Total £
Dated this day of 18__
Witness:
Engineer.
CHAPTER II.
Works of construction: Earthworks, Culverts, Bridges, Foundations, Screw piles, Cylinders, Caissons, Retaining walls, and Tunnels.
Earthworks.—Under this heading may be classified cuttings and embankments of earth, clay, gravel, and rock.
When setting out a line and adjusting the gradients, an endeavour is usually made to so balance the earthworks that the amount obtained from the cuttings may be sufficient to form the embankments. With care, this may be effected to a considerable extent; but there will be places where the material from cutting is unavoidably in excess, and others where the cuttings are too small, or contain good rock, or gravel, which can be more advantageously used for building and ballasting purposes than for ordinary embankment filling. Or there may be a large cutting which will provide enough material to form three or four of the adjoining embankments; but the distance, or lead, as it is termed, to the far embankment may be so long, and, perhaps, on a rising gradient, that it would be cheaper to run the surplus cutting to spoil, and borrow other material for the far embankment from side cutting or elsewhere. A long lead adds materially to the cost and time of forming an embankment, as it not only necessitates a considerable length of service, or temporary permanent way, but also occupies much time in the haulage of the earth waggons. For distances of half a mile and upwards, a small locomotive is more suitable than horses for conveying the waggons.