Six ships were built to this plan for the New Zealand Lines (see Haparangi) and Federal Line. Hertford had Federal Line sisters in Huntingdon & Cumberland. Hertford was built by Vickers Armstrong in 1948 and they were used on the route from the UK to Australia & New Zealand. The ships became P&O in 1971 and Hertford was transferred to Cyprus ownership in 1976 and re-named Thia Despina. In 1977 she was sold and re-named Georgios Frangakis and scrapped in Turkey.