The question of avoidance of obstruction by snow is a very serious one upon the Rocky Mountain lines, and they could not be worked without the device of snow-sheds—another purely American invention. There are said to be six miles of stanchly built snow-sheds on the Canadian Pacific and sixty miles on the Central Pacific Railway. The quantity of snow falling is enormous, sometimes amounting to 250,000 cubic yards, weighing over 100,000 tons, in one slide. It is stated by the engineers of the Canadian Pacific, that the force of the air set in motion by these avalanches has mown down large trees, not struck by the snow itself. Their trunks, from one to two feet in diameter, remain, split as if struck by lightning.
Snow-sheds, Selkirk Mountains, Canadian Pacific. The winter track under cover; the outer track for summer use.
After the railway line has been finally located, the next duty of the engineers is to prepare the work for letting. Land-plans are made, from which the right of way is secured. From the sections, the quantities are taken out. Plans of bridges and culverts are made; and a careful specification of all the works on the line is drawn up.
Making an Embankment.
The works are then let, either to one large contractor or to several smaller ones, and the labor of construction begins. The duties of the engineers are to stake out the work for the contractors, make monthly returns of its progress, and see that it is well done and according to the specifications and contract. The line is divided into sections, and an engineer, with his assistants, is placed in charge of each. Where the works are heavy, the contractors build shanties for their men and teams near the heavy cuttings or embankments. It is the custom to take out heavy cuttings by means of the machine called a steam shovel, which will dig as many yards in a day as 500 men.