LAND-SLIP ON NORTH MIDLAND LINE, NEAR AMBERGATE.
On the Midland, as on other lines, water was the great enemy to be fought against—water in the Claycross and other tunnels—water in the boggy or sandy foundations of bridges—and water in cuttings and embankments. As an illustration of the difficulties of bridge building, we may mention the case of the five-arch bridge over the Derwent, where it took two years' work, night and day, to get in the foundations of the piers alone. Another curious illustration of the mischief done by water in cuttings may be briefly mentioned. At a part of the North Midland line, near Ambergate, it was necessary to pass along a hill-side in a cutting a few yards deep. As the cutting proceeded, a seam of shale was cut across, lying at an inclination of 6 to 1; and shortly after, the water getting behind it, the whole mass of earth along the hill above began to move down across the line of excavation. The accident completely upset the estimates of the contractor, who, instead of fifty thousand cubic yards, found that he had about five hundred thousand to remove, the execution of this part of the railway occupying fifteen months instead of two.
The Oakenshaw cutting near Wakefield was also of a very formidable character. About six hundred thousand yards of rock shale and bind were quarried out of it, and led to form the adjoining Oakenshaw embankment. The Normanton cutting was almost as heavy, requiring the removal of four hundred thousand yards of the same kind of excavation into embankment and spoil. But the progress of the works on the line was so rapid during 1839 that no less than 450,000 cubic yards of excavation were accomplished per month.
BULL BRIDGE, NEAR AMBERGATE.
As a curiosity in construction, we may also mention a very delicate piece of work executed on the same railway at Bull Bridge in Derbyshire, where the line at the same point passes over a bridge which here spans the River Amber, and under the bed of the Cromford Canal. Water, bridge, railway, and canal were thus piled one above the other, four stories high. In order to prevent the possibility of the waters of the canal breaking in upon the railway works, Stephenson had an iron trough made, 150 feet long, of the width of the canal, and exactly fitting the bottom. It was brought to the spot in three pieces, which were firmly welded together, and the trough was then floated into its place and sunk, the whole operation being completed without in the least interfering with the navigation of the canal. The railway works underneath were then proceeded with and finished.
Another line of the same series, constructed by George Stephenson, was the York and North Midland, extending from Normanton—a point on the Midland Railway—to York; but it was a line of easy formation, traversing a comparatively level country. The inhabitants of Whitby, as well as York, were projecting a railway to connect these towns as early as 1832, and in the year following Whitby succeeded in obtaining a horse line of twenty-four miles, connecting it with the small market-town of Pickering. The York citizens were more ambitious, and agitated the question of a locomotive line to connect them with the town of Leeds. Stephenson recommended them to connect their line with the Midland at Normanton, and they adopted his advice. The company was formed, the shares were at once subscribed for, the act was obtained in the following year, and the works were constructed without difficulty.
As the best proof of his conviction that the York and North Midland would prove a good investment, Stephenson invested in it a considerable portion of his savings, being a subscriber for 420 shares. The interest taken in this line by the engineer was on more than one occasion specially mentioned by Mr. Hudson, then Lord-mayor of York, as an inducement to other persons of capital to join the undertaking; and had it not been afterward encumbered and overlaid by comparatively useless and profitless branches, in the projection of which Stephenson had no part, the sanguine expectations which he early formed of the paying qualities of that railway would have been more than realized.