Fig:Self unloader discharging stone cargo
The vessels draft with the density, and restriction of depth is also to be declared on arrival at the
The rate of loading or discharging will be stated as a figure per working day, or the actual minimum
rate, or to the ground in the case of the vessels rated capacity to discharge. If the Master determines
that the vessel is in any way unable to achieve this rate, he must notify the relevant Management office
immediately with the reasons.
The voyage instructions will contain concise information regarding, grades quantities, the sequential
order of loading, segregation, the verification of sensitive, and optional quantity grades, the latter
ideally being used for trimming.
The sequence of discharging of the various grades must be established and followed. The procedure at
a change of grade is to be strictly adhered to. When submitting the loading plan to the shore terminal,
agreement to the figures planned by the terminal must be ensured, and also that they have not
changed any figures or grades which will require revision of the loading plan. The relevant
Management Office must also be notified, and the loading plan prepared again to the satisfaction of the
The bill of lading
The Bill of Lading sometimes used in the self unloading vessel trade may be of format agreed upon by
the Owners, Shippers, and the Charterers. If the Master is in any doubt regarding any aspect of the Bill
of Lading, he must contact the relevant Management Office before signing the same. Letters of
Indemnity are not used in this trade, and the Master must contact the relevant Management Office if
one is issued.
The Owners have expressed that their customers on the USA coastal trade are known, and the Master
must not await the signed B/L and other instructions before releasing the cargo. This is a non-standard
procedure, and if in doubt the Master is to contact the Company or Owners for clarification.
The reasons for the vessel listing during cargo operations may be as the result of:
- Uneven ballasting.
- Water re-entering a stripped tank owing to a faulty valve.
- Uneven discharging, due to faulty listometer lights.
- Transfer of bunkers.
The cause for the vessels list must be ascertained, and corrected immediately.
Increase in draft due to list
On arrival at the discharge port, care must be taken not to list the vessel, when swinging out the boom.
The heeling tank (or Wing Tank) on the opposite side must be gradually filled in as the boom is being
slewed out. Double bottom tanks, which will cause more of a bodily sinkage, than a list correcting
effect and thus increasing the vessels draft, must never be used.
Segregation of various grades ( Discharging )
Prior to arrival at a discharge port the entire SUL system, and its associated structures, and in particular
areas where vibration may bring down a previous cargo residue, must be thoroughly inspected and
The system is initially to be run empty onto the main-deck , to ensure that it is clean.
The discharging plan/sequences must be accepted and approved by the receivers (terminal). The
vessel is required to provide clear instructions to the Shore Terminal of any change of
grade and to receive clear acknowledgement from the Shore Terminal to do so.
The Shore Terminal will require some time to prepare for the change of grade. The vessel must run
the system empty for 15 mins between grades, and visually inspect that no previous grade is observed.
The gates of all holds must be shut and isolated with no leakage. The hold gates for the next grade in
sequence must be identified and marked. It is the responsibility of the Chief Officer and Duty Officer to
ensure that the correct gates are being operated.
An independent surveyor may be employed at a change of grade, however, it remains the responsibility
of the Master to ensure compliance. You are to wait for directions from ashore before starting the next
grade. When cargo dividers are set on open pads, care must be taken to keep within the dividers to
avoid mixing onshore.
If for any reason it is felt that a mixing of grades or contamination by other grade has occurred, the
relevant Management Office must be informed immediately. The agents and P & I will then be put on
The stages of SUL discharging:
- Understanding the voyage instructions and preparing the discharge plan.
- Inspection of the SUL system followed by trials.
- Completion of Discharge Preparation (Deck)
- Positioning the Boom, and compensating for list.
- Dipping sequence, starting with gates fore and aft.
- Main Discharge, as per discharge plan.
- Ballasting as per plan
- Regular inspection rounds of the SUL system.
- Draining and Cleaning Out.
- Clearing Hang-Ups as required
- Completion of Checklist handover each watch.
- Inspection of the SUL system to be in accordance with the planned maintenance system
Tie downs, locking pins and wire pendants with bottle-screws, are all to be used to secure the boom
when stowed. The boom locking pins provided on the parking bolster, have sensors that complete an
electrical circuit when the boom is locked in the stowed position. This is a safety arrangement so that
the boom luffing pump motor will not start, until all the locking pins are removed. This is not entirely
foolproof, and a visual check must be made by the Chief Officer, and the Electrical Engineer. There is
no such safety system on the wire pendants, and care must be taken to ensure that they are free and
clear.Read more on general precautions for boom operation & safety
Discharging to the ground
Discharging to the ground means discharging as fast as possible to an open pad, or a designated area
on the shore. These designated areas, spaces or pads may be areas of limited weight bearing ability
and the maximum height of cargo above the ground must be ascertained. This area may also have
limited space, and cargo will be spread using bulldozers, therefore care must be exercised to avoid an
overflow into the water or river.
