Design to Production for the Air Warfare Destroyer

Transcription

1 Design to Production for the Air Warfare Destroyer J.A Carr Air Warfare Destroyer Alliance INTRODUCTION The Air Warfare Destroyer (AWD) Program is executed by the AWD Alliance consisting of the Commonwealth of Australia and the Industry Participants, namely ASC and Raytheon Australia. The AWD Alliance is empowered and is responsible for the conduct of the AWD Program, including the platform system design. The Commonwealth has engaged Navantia as Platform System Designer (PSD). The AWD is constructed at ASC in Adelaide with blocks being built at sites in Adelaide (ASC), Newcastle (FORGACS), Ferrol (Navantia), and Melbourne (BAE Systems). The existing F104 ship baseline was upgraded to accommodate design modifications introduced in F105 ship which is in construction concurrently with the AWD. It also includes modifications resulting from obsolescence, Australian legislative compliance, and the introduction of an Australian Combat System. BACKGROUND The construction of the AWD involves a widely dispersed manufacturing capability both nationally and internationally. The build strategy for AWD has remained the same since the selection of ASC as primary shipbuilder in May of 2005 to construct the ship in more than one building location. This strategy was implemented to both mitigate labour resource limitations within any one major industrial location of Australia, as well as increased flexibility to select the best capability for specific manufacturing tasks. The selection of the F100 existing platform in June of 2007 introduced a new challenge for the Alliance in maintaining the build execution in multiple locations, as the F100 design was structured to a single location build strategy. Additionally the PSD Contract made provision for the design to be released under a technical data package that is predominantly a 2D paper construction drawing based with limited provision for the release of Computer Aided Design (CAD) data. The limitations in the technical data package provisioning arrangement have resulted in increased production engineering responsibility for the Alliance in supporting manufacturing in multiple locations. If left untreated, these limitations would have also significantly constrained the use of computer-aided manufacturing techniques leading to inefficiency in the production design and production support activities. The Alliance engineering team has worked with the PSD to maintain the original AWD dispersed build strategy and to exploit opportunities across the AWD manufacturing streams to allow for efficient use of modern CAD/Computer Aided Manufacture (CAM) production design tools. This paper will outline some of those areas exploited and adopted from initial structural fabrication through to waterfront technical problem solving.

2 Structural NC Cutting Post Processing The AWD structural design released from the PSD began in early The design was released as a combination of structural drawing products and a set of cut files as Numerical Code (NC). The Alliance shipbuilding engineering team, working with the PSD, conditioned the NC data for plasma/oxy cutting machines used to cut steel for AWD. The steel fabrication occurs in locations in Australia using different burning technology. The PSD structural application (FORAN) includes the provision of automatic plate nesting and cutting of ship s hull plate and structural sections. The FORAN output CAD/CAM data in its native format was not suitable for all the NC plate cutting machines employed at the AWD manufacturing sites. To achieve full use of the data, a post-processing step was developed. The post processing for each fabrication site was achieved by building a series of test plates for each fabrication area to validate that cutting actions required were executable. The resultant CAM data output for both ASC and Block Subcontractor sites as depicted in Figure 1. NEST FORAN PP1 NC FILES ASC Project Database PP2 NC FILES Block 1 PP3 NC FILES Block 2 Figure 1 The production output file can currently be deployed in any of three locations in Australia or in Spain without having to modify the baseline design product in the native CAD file. Common Welding Processes and Procedures The welding requirements for the AWD at the time of contract in 2007 were those set by the F100 baseline specifications and were conflicting in direction. The requirements specified that welding was to be in accordance with the PSD production procedures which were supplied as reference data and were developed to AH grade material. The requirements also mandated material selection for welding and inspection to be in accordance with Lloyds Register rules. The shipbuilding team within the Alliance chose at the time of contract to develop and qualify weld procedures for AWD that were in accordance with Lloyds Naval ship rules from January 2006 as that was the most current set of rules invoked at the time of contract award. The decision, although resulting in some

