Mitsui Augments Engine Production Range

Moreover, through the takeover of the large-bore marine engine business of IHI Power Systems (IPS), the WinGD low-speed range and MAN’s four-stroke Pielstick marque have been added to the MES portfolio under the guise of Mitsui E&S DU. The latter’s production lines are located at Aioi, in Hyogo Prefecture. With the new double licensing structure, aggregate deliveries of two-stroke types by the Tamano and Aioi factories during the current fiscal year are expected to amount to 160 units of 3.25m bhp (2.42m kW).

MES had concluded an agreement in September 2022 with IHI Corporation and IPS for the transfer of the IPS interests in large-bore marine engines and related products. This saw the interim creation of IPS Aioi Co, in which all shares were acquired by MES on 1 April 2023, and which was thereupon renamed Mitsui E&S DU.

The strengthened position of MES as a producer and technology source is pertinent not only to the process of industrial consolidation but also to Japan’s far-reaching economic security law passed in May 2022, the Economic Security Promotion Act, in which two-stroke marine engines have been designated as a field of critical material importance.

Towards the end of last year, MES announced plans for the expansion of capacity at Tamano, on the back of rising demand for dual-fuel engines and to prepare the way for volume output of machinery capable of operating on next-generation fuels. Bolstered R&D expenditure includes work on ammonia-fuelled two-stroke propulsion solutions. The various initiatives have gained added dimension as a result of the company’s widened licensing scope.

One strand of technological development involving Mitsui E&S DU and its antecedents recently brought to fruition has involved a variable compression ratio (VCR) system devised in cooperation with WinGD.

An engine’s compression ratio is usually a fixed parameter, pivotally influencing power and fuel efficiency. However, with VCR in application to a dual-fuel or multi-fuel, low-speed prime mover, the engine adjusts to the optimal compression for whatever fuel is in use. Initially offered as an option on WinGD X-DF series dual-fuel models, the system promises significant consumption economies in both gas and diesel operating mode.

DU, as Diesel United, had been established in 1988 through the combination of the diesel divisions of IHI and Sumitomo Heavy Industries. The company became part of IHI Power Systems in 2019 when IHI decided to integrate its engine, propulsion and power plant activities into a single organisation.