Design Assessment of Ship Interface Template Set (SITS) Channel System for Mounting of Submarine Rescue System (SRS)
Abstract
This primary aims of this project was to determine the possibility of a reduction in welding time for installing the LARS base and/or SITS structure and also to determine if changing channel material from EH-36 to a reduced grade (such as AH-36) was acceptable. The means of determine the project aims were drop tower testing, finite element modeling, and calculations of welding time and other production welding activities. Drop tower testing of welded channels to the deck plate showed cracking in the welds but not separation or cracking into the channel or deck. The demonstrated robustness of the channel to deck system with non-design impact loading provided reassurance that the channel to deck system should hold up in most sea conditions. Modeling efforts were performed to determine if a change to the welds on the LARS base could be implemented. Stiff boundary conditions used in the models showed that there was enough loading on the welds that redesigns of LARS Base area welds were not attempted. While a general reduction to weld time by changing to smaller welds overall was not found, a specific change to welds shorter than 6-in. long in areas forward of the LARS base was found to provide savings in weld time of about 3 hours under reasonable assumptions of activity time and conditions. This change can be justified by comparing to the previous justification for the weld sizing of welds in this area. While one of the original aims involved a potential material substitution (from EH-36 to AH-36) to account for material acquisition issues, it was later determined that the original material acquisition issue was a non-critical path element, so material substitution became a non-issue.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 23, 2019
- Accession Number
- AD1091068
Entities
People
- Bill Mohr
- Neal Birchfield
- Steven Blevins