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The methods of handling these four classes of cargo, as shown by experience to be suitable under conditions existing at many piers, are as follows:

Class 1.-Miscellaneous light-weight cargo must chiefly be moved horizontally, the need for separation and classification of individual shipments tending to prevent high tiering. Satisfactory equipment for horizontal movement consists of tractors and trailers and fork trucks, supplemented by hand trucks. For loading and discharging, power belt conveyors or gravity roller conveyors are used where practicable.

Class 2.-Carload freight may also be well taken care of by means of tractors and trailers for the horizontal movement. If storage is necessary, and particularly if floor space is at a premium, this class of cargo may be put on pallets, moved horizontally by trailers, and then tiered by means of a fork truck. It may also be handled by platform lift trucks of the elevating platform type, particularly if kept in storage for a relatively short time, in which case a number of platforms that might be used elsewhere will not be tied up.

Class 3.—Heavy concentrated cargo can usually be well handled by fork trucks, owing to the nature of the packages.

Class 4.-Heavy, awkward-to-handle cargo frequently requires a crane or a crane truck, either to pick up the packages and place them on proper trailers for a horizontal movement, or in some cases for transportation from one position to another by the crane or crane truck. It can also be conveniently handled by means of fork trucks.

Some coastwise steamship companies, whose vessels load through side ports, economize by placing cargo, when received at the dock, on the pallets used with their fork trucks, then transferring the loaded pallets directly to the ship when loading commences. The loaded pallets are then kept on the ship and carried to destination, where they are unloaded onto trailers by a fork truck working in the ship.

Other steamship companies, whose vessels are loaded through hatches, sling loaded trailers and skid platforms from the apron of the pier into the ship, thus saving the time and the extra handling that would be involved in making up a draft in a sling. These loading methods are referred to in greater detail in chapter II, Loading and Unloading Equipment and Methods.

An effective combination of two types of power equipment has been developed at Cristobal, C. Z., where a good deal of cargo is transferred from one pier to another. Here, the tractor and trailer system is used in combination with elevating platform lift trucks and skid platforms. Cargo to be loaded on a ship is first placed on a skid platform; the platforms are then placed on trailers and are carried to their proper piers. There the lift trucks remove the skid platforms from the trailers and deliver them to the ships to be loaded.

HANDLING CARGO DISCHARGED FROM THE SHIP

Handling inward general cargo discharged from a large ship is frequently a much more complicated procedure than handling an outward cargo. This is largely because the inward cargo must usually be sorted according to marks and consignees, so that all the goods in each individual lot may be put together in one place or pile. If errors are made or if adequate space is not available, and one consignment is piled on top of another, it is necessary later to break out these piles and move them about the wharf. This is all waste that should be eliminated through proper organization and planning, and, where possible, proper wharf design.

When there are thousands or even tens of thousands of packages or pieces of inward cargo, as is frequently the case, the marks or labels of which have to be individually inspected, the magnitude of the operation and the possibilities for delay in its execution may readily be imagined.

Following the sorting of the cargo, the principal movements are: (1) The delivery of goods to railroad cars; (2) to trucks; (3) to lighters; or (4) to a warehouse adjacent to the pier. The placing of the cargo on the dock must be done with the further movement or disposition of each particular consignment in mind.

As a rule, inward cargo is sorted and classified immediately after the sling load is landed on the apron of the pier. The small area under the ship's hook on the apron of the pier is, consequently, one of the key points in determining the rate of discharge of miscellaneous cargo. While the dock crew is occupied in sorting a sling load, the hook of the ship either stands idle or hangs over the deck of the ship with another load of cargo ready to be lowered onto the apron. The speed of discharge will vary, therefore, according to the speed with which each sling load is sorted and removed from the apron to its further destination on the pier.

SPEEDING UP THE SORTING OF INWARD CARGO

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It has been asserted by competent terminal engineers that sorting of inward cargo costs hundreds of millions of dollars yearly and, when ship's time and all the other cost factors involved are taken into account, this may well be the case. While many other operations on the pier have been greatly improved by the introduction of proper equipment, no new device has been developed to hasten the absolutely necessary sorting operation.

There appears to be only one method by which sorting can be simplified and speeded up. This method is relatively easy to put into operation and, of greatest importance, experience has shown that it works. This is to organize the stowage of the cargo at the port or ports of loading, insofar as possible, so that all the packages in any one consignment are kept together in what are sometimes called "blocks," meaning separate easily identified groups. Admittedly, it is sometimes difficult to carry out such a plan, particularly when a ship's schedule calls for loading at a number of ports; but it is reasonable to believe that a determined effort would bring a definitely worthwhile result.

One American steamship company has reported that it reduced its costs of discharge in United States ports approximately 20 percent on an average of 6 months, as compared with the preceding 6 months. This was done chiefly by proper stowage on the ship at loading ports, by which cargo was put into blocks according to the marks. Some steamship companies have adopted the practice of separating individual shipments by means of heavy paper. This has been found very satisfactory with cargoes such as coffee and cocoa beans, of which there may be on a single vessel 200 or more separate

Brinton, Willard C. Marine Terminal Operation. (A paper presented before the First National Meeting of the A. S. M. E. Materials Handling Division, Philadelphia, April 1928.)

consignments. With block stowage of this type it is possible to make up sling loads inside of the ship so that each draft will contain packages bearing the same mark. No sorting then has to be done on the apron, and an entire draft can be taken at once to the position previously selected for it on the pier.

