John and Mary Marshall have built a large blackthorn graduation tower in Ayrshire to revive a historic salt-making method [1].
The project preserves a rare production technique that is unique within the United Kingdom [1]. By recreating this specific infrastructure, the couple aims to ensure that a traditional craft, which had largely disappeared from the region, returns to active use [2].
The new structure is a significant engineering feat for the local area. The tower stands 12 meters high and extends 25 meters in length [4]. It is constructed primarily from blackthorn, a material essential to the graduation process used to purify brine before it is boiled into salt [1].
Salt production in Ayrshire has a long history, but the specific use of graduation towers has become an anomaly in the UK [1]. These towers allow brine to trickle down through layers of brushwood, where impurities are filtered out, and the salt concentration increases naturally through evaporation [3].
The Marshalls' effort to scale this process with a larger tower suggests a move toward expanding the availability of this traditional salt [3]. The construction represents a bridge between historic industrial practices and modern artisanal production in the Scottish countryside [1].
Because the method is so rare, the tower serves as both a functional production site and a living museum of Scottish industrial heritage [2]. The couple has focused on using traditional materials to maintain the authenticity of the process [1].
“The tower stands 12 meters high and extends 25 meters in length.”
The revival of Ayrshire salt-making through the construction of a graduation tower highlights a growing trend in the preservation of 'intangible heritage.' By combining traditional materials like blackthorn with large-scale infrastructure, the project demonstrates how niche industrial history can be transitioned into sustainable, artisanal business models while preserving regional identity.
