Trinity Dredge Hercules, 1825—1827, 1854

Steam Boat Engines (11 items).

1164a. Trinity Dredge Hercules (SD). Jun., Aug. 1825, Mar. 1826, Jun. 1827, May 1854. 11 items.
20 horse power independent crank engine, with 25½ inch cylinder, 3½ foot stroke, [cast iron beam, cast iron connecting rod].

Plan, side view and section of the "dredging machine" (boat, engine, scoops etc.); small sketch plan of boiler; side view of the engine and section of the boiler, plan of the engine and boiler - 2 reverse drawings; section and plan of the boiler - partially coloured original and reverse drawings (drawings made in Jun. 1827 and used for other boilers including the Hamburg and Genoese dredges).
Also the following later items: sections and plan of boiler - coloured original and coloured reverse drawings made in the London office, May 1854; small coloured plan of boiler on tracing paper (not dated). All the drawings except the small plans of the boilers bear letter codes.

Original Portfolio or 'Book' No. 801.

For the Corporation of Trinity House, London. Dredging boat. The engineer for the boat was James Walker, and the dredging apparatus was made by Hunter & English. This engine was omitted from the Catalogue of Old Engines.