The Accelerator tunnel (G01) was officially handed over to ESS on Tuesday, May 2, signalling the formal completion of civil construction for the building and the beginning of technical installations by ESS and in-kind partners. The first planned works in the tunnel include temporary marking and drilling for machine installation. The Cryo-Compressor Building (G04) has also been handed over to ESS, along with the commissioned electrical substations H05 and H06 . Last week, the installation of 221 concrete link plates, each weighing 3.5 tonnes, was completed. The plates make the connection between the Gallery Building and the Accelerator’s green roof, and waterproofing is now underway. The steady work of forming out and casting the Target areas (D02) continues, and work is moving quickly to prepare the Guide Hall (E01) and other E buildings for erection of the superstructure. Finally, work in the Cryo-Compressor Building (G04) , recently featured in an article in Sydsvenskan , is also moving quickly in preparation for this month’s delivery of the first of nineteen 10-metre-high helium tanks that will feed the Target and Accelerator cooling systems.