Repair of a propulsion gearbox after cracked casing

Stork Gears & Services was approached by a maritime customer to discuss the options for a complete repair of a highly damaged gearbox based on a new casted casing.damaged gear teeth propulsion gearbox

The customer gave us green light to do the reparation so that they could minimize the downtime of the ship.

Repair propulsion gearbox casingThe problem of the Lohmann & Stolterfoht gearbox was major: the propeller of the ship caught a fishing net which was wound up between its hub and the ship’s hull. This caused such extreme forces that the stern shaft was pulled out, causing the gearbox casing to crack. Due to the size of the crack it was not possible to repair the casing and we were asked to let the ship sail again by repairing the gearbox to its original dimensions.

To repair the gearbox using the best methods to minimize the downtime we followed several steps:Dismantling Cleaning and inspection Propulsion Gearbox

  • Dismantling, cleaning and inspection of the gearbox
  • Revers engineering of the casing and discuss engineering parameters with classification company
  • Manufacture a new middle section casing
  • Grind gear teeth of bull gear
  • Manufacture Both input pinion shafts
  • Re-metal sliding- and thrust bearings
  • Renew roller bearings and seals
  • Assembly of gearbox onsite
  • Test run
  • Installation of gearbox onsite
  • Commissioning and sea trialsAssembly and test run propulsion gearbox

With the reparation the customer can sail in as little as 9 weeks from reception in our workshop. The original equipment manufacturer offered a delivery of 12 months for the casing. Stork Gears & Services minimized the downtimes so that they could save a large amount of money.

Location Workshop Rotterdam 
Market segment Maritime 
Gearbox specifications Manufacturer: Lohmann & Stolterfoht
Type: GVA 1250
Imput speed: M1 = 825 rpm
Power: 2x 2590 kW
Scope of work 
  • Dismantling, cleaning and inspection of the gearbox
  • Revers engineering of the casing and discuss engineering parameters with classification company
  • Manufacture a new middle section casing
  • Grind gear teeth of bull gear
  • Manufacture Both input pinion shafts
  • Re-metal sliding- and thrust bearings
  • Renew roller bearings and seals
  • Assembly of gearbox onsite
  • Test run
  • Installation of gearbox onsite
  • Commissioning and sea trials

Contact Stork Gears & Services

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