nˈuː lˈɪɾəl ɪmpɹˈuːvd vˈɜːʒənz ʌvðɪ ˌɑːɹɹˈɛn ˌɛmkˈeɪ nˈaɪntiːn twˈɪn ˌeɪˈeɪ ɡˈʌnz wɜː fˈɪɾᵻd ɪn ˌɑːɹɹˈɛn kɹˈuːzɚ ɹˈiːfɪts θɹuː ðə nˈaɪntiːnhˈʌndɹɪd fˈɪfti z, fɚðə lˈæst tˈaɪm ɪn ˌeɪtʃˌɛmˈɛs bɜːmjˈuːdə ɪn nˈaɪntiːnhˈʌndɹɪd fˈɪfti sˈɛvən ænd bˈɛlfæst ɪn nˈaɪntiːnhˈʌndɹɪd fˈɪfti nˈaɪn bˌʌt wɜːɹ ˈɑːbsəlˌiːt ænd ɪnˈækjʊɹət kəmpˈɛɹd wɪð sˈɪŋɡəl ˌɛmkˈeɪ fˈaɪv fˈɪfti fˈaɪv dᵻɡɹˈiː ˌɛlɪvˈeɪʃən fˈoːɹ.fˈaɪvˈɪntʃ ɡˈʌnz ɹˈiːfɪɾᵻd ɔnðə kˈɑːklˈæs dᵻstɹˈɔɪɚz ænd tˈaɪp ˈeɪɾi wˈʌn tɹˈaɪbəl klˈæs fɹˈɪɡəts fɹʌm nˈaɪntiːnhˈʌndɹɪd fˈɪfti fˈaɪv.
New little improved versions of the RN Mk 19 Twin   AA guns were fitted in RN cruiser refits through the 1950s, for the last time in HMS Bermuda in 1957 and Belfast in 1959 but were obsolete and inaccurate compared with single Mk 5 55 degree elevation 4.5-inch guns refitted on the Ca-class destroyers and Type 81 (Tribal) class frigates from 1955.