New low-speed engine a success

Orders for a total of 30 seven-cylinder Wärtsilä RT-flex82T engines have been received in recent months, including:

– Six engines for VLCCs to be built by Dalian Shipbuilding Industry
– Six engines for VLCCs to be built by Shanghai Waigaoqiao Shipbuilding
– Two engines for VLCCs to be built by Hyundai Heavy Industries
– Sixteen engines for VLOCs to be built by Jiangsu Rongsheng Heavy Industries

Wärtsilä enjoys a global market share of approximately 50 percent in electronically-controlled low-speed engines. During the past two years, orders for 140 of the company’s 82-cm bore marine engines have been placed. Of these, some 120 are for the RT-flex common-rail version.

The new 82 cm bore, Wärtsilä RT-flex82T low-speed marine engine successfully completed the type approval test carried out at Hyundai Heavy Industries (HHI) in Korea. This test was carried out in the presence of representatives from the major classification societies.

The first engine was installed in a VLCC built by HHI. The tested 7-cylinder RT-flex82T has a maximum continuous power of 31,640kW at 76 rpm.

The RT-flex82T is an electronically controlled engine for large tankers, namely VLCCs and ULCCs, as well as for very large bulk carriers of between 200,000 and 400,000 dwt. The engine, having a low rpm, is also an attractive alternative to the higher rpm engines normally used in container ships. The lower rotational frequency offers fuel cost savings that are attractive in projects where fuel efficiency is high on the agenda.

The four 82-cm bore engine types in Wärtsilä’s portfolio, the RT-flex82C, RTA82C, RT-flex82T and RTA82T, are designed to offer the same economic and environmental benefits to different vessel types, according to their operating requirements. The programme was first introduced in November 2005, and all versions are based upon a common platform with as many parts as possible being shared. This enables benefits of rationalisation in design and manufacturing, optimized manufacturability, and spare part stocks, to be realised.

The Wärtsilä RT-flex engines feature common-rail technology which offers greater parameters for propulsion plants with optimum cost efficiencies for large tankers and very large bulk carriers. The complete flexibility in engine setting, that is an integral feature of the RT-flex common-rail system, includes optimized fuel injection pressures and timing for all loads. It is employed in special tuning regimes to optimize brake specific fuel consumption (BSFC). The concept has now been extended to low-load tuning, which provides the lowest possible BSFC in certain operating engine loads which not only allows fuel cost savings, but also enables lower exhaust emissions of CO2.