Inspection tools4 December 2011
A range of new products have been developed to ensure efficient underwater inspections at hydroelectric and dam projects
Long range tunnel inspection
Hibbard Inshore is pleased to announce four major advances to address the inspection of long range tunnels. Because its customers have continued to seek alternatives to dewatering their long tunnels, the underwater services company says it has continued to engineer and upgrade its fleet of Remotely Operated Vehicles to provide cost effective alternatives to provide the data needed to make maintenance and capital decisions.
The four options Hibbard Inshore has added to address long range tunnels are scaled for both distance and power to allow the equipment to fit specific project needs. Two of these options are traditional swimming Remotely Operated Vehicles (ROVs) modified to address distance needs, one is an extremely long range Hybrid Autonomous Underwater Vehicle (AUV/ROV), and the last is a large, robotic crawling vehicle for dry inspection where walkthroughs are deemed unsafe. All of these options are air shippable to any spot in the world. In addition to having high power to weight ratios, all of the vehicles can provide real-time data from multiple sensors and cameras during the inspections allowing engineers or owners present to help direct the inspections to be as thorough as possible.
The first system announced by the company is a Long Range, Deep Rated Seabotix LBV. This vehicle is small in form to fit into small access points, is 600m depth rated, and Hibbard Inshore has upgraded its capabilities to make runs of up to 2km from a single access point. This vehicle can be fit with multiple types of sonar including both imaging and dimensioning units, ultrasonic thickness sensors, and both low-light monochrome and color cameras.
Hibbard Inshore’s second long tunnel system is a Long Range Sub-Atlantic Navajo. This vehicle is also small in form. In addition to inspection, the Long Range Navajo can carry vehicle based tooling and increased sensor payloads to a range of 5 km. The Navajo is easily capable of providing 3D tunnel mapping or running many sensor packages concurrently.
In addition to these two ROV systems, Hibbard Inshore has recently added a 3rd swimming option to its long range fleet. That is a Saab Hybrid AUV/ROV. This vehicle is truly unique in that it is the first of its kind outfitted for extremely long range tunnel inspections. The vehicle can run in either AUV mode or ROV mode meaning that it can follow a pre-programmed route or take real-time control commands from an operator. With the power of an AUV and the control of an ROV, this vehicle can perform tunnel inspections out to 20+ km while supplying real-time data. It is able to stop and hover like a traditional ROV and can carry the largest payload of Hibbard’s long range vehicles. It can also operate in flows that typical tunnel inspection ROVs cannot negotiate. The AUV/ROV also has the unique capability to swim home should its tether be compromised during an inspection.
Finally, in addition to these fully flooded tunnel solutions, Hibbard Inshore can provide 3D laser and video inspections of large diameter, dry tunnels up to 3.2 km in length utilizing a long range crawling vehicle. This vehicle is much larger than a typical sewer inspection crawler and can negotiate larger debris as a result. The lighting, cameras, and 3D laser system are capable of imaging and precise dimensioning in tunnels 10 m in diameter and larger.
SeaOtters help with dam inspections
The SeaOtter-2 ROV from JW Fishers is suited to working in areas with low to medium currents, while its small size and light weight make it easy for one person to deploy and operate. Fitted with front and rear colour cameras with pan and tilt options, illumination for the front camera is provided by two 50W tungsten halogen bulbs and the rear by a ring of high intensity LEDs.
SeaOtter-2 has a 15.24m depth rated housing and comes with 76.2m of cable. System controls are cleanly laid out in a high impact waterproof case with an ultra bright 26.4cm flat screen monitor built into the lid. Command of the ROV's thrusters, cameras and lights are managed with a PS2 controller. A wireless controller can also be used to give the operator even greater freedom.
The control panel has jacks and amplifiers which make it adaptable to the requirements of each job. A video output jack allows an additional remote monitor to be used simultaneously with the internal flat screen monitor.
Options available on the SeaOtter-2 are:
• On-screen display for time/date/GPS/compass heading/depth.
• Auto depth control.
• External DVD recorder.
• Manipulator arm.
• Metal detector.
• Scanning sonar.
Bowtech expands underwater lighting range
Bowtech Aquavision LED lights utilise the latest quad cluster LED technology which generates more than four times the light output per watt than an incandescent bulb, and without the vulnerability of fragile filaments. They are extremely robust and highly shock resistant with an effective lifetime of over 100,000 hours.
