VESSEL REVIEW | Gas 96 – Shallow-draught diesel-electric gas tanker built for low-water Rhine service

HGK Shipping's inland gas tanker Gas 96 has been in service on the Rhine between Rotterdam, Antwerp and Cologne since its naming in Rotterdam, carrying pressurised liquefied gases under a long-term charter to chemical producer LyondellBasell (LYB).

The Bureau Veritas-classed vessel is the third gas tanker in the HGK fleet to pair a hull optimised for shallow water with a diesel-electric drive that the company markets as future-fuel-ready. It was designed at HGK Shipping's in-house Design Center, and the company said no other vessel then operating on the Rhine and its tributaries matched its combination of a 110-metre (360-foot) length, a 15-metre (49-foot) beam and the ability to carry 300 tonnes when navigating in 1.2 metres (3.9 feet) of draught.

The order for Gas 96 was placed with De Gerlien van Tiem in the Netherlands on September 15, 2023, with delivery targeted for the fourth quarter of 2025.

Construction was split between two yards: Severnav in Romania completed the hull, and De Gerlien van Tiem carried out the superstructure and outfitting work before the vessel was handed over roughly on the original schedule.

Significant capacity considered unusual for Rhine operation

Cargo is carried in four pressure tanks with a combined volume of 3,256 cubic metres. The design's key feature is its payload range at different Rhine water levels. Gas 96 can still carry more than 300 tonnes of cargo while drawing just 1.2 metres.

Under ideal conditions, its maximum load per voyage exceeds 2,500 tonnes. The wide beam makes this possible, spreading displacement over a broader footprint preserves payload when deeper-draught tonnage is forced to lighten or stop altogether during low-water periods.

When HGK announced the order in 2023, it described the dimensions as unusual for the Rhine and said the intention was to maintain high loading capacity for two chemical customers in the Netherlands and Germany during periods of restricted water depth.

The commissioning announcement later identified those customers as LYB and its joint venture partner Covestro.

Able to accommodate future integration of alternative fuels

Manoeuvring is handled by azimuthing rudder propeller units. HGK Shipping said these enable safe handling of the vessel amid severe changes in water levels, where a 110-metre by 15-metre hull with limited water under the keel would otherwise be difficult to control in current and at berths.

Propulsion is diesel-electric. A power-management system matches the generating capacity brought online to the actual propulsion and hotel load demanded at any given moment.

HGK Shipping said this cuts both fuel consumption and exhaust emissions compared with a conventional direct-drive arrangement.

The electrical architecture is also the basis of the future-fuel claim: the drive train is arranged so that alternative fuel or propulsion systems can be retrofitted as they mature, without rebuilding the vessel around a new engine room.

Anke Bestmann, director of gas shipping and managing director of HGK Gas Shipping, set out the thinking at the naming ceremony.

"Goods that will need to be transported in future, such as ammonia, and fuel systems that are just being developed, such as methanol, have already been taken into consideration with this vessel design.

"In addition, the power management system on the new vessel reduces fuel consumption and waste gas emissions, as it already adapts the power that's made available to the output that's required."

The ammonia provision extends to the cargo system. HGK said at the time of the order that the loading system was prepared for the potential transport of ammonia, positioning the vessel for a cargo that European chemical and energy companies claim to expect to move in larger volumes.

The design draws on two earlier HGK projects. Bestmann said in 2023 that the concept, "ideally combines the pattern of Gas 94 and that of mega-barges, which have already enabled us to prove that we can transport unusual dimensions along inland waterways efficiently and reliably."

Combining two different vessel design philosophies

The mega-barges referred to are the four large gas tankers built for Ineos, the first three of which entered service from May 2020 and the fourth in April 2021. HGK advised on their design, supervised construction and delivery, and operates them under a long-term arrangement. The company said they remain the four largest gas tankers on the Rhine.

Gas 96 combines the payload logic of those large barges with the low-water performance and diesel-electric layout first applied on Gas 94. HGK said it was the first operator to introduce that pairing of shallow-water capability and an alternative drive system in inland gas tanker shipping.

The charter itself was signed with LYB, whose Rhine production depends on continuous feedstock movements between the Rotterdam and Antwerp port complexes and the Cologne chemical belt.

HGK Gas Shipping operates 19 inland vessels in total, comprising 15 company gas tankers and four operated vessels. The company lists Gas 95 as under construction and said a further four tankers, Gas 97 through Gas 100, are in planning, with delivery expected progressively over the coming years. HGK also said the shallow-draught and alternative-propulsion approach developed on the gas tankers is being applied in its other transport segments.