Calculations have always been a vital part of the insurance trade, but in the days before the modern computer it came down to humans to do the maths.

Eastern Daily Press: The first Orion computer arriving at Norwich Union in 1964. Picture: Aviva ArchiveThe first Orion computer arriving at Norwich Union in 1964. Picture: Aviva Archive (Image: Aviva Archive)

To assist in this, a variety of machines and charts were used to help actuaries quantify the 'probabilities of the affairs of life'.

Among these instruments were the Colmar arithmometer and Tate's improved arithmometer – which was used by Norwich Union from 1902. Tate's machine came at a cost of £40, the equivalent of the yearly wage of a 20-year-old clerk with three years' experience in London.

When Norwich Union installed its first computer system, the Orion 1, in 1964 it was delivered on the back of a lorry and required a crane to manoeuvre it into the Surrey Street offices. Just two years later, Norwich Union forked out £380,000 for the Orion 2.

By 1991, Norwich Union had 10,500 terminals throughout the UK linked to four mainframe computers based at Bowthorpe.

Eastern Daily Press: A look through the archives at Norwich Union.Byline: Sonya DuncanCopyright: Archant 2017A look through the archives at Norwich Union.Byline: Sonya DuncanCopyright: Archant 2017 (Image: ARCHANT EASTERN DAILY PRESS (01603) 772434)

Eastern Daily Press: A look through the archives at Norwich Union.Byline: Sonya DuncanCopyright: Archant 2017A look through the archives at Norwich Union.Byline: Sonya DuncanCopyright: Archant 2017 (Image: ARCHANT EASTERN DAILY PRESS (01603) 772434)