The LED-6000-AC is Bowtech Products’ brightest 120V AC underwater LED light to date. The bright 6000 lumens white light produced is ideal for colour video inspection or viewing tasks. The hard anodised aluminium housing is available in either 3000m or 6000m depth rating. It is retrofittable to existing 120V AC systems.
The LED-1600-IR is an infra-red LED light, ideal for non-intrusive observations of marine ecosystems. Featuring the latest LED technology, it is fitted with a cluster of near infra-red LEDs with a wavelength of 850nm which produces a high output of infra-red light with better transmission through the water column.
The LED-K-365UV-DC ‘black light’ is ideal for oil leak detection. It produces and emits only UV light and, as a result, far more usable UV is present for inspection tasks without the requirement for heavy and costly ballasts and filters.
The LED-430 is the smallest in the company’s range of LED lamps. Measuring less than 130mm and weighing only 146g it delivers a bright white light of 430 lumens. When manufactured with an anodised aluminium housing it is rated for use to 300m depth.
This focused light is ideal for colour video inspection or viewing tasks especially for diving and ROV applications, where a compact light source is paramount.
New ROV mounted water blasting system
Seanic Ocean Systems has developed a unique subsea water blasting system (ECB) that incorporates cavitation technology capable of being used with most work class ROVs.
The cavi blaster was built to solve an industry-wide problem where traditional 5K pressure washers are extremely inefficient for heavy marine growth and 10K pressure washers could potentially damage sensitive materials such as rubber, paint or anti-fouling coatings. The ECB pump is extremely efficient and powerful and can be mounted on ROVs.
Andy Guinn, VP of Operations said: ‘We have been consistently satisfied with the performance of the pumps. To date, our fleet of models are being used on diverse campaigns throughout the Gulf of Mexico. I am also excited to report that our rental partner, Ashtead Technology, has several units working in Southeast Asia and Australia, as a result of the success in the Gulf of Mexico.’
Seanic Ocean Systems, based in Texas, US, was formed to address the growing demand for simple, rugged and reliable underwater tooling for remote intervention. Along with engineered solutions, the company also offers a standard product line of ROV tooling for purchase or rental.
Looking at Seaeye ROVs
The Seaeye Panther-XT Plus has been developed as a high performance version of the proven and versatile Panther-XT ROV. This new high performance model combines the capability of precision manipulative tasks with operation in high currents, whilst maintaining a very compact package and footprint. With a new design of front end and enhanced tooling capability, the Panther-XT Plus can be fitted with Schilling Orion manipulators and boasts a power to weight ratio of more than twice that of its competitors.
Claiming to be probably the fastest swimming light work ROV in the world, Panther-XT Plus can travel at over four knots. Its ten SM7 thrusters not only power the ROV along but hold the vehicle steady in strong currents during work and observation tasks.
Also available from Seaeye is the Falcon ROV. Features of this include:
• 300m depth rating, 14 kilo payload.
• Magnetically coupled brushless DC thrusters with velocity feedback loop.
• Four vectored and 1 vertical thrusters.
• Distributed intelligence control system.
• Integral system diagnostics.
• High resolution colour camera on 180° tilt platform.
The Falcon DR offers the additional capability of a 1000m depth rating, 1100 m umbilical length with 14 mm diameter umbilical, and a F2 fibre optic data and video transmission system
The Seaeye Falcon DR was introduced in 2006 following a number of successful operations conducted by Chris Bryant of Subsea Vision. He used a standard Falcon which was upgraded to a specification that would form the basis of the new system. Subsea Vision's requirement was to penetrate 1600m into a pipeline running 600m down a mountain side in a hydroelectric scheme. In order to transmit video and data over this length of umbilical it was necessary to add the F2 Fibre optic pack to his Falcon.
The Falcon DR is rated for operations to 1000m to cater for similar operations in deep tunnels as well as for fly away operations in deeper water offshore.
The ease with which tools and sensors can be added to this modern open frame vehicle without upsetting its performance and stability has found favour with scientists, environmental groups, civil engineers and deep penetration internal tunnel surveyors.
