Source: "The Midland railway: its rise and progress. A narrative of modern enterprise" by Frederick Smeeton Williams, published by Strahan & Co London (1876). The following extract is from pages 494-497, 498 and 501:
The first work at the tunnel itself was the sinking of the shafts. This was done by the aid of a “jack roll," which is like the windlass over a common well, until horse gins could be got into position; and these in their turn were superseded by four winding engines, placed at the four principal shafts, with which the work involved in making the shaft and lifting out the debris was accomplished.
"But how in the world did you ever manage to get that lumbering, ponderous engine up here?" we inquired of our friend, Mr. Ashwell. "Pulled it up with a crab," he replied. "A crab!" we asked, "what's that?" “'Well, a windlass perhaps you call it. We fixed the windlass in its place; laid a two-foot gauge road up the hill-side in places sometimes as steep as one foot perpendicular rise in two and a half feet length, and then dragged it up 1300 feet above the sea. By having crabs placed one above another, we pulled up first the boiler which weighed two tons and a half, and then the engine, the lot weighing very likely six tons. The riveters put it together. It was a strange thing to hear the ‘tap, tap' of the riveters' hammers up there in that howling wilderness. When one engine was set to work, we used it for drawing up some of the others."
"And did you get them all up that way ? " "Well, no; we had to get another up the flatter side of the hill; and that was more difficult still, because of the bogs. We managed that on a drug,—a four-wheeled timber wagon sort of thing. It was an uncommonly strong one, you may be sure. We brought it along the Ingleton road and then, for two miles and a half, we pulled it by means of two ropes working round the boiler; as one rope was drawn off the other was rolled on. And so, stage by stage, we dragged it over the rugged and boggy ground, and up to the top of the mountain on which it stands." And there for four years and more those engines did their almost ceaseless work, the two at either end winding materials or men up the inclined planes from near the tunnel mouths, while the others were lowering bricks and mortar in "skeps" down the shafts, or raising the excavated rock or the water that found its way into the workings, and threatened, ever and anon, to drown them out.
From the tunnel ends, and from the bottoms of the shafts "headings" were run till they met. "You see," said Mr. Ferguson, the engineer, "there is room for only four men to work at one time and one place in making a tunnel; and if we had not had shafts from the top, the tunnel would really have had to be bored by eight men, and I am afraid the patience of the Midland shareholders would have been exhausted before the Blea Moor tunnel was finished. But every shaft we sank gave us two more faces to work at, and two more gangs could be put on. By such an arrangement, seven shafts and two tunnel entrances would give sixteen tunnel faces; sixteen gangs of men, day and night, could work; and thus the tunnel could be completed in four years, instead of thirty-two, a period which would have landed us in 1903." Besides, four at least of these shafts are permanently required for the proper ventilation of the tunnel."
"When we had made our shafts," continued our engineer, "we began to run headings north and south, till, at last, they met. The strata through which we had to pass were limestone, gritstone, and shale; but in making the heading we chiefly followed the shale, because it was the easiest, though this sometimes brought us to the level of the rails, and sometimes to the top of the arch. We now started what we termed a ‘break up'; that is, we enlarged a certain portion of the tunnel sufficiently to enable us to put in the arch in brick, filling in the space behind the brickwork with debris, which, being interpreted, means any loose rock we could get hold of. We then excavated the tunnel down to the floor, till the level of the future rails was reached."
So the work went on, from Sunday night at ten till Saturday night at ten; relays of men relieving one another at six in the morning and six at night. The rock was broken up by hand-drilling, the holes being filled with dynamite, guncotton, or gunpowder, and fired by means of a time fusee. "What is dynamite?" Dynamite looks very much like potted lobster. It will not explode unless heated to 420 deg. Fahrenheit. If a match is placed against it, it burns like grease. It can be carried about in one's pocket; and is even carried about in the men's trousers' pockets to warm it for use. At the same time it has such terribly explosive powers that railway companies dare not convey it; and every ounce used on this line had to be carted from either Carlisle or Newcastle, and cost about £200 a ton, or more than five times as much as gunpowder. We may add that the temperature of the headings, before they were joined, was 80 degrees; but, when the passage was made through, the heat fell 23 degrees, and the thermometer stood at 57. Black damp was met with in the headings, and also an explosive stone; yet, although the strata through which the tunnel passed were of so hard a nature as to require blasting throughout, the compressed air in the hill forced the stone outwards where excavations had been made; and the atmosphere had such an effect on the rock, that the tunnel had to be arched from end to end. It was anticipated that the cost of the tunnel could not be less than £45 for every yard formed, and we have no doubt these expectations have been more than realized.
... We can now see through the “spectacles” of the powerful little engine which is drawing us, that we are approaching the mouth of what may perhaps be more strictly called the " covered way" that leads to the famous Blea Moor Tunnel. It was intended to make the entrance some distance farther north; but eventually it was thought safer (in order to avoid any slipping of earth down the mountain or down the sides of the cutting, which would have been nearly 100 feet deep) to cover in the cutting, and, in effect, to commence the tunnel 400 yards farther south.
... Four hundred yards from the southern entrance of the tunnel we were at the summit level of contract No.1; some 1150 feet above the sea.
... the tunnel itself inclines downwards, and its drainage runs north.