The beginnings of the worldwide Wärtsilä Corporation, with head office in Helsinki, Finland, dates back to the same year, when Sulzer Brothers in Winterthur, Switzerland was founded, that is 1834.

In this year a saw mill was founded in the small finnish town of Värtsilä, in the province of North Karelia, belonging today to Russia. Two years later, the industrialist Nils Ludvig Arppe (1803-1861) took over the saw mill and in 1851 he added an iron work. From his heritage emerged the concern Wärtsilä AB in 1898. In 1935, before the Soviet-Finnish winter war broke out (1939-40) the head office was moved to Helsinki. 

After a licensee agreement was concluded with the Germaniawerft in Kiel, Germany, belonging to Friedrich Krupp, the construction of diesel engines was commenced and in 1942 the first engine was delivered. In 1983 an own shipyard was taken in service in Turku, Finland. During the same period the shipyards of Valmet AB were taken over, however in 1989 the whole shipbuilding division went bankrupt and was suspended. 

In the years after 1980 many companies, engaged in ship propulsion were taken over, such as Stork Werkspoor Amsterdam, SACM Mühlhausen, GMT Grandi Motori Trieste, Nohab Diesel, Deutz MWM Marine Service (2005). Today the company offers a wide selection of products for the shipping industry, such as two- and four-stroke diesel engines, diesel generator sets, controllable pitch propellers, azimuthing thrusters, water jets, automation, ship’s design and much more 

1995 began also a cooperation with the US-American diesel engine manufacturers Cummins.

In 1997 the complete diesel engine construction division in Winterthur, Switzerland, the NSD New Sulzer Diesel was amalgamated with Wärtsilä and Fincantieri, Italy. The new company was called Wärtsilä NSD Corporation. In the year 2000 the company finally changed to it’s today’s name Wärtsilä Switzerland Ltd., henceforth the famous name Sulzer only continues to live in maritime history. The last diesel engine built and tested in Winterthur was delivered in December 1988. It was a stationary engine, type: 8 RNF 68M for an electric power station in the Bahamas. 

Initially Wärtsilä was engaged only in the manufacturing of small, high speed four stroke diesel engines, but with the acquisition of New Sulzer Diesel the breakthrough into the market for large, slow speed diesel engines was achieved, a market dominated today by MAN-B&W und Wärtsilä.

Already before the sale of the diesel activities, Sulzer radically changed in 1983 their design of the slow speed, two stroke engines from the well proven loop scavenging to the uniflow scavenging system. The change to uniflow scavenging (with an exhaust valve in the cylinder head, like on a B&W-engine) was a physical necessity, in order to increase the bore/stroke ratio and hence to achieve a better efficiency. These new engines were termed the RTA-series, first with bores of 380 to 840 mm, later up to 960 mm. in 1991 the first experiments with electronic injection were carried out on a 4 cylinder test engine. 

In October 1995 the new built Diesel Technology Centre in Winterthur was inaugurated, located in the large industrial site of Sulzer Brothers Ltd. in Oberwinterthur (about 4 kilometers from city centre). Today various tasks are carried out in this centre, running tests are conducted on the large 4-cylinder experimental engine RTX-4, basic research, training of operating crews and high precision parts for fuel injection systems are fabricated and tested. Presently the experimental engine is rigged for two-stage turbo charging and tests are run to reduce NOx content in the exhaust gases. A non-operational demonstration engine is displayed in the training hall with partly opened crankcase and removed cylinder covers to introduce visitors to the construction of a modern diesel engine. 

Technology_Centre.jpg (146541 Byte)  Please click on the small pictures to enlarge them and vice versa.
Photo: Diesel Technology Centre (courtesy of Wärtsilä Switzerland Ltd.)

rtx-4.jpg (218337 Byte)
Photo: Experimental engine  RTX-4 (courtesy of Wärtsilä Switzerland Ltd.)

The first engine working with electronic injection was a 6RT-flex 58T-B with 11'275 kW at 93 RPM and it was installed and taken into service in September 2001 in the bulkcarrier “GYPSUM CENTENNIAL“

These engines are principally normal, slow running, two-stroke, crosshead engines, but with radically changed fuel injection system, based on the “common rail system” (older marine engineers probably will remember this system from the Doxford engines). A fuel booster pump creates a pressure of about 850 bar in the “common rail” (a common pipe, serving all cylinder units). From the “common rail” the fuel is distributed by electronic / hydraulic control units to the fuel injectors in exact time intervals and quantities. This electronic injection results in cleaner exhaust gas and reduced fuel consumption. Also much improved values at slow manoeuvring speeds are obtained (for more technical details, see attached brochure). The world most powerful diesel engine is today the 14-cylinder Wärtsilä RT-flex96C with a power output of 80,080 kW (108,920 bhp) and a cylinder bore of 960 mm. The first engine of this model was taken into service in September 2006 and is also used for the propulsion of the world’s largest container vessels of the Emma Maersk class. 

Today about 560 persons are employed in the Diesel Technology Centre and in the offices of Wärtsilä in Winterthur, in research and development, marketing and service, however the production of the engines takes place almost to 100 % in the large shipbuilding nations of the Far East. In Europe and South America only a very few engines are manufactured, since shipbuilding in these countries has decreased drastically. 

injection.jpg (98875 Byte)                              To enlarge the diagram please click on it.
Diagram: Schematic diagram of RT-flex injection (courtesy of Wärtsilä Switzerland Ltd.)

Brochure: Wärtsilä RTA96C Engine Technology Review (courtesy of Wärtsilä Switzerland Ltd.)

July 2010