Sulzer restores operational integrity of steam turbine on container ship
GEARS , DRIVES & MOTORS STEAM TURBINE OVERHAUL
SULZER
Sulzer restores operational integrity of steam turbine on container ship
Container ships are the lifeblood of global supply chains , with the World Economic Forum estimating that 90 % of goods are transported by sea . 1 For operators , it is essential to have vessels out at sea meeting schedules and returning profits . When a container ship owned by one of the top three global shipping companies required a steam turbine overhaul , a regional team of Sulzer experts collaborated seamlessly to deliver a turnkey repair . Innovative reverse engineering restored the operational readiness of the legacy steam turbine .
Ship-shape turbines
For a working vessel like a container ship , all maintenance must be completed within the timeframe that the ship is in harbor . Any delay risks increased docking fees from the shipyard , a failure to meet shipping schedules and lost profits . While many modern container ships use more efficient diesel engines , some older vessels still rely on steam turbines for propulsion , which require specialist servicing .
In a recent project , an 18-year-old 5 MW steam turbine of British original equipment manufacturer ( OEM ) origins installed on a 98 ’ 000-ton container ship had suffered damages due to operational wear and tear . The unit had been at a standstill for 2
years due to a generator replacement , which delivers essential power for ship operations . With this complete , there was a window of opportunity to conduct repairs at the Port of Shanghai as part of the vessel ’ s scheduled maintenance .
However , the UK turbine OEM
couldn ’ t provide support in China due to the absence of local manpower . The cost of flying in experts was an extra financial burden that the vessel owner didn ’ t want to bear . Therefore , the vessel operator ’ s central procurement team based in Singapore contacted Sulzer Singapore due to its OEM agnostic repair support and reputation for quality . Subsequently , Sulzer ’ s technical team was dispatched to China and carried out a full inspection of the unit , which operates at speeds of 6 ’ 800 rpm .
Expert turbine assessment Sulzer is a leading independent service provider ( ISP ) for all types of rotating equipment , including turbomachinery . The business has successfully serviced over 1 ’ 500 steam and gas turbines in Asia . Upon a methodological assessment of the turbine , Sulzer experts discovered the damage extended beyond the initial assessment of the vessel ’ s maintenance team .
A combination of visual inspections , non-destructive testing and root cause analysis revealed damage to the 3rd , 8th and 9th stages of the turbine . The trailing edges of the 3rd stage had suffered impact damage , the 8th stage had blades that were bent and cracked and the 9th stage had visible cracks and a completely broken blade . Bolts on the upper cover diaphragm were damaged and the retaining rings couldn ’ t be removed . In addition to this , the rotor journals had light scoring . It was also determined that the labyrinth seals would need to be replaced to ensure reliable running long into the future .
Ready to set sail
With all repair work complete , the turbine was reinstalled on the ship and commissioned . As a result , the vessel could return to sea on schedule and begin generating profits for the operator .
The repaired turbine is expected to offer an extended service life of up to 15 years , ensuring that the ship can continue to reliably deliver cargo long into the future . In addition , the customer was assured by Sulzer ’ s international coordination and overall project management despite a rather sophisticated repair .
After some underwhelming experiences with other service providers , Sulzer was able to win the trust and confidence of the customer . Consequently , the shipping company is organizing additional turbine and generator maintenance jobs with Sulzer for its container ships that will be travelling through Asia over the coming months .
For further information , please visit www . sulzer . com
68 PECM Issue 67