3 added engineering work for the Alliance during start-up phase of the contract, has benefitted the program in common weld processes, procedures and qualifications across all structural welding sites that have been approved by the Class Society. The common procedures also resulted in common weld consumables at all sites and the sharing of lessons learned by each of the block builders. Lifting Handling and Transportation The AWD build strategy has block construction in multiple locations with different facility constraints. Blocks are then transported to ASC via a sea-going barge. Each lift and transport must be engineered to insure safe working loads. The shipbuilding engineering team employs a group of computer engineering tools to conduct the design and to analyse each element. Concept designs are developed initially in 2D CAD and used for liaising with production and planning groups regarding requirements and applicability of desired mocks, jigs and fixtures. Final designs including calculations, reports and CAD detail drawings are analysed in a Strand 7 finite model tool. The below figures 2 and 3 depict completed assemblies. Figure 2 is the design for lifting the aft deckhouse block. The modelling identifies back up structure requirements and picks optimum pad eye location to support safe lift. Figure 2 Block 703 Block Straight Lifting Analysis Figure 3 is the completed analysis for rotation of a sub-block assembly. Each sub-block is analysed to allow for use of a common rotating beam and lugs at ASC. This approach allowed for the rotations to be set up as a repeating work station under the as large gantry crane. Figure 4 shows the completed assembly in the yard being rotated.

4 Figure 4 Block 413 Sub-block rotation

5 Piping Support System (PSS) & Electrical Support System (ESS) The Alliance shipbuilding engineering team develops and maintains a Piping Support System (PSS) and an Electrical Support System (ESS) throughout the Production and Test phases of the project. PSS and ESS allow management and analysis of data related to piping and electrical cable and component installations on AWD. The AWD piping systems contains more than 22,000 unique pipe assemblies to be fabricated tested and installed in the ship. The AWD ship contains more 25,000 unique cable runs and 14,000 items of electrical equipment to be installed. The majority of data to support this activity is supplied directly by the PSD, whereas other data is developed by shipbuilding engineering, trade planning and/or captured during production. Both systems allow production to track piping or electrical systems at any phase of the AWD build and input data for analysis and optimisation for each subsequent AWD. PSS and ESS both have the capability to generate a broad list of reports tailored to the end user. The reports are customisable by means of applicable selection criteria. PSS and ESS reports generated are designed to correspond to specific production and testing tasks. Typical excerpt of a report generated is shown in the figure 5. Figure 5 Smart Plant Model The PSD supplies the AWD project with a set of reference 3D models with the release of drawing products. The reference models are a visualisation tool that enables the shipbuilding team within the Alliance to interrogate design areas of the ship for all disciplines. The 3D model is used first in the build planning phase prior to the start of construction of each major block or area. The model allows the shipbuilding planner an opportunity to define the work sequencing and create snapshots of the represented areas to assist the mechanic during construction. Figure 6 depicts a typical build strategy excerpt whereby a piping module which has been planned for installation in the inverted position of the block can be depicted in the build plan document.

6 Figure 6 The 3D model is also used for resolution of production issues whereby the design cannot be accommodated during construction. Alternatively, if the design has an error which is found during construction, the field engineer can quickly give direction to the mechanic on solving the issue and a drawing update can follow. Figure 7 is an example of a design clash found in construction that was interrogated in the model to resolve a production installation issue. The result was the light was relocated at the waterfront using the model information as guidance and the correction was forwarded back to the PSD to have the drawing corrected to match the outcome. CLASH BETWEEN SUPPORT FOR LIGHT AND FOUNDATION FOR HVAC

7 CONCLUSION For modern warship design the use of Computer Aided Design (CAD) and Computer Aided Engineering (CAE) is the most accurate and practical way to implement design for manufacturing. Limitations in contracting decisions that prevent full use of CAD/CAE applications can be treated, but should be avoided as they introduce inefficiency in the production design and production support activities.