Cygnus launches ROV mountable thickness gauge
Cygnus Instruments, UK manufacturer of digital multiple echo ultrasonic thickness gauges, has launched a new range of ROV mountable devices. The new thickness gauges are designed to work at greater depths, streamline the measurement process and provide unrivalled functionality.
With two new models pressure rated to 2000 and 4000msw, the gauges have optional on-screen video overlay of thickness measurements, allowing ROV pilots to guide the ROV whilst viewing measurements simultaneously. It is also the first Cygnus device to offer user selectable output data in both RS-422 and RS-232 without the need for a converter for use with multiplexers.
The standard system will continue to be supplied with Cygnus’ standard Windows-based software, CygLink, for independently monitoring, recording or logging thickness measurements.
With functionality a priority, these latest units provide a switchable deep coat mode for measuring through coatings 20mm thick and a removable cover plate for full serviceability. There is also a safety pressure relief valve and securing eye for added security.
Following extensive sea trials and recent purchases from several leading subsea engineering companies, the company has also introduced the new Cygnus W1 work class ROV probe handler. Complementing the ROV mountable thickness gauges, the probe handler is constructed of 316 stainless steel and has shock absorbing capabilities to protect the ultrasonic probe. The Cygnus W1 can be supplied with either T-bar or Fish-Tail handles to suit various manipulators. The design of double-jointed coupling enables perfect probe alignment.
Mapping out AUV solutions
One solution to collecting high resolution data without getting your feet wet comes from YSI Integrated Systems and Services. The EcoMapper is described as a unique autonomous underwater vehicle (AUV) designed specifically for mapping water quality, water current and bathymetry.
YSI Systems says they have designed a monitoring platform that will generate the highest-resolution data at a low cost and low risk to your personnel. EcoMapper can cover a wide survey area without a workboat or associated staff and features include:
• Flexible options for water quality, bottom mapping, and water current profiling.
• Options for side-scan sonar.
• Deployable by one person.
• Easy and fast mission planning.
• 8-14 hour run times at speeds of 2-4 knots.
• Continuous data stream as vehicle moves through water column.
• Doppler velocity log for accurate navigation below surface.
• A YSI 6600 V2 bulkhead built in for collection of up to ten water quality parameters in large water bodies.
Key applications for the device include:
• Baseline monitoring.
• Source water mapping.
• Event response.
• Bottom mapping.
• Point source and non-point source mapping.
• Oceanographic research.
A typical example of how the EcoMapper can be utilised was during the development of a proposed hydroelectric plant in southeast Alaska when YSI Incorporated was asked to conduct bathymetry studies. The Alaska Department of Fish and Game required volumetric mapping of two remote lakes to assess the potential impact of the plant. YSI carried out studies of the lakes plus a tidal study near the powerhouse construction site to gather baseline data to assess potential dredging requirements.
Although not a primary objective for this project, the AUV also continuously collected water quality parameters including optical dissolved oxygen, pH, turbidity, chlorophyll, temperature and specific conductance. Additionally, water column profiling was conducted in deeper waters to assess salinity and temperature gradients, which impact the speed of sound and thus the accuracy of the bathymetry measurements.
OASIS Environmental was hired by the hydro developers to conduct studies for the proposed project, and was pleased with the AUV’s performance.
‘The EcoMapper is pretty cool,’ said Adam McCullough from OASIS Environmental. ‘It went into the shallower ends of the lakes, in waters two or three feet deep, and it even navigated up the river delta. We got an accurate one-foot vertical bathymetric elevation model from the data it collected.’
Videoray designs for hydro tasks
The P4 HY 300BASE hydroelectric ROV system from Videoray has been specifically configured for engineers and service managers to quickly perform a variety of basic underwater inspection tasks. Getting into tight spaces or intakes is no problem as the maximum diameter of the Videoray is no more than 25.4cm.
Base system components include:
• P4 ROV submersible.
• P4 control panel.
• Standard computer with 15in display (Videoray cockpit control software included).
• Wireless programmable hand controller.
• Plug and play performance tether: 40m neutrally buoyant.
• Three days of training for one operator.
For use in rugged environments were equipment needs to be more robust, the P4 HY 300R ROV system is considered to be more suitable. The standard computer from the BASE system is replaced with a Toughbook i5 computer along with the addition of an industrial hand controller.