Closed-Section Stringer for Autorack Deck Corrosion
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Solution Overview
Problem
Autorack railroad cars face issues with corrosion and dirt accumulation, leading to premature rusting and contamination of vehicles due to inadequate moisture prevention and debris collection in crevices during the shot blasting process.
Innovation Solution
A closed-section stringer design is implemented for the autorack deck assembly, featuring a roll-formed section with capped ends and external welds, which prevents debris and moisture from collecting, simplifying cleaning and reducing rust initiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If open-section stringers are used in the deck assembly, then manufacturing is simpler and easier, but debris and moisture accumulate in the crevices leading to corrosion
Solution Approach 1:
The invention extracts the problematic open crevice section from the stringer design and replaces it with a closed-section configuration. The closed-section stringer eliminates the open crevice that previously accumulated debris and moisture, thereby preventing corrosion while maintaining structural integrity and manufacturability through roll-formed sections with welded seams.
2Manufacturing precision
If shot blasting is performed to remove welding soot, then coating coverage improves, but shot collects in crevices and promotes subsequent corrosion
Solution Approach 1:
The invention applies preliminary action by designing the closed-section stringer configuration before the shot blasting process. The closed-section design prevents shot and debris from entering crevices in the first place, eliminating the need for subsequent cleaning operations and preventing the corrosion that would result from shot accumulation.
3Reliability
If the rack structure is enclosed to prevent moisture entry, then corrosion prevention improves, but cleaning access to internal crevices becomes difficult
Solution Approach 1:
The invention extracts the cleaning accessibility problem by eliminating the crevices that require cleaning through the adoption of closed-section stringers. The smooth, enclosed configuration prevents debris and moisture accumulation, making the structure inherently cleaner and easier to maintain while preserving the enclosed rack design for moisture prevention.
Data Source
AI summary
An autorack rail road car has an underframe having a main deck, and a rack mounted to the underframe. The rack supports one or more decks above the main deck, and also supports, or defines, an enclosure that protects the automobiles carried as lading. One way to prolong the life of the rack is to delay corrosion. Corrosion may start in locations that are difficult to clean, or that have not been cleaned prior to painting. Autorack upper decks may use longitudinally extending stringers. A stringer of closed section may be less prone to facilitating early corrosion, and may be less prone to drip rust-filled water on automobiles carried as lading. In some embodiments the stringer may be placed at a slope discontinuity in the lading deck, and may overlap that slope discontinuity.