Before steel strings became commonplace, most guitar necks were able to remain fairly straight under the low tension of gut strings without any reinforcement. But steel strings have much higher tension, and in order to counteract the pull, guitar manufacturers carved very chunky necks.
We’re not talking cool late-1950s profiles here – because necks from the early steel-string era can be an uncomfortable handful. Clearly, Gibson recognised this and company employee Thaddeus McHugh came up with a design for an adjustable truss rod.
Trussed Up
Born in 1859, Thaddeus (Ted) lived in Kalamazoo all his life and spent 30 years at Gibson. His patent application was filed in 1921 and US Patent #1446758 was granted on 27 February 1923 with an anticipated expiration date of 27 February 1940.
The patent diagram shows a flat-top acoustic with an adjustment nut at the headstock with a rod curving upwards towards the fretboard and an anchor point about halfway down the heel. In the application document he also states: “By
