CONSTRUCTION OF THE GREAT TUNNEL
The basic reason for this was the shortage of funds, largely through the failure of shareholders to pay their calls. For example, by June 1796, when output should have been rising to a peak, some £92,000 had been called for of which £22,650 was in arrears and the company had only £889 in the bank.
In spite of this, the management committee persisted in maintaining several working faces with all the associated equipment and labour that entailed; all this was in a desperate effort to complete the link between two ends of canal then nearing completion.
Impatience only added to their troubles and costs and it was not surprising that £20,049 had been spent of the £55, 187 estimated, for only one-seventh of the tunnelling work completed.
The proprietors' problems were compounded by their failure to find experienced and reliable contractors to take on their massive task. Two major contractors were financially ruined and had broken their agreements by 1798. They were never satisfactorily replaced and most of the remaining work was eventually executed by direct labour.
Something of the methods of working the tunnel can be gleaned from Outram's report of 1796 and also from a longitudinal section prepared by Brown about 1799. A total of fourteen shafts were originally sunk at intervals of between 100 yards and 180 yards from each end, but pumping costs at all of these were high due to an unexpected ingress of water from the millstone grit strata; indeed at the sixth pit from Diggle costs were eleven guineas per week.
A change of plan reduced the number of shafts to those at Cote, Brunn Clough, two at Red Brook, Heathy Lee, Pule Hoyles and Pule Hill. That at Heathy Lee was later abandoned on Telford's instructions but the others remained.
An adit was driven into each of these shafts in a direction approximately at right angles to the main tunnel at depths between 28 and 49 yards below ground level, and as many as four shafts were sunk along the line of these adits in order to expedite construction.
These apparently extravagant temporary works were completed in an effort to draw off ground water from the workings, but, more important, they also provided a drain for the 'water engines' used for hoisting spoil from the tunnel to the surface tips. These simple and effective machines were common in mining practice and operated by means of a water-filled kibble which moved down a shallow balance pit to the level of the adit. By this means and a gearing system, ratios of which were related to the depths of the shafts, spoil was lifted out of the deeper pit from canal level up to the surface.
Initially, some waterwheels were also used, notably at Pule Hoyles, where an elaborate water supply system was built, but generally these wheels provided insufficient power and were soon replaced by water engines.
Steam engines of the Newcomen type, coupled to reciprocated pumps, were also utilised in the engine house at Red Brook and elsewhere for the drainage of the working levels. A small quantity of water was discharged into the top of the pumping shaft at Red Brook, falling as a fine spray and thereby inducing a strong draught of air down the shaft and into the workings far below. This ventilation system had continued in use.
The drivng of the tunnels as achieved by hand drilling and blasting with black powder. Shaft sinking proceeded in much the same way, although a description by Farey gives a graphic impression of the dangerous conditions of working.
A shallow hole would be drilled in the centre of the shaft floor, then thoroughly dried out with Oakum before packing with gunpowder and a clay seal. On lighting a fuse, the miners clung, one above the other, on to a winding rope and at a signal were hauled some distance up the shaft, where they remained until the shots were fired. They were then lowered into the fumes to clear up the broken rock and to repeat the process.
Farey noted that sometimes accidents occurred when the miners were not lifted sufficiently high above the danger zone. A spirit of optimism was generated by the passing of a new act in 1806 to finance completion of the waterway, and also by the appointment of Thomas Telford to survey the canal, to plan for and estimate the cost of its completion.
In his report Telford claimed' a thorough knowledge of the state of the works because I have examined everything twice and even checked the filling and emptying of every lock'.
His plans included for the completion of the tunnel, also an unfinished section of canal from Woolroad to Diggle and new reservoirs, as well as repairs to structures and earthworks. Estimates for these works were £45,000 for the tunnel and £37,498 for the remainder.
Telford meticulously planned progress such as: 280 yards commencing the termination of the last length and ending the fourth pit at the rate of 8 yards per week, which will occupy up the 1st November 1807. The company assiduously followed these instructions during the ensuing years until their canal as finished in April 1811, just five months later than Telford's prediction.
Regrettably, Rooth was to claim in later years that he alone had supervised completion of the works 'without the aid of any engineer', thus ignoring the substantial guidance and advice which had been provided by one of the leading civil engineers of that time.
Throughout those troubled years it was the workforce of miners, tradesmen and labourers who suffered from the frequent stoppages and shortage of funds. Their recompense for working in squalid, brutal conditions was small and too frequently the company was in their debt; indeed at one stage wages were paid only to those owed less than £30, greater sums being paid at five shillings in the pound.
Welfare of workers was of small account; only once was £1 1s. granted 'towards the expense of burying a workman who died today on the line of the canal' and, although a sick fund was set up, the company subscribed only five shillings each week.
The workmen's origins are mainly unknown, although local parish records suggest that many were sojourners of northern stock such as the unfortunate 'John Kell who was killed in the tunnel, a native of Stanhope-in-Weardale 19.3.1810'.
It seems that upwards of fifty men lost their lives during the construction years, but added to this must be the wives of children who suffered and died, having lived in the primitive shanty towns established near the works at Gilbert's Intack, on Puleside and elsewhere, in support of their menfolk who laboured on that great navigation.