Poldice No. 5, 1786

Cornish Mine Engines (19 items).

1311. Poldice No. 5. May-Aug. 1786. 19 items.
Double-acting engine, with 58 inch cylinder, 8 foot stroke, parallel motion, unequal beam, separate air pump beam.

General sections and plans of the engine:
[No. 1 wanting]; No. 2 - reverse drawing showing engine with separate air pump beam, marked "The dimensions of this drawing are in general the same as those in No. 1"; [No. 3 wanting]; No. 4 - reverse drawing marked "Another method adopted"; ground plan of the engine and plan of the house taken at the spring beams - 2 reverse drawings on 1 sheet, numbered 3 & 4 and marked "This plan corresponds with the General Section No. 1 and front view of the engine house No. 6"; ground plan of the engine - reverse drawing numbered 5 and marked "according to drawing No. 2"; front view of the engine house and plan and side view of the V bobs - reverse drawing numbered 6.

Front view of the nozzles and perpendicular pipes, section and outside view of nozzle, section and plan of the condenser and air pump, plan and sections of the cylinder and piston, gudgeons and plummer blocks, parallel motion, view looking upwards of the parallel motion, beam to work the condenser, gudgeons and plummer blocks for the T bobs - reverse drawings; steam pipe; plan and cross-section of the boiler; piston rod cap - full size drawing; draft general section and plan of the engine showing separate air pump beam; sheet of calculations.

Original Portfolio or 'Book' No. 78. Catalogue of Old Engines p. 300.

For Poldice Mine. This engine was also referred to as "Oppy's Engine". According to the List of Engines made at Soho, the engine was stopped in Dec. 1796 and sold to Wheal Unity, where it began work in Jan. 1797, and where it was still at work in May 1798.