Th e Analysis of the Possibility to Improve the Effi ciency of Container Transport Via the Oder Waterway with the Use of the RIS System

The topic of this article is the analysis of the possibility to improve the effi ciency of container transport in two layers via the Oder Waterway (pol. Odrzańska Droga Wodna ODW) with the use of the RIS system (River Information Service). Taking into account the fact that the number of containers shipped during one voyage depends mostly on the construction of the vessel on which they are transported and on the technical parameters of the waterway, especially transit depths and bridge clearances, the article presents the results of the analysis of inland vessels used for transporting cargo on the ODW (pol. Odrzańska Droga Wodna), which – in view of the current state of fl eet – best accommodate container transport, i.e. pushed convoys consisting of one Bizon III pusher and two BP- 500 pushed lighters. Additionally, the study includes the probabilistic analysis of water levels, carried out based on historical data obtained from reliable water gauges during the 1990-2015 period by the Institute of Meteorology and Water Management, which determine navigation conditions. This allows for determining the probability of passage of a loaded vessel under certain critical bridges, i.e. bridges limiting the navigation due to their inadequate clearance and making it impossible to perform transport tasks on certain sections of the waterway. The further part of the article synthetically presents the possibility to utilise the RIS system (River Information Service)


INTRODUCTION / Uvod
The profi tability of inland container transport is primarily determined by the reliability and timeliness of the transport service provided. This is due to the fact that inland navigation is one of the most cost-eff ective means of transport, especially if the transport costs include external costs of transport (e.g. congestion, noise, accidents, environmental pollution).
The possibility of transporting cargo via inland navigation is largely determined by the operational parameters of waterways, which depend mainly on the class of the river. Required parameters for each class are described in detail in the Regulation of the Council of Ministers of 7 May 2002 on the classifi cation of inland waterways (Journal of Laws Dz. U. 2002 No 77, item 695). Those parameters are, however, purely theoretical as in many places the requirements have not been met, which has been proven by multiple analyses (e.g. reports of the Supreme Audit Offi ce). Hence a number of academic papers concern the limitations of providing inland waterway transport due to poor technical condition of waterways (Ekiert 1981a;Ekiert 1981b Contrary to other EU countries, Poland has virtually no containerized cargo transport by inland waterways (GUS 2015, Kulczyk & Skupień 2010, Woś 2005, Hann & Woś 2016 and that is despite the fact that the fi rst attempts to transport containers (standard, type 1C) from Polish inland ports took place as early as 1979. In his article (Krautwald 1981) the author describes the results of practical tests for the transport of containerized cargo on the ODW using vessels that are still in service today. The author also indicates that a pushed convoy, consisting of a pusher and two BP-500 barges, is the most suitable for transporting containers on the ODW. Subsequent studies from 2010 (Kulczyk & Skupień 2010) justify using container transport along the Oder River from an economic standpoint.
It is a widely held opinion that the transport of cargo in two layers (which determines the profi tability of transport) is not possible due to low bridges (Pluciński 2016), even though in 2014 a research experiment was conducted -the so-called "truth cruise", whose purpose was to prove that the transport of two layers of containers on the Oder Waterway is possible. However, the results of this experiment were considered disputable by the navigation community, mainly due to the desire to upgrade the ODW class. The critics have argued that the "truth cruise" was carried out only once, at a selected time of year, with a favourable attitude of the waterway administration, which, for example, enabled the vessel to overcome bottlenecks and thus complete the cruise thanks to additional, non-standard water discharges.
The need and possibilities to include inland navigation within the intermodal transport chain are a subject of many publications One of the few publications on probability analysis and reliability testing methods in water and inland waterway transport (Gucma 2013) presents the problem of collisions of vessels with bridges in detail. In addition, the author presents the risk analysis of a vessel collision with bridges, risk assessment and criteria for its acceptability as well as models and methods used to estimate the probability of a vessel collision with a bridge. The conclusion about the need to forecast container transport conditions on the ODW, based on statistics of water levels, is presented in a monograph (Hann & Woś 2016).
