Metal Stitching Repair on a Small Diesel Engine Bed Plate

A customer reached out to us in May 2022 in Singapore, asking for our help in repairing a damaged two-stroke engine bed plate. The cast iron bed plate suffered from cracks and missing material, inflicted as consequential damage following a connecting rod failure.

Our experts immediately carried out an inspection on board. They found this main engine bed plate to be repairable, but determined that the damage area could not be accessed properly without removing the engine’s A-frame. The shipowner therefore decided to bring the 19-year old, 100 m long asphalt carrier alongside a ship repair yard in Singapore.

“We are very satisfied with your service.”

Customer’s Technical Superintendent, by email, August 2022

Damage location
Damage location

While the shipyard’s personnel dismantled the ø 38 cm bore, japanese-made engine, our specialists prepared a repair plan and discussed it with the customer and classification society. Simultaneously, they arranged for a tailor-made repair patch to be made, including a set of accompanying classification certificates.

In late June 2022, once the engine had been suitable dismantled, three metal stitching specialists from QuantiServ Singapore carried out the bed plate repair. They first removed all damaged and deformed material and dressed up the facture. They then installed the newly fabricated cast iron repair patch with Castmaster™ stitching pins. They repaired all cracks in the same manner, including a 150 mm long one that had not been visible until the deformed material had been removed.

Once all stitching pins had been installed, our specialists then added high-strength locks, made of heat treated steel. These are always installed perpendicular to the fracture line and serve to distribute stresses over a wider area. They also add additional strength to the repair.

The completed repair was thoroughly checked by Magnetic Particle Inspection (MPI). The attending classification surveyor witnessed this. And last but not least, our in-situ team carried out a laser alignment check of the main bearing pockets. This was done to rule out any deformation in the bedplate due to the impact forces exerted upon it by the broken connecting rod.

Damaged bed plate prior to repair
Damaged bed plate prior to repair
Damage area prepared for stitching repairs
Damage area prepared for stitching repairs
Classification surveyor attending the Magnetic Particle Inspection (MPI)
Class surveyor witnessing Magnetic Particle Inspection
Installation of stitching pins along the crack line
Installation of stitching pins along the crack line
Stitching in the repair patch
Stitching in the repair patch
Magnetic Particle Inspection (MPI) of the completed repair
Magnetic Particle Inspection (MPI) of the completed repair
Magnetic Particle Inspection (MPI) of the completed repair
Magnetic Particle Inspection (MPI) of the completed repair
Preparing the repaired bed plate for laser alignment check of the main bearing pockets
Preparing the repaired bed plate for laser alignment check of the main bearing pockets

More Than 1,000 QS50K Pistons Delivered – And Counting!

In 2019, following an extensive research and testing period, we have introduced the first QS50K pistons into the market. It was the beginning of a lasting success story: Ever since, we have produced and delivered more than 1’000 pieces, to many different customers.

These pistons are now installed all around the world, in ocean going vessels and in power plants. They are performing extremely well and achieve time between overhauls (TBO) that hitherto were unthinkable. The earliest QS50K pistons have accumulated well over 30,000 running hours and are still in service!

Rebuilding the piston ring grooves
Rebuilding the piston ring grooves

Benefits of the QS50K technology

With the introduction of the QS50K coating technology, QuantiServ has redefined the piston reconditioning process. This proprietary technology was developed by QuantiServ and offers the following important advantages:

    • Extremely durable, wear resistant coating, resulting in very long life-time / time between overhauls (TBO)
    • Fully automated process carried out by a robot, resulting in a top-quality product due to the robot’s very high accuracy, repeatability and consistency.
    • Faster than chromium plating, therefore shorter turnaround times
    • Less heat input into the piston, eliminating any residual stresses that over time could develop into cracks
    • Environmentally sound, non-toxic process

Availability

We offer the QS50K technology for any engine brand and for any cylinder bore above ø 48 cm. The QS50K pistons that we have delivered so far covered the bore range, from ø 48 cm to ø 98 cm. They were destined for engines manufactured by the big three OEMs, in an approximately 45%/45%/10% ratio.

At this moment, our recon centres in Kruiningen (The Netherlands) and Suzhou (China) are equipped with the required machinery to offer this product. Our large recon centre in Singapore will follow very soon.

24,000 Hour Ring Groove Life Time. Guaranteed!

