Research on the Quadrise Marine market - How Many RT-Flex Engines are there?10 Apr 2026 14:36
As it looks certain that MSAR is being positioned for rollout as quickly as possible after it's short Proof of Concept trial, I thought it would be worthwhile looking at how big the market if just for the RT-Flex engine that the Interim LONO covers. On the IMC meeting, Jason said that Wartsila were looking at expanding the LONO to other engines, I take it they will all still be RT-Flex though from what Jason said about the fuelling system on that type of engine.
For MSC there's 6 initial Leandra V sister vessels: MAERSK BALTIMORE, MAERSK BOSTON, MAERSK BROWNSVILLE, MSC BREMERHAVEN, MSC INIYA V, MSC RITA V
After that it gets very interesting and this is where I think MSC are looking with the need for Singapore supply:
Wärtsilä achieved the milestone of 1,000 orders for its electronically controlled, common-rail RT-flex low-speed 2-stroke engines in August 2012, just 11 years after their 2001 introduction. The 1,000th order was for a 7-cylinder RT-flex82T version B engine, destined for a VLCC tanker and built by licensee Diesel United Ltd in Japan
https://www.wartsila.com/media/news/01-11-2012-wartsila-rt-flex-low-speed-engines-achieve-1000-orders-milestone
We are now 14 years ahead of that, so likely another 1000 added and delivered by now. Plus, there are numerous other companies making identical RT-Flex engines under license.
RT-Flex engine technology (formerly Sulzer, now under Winterthur Gas & Diesel - WinGD) is licensed to several major shipbuilding and engineering manufacturers globally, particularly in East Asia. Key manufacturers include:
Hyundai Heavy Industries Co., Ltd. (HHI-EMD): Based in South Korea, a major manufacturer producing a wide range of RT-flex engines.
CSSC Marine Service Co. Ltd. (CMS): Part of China State Shipbuilding Corporation, involved in manufacturing and service.
Hudong Heavy Machinery Co., Ltd. (HHM): A Shanghai-based licensee under the CSSC group.
Diesel United Ltd. (DU): Based in Japan, known for producing Sulzer RT-flex engines.
Qingdao Qiyao Wartsila MHI Linshan Marine Diesel (QMD): A Chinese joint venture licensed for RT-flex engines.
Yichang Marine Diesel Engine Co., Ltd. (YMD): Part of China Shipbuilding Industry Corporation.
Zhuhai Yuchai Marine Power: A licensed manufacturer in China.
Doosan Engine Co., Ltd.: A major Korean manufacturer.
Mitsui E&S Diesel United: Listed as a manufacturer under WinGD.
Vinashin (Vietnam Shipbuilding Industry Corporation): Licensed to build Wärtsilä low-speed engines, including RT-flex designs
The RT-Flex engines were originally developed by Wärtsilä, but are now managed by WinGD (Winterthur Gas & Diesel), which is 100% owned by CSSC.