General Cargo series | Part II | Voyage instructions

Welcome back to our series focusing on General Cargo ships. In this series, we are primarily talking about cargo operations onboard General cargo vessels which carry very unique and specialized cargoes. In this blog, we shall be talking about how Voyage instructions onboard a general   cargo vessel looks like. So let us read the instructions –

Voyage Instructions

QUOTE ——-

VOY NUMBER XXXX/2021

Good day Captain,

I am your Operator for this voyage and will be responsible for the day-to-day operations of your vessel.

Schedule – Port rotation and dates

Please find below vessels current schedule.  Current schedule is subject to change

Port restrictions

Please find below port restrictions – same to be checked with local agents

CLU and request for stowplan

Please find below attached current Cargo Line up (CLU). Please revert with a pre stowplan acceptable in all stages of the voyage, arrival and departure drafts for all ports of call must be included.

Speed

Please proceed at  ECO SPEED for this voyage – weather, safe navigation permitting.The target fixed consumption is 31.8 mt per day. The fixed target consumption included Main and Auxiliaries Engine(s) consumption.

Deadweight Checks

Deadweight checks must be conducted by Ship’s Staff for all load and discharge ports to ensure that all Master and OOW’s are aware at all times of the draughts in relation to the available depth of water and the quantity of cargo on board to enable all voyages to be conducted in a safe and professional manner. Additionally, on some trades, the deadweight check can be of particular importance for breakbulk cargoes where shippers may have under declared weight compared to what is declared (documented).

Cargo hold preparation and requirements

No loose rust, scale, paint, cargo residue, blisters or any other loose substance on any surface of the hold including hatch coaming, underside of hatch covers, lower bulkheads and tank tops will be accepted by surveyors.Please keep in mind when preparing holds and in order to avoid any contamination of cargo, all rust bleeding areas to be neutralized by application of Phosphoric Acid or light paint, after following the proper preparation procedures. If more time is required for hold preparation prior inspection this must be discussed with the Voyage Officer at the earliest opportunity so any additional time can be planned in the most effective way.

Hold maintenance.

The cargoes to be carried on the subsequent trade may require holds to be in good and clean condition. Please ensure vessel is fully equipped to meet any hold cleanliness requirement for those intended cargoes and order materials as required at earliest opportunity.

Cargo care

Master is responsible for the safety of the crew, efficient transit of the vessel, and must be fully aware that Cargo Care is always the priority over maintaining ETA.

—- UNQTE

The above is just cargo related details taken from the voyage instructions. The actual voyage instructions are always detailed and consists of additional information pertaining to the voyage. For the sake of simplicity, we have kept the voyage instructions focused on cargo matters.

Understanding the Voyage Instructions

In all cases, I simply break down the voyage instructions such that the complete voyage and the requirements can be easily understood and later explained to the concerned officers. Till the time you yourself have not understood the voyage instructions properly, you will not be able to execute the voyage efficiently. Let us begin.

As you can see that the trade which the vessel is executing is Liner in nature. The vessel is presently at discharge port Qingdao (in China) and has to load again at Qingdao. The cargo is not specified here because unlike bulk cargo, the vessel is loading general cargo which is of varied nature. The cargo which is planned to be loaded is specified in the attached STOWAGE PLAN or CLU (Cargo Line Up) sent by the charterer. We shall discuss that thing later, but for now let us focus on information provided. We know that –

Loadport 1 : Qingdao
Density : 1.024
Draft Limit : 13 mtrs
Cargo : <will come to this later>

Load port 2 : Xingang
Density : 1.023
Draft Limit : 15 mtrs
Cargo : <will come to this later>

Discharge port : Guayaquil
Density : 1.018
Draft Limit : 9.75 mtrs

Clearly, the limiting point in the Voyage is at Discharge port Guayaquil (Ecuador). So, loading at last port has to be determined by the limitations at discharge port, such that when the vessel reaches discharge port Guayaquil, it’s draft shall not exceed more than 9.75 meters.