In addition to works aimed at improving the technical parameters of the waterway, activities are carried out to improve the effi ciency and safety of inland waterway transport. In 2013, a pilot system of harmonized river information services (RIS) was implemented on the Lower Oder, which allows for better organization and management of transport on inland waterways and optimization of the use of existing fl eet and infrastructure. Until now, however, there has been no comprehensive research on the possibility of using the already implemented system to improve the reliability of container transport by the Oder Waterway due to the passage of inland vessels under bridges.
The article is a synthetic summary of the research results of this issue for the Oder Waterway from Kędzierzyn-Koźle to Szczecin, described in detail in the doctoral dissertation entitled "Probabilistic analysis of a transport system using two layers of containers via the Oder Waterway (ODW) with the use of the RIS system". In the above-mentioned doctoral dissertation, 6 variants of container masses were analysed: -medium weight containers -10.9 t, -containers lighter by 1 standard deviation from the average -7.9 t, -containers heavier by 1 standard deviation from the average -13.9 t -empty containers -2.25 t, -very heavy containers -24 t, -optimum containers when the barge's draft is equal to the pusher's draft (for most bridges) -20.94 t. The article discusses the results of the analysis of containers with a medium weight, i.e. 10.9t.

CHARACTERISTICS OF THE ODER WATERWAY / Karakteristike vodenog puta rijeke Odre
The Oder Waterway, although it is the best developed waterway in Poland, in terms of its adaptation to navigation needs remains a shipping route of regional importance, with navigability class parameters from I (lowest regional class) to III (domestic navigation class) on the majority of its length. Only a few short sections of ODW (pol. Odrzańska Droga Wodna) have the highest classes IV and V, i.e. international shipping classes. In addition, the existing river infrastructure is not adapted to transport needs and, due to insuffi cient maintenance works, it is also prone to damages.
The following table shows the technical requirements for waterways of particular classes. It should be emphasized, however, that many sections of the Oder Waterway, despite having a certain navigability class, do not meet all the technical parameters resulting therefrom (e.g. in the Szczecin Water Junction, the Oder River has the highest class -Vb, excluding the railway bridge in Podjuchy, which does not meet the requirements of minimum clearance under the bridge).
The analysed section of the Oder River, i.e. from Kędzierzyn-Koźle to the marine port in Szczecin, due to the diversity of structures and operational parameters, can be divided into the following navigation sections: Additionally, 61 bridges intersect the ODW on the analysed section. 14 of them can be considered dangerous because their clearance is less than 400 cm at HNWL 1 .

RIS SYSTEM / RIS sustav
River information services support inland waterway transport to make it a sustainable mode of transport. RIS improves the competitiveness of inland waterway transport and contributes to the overall objective of making inland waterway transport a safe, effi cient and environmentally friendly link in the logistics chain (PIANC, 2018). It is a widely understood service packet, with various services that are aimed at optimizing traffi c and transport fl ows.
There is no one commonly accepted defi nition of RIS in Europe. Each country decides to what extent it will implement the RIS system. For example, in case that ship reporting in inland navigation is required by national or international law, then also the Member State needs to support electronic reporting. In the present IWT market, ship reporting is not common but limited to certain operating areas and types of cargo. It is at present only obligatory for the Netherlands, Belgium, Germany, France (only Rhine river in container transport), Luxembourg RIS (River Information Service) is an information system based on the harmonious interaction between three elements: devices, software and operators. The link connecting all these elements is a communication system, both wired and wireless ). Thanks to this system, it is possible to increase the safety of navigation and its effi ciency. RIS also modernizes the exchange of information between waterway administrators and users. RIS systems use common systems to connect pilots, transport companies, operators of lock, ports and terminals, RIS operators, and waterway administration and emergency services. They also allow better law enforcement and collection of statistical data and they facilitate the calculation of port fees and waterway toll charges.
Four basic technologies are used to provide RIS services (Ch. Plasil, 2011): Additionally, data displayed on dedicated devices can also be integrated with information obtained from the AIS system (Automatic Identifi cation System) (e.g. movement of other ships), NtS navigation messages, hydrometeorological sensors, vessel's GPS data.
