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.


    © 2022 Wärtsilä