Part Iii.—Dock Shunting

Too much importance cannot be attached to the provision of facilities for the handling of wagons on docks. Continual attention is being paid to the installation of the most up-to-date mechanical devices for handling cargoes, and much has been written on the subject but very little is heard of the efforts directed towards economy and efficiency in shunting to and from docks and on the quay side. Where direct handling, as between wagon and ship, takes place, full use of the most expeditious methods of loading and unloading cannot be made unless the facilities for moving wagons are such that the demands of the ships can be met with regularity, with the minimum of delay, and with the minimum of inconvenience to the dock operations in general.

Docks, unlike stations and marshalling yards, cannot be shifted and remodelled on more convenient sites when the traffic outgrows the facilities. Hence it behoves those responsible for shunting operations to study with particular care and forethought any proposals regarding the construction of additional wharves and necessary railway connections. Railways all over the world, more especially in the older countries, are spending enormous sums in carrying out shunting operations which they know are uneconomical solely because, when the docks were constructed, little or no thought was given to the railway facilities and the need for making allowance for future requirements. Consequently we see wharves in the most inaccessible places, with curves and draw bridges limiting the size of the engines; with crossovers most inconveniently situated; with lines running along busy streets and over congested level crossings; with leads from one wharf fouling those to another, etc. The overall cost of running a shunting engine varies from 15/- to 20/- per hour. It can be seen, therefore, that there is a real need for ensuring the minimum number of engines and the maximum amount of work per engine hour. Any of the disabilities just mentioned reduce the efficiency and increase the operating costs.

Delay in shunting operations, and consequent disorganisation, results in higher cost not only to the Railway Department but to the innumerable companies, agencies, private individuals, etc., that are intricately bound up with the activities of present day port operations. In this country the Railway Department makes no charge for shunting services on wharves owned by Harbour Boards, consequently any additional costs brought about by inadequate facilities or bad regulations are borne by the Department. The use of two engines instead of one does not concern the trader; in other countries, where a charge is made, it concerns him very closely. As the burden here falls on the Railway Department, it can be understood there is more than ever a real necessity for the study and adoption of the most up-to-date methods known.

Electric Capstans and Horses are extensively used for moving wagons on the wharves but engines have to be used to haul wagons to and from the Railway depot. In considering facilities, therefore, the first point is the provision of easy ingress and egress in the station yard. This is best provided by laying down exchange sidings. Secondly, storage sites at convenient points inside the dock area—more especially where the exchange sidings are some distance from certain wharves—are page 25 useful adjuncts. Here can be concentrated empty wagons made on the docks and loads awaiting removal either to the railway line or to the ship's side.

On the wharves themselves crossovers should be so placed that they do not come opposite holds of ships. This is a difficult matter to arrange, as ships vary in length. It is better therefore, to have too many crossovers than too few. The ideal lay-out on the wharf is three tracks, the outside one for loading from wagon to ship, the inside one for discharging from ship to wagon, and the centre one for circulating purposes. With this arrangement, wagons can be circulated freely and engines can work on one ship without interfering with an other.

The gravity System of Shunting as Applied to Wharves. An excellent example of how the most up-to-date railway facilities can be incorporated with the most mechanical dock handling appliances is furnished at Immingham Dock on the Humber. This Dock was built principally for the export of coal, and very particular attention was given to shunting facilities. At an enormous capital outlay, gravity shunting was introduced for running wagons to and from the wharves. The experiment has been amply justified for, with the docks working at full pressure, at least 16 additional engines and numerous capstans would have been required to work the traffic.

The coal is shipped by eight coal hoists similar to that shown in illustration (No. 1) seven are situated on one wharf, and one on a jetty in the river. Each of the hoists can handle seventy tons per hour. In a day of only ten hours, therefore, 5,600 tons of coal can be shipped. However fast the ships work there is no possibility of delay in getting the wagons down to the hoists, for the accommodation provided is enormous. Each separate hoist is furnished with a group of eight sidings, and each of these sidings can take forty, ten or fifteen ton wagons, or a total of 320 wagons for each hoist and 2,560 for the entire group. This, however, represents but a small fraction of the whole of the accommodation, for in the storage and reception sidings close at hand, no fewer than 9,120 wagons can be stored. The full capacity is thus sufficient for over 11,600 wagons, accommodating in all 110,000 to 175,000 tons of coal. Illustration No. 2 shews a “sea of coal” waiting shipment. The total length of siding accommodation and running lines is 170 miles.

The method of feeding the hoists is as follows:—Illustration No. 1 shews one of the eight hoists and a ferro-concrete overbridge. The loaded wagon arrives at the bottom of the hoist, travelling from the storage sidings, by gravity, down an inclined road terminating at the base of the hoist. After being raised to the necessary height it is discharged by being tipped, and then lowered and run off on the overbridge down an inclined road to the emptied wagon siding.

The whole system is such that the operation of feeding the wharves can be conducted with mechanical rapidity and precision, an arrangement of no slight importance in view of the magnitude of the undertaking and the speed with which wagons can be unloaded after arrival at the wharves.

High Steam Pressures.

The German State Railways (says the “Railway Gazette”), are at the present time experimenting with a 4-6-0 type express engine having a special boiler built for two working pressures, namely, 853 lb. per square inch in the rear or ultra-high pressure boiler, and 199 lb. per square inch in the boiler barrel proper. The inner firebox is formed by water tubes, the bottom ends of which reach into the water chambers of a hollow foundation ring, while their upper ends discharge into steam collectors. The system is filled with chemically pure water up to the tube ends in the steam collectors, and from the latter steam rises through vertical tubes to heating coils the firebox. The heat from the coils is absorbed by the water in the special boiler, and the condensate falls back to the foundation ring chambers through another set of tubes and thence starts the circulation over again. The working pressure in the firebox and heating coils is from 1,100 to 1,300 lb. per square inch.