Dealing with Cargo Hang-Ups
- Hammering on hopper sides.
- Using vibrators.
- Using fresh water hose from the gate-side or hold side, this being subject to written
permission being obtained from the consignee, and informing the relevant
Management Office and Owners accordingly.
- Air-lances, using compressed air from gate-side or hold-side.
- Complete the checklist for man-entry and carry out the man-entry procedure.
- The cardox system. NB Use of Cardox System is prohibited without prior approval
from the management office.
Note the following for CSL / Marbulk vessels:
If hang-ups are encountered during discharge and vibrators and hammering have no effect, then
the CSL office contingency team must be contacted in order to obtain further expert advice with
respect to procedures and to liase with the customers at the discharge port.
For vessels calling at Point Tupper it should be noted that the following preventative measures are
to be adopted in order to avoid hang-ups of gypsum during the winter season:
The Cardox System:
- Hatches not in use are to be kept closed during extreme cold temperatures
- Loading is to be stopped and further advice obtained if large pieces of frozen cargo are seen
to be loaded
- The fresh water availability at discharge port, vessel capacity and onboard equipment to be
- If possible an agreement to be reached with the discharge port customer to use fresh water
as an emergency measure to deal with hang-ups.
IMPORTANT: When discharging GP
Gypsum, permission to use fresh water is to be obtained from the Plant Manager and his
presence onboard is MANDATORY when using water.
- Hold plastic sheeting is a vital factor and therefore is to be properly maintained with any
damaged sheets replaced and allowance made for a sufficient stock along with tools to be
- For all load ports, vessels loading wet gypsum are to give advance notice to the Boston
office that possible cargo hang-ups at discharge port could be expected. In such cases the
cargo and weather conditions are to be included in the Statement of Facts
The Cardox system is a potentially lethal method of clearing hang-ups and is only to be used with
office approval and after a full risk assessment has been made.
The cardox system was developed in the United Kingdom during the 1920’s for use in coal mines
where there was a high methane content in the coal. It uses the rapid expansion of carbon dioxide
gas as an explosive force to break up large masses of material. The system consists of steel “shells”
which are rechargeable. The shell consists of three sections:
- Activating head.
- Main CO2 Chamber.
- Discharge Cap.
The main CO2 chamber has a heater or detonator fitted at the upper end which has to be replaced
after an explosion. The heater is connected electrically via the activating head. It is very important
that the electrical connection of the heater is checked for continuity before the shell is charged, as
the shell will not explode if the circuit is incomplete.
Between the lower end of the main chamber
and the discharge, a bursting disc cap is fitted, which has to be replaced after each explosion. The
shell has to be fully assembled, weighed and the weight recorded and then placed into the charging
stand where it is connected to a charging pump. The charging pump is in turn connected to a CO2
bottle. The charging pump has a pumping ratio of 60 to 1, (which means that very high pressures
are involved inside the Cardox shell). The charging valves can then be opened and charging can
commence. Charging is complete when the charging pump stalls (usually after 2 to 5 minutes). If
the charging pump does not stall the CO2 bottle is becoming depleted and should be changed for a
The charging valves are closed and the shell weighed again. The weight of the shell
should have increased by 1.25 KG (full charge) although 1.10 KG is acceptable. Any less than this
will result in a failed charge. The shell is then ready for use.
When using the cardox system it will be necessary for all “cargo hold man entry” precautions to be
carried out. The cardox shell is most effective when a hole is drilled into the base of the hang-up.
The hole must be deep enough so that the charge is buried with only the activating head visible. A
length of heaving line is to be tied to the eye bolt in the activating head as the Cardox shell drives
itself forward into the pile when it explodes. The heaving line will make retrieval of the shell much
easier after the explosion. The two electrical conductor wires are then connected to the length of
blasting wire and the man entry team retreats to a safe distance.
The team must either leave the
cargo hold together or take cover in an empty door away from the hang-up. The electrical
detonator is then, and only then, connected to the open end of the blasting wire. When it has been
ascertained that everyone is aware that the Cardox is set to explode, and has taken cover, the
detonate button may be pressed.
The Cardox shell will emit a powerful explosive force, which is capable of shifting up to two tonnes
of material. Several Cardox shells can be connected together in parallel, and detonated
simultaneously to create a larger effect on the hang-up. All spent Cardox shells must be retrieved
from the hold so that they cannot pass though the gate onto the belt system.
Precautions Against Hang-Ups:
- Ensure UHMW lining is in place.
- Vibrators are operational.
- Close the hold immediately on completion of loading.
- During discharge, it is important to avoid breaks in the flow of cargo through the gate.
When the cargo at a gate shows signs of finishing, then the adjacent gate should start to be
opened, avoiding any overloading of the belt, by maintaining a relatively small flow.
Our detail pages illustrated many safety aspects of Bulk carrier
Home page |||Bulk carrier types
Handling of bulk coal |||Cargo planning
Carriage of grain
|||Risk of iron ores
|||Self unloading bulk carriers
|||Care of cargo & vessel
|||Cargoes that may liquefy
|||Suitability of ships
|||Ballast handling procedure
|||Bulk carrier safety
|||Fire fighting systems
|||Bulk carrier General arrangement
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
- 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
- Preparations for discharging & related guideline
- 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
Copyright © 2010 www.bulkcarrierguide.com All rights reserved.