Photogrammetry and Multi-Headed Theodolite Systems as Complimentary Tools
PHILADELPHIA NAVAL SHIPYARD PA
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Foundations for wet accumulator bottles WABs are large, complex structures that require fabrication in accordance with exacting dimensional tolerances. WABs are those tanks that store steam for the launching of aircraft off aircraft carriers. The traditional process for fabrication and installation of WAB foundations is a high risk venture not only from cost and scheduling perspectives, but also from a geometrical perspective. The WAB foundations consist of two units, each with four structural members and two padeyes that require fabrication and installation with respect to an imaginary WAB centerline. Through the complimentary use of photogrammetry and a multi-headed electronic theodolite system, the foundations can be fabricated in the shop to the correct shipboard geometry, and installed within tolerances, and within cost and schedule. With all of the fabrication completed in the controlled environment of the shop, all structural, fabrication, and installation problems can be alleviated before the actual shipboard installation. This paper explains the methods and techniques for using photogrammetry and a multi-headed electronic theodolite system as complimentary tools. It explains the practicality of collecting dimensional data from the existing ship structure using photogrammetry, and using a multi-headed electronic theodolite system to assist in the fabrication of the WAB foundations.
- Marine Engineering