TTMJ stands for Tension Track Milled Joint and is an EU-funded project under the framework of Horizon 2020.The aim of the the TTMJ project is to develop, validate and commercialize a new joint system that will provide foundation specialists with the capability to deliver high quality, watertight and safe diaphragm wall joints at lower costs.The new system, invented and patented by the consortium partner CCMJ System Ltd., offers the possibility to construct profiled joints to increased depth, by maintaining the vertical alignment of the primary panel with a mill or Trimmer that is guided by tracks previously cast into the primary panel (after the secondary panel has been excavated and before it is concreted) ensuring the quality of the joints in the completed diaphragm wall.