Wärtsilä Single Input Gear

Wärtsilä single input, single stage, reduction gears provide a consistent propeller speed and cover a power range from 600 to 24.000 kW. The vertical or horizontal offset between the input shaft and output shaft accommodates a wide range of engine-propeller shaft arrangements.


  • Gears with a vertical offset, types SV and SCV, are available in 15 different gear sizes, covering a power range from 600-24.000 kW
  • Gears with a horizontal offset, types SH and SCH, are available in 15 different gear sizes, covering a power range from 2000-24.000 kW
  • The SCV and SCH types have a built-in clutch, while the SV and SH types are without a clutch
  • A primary driven PTO, rotating whenever the engine is running, or a secondary driven PTO, which is rotating whenever the propeller is rotating.
  • Combined power take-off / power take-in (PTO/PTI) 


    Technical info
    Single input dimensions and drawings
    Single input gears, vertical offset, dimensions
    Single input 2
    Single input gears, horizontal offset, dimensions
    Single input technical info

    Power take-off (PTO)

    All Wärtsilä gears can be supplied with one or more PTOs for driving the shaft alternator, compressor or pump. For single vertical and horizontal gears, the standard PTO is primary driven. For double gears, the PTO is optionally primary or secondary driven.

    A primary driven PTO rotates whenever the engine is rotating.
    A secondary driven PTO rotates whenever the propeller shaft is rotating.

    Power take-in (PTI)

    Most Wärtsilä gears can be supplied with a combined PTO/PTI. In PTI mode the shaft alternator can also be used as an electric motor. PTI is normally used for the following operational modes:

    PTI “Booster” mode is used when the main power of the engine is insufficient in order to increase the total propulsion power. For this mode, no clutches are required on the gear.
    PTI “Take me home” mode is used in case of emergency should the prime mover be inoperable. For this mode a minimum of 2 clutches are required on the gear.

    Hydraulic power unit

    Most Wärtsilä gears are purpose-designed with an integrated hydraulic system for both the gear and the CP propeller. As a separate hydraulic power unit for the CP propeller is superfluous, both installation costs for the yard and operational costs for the owner are reduced. For safety reasons the gear mechanically drives the main pump for the propeller. All gears can also be interfaced with a separate hydraulic power unit.

    Special gears

    Based on the standard Wärtsilä gear types, customized solutions can be delivered upon request.


    • Combined vertical and horizontal offset
    • Multiple power take-off (PTO)
    • High power PTO
    • High power power take-in / dedicated hybrid propulsion gears​
    • Sten Idun
      Sten Idun is a 16400 dwt Chemical Tanker with a Wärtsilä equipment package of engines, gear and propulsors. Sten Idun vas commissioned 2003 and features a PTI booster and takes me home mode.

      Sten Idun

    • Voyager
      The Voyager is deployed in the Irish Sea. Pelagic trawlers are huge vessels built for deep sea fishing, with facilities for keeping the catch fresh over prolonged periods at sea. The hull is designed to ensure safety, and to give good fuel efficiency and high speed.


    • Tong Xu
      The Tong Xu is a large trailer suction hopper dredger delivered in 2008. The vessel is equipped with a complete Wärtsilä package with two 12V38 engines, two gearboxes, two controllable pitch propellers, two transverse thrusters and propulsion controls.

      Tong Xu

    • Quantus
      The Quantus is a modern trawler designed and built for efficient fishing. The vessel incorporates a number of innovative ideas, including a new hull form designed to combine optimum steaming and towing characteristics with fuel efficiency.


    • Oceanic Vega
      The Wärtsilä service agreement is expected to considerably reduce maintenance costs.

      Oceanic Vega

    • Libas
      The Libas, delivered 2004, is a combined purse seiner and trawler designed by Wärtsilä Ship Design for the future needs of the global pelagic fleet.


    • Gitte Henning S349
      The vessel is the largest pelagic trawler in the Danish fishing fleet, and the third vessel with the same name that is owned and operated by the Danish fishing company. The propulsion equipment package include a Wärtsilä 9L32 main engine with new design, gear, controllable pitch propeller (CPP), HR Nozzle, Wärtsilä 8L26 auxiliary engine, as well as related equipment – including NOx reducers for both engines. The previous Gitte Henning was also designed by Wärtsilä Ship Design, back in 2008.

      Gitte Henning S349

    • Christina S
      Delivered in 2008, the Christina S was designed by Wärtsilä Ship Design and is fitted with a complete Wärtsilä propulsion solution, comprising a 12-cylinder Wärtsilä 32 engine driving a reduction gear and a controllable pitch propeller. Wärtsilä also provided the control system for the installation.

      Christina S

    • PZM Comandante Toro
      The Patrulleros de Zona Marítima (PZM) are a series of offshore patrol vessels being built for the Navies of Chile, Argentina and Colombia.

      PZM Comandante Toro

    • Bit Viking
      In 2011, the first ever marine conversion of Wärtsilä 46 engines to Wärtsilä 50DF dual-fuel engines was carried out on the product tanker Bit Viking, owned by Tarbit Shipping of Sweden. It also represented the first Wärtsilä 50DF dual-fuel marine installation with mechanical propulsion.

      Bit Viking

    • Bitflower
      Delivered in 2003, the tanker Bitflower features a complete Wärtsilä machinery installation incorporating a Wärtsilä 6L38 main engine. Bitflower belongs to Tarbit Shipping AB, a Swedish shipping company that has been shipping asphalt, petroleum products and chemicals since 1962.


    • Siem Pearl
      The Siem Pearl became operational in August 2009. The Wärtsilä clean design hybrid solution consists of a combined diesel-electric and diesel-mechanical system. This means the ship can switch between different modes to achieve continuous and optimal efficiency. Compared to conventional diesel-mechanical vessels, dynamic positioning operation offers fuel savings of up to 50%.

      Siem Pearl

    • Normand Ivan
      With a total installed power of 14,720 kW, the Normand Ivan from Wärtsilä Ship Design is among the most compact and powerful AHTS vessels.

      Normand Ivan

    • Normand Installer
      Delivered in 2006, the Offshore Construction Vessel Normand Installer by Wärtsilä Ship Design is equipped with a complete Wärtsilä package.

      Normand Installer

    • Tarbit Shipping
      Bit Viking - LNG Conversion for environmental sustainability.

      Tarbit Shipping


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