The following fi gure shows the diagram of the RIS system in Poland.
The RIS system was implemented in Poland only on a short, estuary section of the Oder River. The need to implement harmonized river information system on the Lower Oder by the end of 2013 resulted from the provisions of Directive 2005/44/ EC of the European Parliament of September 7, 2005. According to the directive, the member states of the European Union were obliged to implement the RIS system on all class IV (and higher) waterways if they connect with other waterways of the same standard. In Poland, only the lower section of the Oder River meets all these requirements, hence the obligation to implement the system.

RESEARCH METHODOLOGY / Metodologija
The aim of the research was to determine the reliability of container transport in two layers via the Oder Waterway and analyse the possibility to improve the probability of a vessel's passage under selected bridges by using the RIS system to support vessel's captain decisions during the loading and ballasting of the vessel.
A pushed convoy was selected for testing the transport system in two layers, which was structurally adapted for navigation on the Odra Waterway, i.e.: -Bizon III pusher -a single-deck motor river pusher, which constitutes the basis of the Polish fl eet. The unit of this type was designed over 50 years ago, in 1960s/1970s; -two BP-500 barges -each barge allows the transport of up to 15 20-foot containers (type 1C) in two layers. The nominal barge draft is 1.6 m.
The following simplifying assumptions were adopted in the analysis: -the draft of the vessel and its height above the water level (in the case of a barge measured with the load) is constant for the pusher, and for the barge it depends on the weight of the transported load and possibly on the use of ballasting system. -the mass of cargo on one barge is the product of (assumed for a given vessel) the average container weight and the number of containers, i.e. 15. To achieve this goal, a probabilistic method was chosen, which allowed for determining the probability of passage under certain critical bridges on the basis of statistical data obtained from reliable water gauges during the 1990-2015 period by the Institute of Meteorology and Water Management. The research was based on the reliability theory, with particular emphasis on Boolean algebra. The eff ect of research is calculating the probability of completing a transport task consisting in transporting containers in two layers via the Oder Waterway from Kędzierzyn-Koźle to Szczecin.
To perform the reliability analysis of the studied system, it was necessary to determine the following parameters: To calculate the probability of both types of collisions, it was necessary to determine: -bridge clearance, -transit depth under the bridge, -the minimum clearance under the bridge required for the ship, -the minimum waterway depth required for the ship.
Bridge clearances and transit depths for each bridge were calculated on the basis of statistical data obtained from reliable water gauges during the 1990-2015 period by the Institute of Meteorology and Water Management.
The transit depth was calculated as follows: (1) where: h t -transit depth of a given section of the waterway, h w -reading of a reliable water gauge for a given section of the waterway, p -correction parameter for a given section of the waterway published by Regional Water Management Board.
To calculate the transit depth under the bridge, a simplifi cation was adopted consisting in the use of a fi xed correction factor p for a given section of the waterway (on which the critical bridge is located). The correction factors adopted for each of the critical bridges were obtained/calculated on the basis of data published on the websites of the Regional Water Management Boards in Szczecin, Wrocław and Gliwice 2 .
The clearance under the bridge was calculated as follows: (2) where: h m -clearance under the bridge h wwż -HNWL value for a given bridge h w -reading of the water gauge for a given section of the waterway h pw -clearance value for a given bridge at HNWL.
In addition, the clearance under the bridge was correlated with the value of the transit depth under the bridge: (3) Therefore: (4) where: h m -clearance under the bridge h wwż -HNWL value for a given bridge h t -transit depth of a given section of the waterway p -correction parameter for a given section of the waterway h pw -clearance value for a given bridge at HNWL.
Thanks to this, it was possible to reference the limiting parameters for which the barge will pass under the bridge (i.e. at the same time there will be no collision with the bottom and no collision with the bridge structure) through one value -transit depth. For instance: for the Bizon III pushed convoy and two BP-500 barges with containers with an average weight of 10.9 tons to pass under the bridge in Nietków, the following conditions must be satisfi ed: 1. minimum water depth -120 cm (Bizon III draft: 120 cm; BP-500 barge with 15 containers draft: 76 cm), 2. the minimum clearance under the bridge for the barge -442 cm (which means maximum water depth of 315 cm).

