Wilczyński P.
Maritime University, Gdynia, Poland
Abstract: Transport and storage of containers containing dangerous cargo or hazardous wastes cause serious danger to port areas, to ships mooring alongside and people working in port companies, to the nearest vicinity and also to the natural environment. Proper conditions have to be created to reduce the number of accidents with dangerous and hazardous materials inside port areas, where they are loaded, discharged, shifted and stored. Only proper management and coordination of the container's movement allow to achieve good level of safety and security in port terminal. This problem may be solved by using model of mass service theory as a tool for the control and coordination of the movement of containers containing DG and to reduce possible occurrence of danger.
1. Introduction
The containerization is today one of the multimodal transport technologies, which is still in very fast progress. The number of containers being handled is still rising in all sea container terminals all over the world. The rising tendency has been at the same level for the past few years, and the forecast for the next years indicates further increase in the number of units handled in sea ports both these bigger ones and also these smaller. The latter are very important local logistic centers. Diagrams bellow show the quantity of TEU handled in different ports within one year over the period 2000- 2004.
Fig.1. Quantity of TEU handled per year in export, import and total in select European ports [5, 6, 7]
This number of handled containers only in port terminals shows the growing importance of containerization as means of delivering cargo ‘door to door’.
Vulnerability of cargo for containerization and development in building and equipment of new containers caused that wide variety of general cargo is carried in containers. Among different types of general cargo which may be transported in containers are dangerous goods – later called DG. They are carried in specialized units specially designated for this purpose according to different physical and chemical attributes of these goods in order to avoid danger during transport and storage.
1.1. Legal conditions concerning transport, handling and storage of the DG
Sea container terminal are logistic centers where container units may be transported by different means of transportation, for example by:
ships - technologies lo-lo, con-ro, ro-ro, barges,
railways, road transport.
For each type of transport there are international rules concerning safety of transport of dangerous cargo and for:
sea transport - Convention SOLAS 1974, IMDG Code, International Maritime Dangerous Goods Code),
railways - Convention RID, Regulation to the International Transport. of Dangerous Goods by Rail,
road transport - Convention ADR (European Agreement Concerning the International Carriage of Dangerous Goods by Road)are used respectively.
All a/m Conventions comprise the main sources of international rules in transport of dangerous goods and have the same aim- improve safety in their transport. Unfortunately, so far any international rules for handling and storage hazardous cargo in port terminals have not been introduced. Instead of them many container terminals use IMO
GATES - IN & OUT
in the structure of the port, its infrastructure and equipment which have direct influence on the service of dangerous cargo.
Not all classes of DG may be handled and stored in port areas because of the infrastructure of container terminals and their location in ports. For some classes of DG there is also restriction concerning the amount of cargo being both handled or stored even in a single operation. Part of hazardous materials with physical and chemical properties likely to cause risk or danger for terminal during their storage have to be loaded on other means of transport and leave the port area as soon as possible. Due to large risk of danger, storage of a/m goods is prohibited. It is permissible only to transship such cargo directly from ship to other means of transportation- so called ‘direct handling’. Organization of these operations leads to improprieties caused by different reasons. For example:
improper circulation of information about the cargo, incorrect organization of handling operations,
failure of the handling equipment and means of transportation or delay of the means of transport,
preparation of improper or wrong means of transportation, failure or damage to the container carrying hazardous material.
2. Container terminal overview and proper way of stowage of DG in
containers in port area
Owing to handling operations, Container Terminal (Fig. 2) is divided to several sectors, which are designated for special aims. Terminal consists of sectors designated for: storage of containers - storage area sectors A, B, C - T,
handling of the units - handling area along HELSKIE QUAY, in the vicinity of terminal gates, and railway terminal,
stuffing container units - WAREHOUSE M25, WAREHOUSE R25, control and verification of container's data - terminal gates.
Fig.2. Plan of the container terminal – Baltic Container Terminal Gdynia [5]
Position designated for storage of containers containing DG of different IMO Class should be assigned according to IMO Class, prepared properly and secured to eliminate risk of danger to minimum. Distance between two incompatible cargos in two different containers is very important and cannot be neglected.
Recommendation from IMDG Code - Chapter 7 Segregation is used as the guidelines in such a case (following numerous publications). These Recommendations deal with segregation of containers containing dangerous cargo on board container vessel - "on deck stowage"[1].
The figure below shows, recommended by IMO, proper way of segregation of containers with dangerous cargo on storage places inside terminal. In the container storage area every first position of the odd-numbered lanes is dedicated for the storage of a container with dangerous goods. The lanes are marked with striking red triangles.
The containers are always placed with their door to the roadway and never stacked on top of each other[3]. Sectors for storage of containers with DG should be adapted properly. Most of DG require unchanging and special voyage conditions that is why storage areas for these type of DG have to be equipped with power supply, refrigerating or fire-fighting installations.
Other example of special treatment of DG is storage of chemical liquid of IMO Class 3 and 8, which are also marine pollutants. They need special place of storage. Where practicable, wherever such substances are present in the port area, suitable means should be used to prevent these substances entering into the soil, water areas or drainage systems. This also applies to pipe and conveyors bridges. In other areas other means, such as absorbents, should be available for use in case of an accidental spillage [3].
Explosives should not be permitted to enter the port area unless regulatory authority has granted permission to handle explosives. For this type of DG, which have to be handled directly from ship to others means of transport have to be designated special areas. Any such site should be fenced off to prevent entry of unauthorized persons and should have facilities for watchman, including adequate means of communications [3].
enable, in a simply way, to coordinate and control flow and storage of DG containers on the port premises.
