Onboard inspection and repair of a Hangzhou gearbox, Turkey








Associated capabilities

A German shipping company invited Stork Gears & Services to visit one of their merchant vessels in Turkey because of problems with the propulsion gearbox, Hangzhou type 52.59.

After performing a visual inspection, our customer discovered that the ahead pinion shaft and bull gear were damaged. Stork Gears & Services was asked to carry out a complete onboard inspection and repair advice. As soon as the ship - the MT "Global Hekate"- arrived at the yard in Iskenderun, our engineers opened the inspection cover and noticed that the primary gears and the astern pinion shaft were also damaged badly. We advised our customer to repair the gearbox prior to continue sailing. We disassembled the gearbox and performed a thorough inspection and repair proposal. 

Onboard gearbox inspection and gearbox dismantling

Our onboard inspection involved the ahead and astern pinion shaft as well as the bull gears. At both shafts we noticed cracks and pieces of the teeth were broken. This was caused by high stresses in the teeth as well as pieces of the ahead shaft teeth running through the astern pinion shaft and bull gear. The bull gear was also irreversible damaged due to material running through during operation. Furthermore, one of the teeth appeared to be bend, according to the marks of full metal contact that were found on the bull gear. We recommended
our customer to change all bearings and to transport all internal parts of the gearbox to our workshop in Rotterdam for further inspection.

The damaged parts of the gearbox were transported by plane. In the meantime in Rotterdam we started to manufacture the pinion shafts and bullgear according to the fabrication drawing packages which we had already obtained in the past. 

Scope of work

  • Complete gearbox inspection
  • Manufacturing of astern and ahead pinion shaft
  • Manufacturing of output shaft and bullgear
  • Renewal of bearings, seals andlubrication pomp
  • Crack examination
  • Oil cooler inspection
  • Thrust collar modification
  • Sea trails
  • Several tests during sea trails (bearings temperature, lubrication pressure etc.)


Because we have the Hangzhou fabrication drawing packages, class approved stock material and in-house manufacturing facilities we were able to manufacture these components much faster than other gearbox repair companies. 

Hangzhou gearbox repair  

Stork Gears & Services has drawing packages of Hangzhou gearboxes. This enables us to supply the spare parts in accordance with the original measurements and types of material. 

Class approved stock material

Ships built under Bureau Veritas class must be fitted with materials and equipment approved by Bureau Veritas. We have class approved materials in stock which enables us to significantly shorten delivery.

Fast facts

Location Iskenderun, Turkey
Market segment Merchant shipping, merchant vessels
Gearbox details Propulsion gearbox
Hangzhou Advance
Type 52.59
P= 2500 kW, N1= 750, I= 4:1
Overview of gearbox application