How should an apparently new gap between wind-equipment parts be investigated?

The short answer

An apparently new gap can reflect real displacement, a seal change, temperature-dependent geometry or simply a different view. First establish that the same reference points are being compared. The relevant decision is whether the assembly geometry changed outside its intended condition, not whether a dark line looks wider in one photograph.

Compare a repeatable geometry

Use the same surfaces and orientation where possible. Shadows, wet edges and perspective can make a gap appear larger without movement. A scale in the correct plane can help a qualified dimensional comparison, but a ruler elsewhere in an image cannot establish the gap accurately. Include whether the feature is local or follows a whole boundary and whether earlier evidence actually resolves it.

Connect any change with physical function

A gap at a weather seal, a cover edge and a load-carrying interface raises different concerns. Ask whether it changes barrier contact, clearance or alignment in the documented design. Actual temperature and machine state can matter, but they should not become an unsupported explanation for every difference. The reviewer may need controlled inspection to distinguish a displaced part from an intended movement or a changed seal profile.

If the apparent gap changes only with the camera angle, the first problem is comparability of the image. If the same reference surfaces show a repeatable dimensional change, the question becomes physical condition. Keeping those stages separate prevents an unnecessary adjustment based on perspective.

Decide before closing the gap

Do not force parts together, add filler or retighten hardware merely to restore the earlier appearance. Those actions can conceal the cause or alter load paths and protection. Ask the supplier or engineer which dimension and state define the intended assembly and what evidence establishes the current condition. No MARSTON gap tolerance or generic adjustment is provided; the assessment must match the particular interface and function.