THE RELIABILITY OF THE CONTAINER TRANSPORT SYSTEM / Pouzdanost sustava kontejnerskog prijevoza
The profi tability of inland container transport is primarily determined by the reliability and timeliness of the transport service provided. This is due to the fact that inland navigation is one of the most cost-eff ective means of transport, especially if the transport costs include external costs of transport (e.g. congestion, noise, accidents, environmental pollution). The only obstacle limiting the development of river transport in Poland is (at least in the more common opinion) its vulnerability to external factors that hinder or even prevent transport activities, and thus negatively aff ect the reliability of transport. Due to the above, in order to assess the possibilities of commercial container transport on the Oder Waterway, it is necessary to determine the reliability of this process. In order to determine this reliability, especially when it comes to passing bridges, the following assumptions were made: -length of a cruise from Kędzierzyn-Koźle to Szczecin -1 week; -navigation period -8 months (March -October); -number of weeks in the navigation period -32; -number of critical bridges -5; -number of vessels in the entire navigation period -1920; -system performance (capacity) -58.000 containers/yearly navigation period. Due to the above, the maximum number of convoys, i.e. pushed sets performing this task in weekly cruises is: It has been assumed that the convoy would only consist of vessels that would pass under critical bridges, which means that the size of the convoy would depend on navigation conditions (month) and the weight of the load carried.
The number of vessels that will not pass under a given bridge was calculated according to the following formula: (6) where: P ikprobability of passage under i bridge for a given vessel in the k week of a given month, Fmaximum convoy size [pcs.].
It has been assumed that in all weeks of one month the water level is constant and equal to the average for a given month.
If the number of bridges is m, the total number of vessels that will not pass under the bridges amounts to: The probability of such an event should be determined for the number of attempts to pass which is: (8) hence: (9) This parameter determines the intensity of collisions in a given week of a given month.
Therefore the reliability of overcoming bridge obstacles in the following weeks of the sailing period amounts to: (11) On this basis, the reliability of the Oder Waterway container transport process has been determined for vessels with medium-weight containers.

RELIABILITY OF MEDIUM WEIGHT CONTAINER TRANSPORT / Pouzdanost prijevoza srednje teških kontejnera
The analysis of available data shows that the greatest diffi culties with the passage of pushed convoys with medium-weight containers occur under the bridges in Nietków, Kostrzyn and Opole. The observed diffi culties, however, are present in diff erent months. In Nietków they occur mostly in May and June, in Kostrzyn -in September and October, and in Opole -in July, September and October. The results of the analysis are presented in the table below, which collects data on the number of vessels carrying containers with average mass that would not hypothetically pass in selected months under the selected critical bridges. When considering the passage of a vessel in terms of overcoming all tested critical bridges for each month, the highest reliability of the transport process can be observed in April (90%), May (88%) and July (85%), while the smallest is in September (68 %) and October (66%).
In all months the results are better than for ships with empty containers. Detailed results for individual months are presented in chart 1.
In order to determine the reliability of the container transport process for the entire navigation period, the number of vessels carrying out the transport has been compared. The results of the analysis are presented in the chart below. The analysis of the intensity of collision probability of pushed convoys with medium-weight containers shows that this value is steadily increasing (excluding April and July) and amounts to the highest value in October. The analysis results are presented in the chart below.
The above analysis concerns the reliability of the transport process regardless of the cause of the potential failure. In case the navigation was conducted only during the two most favourable months, i.e. April and May, the risk of failure to complete navigation would only amount to 5% for an optimum  The risk value depends on the weight of the transported cargo and the length of the navigation season. In the short season, the risk value is more than twice as high for a medium weight pushed convoy than for an optimal weight pushed convoy. The chart below presents a comparison of risk values for the analysed seasons and pushed convoys.
