The dome is built on a steel framework, and during construction was supported on an immense scaffold structure, which when removed in early 2012 resulted in the dome sinking 20mm.
ðə dˈoʊm ɪz bˈɪlt ˌɔn ɐ stˈiːl fɹˈeɪmwɜːk, ænd dˈʊɹɹɪŋ kənstɹˈʌkʃən wʌz səpˈoːɹɾᵻd ˌɔn ɐn ɪmˈɛns skˈæfoʊld stɹˈʌktʃɚ, wˌɪtʃ wɛn ɹᵻmˈuːvd ɪn ˈɜːli tˈuː θˈaʊzənd twˈɛlv ɹɪzˈʌltᵻd ɪnðə dˈoʊm sˈɪŋkɪŋ twˈɛnti ˌɛmˈɛm.