On October 11, the company successfully completed the acceptance and delivery of the 5RT‑flex58T‑D intelligent main engine. Following the 6RT‑flex58T‑D main engine, this unit is another new member of the RT‑flex58T‑D main‑engine series. It has an output power of 9 760 kW, an output speed of 92.9 rpm, a mean effective pressure of 19.8 bar and a maximum firing pressure of 149 bar, complying with Tier II emission requirements.

The main engine will be installed on an 82 000‑DWT bulk carrier built by Beichuan Heavy Industry for Hebei Ocean Shipping Co., Ltd. During the design and construction of the engine, the company fully considered the customer’s practical requirements and made strenuous efforts to meet the shipyard’s engine‑in‑yard acceptance schedule.

Given the relatively compact engine room of the 82 000‑DWT bulk carrier, designers carried out repeated calculations based on the engine‑room arrangement drawing to make extensive modifications to the access platform of the 5RT‑flex58T‑D main engine. Corresponding piping layouts were completely redesigned to satisfy multiple requirements including vibration standards and convenient maintenance and disassembly. As a new‑type design, the fuel‑supply unit of the 5RT‑flex58T‑D main engine is arranged on the fuel‑oil side.

Substantial delays and omissions of design drawings from the licensor, together with numerous errors in construction drawings, created major challenges for main‑engine construction. Faced with a tight schedule and heavy workload, technical personnel drew on construction experience from the RT‑flex58T‑B main engine. All design drawings that the licensor failed to deliver on time were independently developed in‑house to ensure smooth construction progress.

Furthermore, unsatisfactory torsional‑vibration calculation results after the main engine was to be fitted onboard prompted repeated calculation revisions jointly performed by the company, Wärtsilä and the Geislinger damper manufacturer. Without altering the shipyard’s shafting system, a D280 torsional‑vibration damper with special balance weights and a specially‑designed over‑weight flywheel were added to the engine. The main‑engine crankshaft was changed to a solid crankshaft without lightening holes, and all associated components were redesigned and modified. These changes further aggravated the already tight delivery schedule.

All departments worked at maximum efficiency throughout torsional‑vibration calculation validation, drawing revision, and component ordering and manufacturing. After overcoming numerous difficulties and setbacks, the company finally successfully delivered a high‑quality 5RT‑flex58T‑D main engine that satisfied the ship‑owner. This achievement demonstrates the company’s solid manufacturing capability built over more than 20 years and accumulates valuable experience for future independent design and drawing development.