Cargo Handling and Stowage

A Guide for Loading, Handling, Stowage, Securing, and Transportation of Different Types of Cargoes, Except Liquid Cargoes and Gas

Peter Grunau

• Publisher: Books on Demand
• Year: 2015
• Print ISBN:
  9783739217574
• Edition: 1
• eBook ISBN:
  9783739266367
• Topic: Biological Sciences
• Subtopic: Science General
• Index: Biological Sciences

A Guide for Loading, Handling, Stowage, Securing, and Transportation of Different Types of Cargoes, Except Liquid Cargoes and Gas.The most common cargoes and their stowage and calculation are described - Container Cargoes, Reefer Cargoes, Bulk Cargoes including Grain and Grain products, Heavy Lift Cargoes, Timber Cargoes, Steel Cargoes and Ro-Ro Cargoes.For each cargo the stowage and loading principles are described as well as the securing of these cargoes which includes all necessary calculations.

1.1 What is Cargo?

Answering the question will be difficult because cargo is only a name for different kinds of products which will be transported from one point of the earth to another. This can be done by car, aircraft, truck, or ship. The most useful kind of transportation and also the most efficient kind of transportation is the ship.

A ship can carry, compared to a truck or railway, much more different products and also more masses. These goods will be transported generally for commercial gain.

1.2 What Kind of Cargoes do we know?

In general we know:

• Liquid cargoes
• Dry cargo in bulk
• Heavy Lift/Project cargo
• Reefer cargo
• General Cargo

There are also some special cargoes which are partly belonging to the kinds of cargoes mentioned above, like dangerous goods which can be either dry cargo, refrigerated cargo or liquid cargo.

Each of the above mentioned kind of cargoes has special parameters to be known. Without knowing these parameters, a transportation of cargo is not possible. The different cargoes will be discussed in chapter 2, but for all cargoes to be loaded, general guidelines can be worked out. These guidelines should be followed prior loading, during loading, prior and during discharging and also during the voyage.

1.3 The Parameter to Carry Cargo Successfully

1.3.1 The Planning

The planning for loading and discharging of cargo is a compact unit. First of all we have to calculate the cargo, which means how much cargo can be loaded. The planning for the cargo operation is based on the cargo to be loaded. The quantity of the cargo to be loaded will be given by the charterer. The Master and/or Cargo Officer (normally the Chief Officer) have to check and clarify if the ship can load the said amount of cargo.

The next step – and for most of the vessels the first step – is where is the cargo bound for – what is the discharging port(s). For the calculation of the planned voyage the master not only needs to know how much cargo can be loaded, further he also must know:

• Properties of the cargo to be loaded
• Distance between port of loading and port of discharging
• Climatic changes during the voyage which might influence the cargo
• The Energy Efficiency Operation Index (EEOI) given by the company and how he can achieve the EEOI
• The fuel oil consumption and average speed in accordance to the EEOI
• The weather condition expected for this voyage – meteorological voyage planning and voyage/passage planning
• The expected stability/trim condition during the voyage
• The ballast water management regulations valid for this voyage and how it can be achieved in regards to the stability condition of the vessel, if ballast water management must be done (voyage plan)
• Tidal condition on port of loading and port of discharging
• Draft limitations in the port of loading and port of discharging
• At what hatches will be loaded or discharged at the same time (important for the distribution of the cargo)
• Comply with the international load line regulation
• Comply with the terms given in the charter party

There are for sure many more aspects the ship command must take into account, but these are the most important ones.

The distance between the POL and POD¹ will be needed to calculate the required amount of fuel oil which will be consumed during the voyage. The HFO and MDO consumption has a direct influence on the load line regulation and the stability/trim of the vessel and as well for the distribution of the cargo. The consumption of fuel oil is one of the most important parameters to know prior loading especially when loading cargo in bulk.

The simple formula for the calculation of the consumption is:

Total consumption = Total time used for the voyage (in days) * HFO (MDO) consumption per day

There is still one factor missing in the consumption calculation. The factor missing is the safety margin for weather influences (bad weather on the voyage which causes the ship command to deviate from the origin voyage plan). This will result in more consumption of fuel oil which must be taken into account. The safety margin can be obtained by 15% to 25% more bunkers to be on board.

