Papers, [1790]-1921, of and collected by Benjamin Piercy and his estate, relating to civil engineering projects and to the Piercy estate in Flintshire and Denbighshire. They include copies of plans of the following railways: the Wrexham, Mold and Connah's Quay; the Whitchurch, Wrexham and Mold; the Flintshire, Oswestry and Newtown; the Oswestry and Llangynog; the Denbighshire and Shropshire; the North Wales and Birkenhead; the Birkenhead, North Wales and Stafford; the Porthdinlleyn; and the Llangammarch and Neath. There is also a large number of working plans of railways in north-east Wales, particularly those for which Benjamin Piercy was engineer, as well as collections of Acts of Parliament relating to railways in England and Wales, bills, minutes of evidence, speeches, petitions and reports of Railway Commissions. The archive also includes a volume of Acts of Parliament relating to the navigation and conservancy of the river Dee, some Acts relating to north Wales waterworks, copies of correspondence, 1881-1885, between Benjamin Piercy and Henry Robertson of Pale, and minute books, 1888-1920, of the Piercy Trustees, and papers and deeds of Benjamin Piercy's estate mainly in Wrexham, and Marchwiel parish, 1881-1921.

Papers relating to T. E. Owen and his father T. Owen, 1820-1936, including diaries and memorandum books, 1820-1905; correspondence, 1878-1907; a time-book of men building the railway bridge over the Rheidol, 1887, kept by T. E. Owen; monthly summaries of materials used, 1880-98; hay account, l873-1899; printed reports of the Manager and Receiver of the Manchester and Milford Railway, 1882-1894; statements of accounts, 1881-2; rules and regulations of the railway, 1865, 1897; rules of the M. & M. Railway Friendly Society, 1868; balance sheets, 1877-1904; plans and photographs of buildings, rolling stock and personnel.