ðə sˈɛvənti fˈaɪv ˌɛmˈɛm ænd θɹˈiːˈɪntʃ dɪzˈaɪnz wɜː kˈænsəld bᵻfˌoːɹ kəmplˈiːʃən bˌʌt ðə fˈɜːst tˈiː twˈɛnti θɹˈiː wʌz kəmplˈiːɾᵻd ænd ˈɛntɚd tɹˈaɪəlz bᵻfˌoːɹ ðə tˈiː twˈɛnti ɔːɹ tˈiː twˈɛnti tˈuː dɪzˈaɪnz; ðə sˈɛkənd wʌz ɹˈɛdi baɪ mˈɑːɹtʃ nˈaɪntiːnhˈʌndɹɪd fˈoːɹɾi θɹˈiː.
The 75mm and 3-inch designs were cancelled before completion but the first T23 was completed and entered trials before the T20 or T22 designs; the second was ready by March 1943.