Engineering Wonders of the World
Volume I

THE ROTARY AT WORK ON A HEAVY GRADE IN DEEP SNOW. RAILWAY SNOW-PLOUGHS. IN countries where severe snowstorms are of rare occurrence, and where the average snowfall is of but moderate depth, the wedge-shaped plough, propelled by two or more locomotives, usually suffices to clear snow from a railway track. But if deep drifts form they have to be charged repeatedly, and it sometimes happens that plough and locomotives get stuck, and must be dug out. On many lines of the United States, es- pecially on the mountain sections, the type of plough just referred to would be quite unable to cope with the drifts which must be penetrated again and again in the winter, and have a foundation of hard-packed icy snow. Necessity, the mother of invention, produced., in th© late ’eighties, th.© now world- famous rotary snow-plough, so designed as to eat its way steadily through a drift, much as an auger penetrates wood, and to rid itself of its take continuously by centrifugal force. (1,408) ' _ n 16 By the courtesy of the American Locomotive Company we are able to reproduce some excellent illustrations of the rotary at rest, to show its design, and engaged in fighting the snow. The plough, mounted on two four-wheeled bogie trucks, consists of two main elements : the boiler (of locomotive type) and engine (reversible) ; and the cutting-wheel, driven through the medium of bevel gearing. The wheel is composed of ten hollow cone- shaped scoops, perfectly smooth inside, so as to afford no lodgment to snow. Each scoop has an opening along its front side. Knives are hinged one on each, side of the opening, and, as will be gathered from the illustration on page 242, each knife is connected by a bar to its near neighbour on the next scoop. This arrangement brings into action auto- matically in each scoop that knife which is required to do the work ; as those knives vol. n.