Procurement of the dome and the telescope structure of the ESO ELT: status report

The Dome and the telescope Main Structure of the ELT are being procured by ESO as an integrated unit, which includes also the technical buildings needed to host the various system plants and the primary mirror maintenance facilities. At conclusion of a Call for Tender, ESO has signed in May 2016 a contract with the Italian Consortium ACe for the design, manufacture, transport and construction at Cerro Armazones in Chile of the Dome and Telescope Structure (DMS) of the ELT. The Consortium is constituted by Astaldi S.p.A. and Cimolai S.p.A. The first step of the design phase, namely the Preliminary Design Review (PDR) of both Dome and Main Structure has been completed, and rapid progress is being achieved toward the completion of the detail design. For some long lead items, the procurement via Critical Design Reviews (CDRs) is taking place in parallel to the detail design phase. The Contractor was given access to the Armazones site, including the levelled ELT platform in June 2017, and he has prepared at the base of the Armazones peak a large construction camp with dormitories and construction facilities. At the top of the mountain the excavation for the ELT foundations are completed, and foundation construction is starting. The overall status of the procurement of the DMS and some key aspects of the design will be described herein.