Let us use the trim and stability booklet (loading manual) for the vessel and calculate what is the maximum amount of cargo that can be carried by the vessel basis limitations at Guayaquil, Ecuador.

Let us convert the displacement to density 1.018; we obtain : 45218 mt
Subtracting lightship value we obtain max allowable deadweight as : 32984 mt
Now we need to calculate the following values in order to obtain max cargo intake
Bunkers @ Arrival Guayaquil (given by Chief Engineer) : 700 mt
Unpumpable ballast @ Departure Xingang : 250 mt
Fresh water ROB  @ arrival Guayaquil : 200 mt

Using the above figures, let us now calculate the max cargo intake at Guayaquil, bss Draft restriction of 9.75 mtrs at density 1.018. This can be put simply as below –

So we know that max cargo which the vessel can carry without exceeding 9.75 mtrs draft at Guayaquil is 31834 mt. 

Let us now check the Stowage plan which was sent along with the Voyage instructions.

Always remember that the main difference between loading a general cargo and bulk cargo is that the former is usually prepared by the shore personnel (and verified by the ship) while the latter is prepared by the ship and tendered to shore for their approval. However, in some exceptional circumstances, the chief officer might be required to prepare the stowage plan for the general cargo. We shall discuss that possibility later. For now we shall focus on the stowage plan which is tendered by shore for vessel’s verification.

Stowage plan sent by charters for the above voyage is as follows –

This stowage plan, as advised, is tentative in nature and therefore, charters require you to check and verify whether it is acceptable. In majority of the cases, the plan needs a bit of fine tuning – as far as drafts (arrival or departure), trim and SF-BM values are concerned.

So, the aim of chief mate in this case is to fine tune this stowage plan so that it results in all parameters to be acceptable once the vessel is loaded. This is primarily done through keeping in mind few considerations which are as follows –

1. The vessel does not exceed Max draft allowable at Guayaquil
2. The vessel does not exceed Max draft planned at Tianjin
3. The vessel does not exceed loadline zone during the voyage
4. The vessel arrives on / close to even keel at Guayaquil
5. The stress values (SF/BM/Hold mass) are within permissible limits
6. Overall the loading condition is satisfied
7. In case of more than one discharge port (which is not applicable in this case), the cargo to be discharged at first port is loaded on top

We know from above that the max cargo intake bss limitations at Guayaquil is 31834 mt.
We also do not have any concerns with respect to Loadline zone as we are not exceeding them.

Now let us consolidate the information we are obtaining from the stowage plan in a simple manner as shown below –

Cargo to be loaded at 1st Load Port Qingdao

So, at our first loading port Qingdao, the vessel is loading only in Cargo Holds 1,4,6,8 and 9. The below image for Stowage plan shows the data values as taken above –

Using the above image guide, we can now tabulate below the cargo which is planned for loading at Xingang.

Cargo to be loaded at 2nd Load Port Xingang –

BASED ON ABOVE TWO TABLES THE TOTAL CARGO TO BE LOADED IN HOLDS IS : 30330 MT 

In addition to above, the vessel is loading deck cargo of 52 trucks on top of hatch covers 11, 10, 9 , 8 and 7. This is shown in the stowage plan. This will be loaded when the loading is completed in holds 9, 8 and 7 and all hatch covers are secured. Also, Tween deck panels needs to be fitted in Cargo Hold No 4 and 8. This is also marked in the Stowage plan above. No cargo will be loaded in Cargo Hold No 10.

As you may note, this is a classic example of general cargo loading involving – steel cargoes (coils, plates and pipes), bagged cargo, bulk cargo and deck cargo. This will help us to understand and discuss the procedures and precautions in loading and securing these cargoes. However, the basic principle of loading, stowage and securing will always apply.

In our next blog we shall discuss about devising Final – Stowage plan using the loadicator basis above tabulated data.

Stay tuned.

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