For example:

The daily consumption of the vessel = 35mt. The voyage takes 10 days.

Consumption = days * consumption/day
= 10days *35mt = 350mt/voyage
SafetyMargin = 25%
25% of 350mt = 87,5mt
Total Bunkers on Board = 350mt + 87,5mt = 437,5mt

The conclusion will be: Total consumption + Safety Margin = Required Bunkers/Voyage

The safety margin will differ due to the different bunker capacities of the ships and the daily consumption rate.

Another parameter for the pre-calculation of the cargo is the deadweight and displacement of the vessel. The detailed calculation is part of “Stability &Trim”. But the draft of the vessel is important for the planning of the voyage because the ship command must comply with the load line zones the vessel will trade in. Furthermore, the required maximum drafts in the POL and POD – given in the draft limitations – are part of the displacement calculation.

1.3.2 Stowage and Cargo Hold Space

After knowing how much cargo must be loaded (charterer’s figures) the ship command must calculate if the cargo can be loaded on board of the vessel.

Each cargo requires a different kind of stowage (see also Chapter 2 – “The different types of cargo”). For this reason the ship command must check prior loading if all necessary stowage material and lash material is available on board to guarantee a good stowage and loading/discharging procedure. All checks should and must be done prior loading. The ship command has to declare that the vessel is ready for loading (N.O.R)².

For the stowage of the cargo, the Stowage Factor (S.F.) of the cargo must be known. The stowage factor is a mathematical figure which expresses how much space will be occupied by the cargo if the said cargo will have certain measurements (H*L*W)³. This will be expressed in the S.F. It is the Volume occupied by the unit weight of cargo expressed in cubic meter or cubic feet.

The stowage factor will normally be given by the charterer, but it can also be calculated.

Formula for S.F.:

For example:

The total cubic meter of the hold = 3000m³. The vessel has actually loaded 650mt.

For most of the cargoes to be loaded, the stowage factor is already known or given by the charterer in advance. It is necessary for the ship command to have the S.F. in advance to prepare a preloading plan. The measurement of the hatches and the theoretically cargo to be loaded can be found in the vessel’s capacity plan.

The stowage of the cargo differs also with the cargo to be loaded and how exact the stevedores will work as well as how exact loading and stowage of the cargo will be supervised by the Officer of the Watch.

For a tanker, for example, the maximum filling of the tanks depends on the property of the cargo⁴. In general, the upper limit = 98% of the tank volume.

Starting from the vessel’s displacement on departure, the net in taken cargo can be calculated by subtracting the vessel’s light ship. Therefore: Departure displacement – light ship weight = gross displacement. If subtracting all other weights (fuel oil, provision, ballast water, crew effects, paints etc.), except for the cargo weight, from the gross displacement, you will get the net displacement of the ship.

Another important factor in respect to the stowage of the cargo is the broken stowage. The broken stowage can be also calculated.

Broken stowage is defined as the amount of space on a ship that is lost during stowage, measured in percentage of total bale space⁵. The percentage of space lost varies depending on the type of cargo, container shapes, and the bays used.

Therefore:

where: V = Total volume of the cargo Hold

v = Volume occupie...

Table of contents

• Table of Contents
• 1.1 What is Cargo?
• 2. The Different Cargoes
• 3.0 Lashing Material and Lashing Arrangement for Containerized Cargoes
• 4.0 The Reefer Container
• 5.0 Reefer Cargo
• 6.0 Bulk Cargo
• 7.0 General Cargo
• 8.0 Heavy Lift Cargo
• 9.0 Loading of Heavy Lift in Single Crane and Tandem Crane Operation Lifting Symmetric and Asymmetric Cargoes
• 10. Timber Cargo
• 11.0 Steel Cargo
• 12.0 General Introduction of Roll-on/Roll-Off Cargo and Ships
• Table of Illustrations
• Bibliography
• Index
• Copyright