Shipyard fillet weld measurement dispute

Tom evaluated a Maritime Administration program for an automatic laser-based fillet-weld size inspector accurate to ±0.010 inch. Field testing against shipyard inspectors using hand gauges showed inspectors could not do better than ~±0.020 inch. The new instrument exceeded inspector accuracy by 2x, but Tom recounts an Electric Boat engineer telling him years earlier: "the last thing I want is another thing I can measure, because I'm going to be held to that standard." Used to make the broader point that improving measurement capability creates disputes the original specification never anticipated.

When I've been to places like Bath Iron Works or Newport News or Electric Boat, these fights occur all the time, and there's not a great relationship between SUPSHIP and the yard in most cases. I remember I was evaluating a program for the Maritime Administration on an automatic inspector of the size of fillet welds. The fillet weld, let's say, was supposed to be a quarter-inch fillet weld. They developed this little laser-based inspector that could scan along the weld and automatically inspect — it could detect the size of a fillet weld. A fillet weld is, if you have a plate like this, it intersects a plate like this, and you put a weld in the corner — that's a fillet weld. Lots of these on ships.