By LT Timothy Erickson RNZN, Engineering Change Group, Logistics Command (Marirtime)
In mid-April 2010 the Engineering Change Group (ECG) was given the project to replace RESOLUTION’s aging hydrographic sonar, the FANSWEEP 20. The old system had significant reliability issues due to the age of its components. For the Defence Force to continue to meet its LINZ survey commitments, a new hydrographic sonar system had to be procured quickly. Our team at ECG had to identify a suitable replacement system, procure the equipment and have it installed in the ship during her docking period planned for last November.
Time was a big challenge, due to the comprehensive tender process the project had to follow. In early May 2010, ECG released the tender and project requirements documentation to industry. Comprehensive responses (including recommended systems, timeframes and costs) had to be submitted by early June. An elaborate selection process was undertaken by a number of key stakeholders including many of our senior hydrography experts, to assess not only the costings but also the capabilities of the recommended systems against RNZN requirements.
The system that was finally selected, the RESON SeaBat 7125 Multi-Beam Echo Sounder, is a leading edge technological solution. The RESON SeaBat is a high resolution MBES system that provides a turn-key hydrographic survey system which is capable of mapping seafloor/targets at 1-300m over a swath of 140 degrees.
The RESON SeaBat is modular, which enabled the detailed design to be completed quickly and allowed a relatively straight forward installation. The hardest part was to fit the new transducer to the ship’s hull and interface it with a number of the ship’s existing onboard systems. It took a lot of interaction with a number of organisations including the RESON engineers, the RESON NZ agent (Colin Russell of Ocean Systems Ltd) and the Babcock Fitzroy Design Office, to get the design right by the November deadline. As the project manager, this was probably the most stressful time for me!
Some aspects of the installation (cable runs and deflector plate cutting) were begun before the full design was completed, requiring a very high level of project management supervision. This enabled any issues to be addressed and solutions put in place quickly, without detriment to the project timeline. As well we had a change in project manager (to LT Alex Walton) prior to the completion of the system installation.
The installation of the RESON SeaBat system went smoothly. However, one of the unknowns identified during the trials period, was the vast amount of data being captured, stored and requiring processing both onboard RESOLUTION and ashore. The previous system gathered data from a 90-day survey period onto 1TeraByte of disk space—the new RESON SeaBat captures 1.2 Terabytes of data every 10 days! Unfortunately, the existing legacy data storage and processors lacked the capability to undertake the all data analysis and formatting from the new MBES, to the standards required for LINZ. The project scope had to be expanded to include the purchase and installation of a 24TB drive and a new computer system to process the survey data.
From a project management perspective, it was essential to have input from key stakeholders throughout each stage of the project, especially from the various systems ‘experts’ including senior hyrodrography personnel. Very positive feedback has been received from our Hydrographers in RESOLUTION. The RESON SeaBat provides the users with a more user-friendly, Windows-based processing system as well as a reduced maintenance workload. The major outcome is that the new system allows a greater swathe to be scanned at a higher resolution; as well, greater depths can be surveyed. This enables RESOLUTION to survey a larger area either side of the ship while conducting surveys at higher speeds (6 - 8kts).
The project has been a success, with RESOLUTION completing her first survey with the new hydrographic sonar this April.