Parameters of the optimum vessel can be each time determined on the basis of data from the RIS system. Optimal vessel draft values can be achieved by ballasting the ship or adequately selecting the cargo. For a medium vessel to have an optimal draft, i.e. to be an optimum vessel, about 151 t ballast is necessary. Some BP-500 barges are already equipped with a ballast system (depending on the vessel, up to 14 tanks of 8-10 tons each). In addition, you can still use the space between the bottom of the ship, where about 50 tons of ballast will fi t.
In total, the ballasting capacity of such vessels can be estimated at 170 t. Also vessels which are currently not equipped with a ballasting system can be adapted for this purpose. Using the space between the vessel's sides and between the bottoms of the vessels, the vessel can be immersed to the required level.
To conclude collision intensity analysis has shown that, contrary to popular belief, the main problem in the container transport in two layers on the ODW is not the insuffi cient bridge clearance but the lack of adequate transit depth for navigation. The factors determining its capacity are the mass of cargo (which aff ects the vessel's draft and its height above the water) and the navigation period.
The most favourable period for navigation on the ODW from Kędzierzyn-Koźle to Szczecin is the fi rst half of the navigation season, especially April and May. The collision intensity starts to rise in July. If the vessels navigated only in the most advantageous periods, the degree of risk would be much lower. In case the navigation tasks were conducted only during the two most favourable months, i.e. April and May, then the risk of failure to complete navigation by an optimum vessel (loaded according to data obtained from RIS) would only amount to 5%, and for the container vessel of medium mass (10,9 t) -6 percentage points more, i.e. 11%.

CONCLUSION / Zaključak
The article proved on a theoretical basis that the use of the Oder Waterway for the transport of containers in signifi cant quantities is highly probable, assuming adequate technical properties of the fl eet and ports.
Contrary to popular belief, the main problem in the two-tier container transport on the ODW is not the insuffi cient bridge clearance but the lack of adequate transit depth for navigation. The factors determining its capacity are the mass of cargo (which aff ects the vessel's draft and its height above the water) and the navigation period.
The parameters of the optimal vessel can always be defi ned on the basis of RIS data. With RIS system it is possible to obtain real time data, via NtS, Inland ECDIS or VTT, on the current hydro and meteorological situation on the planned section of the waterway, which makes it possible to adjust both the loading of the vessel and the route selection in order to reduce the risks associated with clearance under bridges. For depth, the limit value is the submersion of the Bizon III pusher, which is 110 cm. The barge must transport containers with an average weight of 21t to achieve such immersion. In the study, the pushed convoy loaded with such containers was determined to be optimal.
Optimal draught values of the vessel can be achieved by ballasting the vessel or by appropriate selection of the cargo carried. For an average vessel to have the optimal draught, approximately 151 t of ballast is necessary to be the "optimal vessel". Part of the BP-500 barges is already equipped with a ballast system (depending on the ship up to 14 tanks of 8-10 tons each). In addition, the space between the bottoms of the ship can still be used, where about 50 tons of ballast can be accommodated. In total, the ballast capacity of such vessels can be estimated at 170 t. Ships which do not currently have a ballast system can also be adapted for this purpose. Using the space between the sides of the vessel and between the bottoms of the vessel, the vessel can be submerged to the required level.
The analysis shows that the probability of carrying out the transport task on the Kędzierzyn-Koźle -Szczecin route is higher than for medium-weight containers. The analysis of collision intensity has shown that the most favourable period for navigation is the fi rst half of the navigation season especially April and May. The intensity of collisions starts to i ncrease rapidly at the beginning of July. Should navigation be conducted only in those favourable times, the risk of collisions would be much lower. If vessels were navigated only in the best months, i.e. April and May, then the risk of a failure of passage of an optimal vessel (loaded according to data provided by the RIS system) would be only 5%, and the risk for a vessel with containers of an average weight if 10.9 t would amount to 11%, i.e. 6 pp more. The period of fi ve favourable months (March-July) carries the risk of 8% for the optimal vessel, and for the convoy of an average weight of 10.9 t it amounts to 13%, i.e. 5 pp more.