Crossgrain
Definition
A condition in which the wood fibres run at an angle to the long axis of the piece. In Rail 16, Koehler noted that one section of the rail had cross-grain that made it structurally poor, an observation consistent with its having been cut from a small piece of leftover floorboard rather than from a timber yard length cut for load-bearing use.
- Definition
- Wood fibres running at an angle to the piece's long axis
- Structural effect
- Weaker along the load-bearing direction
- Notable case use
- Lindbergh kidnapping, Rail 16 examination
- Examiner
- Arthur Koehler
Common questions
Why does crossgrain weaken a piece of wood?+
Wood is strongest along the direction its fibres run. When the grain angles away from the piece's long axis, the fibres offer less resistance to bending or splitting along that axis, so the piece fails more easily under a load it would otherwise carry.
How did the crossgrain observation support the source inference in the Lindbergh case?+
Koehler noted that the rail's crossgrain made it a poor structural choice for its use, consistent with the wood having been repurposed from an offcut such as leftover floorboard rather than cut deliberately from timber-yard stock intended for a load-bearing purpose, which fed into tracing the wood's origin.
Related terms
- Grain Matching
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- Rail 16
- Koehler's designation for the left side rail of the bottom section of the Lindbergh ladder. The rail that was matched by grain,...
- Supply Chain Tracing
- In Koehler's investigation, the process of tracking the ladder lumber from the sawmill of origin through the distribution network to the retail...
- Tool-Mark Analysis (Wood)
- Examination of surface marks left by cutting, planing, or shaping tools to identify the tool type, size, and individual characteristics of the...