Showing posts with label cargo. Show all posts
Showing posts with label cargo. Show all posts

22/12/2021

Electrical deck auxiliaries on ships

These auxiliaries, in the main, comprise cargo winches (which may include warping as a subsidiary duty), cranes, capstans, warping winches, windlasses and hatch-cover winches. Except for cranes, each of these may sometimes be used for duties other than those for which they are primarily intended. The systems of control as between these various applications bear a similarity but with variations to suit the operating conditions. It will be convenient to deal with them under their different headings, but there are divergencies between the methods favoured by different makers and descriptions will therefore be confined to representative schemes.

Electrical deck auxiliaries on ships

Electro-hydraulic winches do not call for special mention as they use a continuous running motor, which can be either a.c. or d.c. They can be operated either singly or in groups from one pump. Many electrical deck auxiliary schemes make use of contactors for control purposes and where these are of such size and numbers as to warrant it they can be accommodated in a separate contactor deckhouse instead of in the winch assembly. This increases the amount of cabling but on the other hand it economises deck space in the vicinity of the winch, making for cleaner lines and unobstructed viewing by the operator. It also facilitates maintenance work which in any case is not always opportune to carry out when the ship is in port and when the winches are in use. While at sea maintenance can be carried out under protection from the elements. In every winch, etc., in which the load is lowered while the motor is mechanically coupled such as in systems employing power lowering it is essential to prevent the load taking charge and lowering at a speed which will damage the motor armature. To safeguard against this contingency centrifugal brakes are provided in some cases and they are so set as to enable heavy loads to be lowered with an assurance that the safe speed cannot be exceeded. Provision must also be made to stop the load running back if the power supply should fail or the overload relay operate and in this event the winch, etc., must not restart when power is restored unless the controller has been returned to the starting point, usually the "off " position.

16/09/2014

Shipping business important abbreviations

• a.a. – (Chartering) Always afloat
• Abt. – About
• abt. – About
• a/c – (Chartering) Account
• acct. – (Chartering) Account
• A/D – Alternate Days After date
• a/d – Alternate Days After date
• Ad. val. – According to value
• ad. val – According to value
• A/V – According to value
• A/H – (Chartering) Antwerp, Hamburg range of ports
• AMVER – Automated Mutual-assistance Vessel Rescue
• AS – Annual Survey
• A. T. S. B. E. – (Chartering) All Time Saved Both Ends
• a. t. s. b. e. – (Chartering) All Time Saved Both Ends
• A. T. S. D. O. – (Chartering) All Time Saved Discharging Only
• a. t. s. d. o. – (Chartering) All Time Saved Discharging Only
• A. T. S. L. O. – (Chartering) All Time Saved Loading Only
• a. t. s. l. o. – (Chartering) All Time Saved Loading Only
• A/V – According to value
• A. W. t. S. B. E. – (Chartering) All Working Time Saved Both Ends
• a. w. t. s. b. e. – (Chartering) All Working Time Saved Both Ends
• A. W. T. S. D. O. – (Chartering) All Working Time Saved Discharging Only
• a. w. t. s. d. o. – (Chartering) All Working Time Saved Discharging Only
• A. W. T. S. L. O. – (Chartering) All Working Time Saved Loading Only
• a. w. t. s. . o. – (Chartering) All Working Time Saved Loading Only
• bb – (Chartering) Ballast Bonus
• B. B. – (Grain Trade) Bar Bound
• B. B. – (Chartering) Below Bridges
• B. B. – Bulbous Bow
• BB – Bulbous Bow

10/02/2013

TALLYING CARGO

To tally is "to check" or "keep a record" of all cargo loaded into or discharged from a vessel. It is an essential part of cargo work in order to prevent claims, sometimes illegitimate, upon the ship or stevedores for short discharge or loading.

As is often the case, there are so many channels through which consignments have to pass before they eventually reach the consignee after discharge that much confusion and worry can be avoided, if the shipper and carrier safeguard their own interests.

The tallying of a cargo should be made in alphabetically indexed books, one for each hatch and each port of discharge, and should consist of records of all marks and numbers of the goods, description, quantity, disposition of stow within a compartment.

A ship's responsibility ends when the cargo crosses the rail, therefore tallying should be made on board the vessel and not, as it often happens, ashore in the warehouse.

Tallying is done by shore and ship's tallymen. The tallyman counts the number of cargo pieces in each draft before they are removed from the sling. If a draft is some pieces short or extra the tallyman must inform a stevedore about it on the spot.

Tallies should be compared and agreed at the end of the day between the ship tally and shore tally and any difference immediately investigated. In some cases it may even be necessary to retally a consignment if the discrepancy is large.

CARGOES

Cargoes carried by ships are of two kinds: bulk cargoes and general cargoes. Bulk cargoes may be either solid (grain, ore, coal, green sugar, sulphur) or liquid (oil products, wine, fresh water, spirits). All bulk cargoes are usually shipped in bulk without tare. General cargoes represent various goods differently packed. Goods packed in bags, cases, bales and drums are considered as general cargoes. For example, if green sugar is shipped in the hold without tare, in bulk, it is a bulk cargo and if it is packed in bags, we can consider it as general cargo.

