Attwell migrated to South Africa in 1951 to become sub-warden of St Paul's College, Grahamstown, a theological college of the Church of the Province of South Africa. The next year, he was appointed as Dean of Kimberley and installed at the cathedral on 28 June 1953. At his appointment, at age 32, he was the youngest cathedral dean in any Anglican church. This was a period of anguish in South Africa as Apartheid legislation was passed into law and implemented. In 1956 John Boys, Bishop of Kimberley and Kuruman, appointed a commission to investigate the probable effects of the Group Areas Act in Kimberley – which was resulting in forced removals as different ‘race groups’ were separated and directed to live in designated suburbs or townships. In 1959 the Diocesan Magazine, Highway, stated with respect to the Group Areas Act that: “We in the Anglican Church declare the act to be evil and to be opposed at every point.” During Attwell’s term as Dean of Kimberley decisive steps were taken towards completing the building of the Cathedral. In 1954 materials were ordered for the building of the cathedral tower but it was not before August 1959 — just when Attwell announced his resignation — that work was actually started and the foundation stone laid by his predecessor as dean, Francis Smith
Attwell was appointed to the episcopacy in 1983 when he was appointed as Bishop of Sodor and Man. He was consecrated a bishop by John Habgood, Bishop of Durham, at York Minster on 14 September 1983. At his installation on Man, he pledged himself to serve the island and “to seek to appreciate all that was important in the Manxway of life and to the Manx nation, and would try to master the Manx language.” In their study of “The work of a religious representative in a democratic legislature,” Edge and Pearce remark that the interventions of Attwell, like those of his predecessor Eric Gordon, “initially sought to explicitly identify philosophical foundations for legislative activity” but that though he had been complimented for his attendance in the legislature, his contributions, compared with those of other bishops, had been “relatively low key.” He was concerned with issues of morality – in particular “the importance of the conventional family” in relation to Civil Registration and Matrimonial legislation, but also with regard to education as “character development rather than simply vocational training”, and in relation to the rising tide of illegal drugs. He also engaged with continuing debates on Sunday trading. He was interested in and contributed to debates concerning culture, including the Manx Museum and archaeological matters. Attwell was also concerned with overseas development, making inputs to discussion on the Resolution to approve Public Lottery Regulations 1984. At his departure in 1988, Attwell admitted that he had not found learning Manx an easy task. At a farewell function the Lieutenant-Governor formally thanked him for his work, noting particularly his contribution to debates on “youth, on heart and soul, and on morality in its greatest sense”.
