Pioneering work for sustainable shipping in collaboration with Port of Antwerp-Bruges
It was once known as Sleepboot21 (Tugboat 21), but today, the Methatug is a pioneer in the ambitious greening programme of Port of Antwerp-Bruges. This programme aims to be completely climate neutral by 2050. Our Design & Engineering Office and project overseer Walter Van Leeckwyck played a key role in the transformation of this traditional tugboat into a methanol-powered tug.

In this interview, Walter and Sander Sijssens, Project Fleet Expert at the port authority, share their experiences. They talk about the challenging conversion that pushed the boundaries of both technology and regulations.
FASTWATER: methanol as a sustainable fuel for shipping
The conversion of the Methatug was part of the European FASTWATER project, which aims to demonstrate that methanol is a viable and sustainable fuel option for shipping. The initiative was supported by the EU's Horizon 2020 research and innovation programme.
Sander: "Years ago, MULTI.engineering was involved in the construction of Sleepboot21. Now we called on them again for a preliminary study for the conversion. They provided support in writing the specifications and Walter also supervised the final conversion, which was carried out by IDP Shipyard."
Innovation and safety
The original gas oil tug was given a major overhaul. "The ballast and fuel tanks were removed. The aft deck was cut open to make room for the methanol tank, while the engines were modified to run on methanol by the manufacturer Anglo Belgian Corporation."
A thorough update of the safety and ventilation systems was also required. Methanol is a toxic and corrosive substance. That's why the engine room was equipped with a double-walled system. The methanol tank was given a methanol-resistant coating on the inside and a nitrogen blanket on the outside. The lighting was also completely renewed in accordance with the ATEX guidelines and gas detectors, rinsing showers and a NOVEC extinguishing system were installed. All this was accompanied by the development of new emergency procedures for potential crisis situations on board and procedures for bunkering ashore.
Fireman with a 50-year passion for tugboats
Sander: "Did you know that Walter is the station chief of the fire station in Ranst? His knowledge of hazardous products and procedures for entering closed spaces where methanol is present came in very handy. I definitely learned a lot from Walter. It was a really great collaboration, and he has such a wealth of experience." Walter: "That's true, I guess 😊. Tugboats have been my passion for 50 years. During my career, I first worked in deep-sea shipping and then spent 16 years as an engineer and later as a superintendent for harbour tugs and offshore tugboats with the URS, the Unie van Redding- en Sleepdienst (Towage and Salvage Union Belgium). Since my retirement (Walter is 70), I've been working for MULTI.engineering."
The technical and logistical challenges of a methanol conversion
A methanol conversion is truly pioneering work. "So, it was no surprise that the conversion involved quite a few challenges," Walter admits. "Integrating new systems into an existing ship is always a complex puzzle. During the execution of this project, creative solutions often had to be devised and additional engineering capacity was required to adjust the design."
Sander can testify: "Some components turned out to be unavailable, which meant that alternatives had to be found and implemented at the last minute. And the timing was not always right either: our teams had to weld during a hot summer and paint in the cold. Not ideal conditions for ensuring quality, but luckily we had Walter, who, in his well-known strict and decisive manner, made sure everything was done by the book."
The difficult road to certification
It was also a real feat to get the converted ship certified. "Bart Wilbers from the Design & Engineering Office of MULTI.engineering supported us well with extra knowledge and manpower, including writing texts for CESNI (the European Committee for the development of standards for inland navigation). We then went to the CESNI headquarters in Strasbourg to have our proposals certified. Safety was a top priority for the authorities involved. Hopefully the regulations won't change too much now, otherwise we'll soon have to convert our tug again," laughs Sander.
Working on the edge
That's what Walter calls his experience with the methanol conversion. "With brand-new technology that is still rapidly evolving and regulations that are not yet fully established, it was a challenge for all parties involved. But at the same time, it was also a privileged experience to be allowed to tinker with something completely new that could shape the future of shipping. That moment when the engines fired up and started running on methanol, that was really a 'moment of glory' when you think 'we really pulled it off'. I'm proud that I was able to contribute to that, at my age."
Future possibilities for ships running on alternative fuels
Port of Antwerp-Bruges has indeed succeeded in its plan to convert a traditional ship into a ship running on methanol. With 1 ship on methanol, 1 on hydrogen and soon 1 on batteries in its fleet, the port authority can now test and evaluate how these ships function in practice. Sander: "We haven't yet determined what the best option is for us, but we are at the forefront of all technologies and have already built up a lot of knowledge within our company to make informed decisions in the future.
A ship running on methanol already offers the advantage that it can carry significantly more green energy compared to a ship on batteries or hydrogen. This can be advantageous for longer voyages or when regular bunkering is not possible. In addition, we expect methanol to be available in many places around the world. So, it's definitely a great alternative for the shipping of the future."
With brand-new technology and incomplete regulations, we've done pioneering work. In this way, Port of Antwerp-Bruges is laying the foundation for future-oriented choices in the fleet