As CBI president he witnessed the fall of the administration of Edward Heath in the wake of the miners' strike, and the re-emergence of the Labour Party under Harold Wilson.
He was directly involved, along with CBI director-general Campbell Adamson, in intense and volatile debate on voluntary pay restraint and price controls with Health and trade union leaders.
Clapham who was a classical scholar and a master printer by trade, also invented an isotope diffusion barrier whilst working on silk screen printing techniques during World War II which led to him being seconded to the Tube Alloys Project pursuing the development of the atom bomb.
[2] Clapham moved from Cambridge to Bradford where he worked for printer Lund Humphries, and then, in 1938, to the Kynoch Press in Birmingham which was part of the huge ICI conglomerate.
[3] During the war he invented an isotope diffusion barrier, and consequently found himself seconded for four years to the Tube Alloys Project which was Britain's first attempt to build an atomic bomb.
There he became friendly with an assistant research manager called SS Smith who expressed an interest in the photo-engraving process used to produce ink for newspapers.
He had effectively created an efficient way of filtering out enough of the explosive elements of uranium from its non-explosive isotopes to make a bomb, something physicists had been struggling with for some time.
In 1966 he was offered the managing directorship of the newly formed Labour backed Industrial Reorganisation Corporation (IRC) by chairman Sir Frank Kearton.
The CBI team's impression was that Heath showed a good deal more consideration and deference to the unions and to TUC leader Vic Feather.
[2] However, neither Heath nor Feather could exert much influence over hard line union men Jack Jones and Hugh Scanlon, and little progress was made.
In the meantime the election resulted in the surprise defeat of Edward Heath; the incoming government swiftly abolished the Industrial Relations Act.
Clapham spent much of his life including his later years living in Hill Street just off Berkeley Square in Mayfair where he became president of the Resident's Association.