The quality of our QS50K coated ring grooves is so good that we now offer a 24,000 hour* warranty on fully reconditioned, QS50K coated two-stroke pistons!

Contact us for details

*pro-rata, 24,000 running hours or three years after delivery, whichever comes first

To give maximum flexibility to our customers, we offer three different ways of working to chose from:

  1. Reconditioning on exchange. The customer gets a newly reconditioned component delivered from one of our four reconditioning centres. Once he has installed the component into his engine, he returns his old part to us.
  2. Reconditioning of the customer’s own part. The customer sends the component to be reconditioned to a QuantiServ reconditioning centre, where it undergoes professional reconditioning after which it is returned to the customer.
  3. Straight sale. The customer purchases a reconditioned piston from us, without returning an old one.

We can apply the QS50K coating to pistons that are undergoing full or partial reconditioning.

Full reconditioning

The entire top surface and ring groove area is first machined off and then rebuilt by robotic MIG or SAW welding. Thereafter, the piston undergoes final machining before the QS50K coating is applied to the ring grooves. The last step is grinding of the ring grooves, which completes the full reconditioning process.

If it is requested by the customer, then we can coat the top of the piston by a protective layer of Inconel. This can be a good solution for engines that suffer from excessive hot corrosion at the piston top.

Partial reconditioning

If only the ring grooves are worn and if a piston is in otherwise good condition, then partial reconditioning is possible. A precondition is, however, that none of the ring grooves has worn so much that not only the chromium layer but the steel substrate itself has worn. In this case, partial reconditioning is not possible and full reconditioning is the only remedy.

During partial reconditioning, any remaining chromium is removed before the QS50K layer is applied to the ring grooves. All mating surfaces will be skimmed, to remove any signs of fretting corrosion and if there are small internal cracks, then these will be repaired too.

 

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Our reconditioning centres

We operate four reconditioning centres that are strategically located along major shipping routes: Singapore, Kruiningen (The Netherlands), Suzhou (China), Dubai. Each of the four centres carries a large inventory, so it can offer components on exchange in addition to reconditioning the customer’s own part. Both ways of working are available, it is entirely the customer’s choice.

Our reconditioning centres are the most modern ones within our industry. Welding and QS50K coating is typically performed by robots and machining is done on numerically controlled (NC) machines.

QuantiServ Reconditioning Centres
We operate four reconditioning centres globally.

This enables us to provide consistently high quality and short turn-around times at attractive prices.

 

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QuantiServ Suzhou Workshop
The QuantiServ reconditioning workshop in Suzhou, China. The others are in Singapore, Dubai and Kruiningen (The Netherlands).

Metal Stitching and Line Boring on a Japanese Auxiliary Engine Block

In late 2021, a Greek owner of a 4250 TEU container vessel approached us for the repair of an auxiliary engine. The 26-bore, japanese-made engine had suffered from a so-called “side kick” – the connecting rod had smashed a hole in the engine block, above cylinder #2.

As the vessel was about to call Singapore, QuantiServ Singapore arranged for one of its metal stitching specialists to go on board to conduct a comprehensive damage assessment.

As is nowadays almost always the case, our specialist deemed the engine block damage to be repairable. We engineered a repair proposal, consisting of metal stitching and in-situ machining to be carried out in our workshop in Singapore. The customer gladly accepted our repair proposal due to the obvious time and cost savings compared to replacing the engine block. He made arrangements for the 12-year old engine block to be sent to our Singapore workshop for repair.

The block arrived at our workshop in March 2022 and was immediately attended to. The repair work carried out included the following main steps:

  • We arranged for a tailor-made cast iron repair patch to be cast in a certified partner foundry. The repair patch was then stitched in place using Castmaster™ stitching pins and matching locks. This provides for a permanent, very strong repair.
  • As the damage extended into the lower cylinder liner bore, a repair sleeve was installed there. The repair sleeve guarantees a good fit with the cylinder liner o-rings, preventing water leaks.
  • The ovality of seven out of nine main bearing pockets was found to be excessive. This finding was independent of the accident but needed attention too. We corrected the ovality with in-situ line boring.
  • All eight cylinder liner landing surfaces in the engine block were machined to clear them from corrosion and cavitation damage.

A Magnetic Particle Inspection (MPI) was carried out on the completed repair to the satisfaction of the customer and attending class surveyor.

