From Graces Guide
of By-Products Department, Aberdare House, Cardiff, South Wales. Telephone: Cardiff 7900/1. Telegraphic Address: "Presotim, Cardiff". (1937)
1840-1863 He opened many further deep mines, both in Aberdare (Cwmdare, Abernant, Abergwawr, Middle Duffryn and Cwmpennar) and in the Rhymney Valley. At their peak these collieries produced over 400,000 tons of coal each per annum.
1863 Thomas Powell instructed T. E. Forster, William Armstrong and George Elliot (Later to become Sir George) to put a valuation on all his collieries.
1864 As a result, George Elliot formed the Powell Duffryn Steam Coal Co Limited (PDSC) for the purpose of working the whole of Thomas Powell's collieries. At this time the wealth of the South Wales Coalfield was only just being realised.
1867 The PDSC bought the Aberaman Estate from the iron master Crawshay Bailey. The acquisition of the Aberaman Estate was an important purchase, as underneath lay some of the best steam coal in the world and all within easy access to the ports. Aberaman became the headquarters of the company.
1914 The market in France was so large that they registered as Compagnie Francaise des Mines Powell Duffryn, with their main offices at Rouen.
1916 An able businessman, E. M. Hann (who had started his career in the company in 1879) was made director of the PDSC and enabled the company to become the greatest coal-producing company in the world.
1937 Advert for By-Products of British coal: Presotim Wood Preservative; Presomet Rust-resisting Paint; Synthaprufe Liquid Waterproofing and Jointing Material; Synthaflex Plastic Material for filling crevices before final sealing with Synthaprufe; Synthacold Cold Dressing for paths, drives, roads. (Engineering/Metals/Quarry, Roads and Mining/Transport Section - Stand No. B.320)
1944 Formation of Powell Duffryn Ltd and voluntary liquidation of the 3 former companies.
1946 Unlike the main coal production business, several subsidiaries were concerned with fuel distribution, and so would not be nationalised - these were Stephenson Clarke Ltd, Gueret, Llewellyn and Merrett Ltd, Cory Brothers and Co Ltd. Powell Duffryn and International Combustion Ltd jointly established Rhymney Engineering Co to take over an engineering works at Rhymney that Powell Duffryn had been operating during the war. The company would manufacture mining machinery, materials handling plant for collieries and power stations, and other specialised engineering products. Delanium Ltd had developed a new method of making carbon.
1947 The National Coal Board took over all Powell Duffryn's coal mining interests but they indirectly retained a considerable influence on the management of the coal industry with many of their management retaining senior level posts with the N.C.B. particularly in the South Wales area. As a result, Powell Duffryn Co diversified and expanded in other directions, including formation of Powell Duffryn Technical Services Ltd, which would provide consultancy in fuel production, distribution and utilization worldwide, and Powell Duffryn Carbon Products Ltd, as well as acquiring a factory unit at Hayes, to commercialise the new carbon product developed by Delanium; the laboratories at Battersea were renamed Powell Duffryn Research Laboratories Ltd 
1950 Vacuum Oil Co acquired the oil storage, blending packing business at Coryton of Cory Brothers and Co in exchange for shares in Vacuum Oil Co which would be held by Cory's parent Powell Duffryn; together with further investments, this would give Powell Duffryn and Socony-Vacuum Oil Co Inc of USA equal ownership of the Vacuum Co. An oil refinery would be built at Coryton, primarily for the production of lubricating oils.
1953 The compensation for nationalisation of the coal interests was finally settled, at £15million
1955 Cory Brothers acquired J. and R. Gordon of Chester, timber merchants
1956 Had negotiated increased compensation for the coal interests of £15.9million
1957 Cory Brothers timber interests had been expanded substantially
1959 Cory Brothers acquired MacCleaster Chemical Co, maker of anti-corrosion chemicals for ships. Formation of Powell Duffryn Timber Industries Ltd to bring together all of the timber interests. Established Powell Duffryn Modulair to make heating and air conditioning plant.
1960 Formed a business in the manufacturing and sale of heating equipment, based on Janitor Boilers Ltd, of which the remaining shares were acquired; extended the Janitor range of oil and anthracite boilers to smaller boilers for 3-4 bedroom houses. Purchased the Hurseal company, makers of pressed steel radiators
1968 Introduction of divisional structure to rationalise the 80 subsidiaries:
- Shipping and Shipping Services
- Oil and Chemical Storage
- Engineering, Heating and Air Conditioning
- Trade Investments
1969 Sold the light products division to Aeronca Inc of USA. Established Fire Fighting Systems, a joint venture, with athe im of becoming largest supplier in Britain of fire protection equipment
1976 The Engineering division had delivered 38 percent of the group's profits
1976 Acquired an interest in Humberside Holdings, provider of port services around the confluence of the Humber, Trent and Ouse.
By the early 1980s, the company had worldwide recognition in the field of engineering, shipping (travel), bulk liquid storage, fuel distribution, construction, wagon manufacture to name but a few.
In 1980/81 the turnover reached £456m.
Their commercial interests in South Wales included: -
- Powell Duffryn Engineering Co - Llantrisant
- Powell Duffryn Travel - Cardiff
- Cory Brothers - Cardiff
- Powell Duffryn Timber - Barry
- Powell Duffryn Quarries - Merthyr, Machen, Caerffili, Penhow and Newport
- Dan-y-Graig Brick Co - Risca
- Powell Duffryn Wagon Co - Cardiff
- Powell Duffryn Oil and Chemical Storage Co - Barry
- Powell Duffryn Private Railway
1990 Tried to sell the coal distribution business but failed to attract attractive offers.
1992 Part owner of Teeside Holdings (owners of the privatised Tees and Hartlepool Port Authority)
1994 Took control of Teeside Holdings and Humberside Holdings by acquiring most of the remaining shares
2000 The company, a ports operator and engineer company, was acquired by Nikko Securities, a venture capital company
Sources of Information
- According to the Cynon Valley History society, the first mine sunk in Cwmbach was in 1837 by Mathew Wayne of the Gadlys Ironworks and his son Thomas Wayne, at Abernant-y-groes it was then known as Cwmbach pit. There is a blue heritage plaque on the site at Pit Place, Cwmbach
- National Archives 
- The Times, Aug 14, 1946
- The Times, Jun 14, 1947
- The Times, Oct 23, 1947
- The Times, Sep 10, 1948
- The Times, Mar 25, 1950
- The Times, Oct 22, 1953
- The Times, Oct 21, 1954
- The Times, Sep 20, 1956
- The Times, Sep 20, 1957
- The Times, Aug 07, 1959
- The Times, Sep 17, 1959
- The Times (London, England), Wednesday, Nov 11, 1959
- The Times, Sep 22, 1960
- The Times, Apr 03, 1961
- The Times (London, England), Thursday, Sep 21, 1961
- The Times, Aug 24, 1962
- The Times, Jul 18, 1967
- The Engineer of 26th April 1968 p650
- The Times, Mar 08, 1968
- The Times, Apr 10, 1969
- The Times (London, England), Tuesday, Jun 10, 1969
- The Times, Oct 20, 1970
- The Times, Nov 24, 1976
- The Times, Nov 23, 1979
- The Times, Dec 15, 1984
- The Times , March 19, 1987
- The Times, November 24, 1989
- The Times, June 06, 1990
- The Times, December 07, 1994
- The Times, November 04, 2000