This blog continues post series about PORT PERFORMANCE MEASUREMENT (FOURGEAUD, Patrick; World Bank paper), to contribute and establish management concepts related this issues and benchmarks.
2 - APPLICATION
2.1 - containers Container terminals performance depends on:
- ratio loaded vs. unloaded containers: empty boxes are not always included in the port statistics (they may be considered as other tare weights) but have to be handled;
- unproductive moves, i.e., the handling of all the containers that do not have to be unloaded but have to be moved: mostly empty and light containers and those containing hazardous materials, loaded on top or on the deck;
- the level of automation of the gantry-cranes; one of the limiting phases of the handling cycle is the time spent positioning accurately the spreader on a container (loading), or the container on a trailer, a MAFI trailer (specialized equipment used to shift containers within port limits) or a chassis maneuvering on the apron (unloading).
Most modern gantries are automated and equipped with anti-sway devices, and now, the problem is more the capacity to deliver or remove containers without delaying ship-to-shore operations.
- the average weight of containers and the proportion of containers requiring special attention: flats, liquid bulks, reefers etc.; and the mix of containers of various sizes: 20’/40’/45’ which will require to maneuver or change spreaders;
- commercial constraints; most of the lines calling at a port may have similar commercial constraints, leading to unevenly distributed calls.
Highest performance is observed during calls of large container-carriers loading and unloading a large number of containers, with balanced flows of full containers in and out; terminals dedicated to a single company can be highly productive (mainly East-West traffic).
Various analytical approaches have been proposed; in 1998, Drewry proposed linear functions of the vessel size and of the proportion of the ship’s capacity to be handled during one call.
(source: based on Drewry Shipping consultants: World Container Terminals 1997).As far as costs are concerned, and since containerization is a completely standardized process, it is widely accepted that there is a single benchmark for all terminals operating a main flow of containers in optimum conditions: about US$100 for all handling and storage costs from ship to gate. Practically, real costs may vary from US$ 80-90 in some terminals to more than US$ 400.
The case study below compares two different situations in order to demonstrate how different parameters may affect performances.
Case no. 1: ship size: 3rd generation and larger, length: about 300 m, calling for 1,000 containers or 1,500 TEUs, average load per TEU:10 ton, proportion of 40-foot containers: 50 %, proportion of empty containers: 10 %, 2 to 3 gantries per ship (3 gangs).
In that case, the capacity of the gantry cranes can be fully exploited: the commercial output can be 25 to 30 move / hour / crane in average.
According to the above assumptions, performances can be expressed as follows:
TEU f = TEU full TEU e = TEU empty
Ratios:37.5 to 45 TEU f+e /hour/gantry 34 to 40 TEU f /hour/gantry
94 to 135 TEU f+e /hour 85 to 120 TEU f /hour, 850 to 1,200 ton/hour
2 to 3 shifts are required
1 call / 2 days, 180 calls, 180,000 cts
2 calls / 3 days, 240 calls,240,000 cts
240,000 TEU f /year
[i] 320,000 TEU f /year
2,400,000 ton /year 3,200,000 ton /year
8,000 ton /year per meter of berth 10,600 ton /year/meter of berth
This computation presupposes that several berths are available; a one berth configuration would not be flexible enough and could not perform efficiently; as soon as ships are moored, stevedoring operations are supposed to start; they sail off at the end of commercial operations without delay.
Ratios higher than 10,000 ton/year per meter of quay length may be obtained: i) when large container carriers are fully loaded or unloaded; ii) if traffic and port organization allow to raise the berth occupancy rate without congestion; for example, with 6 calls per week, i.e., 300 calls per year, the ratio becomes: 13,250 ton/year/meter of berth.
