Thailand's 14 dams are kept safe and free flowing with the help of a compact remotely operated underwater vehicle (ROV). The Saab Seaeye Falcon ROV recently delivered to the Electricity Generating Authority of Thailand checks for leakage, debris obstruction and supports diver operations and safety.
Chief of Dam Safety, Mr Veerachai Chaisrakeow, says that, in addition to helping with dam security and operation through improved inspection capability, greater diver safety is a major benefit coming from the introduction of the Seaeye Falcon. He cites a number of operational conditions more suited to the free-swimming ROV than a diver. One is checking for debris at the inlet pipes feeding the generators whilst they are still running. This hazardous task for a diver is now undertaken by the Seaeye Falcon which although compact, has the power to hold steady in the strong flow whilst observing the status at the inlet and sending back information to the surface. Another hazardous operation says Mr Chaisrakeow is when a diver had to enter the penstock pipe that feeds the generators through a manhole to check for sediment. Now they simply lower down the Seaeye Falcon.
Checking the overall structure for leakage and other signs of deterioration, normally carried out by a diver, has limitations on time and depth. These tasks are now undertaken by the Seaeye Falcon which can work tirelessly and to depths of 300 metres. Saab Seaeye's deep-rated version of the Falcon can reach 1000 meters and is often used for deep tunnel inspection.
For maintenance and inspection, an additional advantage is for the ROV to accompany the divers, says Veerachai Chaisrakeow. Not only does this offer additional safety for the divers, but the engineers ashore who are unable to dive, can observe the structural issues, such as leakage, via the ROV's observation camera, and instruct the divers as they work.
The Seaeye Falcon has been adopted by the hydroelectric and dam industry after its worldwide success in the rigorous offshore oil and gas industry and national defence forces. Its use in deep tunnel inspection has included entering a pipe running 600 metres down a mountain at a hydroelectric scheme. The concept had been proven in Saudi Arabia where the standard 300 metre Falcon had been sent down tunnels for inspection and mapping work after being fitted with inertial navigation, a Doppler velocity log, profiling sonar and a fibre optic data transmission system.
World-leading in its class, orders for the Seaeye Falcon now exceed 120. Its success has come from being compact, mobile and easy to handle, yet extremely powerful. Also appealing is its operational flexibility which comes through the ease by which standard accessories such as cameras, sonars and manipulators can be readily fitted, and additional custom tooling simply added by bolting on an under-slung module.
This ease of customisation is made possible with a distributed intelligence control system that allows up to 128 devices to be connected together on a single RS 485 serial network. This senses whatever systems are fitted to the ROV - much like a USB port. It also eliminates the need for interface cards, making fault diagnostics easier and the vehicle lighter by removing the need for a large electronics pod.
For finger-tip manoeuvrability in strong currents, the Seaeye Falcon has five powerful independent magnetically coupled brushless DC thrusters, each with velocity feedback for precise and rapid thrust control.
The core Seaeye Falcon comes complete with lights, camera and video options as standard including solid-state gyro, compass, depth sensor and a 450 metre umbilical. The deep rated 1000 metre version has built in fibre optics for high volume data transmission over its long umbilical, and the ability to use broadcast quality video cameras. It also has tilting variable intensity lights linked to its camera tilt mechanism for superior illumination when filming above or below the vehicle.
Formed in 1987, Fareham, UK-based Saab Seaeye is the UKs largest manufacturer of electrically operated ROVs. Recently it was acquired by Saab Underwater Systems, a world leader in underwater systems, with special emphasis on littoral, shallow and difficult underwater environments. The company focuses on sensor systems, precision engagement systems, remotely operated and autonomous underwater vehicles.
Saab serves the global market with world-leading products, services and solutions ranging from defence to civil security. Saab has operations and employees on all continents and constantly develops, adopts and improves new technology to meet customers' changing needs.