It is now generally understood that the rapid deterioration as regards the strength of railway wheels and axles, is chiefly caused by the intense vibration to which they are subjected. This can readily be made evident: - if the journal of an old railway axle is struck with a smith's hammer, it will in many cases break off with a single blow; presenting at the fractured part a weak brittle appearance; whereas the journal of a new axle will take several hundred blows before breaking, a tough fibrous appearance being presented at the fractured part.
Mr. Lipscomb's apparatus for preventing the vibration of wheels is very simple, and we believe efficacious. It has been applied, we understand, to one of the Royal carriages on the Birmingham and London railway. It consists of a plate of zinc placed on each side of a wheel, for the purpose of retaining saw-dust in contact with part of the rim and spokes; each plate has two wooden rings of unequal size permanently fixed to it; the external diameter of the smaller ring, and the internal diameter of the larger ring are shown by dotted circles in the annexed figure, and are likewise flush with the edges of the zinc plates. The combined depth of the corresponding rings is equal in width to the tyre; these rings meet and are screwed together, certain parts of the rings being cut away to let in the spokes. By a reference to the figure it will be seen that the ends of the spokes, adjoining the nave and tyre, are left exposed for the purpose of noticing any defect which may take place in those parts.
The apparatus may be detached from the wheel, by simply taking out the screws which hold the corresponding rings together, and is applicable, with slight modifications, to all existing metal wheels. The cost of the apparatus is 1/. per wheel, and it will last for many years.
Wheels formed of a combination of wood and iron are in partial use upon some railways for the purpose of decreasing noise and vibration, which still exist, notwithstanding, to a very considerable extent.