CHAPTER II

LOADING AND UNLOADING EQUIPMENT AND

METHODS

Cargoes transported by water are of two kinds-bulk cargo, solid or liquid, such as coal, ore, grain, sulfur, or petroleum, all of which are shipped in bulk without containers, and general cargo, which consists of miscellaneous goods packed in boxes, bales, bags, barrels, drums, etc. General cargo may also be classed as mixed cargo, which is made up of numerous different commodities differently packed, and uniform cargo consisting of a single product each unit of which is packed in the same manner as the others. Cargo of the latter type would be, for example, case oil, paper, bagged sugar, rice, coffee, or flour. Such cargoes frequently move in shipload quantities.

BULK CARGOES

The principal bulk cargoes are usually loaded by means of mechanical equipment specially designed to handle the particular commodity involved. Thus, coal and ore are loaded by car dumpers of various types, grain is poured into a vessel through loading spouts, and oil is pumped into a tanker through flexible pipes. Other types of special equipment unload these cargoes in all major ports. The speed of loading and unloading depends chiefly upon the equipment used and the stowage, when required, is done chiefly by trimmers who should be overseen by ship's officers. Since it is a very specialized subject, the mechanical handling of bulk cargoes is not discussed in detail in the present volume. Discussions of the stowage of the principal bulk cargoes, however, are contained in the chapters, "Stowage of Special Cargoes" and "Commodities and Their Stowage," and reference to them is made elsewhere throughout the book.

GENERAL CARGO

General cargo is handled in United States ports chiefly by means of ship's gear or by the ship's gear in conjunction with cargo masts and winches on the dock. In this type of operation, the speed of loading and discharging and the adequacy of the stowage are largely dependent upon the skill and experience of the stevedores, the steamship company's dock force, and the ship's officers. Many hours of ship's time can be saved and other economies can be effected if these men are thoroughly familiar with the various methods of handling general cargo rapidly and safely. Important principles involved in the efficient loading, stowing, and discharging of general cargo are discussed in the following pages.

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In discussing the work of loading and stowing a cargo vessel, Annin1 points out:

The interests of the ship's operators and the stevedores, while not identical, are similar. The operators wish the greatest possible amount to be loaded in the least possible time, because the cargo is paid for by the ton, while the ship costs them a considerable amount each day, and every day that it is delayed is clear loss. The stevedore's interest is the same, because, while he is paid by the ton, he pays his men by the hour; in other words, he is on piece-work, while his men are on a time basis * * * This necessity of keeping his gangs working often brings his interests and those of the operators into conflict, for it will sometimes impel him to take small stowage, such as boxes of dried fruit or condensed milk, and stow it all together, because it is the only cargo available, much to the annoyance of the operators, who have been holding that cargo for the express purpose of using it for beam filling. The operator has to watch for this trick, which is known as "stealing the small stowage."

* * *

The great bulk of the general cargo moving in foreign, coastwise, and intercoastal trade is of the mixed or miscellaneous type, comprising numerous packages or pieces packed in many different kinds of containers, which must generally be handled individually or few at a time. These packages are transferred from the pier to the ship either by way of the ship's hatches, which is usual in most foreigngoing and intercoastal shipping, or by way of side ports, which is the customary method in the coastwise trade and in the Great Lakes "package freight" trade. Many passenger liners and intermediate passenger and cargo liners also load cargo through side ports as well as hatches. It should also be noted that some commodities, such as lumber, are frequently carried on deck, and the problem of transferring such goods from pier to ship and vice versa does not, accordingly, involve passage through a more or less restricted opening, such as a hatch or a side port.

LOADING AND DISCHARGING THROUGH HATCHES

Loading and discharging through hatches is the common method of loading and discharging general cargo carried by oceangoing vessels. Several methods of transfer are employed, as follows:

By means of ship's gear exclusively: (a) Whip or single-fall and skid system (using one winch and one boom, with inclined skids or planks); (b) double whip or split-fall system (using two winches and two booms); (c) burton system (using two winches and two booms); (d) union or married-fall system (using two winches and two booms); (e) ship's deck cranes.

By means of ship's gear used in conjunction with cargo masts on the pier and pier winches.

By means of quay cranes.

By means of floating cranes (chiefly for heavy lifts).

By means of specialized equipment.

TRANSFER BY SHIP'S GEAR

In United States ports the most common method used for loading and discharging general cargo is by means of the ship's own gear or tackle. This is in marked contrast to the general practice in most European ports and in many major ports of the Far East and South America, which are generally equipped with overhead or gantry cranes. These are used almost exclusively for handling cargo from pier to

1 Annin, Robert E. Ocean Shipping. The Century Co., New York, 1920.

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