It frequently happens that some varieties of cargo are carried on deck. It is to be understood that in this case "on deck" means on an uncovered space and that the cargo is exposed to weather.

Many classes of dangerous goods, such as acids and gas cylinders are carried on deck. Small consignments of goods which may damage other cargo are also given deck stowage. Cargo carried on deck is shipped at "shipper's risk", unless contracted otherwise, and Bills of Lading are qualified accordingly, but nevertheless responsibility falls upon the ship to counteract to any possibility of loss and damage. 

Proper means of fastening the cargo must be provided by lashings; protection from the sun and weather can be obtained by the use of tarpaulins where necessary for certain cargoes. All reasonable amounts of wooden dunnage must be laid to provide drainage courses.

Units of especially heavy cargo are frequently carried on deck. Locomotives, lorries, crates of heavy machinery such as transformers and extremely large lengths of heavy timber (logs) find suitable stowage on deck. These cargoes will require wire and chain lashings connected to ring bolts and provided with bottle screws for tightening and shoring with timber, and the building of cradles and beds.

RESPONSIBILITY OF CARGO OFFICIALS AND INSPECTION OF COMPARTMENTS BEFORE LOADING

On board ship the Cargo officer is responsible for the safe and efficient handling and stowage of cargo. This officer should secure proper preparation of the holds before loading and he supervises during the time the ship is receiving or delivering the cargo.

The stevedore is usually in charge of any cargo work that is loading or unloading (discharging). He is responsible for securing the ship with a sufficient number of gangs, cargo-handling machinery and besides he organizes transporting cargoes from the ship to the sheds or warehouses.

The stevedores should inspect the compartments before the beginning of cargo work. The holds and other compartments must be clean, dry and well aired. No dirty or stained dunnage remaining. Cargo battens must be in good condition. Cement chocks between frames unbroken and free from cracks. Scuppers clear. Bilges free and clean. Hatch-boards complete. Appropriate tarpaulins available. Suitable dunnage available. When they are gojng to load grain, at the preliminary survey special attention could be paid to:

  1. plans of the vessel showing the proposals for erection of shifting boards,
  2. sections of the limber boards (they must be clear for inspection of the bilges, which must be clean and clear of any refuse liable to choke the suction pipes),
  3. entering the bilges (they must be absolutely grain-tight),
  4. longitudinal grain-tight shifting boards (they must be fitted from deck to deck or deck to ceiling in any compartment of the hold and must be continuous for the whole length of the compartment or hold),
  5. shifting boards (it is recommended to accept shifting boards of a minimum 2 inches made of good sound timber; shifting boards must be securely fitted at bulkheads).
When bulk does not completely fill the compartment in which it is carried and is secured by bagged grain or other suitable cargo laid on top of the grain in bulk, such bagged grain or other cargo must be laid on platforms which, in their turn, are placed on the bulk grain and so stowed as to prevent the grain from shifting.

The stevedore should supervise cargo work and he should make some entries in his book concerning times of starting and finishing work, times of and duration of any stoppages, with reasons for some. He should know hatches working and number of gangs employed. He should make notes concerning state of the weather and ventillating systems employed, approximate number of tons of cargo worked during the day, draught, fore and aft, and condition of trim.

HATCH COVERING

When the cargo work is over, it is necessary to cover the ship's hatches. Hatches may be covered either with wooden hatchboards or with other special covering systems. Despite the covering system used, the hatchbeams should be fitted into sockets riveted to the inner side of the coamings. The hatchbeams serve to support the hatch covers. It takes much time to close or open the hatches by wooden hatchboards since this work of covering is done by manpower.

Quick operating hatch covers permit the opening or closing of covers in as little time as two minutes per hatch. The handling operations are simple and safe. The covers are hauled over runways by wires attached to winches. Some types of hatch covers are formed of hinged sections, in one or several pairs, and are specially suitable to big hatchways or the wide openings as found in ore carriers. The hinged sections fold up "concertina" fashion and are stowed at the ends of the hatchway. Where space is restricted at the batch ends, a side rolling system is introduced, thwartships from the holds.
The use of the modern form of hatch coverings has the following advantages:
1. Quick working.
2. Reduced cargo handling time.
3. Better use of the space.
4. Elimination of damage due to the presence of coamings.
Saving of time is at least 75% of the time devoted to handling hatch covers of the old type. After finishing loading and before leaving the port, it is obligatory to cover the hatches with tarpaulins to ensure watertightness.

What are holds and hatches on a ship?

The inner space of a ship between the limber boards of a double bottom and the decks is designed for carrying cargoes. We call this space a hold. Holds have different capacity. Big vessels have cargo holds divided into several separate compartments by watertight bulkheads. Each dry-cargo vessel has four or five holds. The holds have bilges which serve to give way for flowing the water which may condensate on metal bulkheads or collect on wooden flooring. The water collected in the bilges is pumped out by a hold pump. To protect the bilges from corrosion they are covered with cement or special anticorrosion substance, besides they are protected by limber boards.

