Tunnel Portland Cement Co
The Tunnel Portland Cement company of West Thurrock, Essex.
1911 Company incorporated
1934 Held a controlling interest in Clyde Portland Cement Co[1]
1938 With Associated Portland Cement Manufacturers acquired Alpha Cement Co
1939 Tunnel Asbestos Cement Co was a subsidiary; others were Tunnel Cement (Pitstone) Ltd and Clyde Portland Cement Co; held 50 percent of Ribblesdale Cement Ltd; also had an interest in Cement Ltd of Dublin.[2]
1968 Name changed to Tunnel Cement Ltd
1975 Name changed to Tunnel Holdings Ltd; Tunnel Cement was an operating subsidiary.
1981 Thomas W. Ward of Sheffield bid for the company but the bid failed[3]
1982 RTZ acquired Thomas W. Ward, thereby gaining control of Tunnel, and undertook to acquire the rest of the shares.
1985 The name of Tunnel Holdings was changed to RTZ Estates Ltd
Tunnel Cement became part of Castle Cement