Conversely, lower performances are recorded when smaller container-carriers call for a limited number of containers and have to handle many empty boxes (mainly North-South traffic).
case no. 2: ship size: 1st and 2nd generation, length: less than 250 m, calling for 700 TEUs or 500 containers, average load per TEU: 13 ton, proportion of 40-foot containers: 40 %, proportion of empty containers: 30 %, 1 to 2 cranes and 1 or 2 ship derricks (3 gangs) per call, 2 calls every 3 days;
Performance: 20 to 25 move/hour with gantry-crane, 12 to 15 move/hour with cranes or derricks,
With this new set of assumptions, the former expressions of performance are modified as follows:
Ratios:28 to 35 TEU f+e /hour/gantry 17 to 21 TEU f+e/hour/crane or derrick
62 to 91 TEU f+e /hour
20 to 25 TEU f /hour/gantry 12 to 15 TEU f /hour/ crane or derrick
44 to 65 TEU f /hour/
572 to 845 ton/hour
2 shifts are required
120,000 TEU/year per berth (cf previous case¹)
1,550,000 ton/year; 6,200 ton/year per meter of berth length.
This last result must be compared with 10,000 ton/m in case no.1; both examples correspond to different but well operated terminals.
2.2- break-bulk :Due to the wide range of products, ships, equipment, methods..., assuming an average performance for all kinds of commodities and packaging makes little sense:
- Specialized traffic like paper, frozen meat, fish or fruits should be studied separately, according to their packaging and to the type of ship and handling equipment (specialized or not); see appendix one, the case of fruit handling.
- Most commodities in big bags, pre-slung or pre-palletized loads, pallets, nets etc., can be handled with a crane; a good organization should adapt to a rhythm of one cycle every 1.5 to 3 minutes (20 to 40 moves per hour), depending on the nature of the cargo, the unit weight of the load, the ship’s size and other factors as weather conditions, tide and swell, etc. Whenever the volume of goods to be handled is large enough to allow for a reasonable cost recovery of additional equipment, special devices can be adapted to improve the unit load or to shorten the cycle.
examples:
cements bags: 2 ton pallets built in the hold or on the apron: 40 ton/hour/crane. Pre-palletized bags: 80 ton/hour/crane, and more with spreaders. Cement in bulk can be handled at much higher speed.
exotic wood: logs up to 6-8 tons, handled by the piece with hydraulic clamps: 120 to 160 ton/hour/crane. Logs handled with slings; less than 100 ton/hour; only in daylight.
2.3- dry bulk traffic
agri-food products / fertilizers :
These low-density products are transported in bulk-carriers ranging from small cargo-boats (5,000 dwt) to cape-size bulk-carriers used for basic products (100 to 130,000 dwt ships).
Handling of export products is operated mainly with conveyors, whenever possible, with performances varying from 100 to nearly 1,000 ton/hour per conveyor, depending on ship size, port equipment, product characteristics and density, brittleness, and environmental and safety considerations linked to dust.
Ship to shore operations of import products require cranes and hoppers (20 to 35 ton capacity - 150 to 300 ton/hour), or elevators (400 to 1000 ton/hour): two to three cranes per ship, or one elevator and two or more cranes on panamax and larger ships.
On the apron, small cargoes are generally loaded in trailers; large cargoes are carried through conveyor belts to warehouses or silos. High performance may be reached only if ship to shore operations are dissociated from commercial operations. Direct delivery alongside is the major cause of poor performance in bulk handling.
Ratios :
small bulk-carrier, 1500 to 3000 t shipment:100/120 ton/hour per crane: 2 cranes operated in one day .
from panamax up to capsize: 60,000 t shipment: 1 elevator and 2 cranes: 1,100 ton/hour, 15 to 18,000 ton/day operated in four days.
That performance may be reduced when operating multi-product cargo-ships. Some sticky, dusty or hard-to-handle products, such as manioc roots, impair the average performance. Brittle or dusty products may require lower handling rate for quality, safety and environmental purposes.
ore - coal : Export cargoes are usually loaded with conveyors; 1,000 to 2,000 ton/hour or more. Import traffic is handled with large gantry cranes geared with very large grabs: up to 1,000 ton/hour/gantry crane or with special devices. Same constraints, related to quality, safety and environment, may have to be taken into consideration.