When discharging different grades to the ground, the piles of different
grades must not touch to avoid commingling and possible claims. The Shore Personnel are to be
requested to provide dividers, or a method of separation. For open pad discharging, the Chief Engineer
is to set the rate to the best possible with regard to the restrictions or limitations if any, of the vessels
SUL system. If no limitations exist, the open pad discharge provides an idea of how efficiently the
vessels SUL system is running.
Discharging to the Shore hopper
Discharging to the Shore Hopper means discharging to a shore facility consisting of a hopper, and
associated conveyor systems. This type of discharging is limited by the maximum rate that the shore
facility can cope with. Many shore hoppers do not have baffle plates at their feeding end, and thus do
not lay the cargo on the belt at a steady rate. The weight of the cargo in this kind of shore hopper will
bear onto the conveyor belt directly and may cause an overload. It is important that the rate of
discharge is gradually increased up to the maximum that the hopper can take-away.
An attentive radio watch must be maintained to listen for any shore requests to stop. The ‘umbilical
chord’ may be activated by Shore facility personnel to stop the ships hold conveyors, however, the
cargo which is still on the conveyor belts may run out before the system stops. This will further
overload or plug the shore hopper, and cause further delay. It may have to be agreed to stop the
ships system by tripping, and retain the cargo on the ships belt if the required rate of discharging has
been low, and the load on the ships belts is well within safe limits.
Discharging to barges
Discharging to barges is carried out in ports where there is no space available on the ground, or where
the cargo has to be taken away to remote places. This kind of discharging, or loading the barge, is
carried out by a ‘Barge Loading Master’ who is an expert in loading barges.
The ships responsibility is mainly to maintain an agreed safe rate of discharging as required by the
‘Barge Loading Master’ and to position the Boom also as required by him. The ‘Ship/Loadmaster’
Checklists will have to be completed. It is often stated on the Checklist and acknowledged by the
Barge Loading Master’s, that the vessel will not be held responsible for loading the barge and that the
vessel is indemnified.
The Vessel’s Master must contact the relevant Management Office if any fault or
claim is brought against the vessel, and he must not sign any such document of acceptance. The
Vessel’s Master is to inspect, note and obtain acceptance by the barge of any damages that may be
caused by the barge to the vessel. Adequate fendering must be provided in advance.
Ship to ship stransfer
Ship to Ship Transfer, is a lightering operation between two bulk carriers, one of which or both may be
of the self unloading type. Transfer of cargo using the SUL-boom, is easier, when one of the vessels
has an articulated Boom. Such an operation requires written orders from the Owners and the
Charterers, who must also ensure that adequate fendering is made available, and the Master must
ensure that this is carried out. It is a manoeuvre which requires planning and extreme caution.
Our detail pages illustrated many safety aspects of Bulk carrier
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Operation of sea going bulk carriers involved numerous hazards . Careful planning and exercising due caution for all critical shipboard matters are important . This site is a quick reference to international shipping community with guidance and information on the loading and discharging of modern bulk carriers so as to remain within the limitations as specified by the classification society.
- Self unloader components
Function of loop & bucket belt elevators
Self unloaders various cargo handling gears
- Various type boom conveyor belts - How the belt sytem practically works ?
Dealing with self unloaders stalled lift belt
Conveyor belt construction & troubleshoot guide
Conveyor belt installation guide
Conveyor belt repair & maintenence guide
Safe working practice onboard self unloading bulk carriers
- Preventing conveyor belt fire onboard self unloading bulk carriers
- Cargo work safety precautions
- Various bulk cargoes - free flow ability
- Various bulk cargoes & dealing with cargo hang ups
- Navigation in
Ice & safety precautions
- Dust suppression procedure & environment protection
- Preparations for cargo planning, handling & stowage
- Maintaining safe stability onboard self-unloading bulk carriers
- Procedure for bulk cargo handling prior to and during loading
- Loading operations - voyage orders, draft restrictions, various grades and rates
- Loading sequence and other related considerations
- Self unloaders discharging operation
- Safety precautions for boom operation
- Directing gate operation, gate problems & crew duties
- Cargo holds/ tunnels cleaning, maintenance and check items
- Procedure for transporting coal on self- unloading bulk carriers
It is vital to reduce the likelihood of over-stressing the ship's structure and also complying with all essential safety measures for a safe passage at sea. Our detail pages contain various bulk carrier related topics that might be useful for people working on board and those who working ashore in the terminal. For any remarks please
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