Air Shaft 3 was created to facilitate the construction of Blea Moor Tunnel and to help ventilate the tunnel during its operational life.
The October 21st, 1871 edition of the Lancaster Guardian provides brief details of the construction and use of this shaft during this early period:
The heading from the north on Dent Head end has been driven a distance of 750 lineal yards, or nearly half a mile, into the hill and is fast approaching the summit. It has been driven under No. 3 shaft, which has been standing for some time, and down which a bore hole has been driven a depth of 84* yards into the heading below. By this means, the water is got out of the shaft and air is supplied to the men below. About 250* lineal yards of tunnel have been completed. At this end, the air is supplied to the workmen at the face of the heading by a simple and effectual contrivance, viz, a long column of water in a wrought-iron pipe, which has its outlet through a rose fixed on the tip. The column of water has a pressure of 120lb per square inch. Consequently, the rush of water drives the air up a pipe 11 inch by 9 inch to the face of the heading. The force of the air is so strong that it will blow a candle out two or three yards from the end of the pipe.
* Note: This transcript was created from a photograph of the screen of a microfiche reader and these figures were extremely difficult to decipher, so the figures quoted here may be incorrect.