How Implacable missed a possible 1942 service date

Implacable and Indefatigable were laid down in 1939, but pauses and repeated changes delayed their launches until 1942 and commissioning until 1944. Illustrious provides the comparison: laid down in April 1937, launched in April 1939, and commissioned in May 1940. Applying that earlier construction rhythm suggests 1941 launches and 1942 entry into service for the later pair, although this remains a counterfactual. Earlier completion would have provided two additional fleet carriers during a difficult stage of the war. The Navy kept pressing for the ships, which Fairfield and John Brown were building in major Clyde yards. John Brown's construction of Hood supports the suggestion that a longer carrier could physically have fitted the yard, although that does not establish that a larger design would have been selected.