What are holds and hatches?

The double bottom is covered with a removable wooden flooring. Cargo battens or "spar ceiling", as they are often called, comprises portable wooden battens fitted to the inner edges of the frames and so form a sheathing to the ship's side. "Spar ceiling" is made up of boards and arranged either horisontally, or vertically between frames. The purpose of this wooden sheathing is to prevent packages of cargo from damage by moisture which may collect on the side of the ship. The space so formed between the "spar ceiling" and the ship's side helps to provide a complete air space around the cargo and thereby improves ventillation. The "spar ceiling" should al-ways be kept in a good state. Each hold has a hatchway. The hatchway is the rectangular opening in the ship's deck. The vertical plating around the hatchway is called hatchway coaming.

LOADING

Before loading a ship a cargo plan must be drawn up. This document is usually drawn up at the Chief Controller's office since this office directs cargo work in the sea-port. While abroad the Agent and the Master draw up a cargo plan. When the plan is ready the stevedore may begin loading. Firstly, he secures the necessary number of gangs, secondly he supplies the tackles which the dockers need in their work and at last the stevedore supervises the correct tonnage allotment for the holds. He checks up if cargoes are stowed and trimmed properly. Even stowage of cargoes secures a reliable stability of the ship loaded.

Before starting loading the crewmen clear the hatches and get ready the winches, derricks and cranes, if any. They roll back the tarpaulins from the hatches, remove the hatchboards or any other hatch covers, remove the beams. When everything is done, they consider the hatches to be cleared and ready for loading.

Different kinds of cargoes are loaded by corresponding equipment and appliances. For example, cases call for steel slings, nets and pallets; bags require cargo nets and canvas slings. Extraweights, if any, are usually loaded by either heavy derricks, the lifting capacity of which is over 5 tons, or by quay cranes.

WAREHOUSES AND SHEDS

Cargoes which must be carried by ships are usually delivered to a port prior to ship's arrival. So on ship's mooring they waist no time and loading operations may begin immediately. Cargoes are of different types and value and most of them are to be stored in special warehouses and sheds. This storing protects cargoes from any damage caused by sun rays, snow, rain and by some other factors. Only a few kinds of machinery and equipment packed in boxes can be placed on quays without roof protection. Warehouses and sheds are used for storing cargoes during any periods of time before they are conveyed to the quays and loaded on board ships.

There are single-floor-, two-floor- and multifloor sheds and warehouses in a modern port. In the warehouses special care should be taken to ensure even distribution of natural and artificial lightning. Walls, roofs and columns should be painted in light colours. Floors must be strong and they must withstand considerable weight of the packages stowed. The construction of warehouses and sheds must be such as to avoid the difficulty in arranging the flow of cargoes from the various floors without interruption. Clearances between the packages stowed in the space of the warehouse must be quite sufficient for free shifting and trimming the cargo. Perishable goods such as fish, meat, fruits, vegetables, paultry, butter and some other goods are kept in port cold-stores. Port's warehouses and sheds are linked with quays by railways and asphalt roads. This makes transportation of goods from the warehouses to the ships easy and convenient.

Types of cargo ships

Cargo ships may be of two types: a) dry-cargo ships and b) tankers.

Dry-cargo ships are divided into the following classes: general cargo ships, bulk cargo ships (ore carriers, coal carriers, grain carriers), container's ships, timber carriers; refrigerators.

Tankers usually carry liquid cargoes such as oil products, spirits, wine, fresh water and the like. In some cases the tankers may carry grain and sugar in their tanks. Besides there are special vessels which do auxiliary service. They are tugs for towing ships, salvage vessels, icebreakers, dredgers, barges and lighters, fishing and whaling vessels.

Sea-going vessels are also classed according to the kind of propelling machinery into:
motorvessels, steamships, turbine-driven ships, electric-driven ships (turbine-electric ships and diesel-electric ships) and atomic- driven ships.

Let's consider one of typical vessels and its principal parameters. For example, a typical bulk-carrier usually carries grain, ore and the like bulk cargoes. The ship is divided by seven watertight bulkheads into eight compartments. Cargo handling is accomplished by grabs from 5-ton electric rotating cranes. The holds are closed with Mac-Gregor hatch covers. On board ship there are two lifeboats with manually-operated propeller drive. Each boat has a carrying capacity of 49 men. The living quarters are centrally-heated and air-conditioned. The engine develops 5400 h.p. at 115 r.p.m.

The main parameters are as follows: 

Length ... 139.5 m
Breadth ...18m
Depth ... 10,3 m
Hold capacity ... 12 000 cu. m.
Ore draught (8980 tons) ...8m
Coal draught (8630 tons) ... 7.82 m
Ballast draught:
Forward ... 3.4 m
Aft ... 5.61 m
Operating range ... 6 000 nautical miles
Displacement 4 200 tons
Deadweight... 12 800 tons
Speed .. . 14.3 knots
Crew ... 37