North Downs No. 3, Halebeagle, 1795

Cornish Mine Engines (14 items).

1285. North Downs No. 3, Halebeagle. May-Jul. 1795. 14 items.
Double-acting engine, with 52 inch cylinder, 8 foot stroke.

Section of engine house and sections of boiler, marked "Sketch of Engine for North Downs" (not dated); front view of the engine and V bobs, general view of the engine and pump shaft, plan of the engine and pump shaft - reverse drawings; plans and section of the cylinder etc. - partially coloured reverse drawing; condenser and air pump - coloured reverse drawing marked "another drawing, this not used"; perpendicular pipes - shaded reverse drawing; nozzles - partially coloured reverse drawing based on nozzles for Poldice No. 5; air and hot water pumps - partially shaded reverse drawing; gudgeons and plummer blocks for pump rod and air pump beam, gudgeon and plummer block for the V bob, gudgeons and sockets etc. for the V bob (partially shaded), main gudgeons and plummer blocks for the V bobs - reverse drawings; V bobs [?] - unmarked drawing. All the drawings except the first and last items bear letter codes.

Original Portfolio or 'Book' No. 229. Catalogue of Old Engines p. 304.

For North Downs Mines. Halebeagle Mine was part of the North Downs Mines. This was the third engine supplied to the North Downs mines; the first two were erected at Wheal Messa [see Portfolio 5/1300] and Wheal Briggan in 1786. This engine was designed by William Murdock and was of an unusual construction. It did not have a main beam, and the cylinder was mounted directly over the shaft. The piston rod was connected to two side rods by means of a cross-head. The side rods worked the pumps by means of two V bobs. According to the List of Engines made at Soho, the engine was still at work in May 1798.
At some point before Henry Hazleton's work in the 1890s the drawings became divided into two sets, with the plan of the engine and the drawings of the various gudgeons and plummer blocks separated. Hazleton placed these latter drawings in Portfolio No. 1313 and listed them as a separate engine on p. 304 of the Catalogue of Old Engines, but both sets have now been re-united here.

See also: Incoming Correspondence (from William Murdock).
Published references: Dickinson & Jenkins p. 144, 145, 194, 196, plates XXIX - general view), XXX - end view, LXII - cylinder, Fig. 23 - cover of cylinder lid.