Fig.3 Segregation of the containers with DG on storage area [3]
3. Container terminal as a system of mass service
Container terminal together with its infrastructure creates a System of Mass Service, later called SMS where the applications are served. In this case application is one container with DG. Containers with DG are served according to certain rules in compliance with local law. In view of specific properties of DG we cannot assume that each entry to the
182 183 184 185 186 187 188 189 190 191 192
Roadway Roadway Roadway
20’ foot container with dangerous goods 20’ foot container without dangerous goods 182 Number of ontainer’s line
Place for container containing dangerous goods
x 1 e x A
1
1/ 0
x e xd asystem will be the same, because the rules of the organizations of service are different and depend on:
local rules,
restrictions due to terminal equipments, and infrastructure,
These factors cause that stream of entries (containers) from ship will be operated in a different way than the stream of entries coming from the means of land transport. It is very difficult to imagine this situation during normal work on a ship that because of only one container with DG a ship would have to be anchored on road, because either the terminal or the receiver were not ready to pick up the unit or there was no place in the storage area designated for this cargo. And when this unit containing DG would enter the terminal it would cause risk or danger in port area and leaving this unit on board the ship until the completion of discharging of containers would be against local law and port regulations. Such a scenario will never take place. Containers with DG are never discharged at the end of discharging operation. In every case containers with DG have priority and are discharged from ship at the beginning of the unloading operations because it is easier to control the delivery of container by means of land transport than to stop the ship and delay the ship’s entry to the port. Therefore the discharging operation on a ship is very important moment in the organization of the work on a container terminal.
The service of the container containing explosives IMO Class 1 is the most spectacular example. To describe this service we may use SMS because during discharging and later we can observe elements which are characterized by SMS.
enter application to system - stream of entry, container = application, beginning of the service,
canal of the service - handling equipments, means of transport, rules of the service - local law, restriction in turnover of cargo,
time of the service for one application - from discharging from ship to the exit from terminal gates,
exit from system - exit from terminal, end of the service.
Discharging of the container containing explosives from a ship and its entering the terminal may be treated as stream of entries - applications. Stream of entries to the system is Poisson stream because the analyzed number of applications over a certain period of time may be regarded as
(1) where, A cumulative distribution (probability) function is the value of the distribution of the length of the period time between the appearance two following entries with the same DG.
Average time “a” passes between two following applications - containers with DG described by the formula below.
stream λ' and λ are equal [2].
Same rules apply during handling operation, what we can describe as the rules of the service. Rules of the service are constituted by local law and technical norms approved by local authorities defining the sequence of discharging the cargo and further way of treatment. A certain period of time passes from the beginning of the service of the container with DG to its end. It is the entire time of the service of one application -container. All the periods of time between particular stages of the service of application are constant and depend only on the possibility and efficiency of the handling equipment and the terminal’s own means of transport.
The observation of the handling operations indicates that we can assume that the average time of the service of one container is constant - deterministic. If the value of time of the service is much different, longer than the average time, we can state that the canal of the service failed or that random disorder connected with the equipment which was used for this service took place.
The container entering this system is served by a single canal of service, called later SC which is made up of cargo handling equipment and means of transport. This SC is busy when this service is carried out. That is why possible damage to this SC may take place during this service [2].
Failure of the equipment or any random disorder observed at any stage of the service causes that the time spent on this service is longer. Port regulations concerning handling of DG make it compulsory to replace the faulty or damaged equipment with good ones and to continue the service of a given application.
The service canal – all the facilities/equipment used in the service /system have their own Weibull random order of work describing the probability of the occurrence of failure during their work/employment [2].
DG – following the port regulations explosives when discharged from a vessel have priority in queuing and are therefore served first. They cannot be stored within the port premises so they leave the port first. It means that the service of the container units with explosives may apply the rule FIFO – first in first out, which is applied to queuing, i.e. the
way the applications-containers are served [2]. The queuing problem describing the service of the container with explosive material can be presented in the following way:
SMS - M / D / n / f i
j (3)
where:
M - the Poisson entering stream of applications,
D - average time of service of a single application, constant- deterministic, n - a single service canal,
f i
j - rules of service,
i - rules of service, j - rules of queuing.
4. Conclusions
The infrastructure of the Polish container terminals enables efficient service of the amount of the container units which are handled there at present. The situation in which the number of containers handled in Polish container terminals increases then there will be a demand for an estimation of the maximum number of applications which can be served. The rising tendency of the number of the containers handled will call for appropriate equipment and cargo handling facilities and also infrastructure to meet the new requirements [4].
The model of mass service theory can be used to solve this problem, still the properties of DG and the port regulations governing their transport and handling in the terminals should not be forgotten. The described model can only be applied to the description of the service of a container unit (with explosives) discharged from a vessel which is directly transshipped on road means of transport because the same rules connected with the service cannot be applied even to the same type of cargo due to different law and port regulations). Adapting the mass service theory for the description of handling the containers with DG in the port terminals will help to assess the proper work of such terminals, that is the probability of proper service of application-container and to indicate the possibility of the failure of the service system when the application is being served as well as to show the probability of its loss.
References
1. IMDG Code” International Maritime Organization, London, 2004. 2. Obretenow A., Dymitrow B.: Teoria masowej obsługi. PWN, 1989.
3. Recommendations on the safe transport of dangerous cargoes and related activities in port areas. International Maritime Organization, London, 1995.
