pˈɛn wʌz ˈɔːɹdɚd ˌʌndɚ ðə wˈɔːɹtaɪm ɪmˈɜːdʒənsi pɹˈoʊɡɹæm ænd wʌz lˈeɪd dˌaʊn æt ðə hˈaɪ wˈɔːkɚ jˈɑːɹd ʌv vˈɪkɚzˈɑːɹmstɹɔŋz ˌɔn twˈɛnti sˈɪks dᵻsˈɛmbɚ nˈaɪntiːnhˈʌndɹɪd θˈɜːɾi nˈaɪn.
Penn was ordered under the Wartime Emergency Programme and was laid down at the High Walker yard of Vickers-Armstrongs on 26 December 1939.