To hit climate goals, greenhouse gas and pollutant emissions must be reduced worldwide. This also applies to inland navigation.
In June 2021, the German Maritime Centre awarded a contract to Lloyd’s Register for a study of the “Development of a proposal for technical regulations on the use of hydrogen as a fuel in inland navigation”.
Up to now, inland vessels in Europe can only be powered with hydrogen (H2) in exceptional cases. In order to promote innovation and the use of new technologies, special permits are granted for pilot projects that deviate from the applicable technical regulations. Ongoing regulatory updates ensure that the regulations are revised to incorporate scientific and technical progress so that safety and efficiency in inland navigation continue to be assured. Clear regulations by legislators on the use of alternative fuels can motivate the industry to implement the necessary innovations for a transformation. This presupposes that the use of hydrogen is possible in principle and that appropriate safety regulations are in place.
On all inland waterways of the European Union, the safety of inland vessels and the protection of the environment and people are ensured by the European Standard laying down Technical Regulations for Inland Navigation Vessels (ES-TRIN). The basis for this harmonised set of rules is EU Directive 2016/1629 laying down technical requirements for inland waterway vessels and the Rhine Vessel Inspection Regulations (RVIR).
The above-mentioned study is tasked with developing a draft regulation for the use of hydrogen to power inland vessels. It also analyses whether the safety concepts can be integrated into the regulations for seagoing vessels being developed by the International Maritime Organization (IMO).
Development of technical regulations for inland vessels
The European Committee for drawing up standards in the field of inland navigation (CESNI) is responsible for the elaboration of technical regulations in the field of inland navigation at European level. In the CESNI PT FC committee (a non-permanent European working group), employees of the Federal Ministry for Digital Affairs and Transport (BMDV) work together with representatives of other EU member states, industry representatives, and experts on regulations for the use of fuel cells and fuels with a low flashpoint. German industry has participated intensively in the work of this committee to date.
The provisions for inland vessels using fuels with a flashpoint of 55 °C or lower (e.g. hydrogen, LNG and methanol) are published in the ES-TRIN (Annex 8). The technical requirements for bunkering and storage of cryogenic and pressurised hydrogen on board are to be developed for the new Section II of Annex 8 (Fuel Storage, Part 2 – Hydrogen).
ES-TRIN (Annex 8) already sets out requirements for LNG. These were reviewed and adapted with the structure and content of the new section on hydrogen fuel in mind. The currently relevant standards and regulations for H2 transport with tank containers or swappable pressure equipment are the European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR) and the European Agreement concerning the International Carriage of Dangerous Goods by Inland Waterways (ADN). Hydrogen is currently not included in the list of dangerous goods approved for transport in tank vessels. The regulatory requirements can not be assumed to be suitable for hydrogen.
A gap analysis was conducted to assess the possible application of technical principles to inland navigation; moreover, other international guidelines for the transport and use of hydrogen were also considered. Depending on their scope of application, existing regulations vary in their capacity to complement the technical basis of the ES-TRIN for hydrogen as a fuel.
The recommendations to the vessel inspection body and the derogations under Directive EU 2016/1629 will make it possible to retain the experience already gained in pilot projects. They have been incorporated into the analysis described above.
Hydrogen – properties, risks
Hydrogen (H2) is a colourless and odourless gas. From nature it is not toxic, but cryogenic burns can cause immediate health and structural hazards. If hydrogen is released into the atmosphere, there is less environmental impact compared to diesel oil. The gas disperses quickly and has no toxic or water-polluting effect. The disadvantage of H2 is the increased space requirement due to its low density, the low ignition energy, and the low and wide flame range. Fires and explosions may occur if hydrogen is released. The biggest challenge is the current lack of experience with the use of the substance in the maritime sector and the lack of rules/regulations.
Hydrogen storage on board ships
Compressed and liquid hydrogen is used as fuel and transported as cargo. For this purpose, H2 is stored in suitable safety containers. There are safety containers for compressed and liquid hydrogen. A distinction is made between permanently installed and replaceable (“swappable”) (pressure) cylinders, or between gas cylinders and containers in varying bundles/weight classes. For the storage of hydrogen on board inland vessels, different safety containers such as gas cylinders, gas bundles and ISO containers will be used in the future, depending on requirements. Since H2 has a very low density compared to diesel oil, large-volume tanks are required for storage.
In maritime shipping, H2 is stored as cargo in Multiple-Element Gas Containers (MEGC). These containers are covered by the regulations applicable to maritime transportation.
An overview of the safety containers associated with relevant inland waterway pilot projects can be found in the following table:
In the draft regulatory text this study has prepared on the use of hydrogen for the operation of inland waterway vessels, the technical regulations are presented on the basis of the aforementioned analyses. These concern, for example, the requirements for the system design and the H2 container system, fire safety, electrical systems and other safety systems. Chapter 2 of Annex 8 (“Marine equipment, ship operation and system design, H2 container system”) regulates that, for example, the mounting and support of the hydrogen tanks must be designed for the applicable loads. Furthermore, proposals are made for the applicability of existing standards to compressed hydrogen. The safety distances mentioned in the draft, for instance, regarding escape routes, accommodation, passenger areas and workplaces, among others, are under discussion.
Since a hydrogen flame is colourless, it is not visible to the naked eye in daylight or bright light (e.g. in the engine room). Therefore, the draft (Chapter 3 – Fire Protection, Fire Alarm System) requires for appropriate ultraviolet (UV) and/or infrared range (IR) flame detectors.
The draft this study has developed has already been presented by the German delegation to the European Committee for drawing up standards in inland navigation (CESNI) to be incorporated in a new version of ES-TRIN as soon as possible. The coordination process has been initiated and the requirements will be further discussed and refined.
The process of developing regulations is being continued with the participation of the Bundesverband der Deutschen Binnenschifffahrt e.V. (Federal Association of German Inland Navigation/BDB), the Verband für Schiffbau und Meerestechnik e.V. (Association for Shipbuilding and Marine Technology/VSM) and the Verein für europäische Binnenschifffahrt und Wasserstraßen e.V. (Association for European Inland Navigation and Waterways/VBW), as well as of manufacturers and responsible national institutions.
Increased safety requirements must be taken into account for the use of hydrogen as a fuel in maritime shipping. In contrast to inland shipping, ocean-going vessels operate at great distances from the coast as well as in much less favourable weather and sea conditions and higher vessel accelerations are to be considered. In addition, depending on the ship type and the operation profile, a larger amount of fuel to be stored can be expected. The specific requirements in the regulatory proposal relate to
- Tanks and distances to the ship’s outer shell,
- Hydrogen storage design, dimensioning and testing,
- Distances to ventilation and safety valve outlets,
- Distances of pipelines to the ship’s outer shell
A re-evaluation of these requirements is necessary with regard to the expected risks (e.g. collisions or leakage scenarios) and the associated consequences for ocean-going vessels.
The expert discussion will continue at the next meetings of the CESNI (in April and October 2022).