From start to finish, the repair work took approximately four weeks to complete, well in time for the engine block to be sent back to the vessel during her next routine call to Singapore.

Engine block damage at cylinder number 2
Damaged engine block
Installation of stitching pins
Installation of stitching pins
Machining of the cylinder liner landing surface
Machining of the cylinder liner landing surface
Engine block debris
Engine block debris
Repair patch installed
Repair patch installed
Cylinder liner landing surface after machining
Cylinder liner landing surface after machining
Newly casted repair patch
Newly casted repair patch
MPI inspection after stitching
MPI inspection after stitching
Another job well done
After completion. Another repair job well done!

Crankpin Grinding in 18 Hours, Between Christmas and New Year

True to our credo of “whenever, wherever”, our in-situ machining specialists in Singapore completed a repair assignment during the final days of 2021 in just 18 hours.

At 22:00 on 29 December 2021, at a time when most people traditionally enjoy seasonal festivities and spend time with their loved ones, they boarded the ship with just a few hours notice. The vessel, a German-owned 4200 TEU box ship had arrived in Singapore 9.5 hours earlier and was now waiting for them on anchorage. Once our specialists were on board, the vessel proceeded to the terminal while our colleagues immediately went to work on one of the three Japanese-made auxiliary engines. This engine had suffered a crankpin failure on one of its units.

The engine is equipped with a hardened crankshaft. This means that the crankpin could not be machined but had to be ground. Through the night, our two specialists ground the pin from 260.00 mm to 259.50 mm so that the first undersize bearing can be fitted.

In-situ crankpin grinding
In-situ crankpin grinding

At regular intervals during and after the grinding and subsequent polishing work, our two in-situ specialists verified the dimensional accuracy and the hardness of the pin. The final hardness was measured to be 625 HB, which is a very good value. And for final verification, our specialists also checked the contact area on the completed pin. For this, they used a specially manufactured template and engineering blue.

Our specialists completed their work and disembarked from the vessel at 16:00 on 30 December 2021. It took them just 18 hours to repair the crankshaft!

Fifty minutes later, after the completion of cargo operations, the vessel left Singapore for China. The ship crew will install the new – 0.50 mm undersize bearing shells once they arrive on board and will then restart the engine.

Verifying the contact area on the completed crankpin
Verifying the contact area on the completed crankpin
Surface roughness measurement on the completed crankpin
Final surface roughness measurement

The Benefits of a Global Footprint: Connecting Rod Repair “On the Fly”

If your ships operate globally, then you benefit from relying on a service partner that has a truly global footprint. This post neatly exemplifies this fact.

The subject is an American-owned, 9’000 TEU container ship with an 82-bore main engine. The vessel experiences a crosshead bearing failure while crossing the Atlantic. We repaired it “on the fly” with a minimum of down-time:

  1. During the last days of 2020, the vessel experiences a severe crosshead bearing failure close to Bermuda island. The crosshead pin and connecting rod are found severely damaged and are in need of repair or replacement. Our experts assess the situation and give remote assistance to the crew during removal of the connecting rod from the engine. Once that is done, the vessel continues its journey towards Europe with one cylinder cut out.
  2. On 15 January 2021, the vessel arrives in Algeciras. The damaged connecting rod gets offloaded and is transported by truck to our workshop in Genoa.
  3. It arrives at our works on 18 January and at once undergoes repairing. After completion of the repair, we ship the connecting rod by air freight from Milan, via Doha, to Singapore. It arrives in Singapore in the morning of 05 February 2021.
  4. Our technicians in Singapore assist the crew to reinstall it. After a short and successful trial run, the ship continues its journey towards the South China Sea.

QuantiServ operates out of 15 locations that are strategically placed along major shipping routes or close to important ports. Wherever your ships go, we are never far away.

Severely damaged crosshead bearing bore
Severely damaged crosshead bearing bore
Close-up of the damaged area
Close-up of the damaged area
While sailing with one cylinder cut out
While sailing with one cylinder cut out
After initial cleaning
After initial cleaning
Remachining of the bore
Remachining of the bore in Genoa
Crosshead bearing bore after machining
Crosshead bearing bore after machining
Corrosion protected and ready for dispatch
Corrosion protected and ready for dispatch
Connecting Rod ready for dispatch
Connecting Rod ready for dispatch

In-situ Straightening (Peening) of a Bent Crankshaft

The pictures below show the straightening and subsequent machining of a bent crankshaft, carried out by our specialists in Singapore. All work was carried out in-situ. The crankshaft was found bent following a crankpin bearing failure.

