Portland Guitar uses a tilt-action neck that is completely hidden from view. In order to make a change the strap pin at the heel-stock is unscrewed and a hex driver can be inserted into the socket. By making a small turn the angle of the neck to the body can be changed from outside the instrument. It is possible for the acoustic guitar owner to make millimeter adjustments to the height of the strings above the fret board without changing the bridge saddle. No more going into a shop for a bridge replacement or fretting over humidity.
The split saddle nut and bridge act together to provide not only acoustic intonation adjustments but also action adjustments. By inserting shims below the saddle and in front of the nut it is possible to raise and lower each string separately with sub-mm precision at both ends. This allows for fine control of the angle and height of the strings above the fret board.
A traditional string has a channel carved into the nut for the it to lay on. The Portland Guitar method splits the channel and contact point. Using a separate wood channel before the nut for the string to lay on. The nut itself now only has the purpose of having the string pass over it. The string can be moved to lay anywhere on the nut now using a comb spacer to set the string separation. A series of combs and shims comes with every Portland Guitar to allow the player to quickly make these adjustments to both acoustic and electric guitars.