Bulk-carriers ranging from the panamax to the cape-size: throughput: up to 15 to 20,000 ton/day.
2.4- liquid bulk traffic
Generally, unloading performances depend on the size of the ship which provides pumps and energy. They depend also on its viscosity, temperature, and on safety regulations, for hazardous products. Most liquid carriers are operated within one day, whatever the size.
throughput: 300 to 1,000 m³ /hour, up to 10,000 m³ /hour and more for very large tankers.
3 – THE LABOR ISSUE
The staffing issue is one of the most complex and its successful settlement is often a key factor in a port restructuring process. Some indications are summarized thereafter.
3.1- principles
Globally, transportation systems are increasingly productive, automatized and capital intensive. In all segments of the transport chain, direct employment tends to be reduced and more qualified.
As far as ports are concerned, the situation where old public organizations integrated many or all port-related functions, which ended usually in a too large and poorly managed workforce, limited or poor level of services and high operating costs, is changing.
Now, the private sector is increasingly associated in more efficient and competitive port operations, mainly through concessioning of infrastructures and privatization of services.
The result is reduced staffing at all levels, higher qualification requirements and improved human resources management. Conversely, better performing ports contribute to foster trade and develop national economies.
Whenever possible, first addressing the overstaffing issue will facilitate the involvement of the private sector[1].
Since this situation is often the result of governmental policies considering port organizations as natural shelters for an unemployed and unskilled workforce, the same authorities have definitively a responsibility in helping dismantle the system and make sure that the consequences are properly cushioned. This supposes that adequate budgetary means and staff management skills are made available early enough in the process.
The concessioning process generally starts with industrial bulk and container terminals, because these activities are easily standardized and can be operated efficiently and with profit. Other fields of the port activity have often more severe problems and excessive staffing levels:
- The remaining port activities depend more on local conditions; they are subject to variations, due to seasonal effects, meteorology, variation in packaging and handling methods, low frequency of some operations etc.;
- with less economies of scale, operators of non unitized general cargo and miscellaneous bulks cannot easily invest in modern equipment and methods and these activities are less often reorganized;
- the status of dock-workers placed under the responsibility of public authorities and hired intermittently by stevedores, once justified because of abusive practices, is still maintained in some countries; but, this organization, created to protect an undifferentiated low-skilled work-force in a context of weak labor regulations cannot evolve and does not correspond any longer to modern trends.
- In addition, some ports still maintain skilled workers and large workshops in order to undertake most or all of maintenance work; same thing as regards dredging;
- specific factors as social commitments of port authorities (health centers, housing etc.), inappropriate monitoring and tariffing procedures based on customs-like tax scales, are an additional cause of excessive administrative staffing.
The overstaffing issue is not easily addressed. Worldwide experience leads to recommend that the trade unions be brought to the negotiations table from the outset, when the reform program starts being devised.
Actually, the most valid way to build confidence in the process while incorporating in it lessons of experience and market-oriented concerns is to bring together port users, port labor and port and maritime employers. The objective is to allow all stakeholders to share common concerns about competitiveness of port services, and a better understanding of how any weakening of this competitiveness would be detrimental to all, and in particular to the workforce which would be the first to bear the consequences of reduced economic activity, both inside and outside the port.
3.2- proposed benchmarks
Port Authorities:
Some tentative benchmarks are proposed for Landlord Ports regulating a diversified activity, managing a proportionate public and private domain and not implied in commercial operations or services to ships such as pilotage or towage.
Size of the Port Authority Recommended staffing level
- small authority: a few millions tons: about 50
- average port authority: 10 to 20 M tons: from 150 to 200
- large ports: example: Rotterdam: 300 M tons: 1,100
More generally, an indicative ratio would be: 100,000 ton per staff per year, with large variations.
- small ports require more than this proportion, large ports are more productive;
- general cargo requires more staffing than bulk traffic.
