 In 1970, seagoing pilots became retrospectively insurable, and gained full social security as members of the Non-Manual Workers Insurance Institute.That same year, a special regulation came into force for District Master Chimney Sweeps, making them fully insurable under the Craftsman's Insurance Scheme.An increase was made in tax-free allowances for children, which enabled 1,000,000 families to claim an allowance for the second child, compared to 300,000 families previously.