One of the Nasmyth platforms on UT1

One of the Nasmyth platforms on UT1 during the installation of the Heidenhain encoder at the altitude axis. The diameter of the hole (and the encoder strip that is affixed to the inner wall) is 1.7 metres. Each of the four telescopes has two such platforms. The first multi-mode astronomical instruments to be installed at the UT1 will be FORS (working in the optical region of the spectrum) and ISAAC (infrared). (Photo obtained on January 28, 1998).