Port operations
Containers:
The recent study by Drewry, cited supra, as well as other comparisons between efficiently run container terminals, show a relatively constant productivity of about 1000 TEUs per staff per year, for a large array of yearly throughput, from 150,000 up to 600,000 TEUs. This includes all staff: operational, administrative and management.
Bulks:
These operations require very few people: most automatized processes include large gantries and belt conveyors, that require only skilled drivers, a few supervisors and adapted crews for instant maintenance in hydraulics, electricity and automation. Additional staff are required occasionally, at the beginning, for preparation, and at the end, for trimming of remaining cargo, and for the cleaning of equipment.
Other operations (small bulks and general cargo): In most cases, licensed port operators have a diversified activity: handling of various commodities, shipping agency, freight forwarding, inland storage etc., that helps them balance the level of employment. Usually, they try to limit the level of unemployment, specially when the old system of guaranteed salary for dockworkers has been rescinded, but they cannot face peak periods. That may occasionally lead to operate undermanned ships, hire temporary workers for low skilled positions, differ storage operations etc. An average productiveness can be computed only as regards cargo handling (ship to shore), for a given commodity and handling technique. Some examples below show the large variation in productiveness[2].
Examples:
1) boxes in 2-ton pallets built in the hold (fruits, frozen goods etc.):
gang: total, 15 to 17 dockers, not incl.: transfer and storage crew, crane driver, maintenance staff; productiveness:
· 50 ton per hour > 3 ton /h / docker
2) pre-palletized boxes, handled with cages:
gang: about 13, including transfer, not incl.: storage crew / crane driver / maintenance staff; productiveness:
· 225 ton per hour > 17 ton / h / docker
3) exotic wood in logs, handled with slings:
gang: 12 to 15 dockers, not incl.: transfer and storage crew / crane driver / maintenance staff; productiveness:
· 80 ton per hour > 6 ton / h / docker
4) exotic wood in logs, handled with hydraulic clamps:
gang: 10 dockers, not incl.: transfer and storage crew / crane driver / maintenance staff; productiveness:
· 140 ton per hour > 14 ton / h / docker
Economic approach
Some modern ports have computed the global workforce related to the port activity, including handling operations, ship services and administration of both authorities and private sector: these figures relate to the port communities and are used in economic studies.
Some examples:
· Rotterdam (1997): 300 M tons about 25,000 jobs
· All (25) French Ports (1995): 275 M tons about 35,000 jobs
NOTES:
[1] Loaded containers; this ratio does not depend on the hourly performance, except from a commercial standpoint.
[1] Some concessions have been granted even though this problem was not solved, concessionaires being requested to hire all existing staff and, if possible, solve the problem later. This results usually in high operating costs as long as the problem is not settled and, afterwards, depending on the financing scheme.
[1] The staffing level of a port system depends on its organization and the way labor regulation are enforced. In the old system with dock-workers under public management, the number of positions in a gang did not usually take into account the productivity of modern handling methods, which might result in a lack of gangs in case of peak activity, even though there were too many dock-workers according to modern standards.
Conversely, dock-workers having a low effective workload may look for overtime pay and try to double shifts. Night shifts, as well as week-end work, may require additional staffing for the same output, depending on existing regulations and the way they are enforced.
Next post we’ll continue Part III.
porte marítimo mundial de cargas, a partir da década de 1960, modificou o perfil operacional das empresas de navegação e da atividade portuária. De um lado, a oferta de serviços de transporte marítimo de contêineres tornou-se progressivamente concentrada devido à necessidade de vultosos investimentos para a aquisição de navios especializados. Além disso, as empresas de navegação expandiram sua atuação passando a oferecer o transporte nos trechos terrestres, prestando serviços logísticos porta-a-porta.Para os operadores portuários a principal modificação advém do acondicionamento das cargas nos contêineres que pode ser descentralizado e realizado na origem das mercadorias, nas fábricas, ou por meio de serviços especializados, dentro ou fora das áreas dos portos. Como resultado, o tempo necessário para transportar as cargas no porto e embarcá-las nos navios foi reduzido substancialmente.