Flywheel In-situ Repair on the US East Coast

Starting up a handymax bulk carrier’s 48-bore, two-stroke main engine with its turning gear engaged resulted in the turning gear shattered and in damage to 12 consecutive teeth on the flywheel.

The turning gear was damaged beyond repair and had to be replaced. Not only was its housing shattered but the planetary gears were completely destroyed too.

Faced with the costly and unpalatable reality of most likely having to replace the flywheel as well, the ship management company turned to QuantiServ for help. Always liking a challenge when we see one, we engineered and delivered a comprehensive solution that consisted of the following:

  • Inspection on board
  • CAD and FEA modeling to engineer an economical yet structurally very strong solution
  • CNC machining of repair inserts in our workshop
  • In-situ machining of the flywheel on board
  • Stitching the repair inserts in place

Our in-situ machining and metal stitching specialists carried out the work in February 2019, during the vessel’s port stay in Florida, without interfering in her schedule.

QuantiServ carries out a number of gearwheel repair assignments every year, mostly for industrial, marine and mining customers.

Repair of Externally Damaged Cylinder Liners

Our reconditioning centre in the Netherlands has just completed the repair of yet another externally damaged cylinder liner. We carry out this kind of repair quite frequently.

External damage to a cylinder liner is usually caused by rough handling. Liners are made of cast iron and cast iron is brittle. If a liner is dropped on the floor or is otherwise handled roughly, then material may chip off. Most damages occur in the vicinity of the o-ring grooves, where the material is thin.

If such a liner has to be scraped, then it is obviously a big waste. This is why we frequently repair them. Typically, the repair costs amount to approximately 20% of the replacement costs.

The following pictures show three examples of such repairs on liners of different sizes: An 84-bore liner, a 72-bore one and a 60-bore one.

 

Metal Stitching of an Engine Block in Tehran, Iran

 

Metal stitching on an auxiliary engine block

Our metal stitching expert traveled to Tehran, Iran, last week to repair a four-stroke main engine block on board a tug boat. It had a crack between the charge air space duct and the cooling water space around one of the cylinder liners, as well as some dents. Cooling water was leaking into the charge air space.

To repair the damage took our expert just one full day of work. The customer was very pleased with the result and was impressed by how fast the repair was being carried out.

Once again it was proved that metal stitching is a quick and reliable solution for cast iron repairs – for jobs big and small!

 

 

Enjoying a cup of tea in the engine room after a job well done

Enjoying a cup of tea in the engine room after a job well done

Metal stitching

A very happy customer

Metal stitching test piece resists water pressure of 12 bars

Metal stitching test piece resists water pressure of 12 bars

Metal stitching, as long as it is carefully and properly carried out by trained technicians, is tight against gases and liquids. To demonstrate this, QuantiServ has manufactured two cast iron half-shells and has joined them together by metal stitching. The resulting container was successfully pressurized to 12 bars (175 psi) and no leak was observed.

This proves that there is no issue to repair cooling water spaces in for example engine blocks, where the cooling water pressure typically lies around 3 – 4 bars (44 – 58 psi), by metal stitching. In fact we knew this well, because we have done it successfully many times. But that the stitching could easily withstand 12 bars impressed even us.