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Cost of |Cost Vertical| Total Cost | Cost of Incline|Cost of Incline
Crosscuts $20| Shaft $75 | of Vertical | $75 per Foot | $100 per Foot
per Foot | per Foot |and Crosscuts| |
-------------|-------------|-------------|----------------|---------------
$17,180 | $112,500 | $129,680 | $114,150 | $152,200
38,220 | 112,500 | 150,720 | 118,625 | 159,500
64,940 | 112,500 | 177,440 | 129,900 | 172,230
107,780 | 112,500 | 220,280 | 114,850 | 195,800
178,760 | 112,500 | 291,260 | 175,050 | 233,400
324,740 | 112,500 | 437,240 | 225,000 | 300,000

From the above examples it will be seen that the cost of crosscuts
put at ordinary level intervals rapidly outruns the extra expense
of increased length of inclines. If, however, the conditions are
such that crosscuts from a vertical shaft are not necessary at so
frequent intervals, then in proportion to the decrease the advantages
sway to the vertical shaft. Most situations wherein the crosscuts
can be avoided arise in mines worked out in the upper levels and
fall under Case IV, that of deep-level projects.

There can be no doubt that vertical shafts are cheaper to operate
than inclines: the length of haul from a given depth is less; much
higher rope speed is possible, and thus the haulage hours are less
for the same output; the wear and tear on ropes, tracks, or guides
is not so great, and pumping is more economical where the Cornish
order of pump is used. On the other hand, with a vertical shaft
must be included the cost of operating crosscuts. On mines where
the volume of ore does not warrant mechanical haulage, the cost of
tramming through the extra distance involved is an expense which
outweighs any extra operating outlay in the inclined shaft itself.
Even with mechanical haulage in crosscuts, it is doubtful if there
is anything in favor of the vertical shaft on this score.

[Illustration: Fig. 6.--Cross-section showing auxiliary vertical
outlet.]

In deposits of very flat dips, under 30 deg., the case arises where
the length of incline is so great that the saving on haulage through
direct lift warrants a vertical shaft as an auxiliary outlet in
addition to the incline (Fig. 6). In such a combination the crosscut
question is eliminated. The mine is