Man Engine

Principles of Metal Mining by J.H. Collins FGS

94. The Man-Engine.-In some of the larger Cornish mines the contrivance known as the " man-engine " is used for raising and lowering the men -a special shaft being devoted to this purpose, except that a ladder-way is also placed in the shaft.

Fig. 31.-THE MAN-ENGINE, in profile and front views. a, a, the rod; b, b, steps; c, c, sollars.

The man-engine consists of a beam of wood called the "rod” a a, fig.31, which is made to move up and down alternately through a space of twelve feet, by means of an engine devoted partially or entirely to that purpose. On the rod, at b b, steps are fixed 12 feet apart, on which the men stand while it is in motion, holding on by iron handles provided for that purpose. When it stops for an instant before the motion is reversed, the steps are level with the "sollars, " c, c, which are placed in the sides of the shaft. It is evident that if the men who stand on the steps during the upward motion of the rod step on to the sollars during its downward motion, and step back to the rod when it again rises, they will be raised to the surface by successive lifts of 12 feet, without any labour on their part except the stepping off and on. As many men may thus be brought up from their work at one time as there are steps on the rod, and, as the sollars are fixed on both sides of the shaft, an equal number of men may be carried down at the same time, each stepping on the rod as the man leaving work steps off. The weight of the rods, with all connections, averages about 25 cwt. per fathom or, for a depth of 200 fathoms, amounts to about 250 tons. The great weight is balanced by several of the " balance bobs," to be described hereafter.

95. Cost of Man-Engine.-The cost of a man-engine, with driving engine, complete to a depth of 200 fathoms, exclusive of the cost of the shaft itself, cannot be taken at less than £2000 to £2500. The interest on the larger sum at 5 per cent., with 10 per cent. added for depreciation of plant and repairs, amounts to £375 per annum. The cost of coal and attendance for driving the engine, for oil, grease, etc., will amount to, say, £250 per annum in addition. The labour of climbing from an average depth of 100 fathoms cannot be taken at less than 1 hour daily, or, with 3 shifts of 50 men at an average of .5d., the amount lost by climbing will be each day 62s. 6d. ; or, for a year of 260 working (lays, say, £800, showing a clear gain of £175. For a depth of 300 fathoms the advantage is many times greater, since the. exhaustion of the men from the labour of climbing and the time occupied will increase in a geometrical ratio. However, setting aside all calculations of cost, it is only necessary to look at the men 'who have just come up by ladders from deep mines to see that some mode of relieving them from such excessive toil is most necessary. I The man-engine originated in Germany, where it is called the "fahr-kunst." The idea occurred to some of the German miners, who saw the reciprocating action of the pump rods, to attach steps to it, and this was actually carried into practice. In Cornwall the idea of a man-engine was first carried into effect by Mr. Loam, in 1835, at Tresavean Mine in Gwennap. The man-engine was so great an advantage to all concerned both workmen and employers -that it would soon have become generally used in deep rnines but for its great expense. But the improvements in the manufacture of wire rope within the past 25 years have been so great, that the chief danger in connection with the use of lifting-cages or skips has now disappeared. And the cost of putting in a " skip way," as well as of working the skip, is far less than that of erecting and working a man-engine, so that it is hardly likely any more will be erected.

back to Archives