The Mechanical Handling and Storing of Material

THE MECHANICAL HANDLING OE MATERIAL 546 The credit is undoubtedly due to C—Tips which Unload Above the Level of Railway Lines, generally called Hoists. — The tips under this head are undoubtedly the most important of the three types, and are generally used in cases where a quay wall is not very high above the water level, or where large ocean-going steamers (the holds of which naturally extend above the level of the quay) have to be loaded with coal and other minerals. It is obvious that in this third type of tips a great expenditure of power is necessary, be- cause not only has the coal to be lifted to a level considerably above the quay walls, but the speed at which it has to be done is great. The first mechanical coal tips of this descrip- tion were lifted and tilted by hydraulic power. Such coal tips are still the most generally used, but electrically driven tips are beginning to be ad- vocated. It may be said that the loading of coal ships has called into use a greater variety of hy- draulic appliances than almost any other opera- tion in the mechanical handling of material. Lord Armstrong, one of the pioneers of the hydraulic system, whose firm, Sir W. G. Armstrong, Whitworth, & Co., Ltd., have always been well to the front in building hydraulic tips for loading vessels. It must be admitted that no fixed rule can be laid down as to the type of machinery to be employed in each