Chapter of The Society for Underwater Technology (SUT) hosted a free workshop exploring the application of robotics in marine operations and their role as an enabling technology for manned and autonomous vessels.
Personnel from STL and the University of Plymouth presented results from the R&D programme together with naval architecture studies and market research findings. The application of robotics to marine operations and its role as an enabling technology for autonomous surface vessels was explored.
A pdf copy of the workshop agenda may be downloaded by clicking here.
The topics discussed at the workshop are listed below for reference. As part of our commitment to publish the results of our ASSP Project, we’ve made copies of the presentations available for download. To download, just click on the relevant topic title.
[Please note that most of the presentations are PowerPoint slide shows. To see all the information, including animations and graphics, it’s important that you ‘play’ the slide show rather than just viewing in edit mode]:-
Topic | Speaker |
Autonomous vessels and robotics | Neil Farrington (ORE Catapult) |
Overview of the ship-based robotics R&D programme | David Kirkley (STL) |
Test facilities for ship-based robotics | Peter Back (STL) |
Robotic arm design | Mike Paton (STL) |
Control System Design – Overview | Lewis Richards (STL) |
Control System Design – Sensors | Peter Back (STL) |
Naval Architecture Studies | Simon Hindley (SOLIS Marine Engineering Ltd) |
Market Research | Paul Weston (Weston Marine Consultancy Ltd) |
Autonomous systems | Philipp Thies (University of Exeter) |
Autonomous marine applications | Alex Whatley (University of Plymouth) |
A 3D CAD model of the ASSP RDU may be downloaded by clicking on the image below. Due to file size restrictions, the model is a Solid Works Part file. However, if you’d like a copy of the full mated assembly, please contact us.
Presentations were made at the All-Energy 2019 conference in Glasgow during May and at the Seawork 2019 ASV Conference in Southampton during June. These were at a relatively early stage of the ASSP project and had the aim of alerting interested parties to the work. Copies of the presentations are available for download by clicking on the links below:-
Event | Speaker |
All-Energy 2019 Conference, Glasgow | David Kirkley (STL) |
Seawork 2019 ASV Conference, Southampton | David Kirkley (STL) |
Please refer to the news page
We are not currently recruiting. However, if you are interested in future career opportunities at Submarine Technology, please contact us using the details below:-
Peter Back
Technical Director
Submarine Technology Limited
peter@stlres.co
As development of our Remote Sensing System (RSS) nears completion, we are pleased to share some of the details in a presentation titled ‘A Motion Compensated Robotic Arm for Use …
We have recently been awarded grant funding by Marine-i, the EU funded programme set up to boost marine innovation in Cornwall. The grant will help fund the development a Remote Sensing System …
Submarine Technology Limited have completed initial space stabilisation and motion synchronisation tests on their new robotic arm. The small-scale, hydraulically actuated arm, known as ASSP (Autonomous Synchronised Stabilised Platform), was …