Supply, Deployment, and Translation of Hydrophones for Underwater Acoustic Facility

NPL is seeking a solution for the deployment and translation of a set of hydrophones into an underwater acoustic facility. The facility is an underwater acoustic calibration tank consisting of a large wooden vessel (5.5m in diameter and 5m deep) filled with potable water.

The calibration activities will be performed with either 2 or 3 hydrophones deployed at the mid-depth point of the vessel. The hydrophones are mounted at the end of carbon fibre poles of minimum size to avoid acoustic reflections.

The size and design of the poles is flexible and may be adjusted to the solution (this will be the responsibility of NPL). The poles may be permanently attached to the solution as long as the hydrophones can be removed and mounted onto the ends.

The schematic and model of the facility attached depict dimensions, swept volume required of each hydrophone (shown as coloured prisms), starting positions of the hydrophones (shown at the top of each prism) and extreme positions of the hydrophones (shown at the bottom of the prisms). The facility is operated from the first floor, and it currently has 3 separate linear axis carriage systems (as shown in the images attached).

The facility features a concrete floor, steel framework around the vessel, a HVAC system and an overhead crane. The size of the room cannot be altered, but modifications to the concrete floor and steel framework are feasible for attachment/fixing of solutions.

NPL has conducted initial research into possible solutions such as industrial robots. NPL is open to explore different solutions to meet the requirements below. NPL is seeking engagement from suppliers who have capability to provide a solution to the following requirements: • The solution must be able to deploy the hydrophones maintaining the poles always in a vertical position for scanning under computer control. • The solution must be able to translate the hydrophones in X, Y & Z against each other effectively scanning a flat plane across the projected beam. • The solution must enable rotation of the poles about their axis to aim the hydrophones. • The solution must be able to lift the poles out of the water for an operator to safely load the hydrophones to onto the end. • The solution must have a minimum payload capability of 300kg. • The solution must be able to scan in incremental steps of 1±0.5mm. • The solution should feature a control software compatible with LabVIEW (other options will be considered) This is not an evaluation exercise and nothing in this activity will limit the opportunity to engage in any follow on ITT.