The crankshaft belongs to a 12-cylinder, 40-bore engine installed on a dredger. A straightness check revealed that its run-out was 0.18 mm, which is far beyond the acceptable threshold.

Our specialists therefore carried out in-situ straightening by peening the shaft. Peening is a cold-process that consists of applying a small force repeatedly to the correct places to bring the shaft back to its original straightness. This took one day and resulted in an improvement of the run-out from 0.18 mm to 0.03 mm.

After straightening, our specialists machined the crankpin to -7.00 under-size and then polished it.

Reconditioning of Two Large Hydraulic Rams in Singapore

Ram 2

In January 2018 our reconditioning centre in Singapore carried out the overhauling and reconditioning of two large hydraulic rams belonging to a major American offshore company. The rams are part of knuckle boom cranes that are installed on an ultra-deep water drill ship that operates off the coast of Myanmar.

We frequently perform this kind of work on rams large and small, often for offshore and construction companies.

The work included chemical stripping of the worn chromium layers, followed by new plating with an underlay of nickel and top-layer of chromium. We also honed the barrel, changed all seals and carried out various NDT tests on the rod and barrel.

All work was carried out in-house and was completed within 14 days.

At QuantiServ Singapore we are able to carry out galvanic nickel and hard-chrome plating and grinding of up to 6,000 mm length and 800 mm diameter.

Update April 2018:

The customer was very satisfied with the two rams that we overhauled for him in January 2018. In March he sent us another two similar ones belonging to the same ship. We have just finished the work on them, which means that we have now reconditioned all four units that are installed on this drill ship.

It’s All in a Month’s Work for QuantiServ’s In-situ Machining Crew!

On board various ships and oil rigs, in power plants and in factories: Far from being idle during the holiday season, during the month of July our in-situ specialists were maintaining and repairing our customers’ equipment in 26 different countries, across four continents. No other in-situ machining company has such global reach and completes more projects than QuantiServ. Wherever the location, whatever the damage – it’s all in a month’s work for us!

Explore the interactive map below and discover what services our in-situ engineers have been providing to our customers during the month of July 2017.

QuantiServ at the Sea Asia 2017 Exhibition in Singapore

Sea Asia Exhibition 4Our participation at the recently held Sea Asia 2017 in Singapore was a big success. We displayed our metal stitching and in-situ machining solutions, as well as the refurbishment of four-stroke cylinder covers by furnace brazing, which we are particularly proud of. These solutions created quite a lot of customer interest and led to many interesting discussions.

Our next stop will be the Norshipping Exhibition in Oslo, 30 May – 02 June 2017, where we will be at booth D 05-34. Come and visit us there.

Crank pin machining mock-up

Crank pin in-situ machining mock-up

Furnace brazed 32-bore 4-stroke cylinder cover

Furnace brazed 32-bore 4-stroke cylinder cover

Fully reconditioned 35-bore 2-stroke cylinder cover

Fully reconditioned 35-bore 2-stroke cylinder cover

ABC Engineering Pte. Ltd. in Singapore joins QuantiServ

abc-logoWe are very honoured and happy to announce that all personnel from ABC Engineering Pte. Ltd. have decided to join QuantiServ with effect from 1 April 2017. This combination of forces further extends QuantiServ’s offering and geographical reach, particularly in Indonesia.

ABC Engineering is a well known company with excellent reputation that has been providing in-situ crankshaft and engine block repair services to customers in Southeast Asia since the 1970s.

The personnel from ABC Engineering and QuantiServ look forward to continue to serve ABC Engineering’s customers as reliably and to the same exacting standards as they always have.

QuantiServ Singapore’s own wharf again able to accommodate vessels

Maintenance dredging at our own wharf in Singapore has just been completed. We are now again able to accommodate vessels of up to 110 meter length and 5.0 meter draft for repair, right next to our very well equipped 10,000 square meter workshop. It does not get any more convenient and economical than this!

Our very own wharf in Singapore, right next to our workshop.

Our newly dredged, very own wharf in Singapore, right next to our workshop.