“Repairing the Unrepairable” – Watch Webinar Recording

On 13 April 2021 we broadcasted a very informative webinar titled “Repairing the Unrepairable”.

In this webinar, Johannes Roberts from QuantiServ Sweden introduced QuantiServ’s in-situ machining solutions while Jeff Reeds from Lock-N-Stitch USA focused on metal stitching and thread repairs. Petter Bodman acted as moderator.

If you missed this session, or would like to watch it again, here is the recording:

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

Comprehensive Repairs: We Succeed Where Others Fail

Example of a Comprehensive Crankshaft Repair Assignment, Started and Then Abandoned by a Competitor

During the last days of 2020, our in-situ repair specialists out of Gothenburg, Sweden, repaired a damaged crankpin on a Korean-made four-stroke engine. The engine has a 32 cm bore and a 40 cm stroke and is installed on a 5 year old, 9’200 TEU container vessel.

When contacted by the ship owner, we proposed to carry out an inspection on board. The shipowner agreed, whereafter our specialist from QuantiServ Panama carried out a thorough inspection in Panama. To our disappointment, the ship owner then awarded the repair work to another company. Their technicians machined the pin to – 0.80 mm undersize and then gave up and disembarked from the vessel.

Finding himself in a tight spot, the customer came back to us and asked us if we could continue the repair that was abandoned by the other company. We took the opportunity to demonstrate that we succeed where others fail. Two in-situ specialists from QuantiServ Sweden joined the vessel and successfully carried out the repair work while  underway from Lima, Peru to Manzanillo, Mexico. They solved the problems as follows:

Issue Action taken Result
Damaged surface and cracks Machining Crankpin under-sized to – 3.00 mm
Excessive hardness Heat treatment (Annealing) Hardness Reduced from 620 HB to 255 HB
Bent crankshaft Peening Run-out reduced from 0.27 mm to 0.03 mm

The customer was very happy with the skills and performance of our specialists. He therefore kept them on board for subsequent reassembly and overhaul works and he also asked us to supervise an  overhaul of a similar engine installed on a sister vessel.

Metal Stitching on Historic Bridge in Washington DC, United States

Our American colleagues have just completed metal stitching repairs on a historic bridge crossing the Chesapeake and Ohio Canal.

The Canal

The Chesapeake and Ohio Canal stretches over a distance of 297 km (184.5 miles) from Cumberland, Maryland, to Georgetown, DC on the US East Coast. It was constructed between 1828 and 1850 by approximately 35’000 labourers, mostly immigrants from Europe. Its purpose was to enable the shipment of coal from the rural but coal rich Allegheny Mountains to the much more densely populated regions and sea ports along the Atlantic coast.

The canal was operated from 1831 until 1924. While originally built for the transportation of coal, it quickly became an important lifeline for communities along its way.

The bridge we assisted restoring. Visible in the foreground is one of the canal's 74 lifting locks
The bridge we assisted restoring. Visible in the foreground is one of the canal's 74 lifting locks

Boats were used to ship agricultural produce and lumber to markets downstreams. They then returned loaded with manufactured goods. These boats typically did not have their own means of propulsion, but were pulled along by mules walking on towpaths located at either side of the canal.

One end of the canal, Cumberland, lies at an altitude 184 m (605 feet) higher than the other end, Georgetown.  This meant that lift locks were needed – in total 74 of them were constructed. One of them is visible in the picture above, in front of the bridge.

In addition to the 74 locks, the canal also featured many other feats of early engineering. There were seven dams, about 240 culverts, a few aqueducts, a tunnel 950 meters (3’120 feet) long and, of course, bridges. A few of these bridges still exist today, such as the one that our metal stitching specialists proudly helped to restore.

Metal Stitching Work Performed

Exposure to the elements for over 150 years took its toll on the bridge structure. Cracks had developed in many of the vertical cast iron columns carrying the bridge deck. In all likelyhood, the cracks that were found were freeze cracks. Freezing temperatures are common in Georgetown from the middle of December until early March. If water enters one of the exposed, hollow columns and gets trapped there, then it very likely freezes during a cold winter night. Over time, the freeze/thaw cycles led to cracks.

All of the cracks ran in vertical direction. They had a cumulative lenght of 7’400 mm (25 feet). Our specialists sealed them with stitching pins and added perpendicular locks for extra strength. They then ground the locks and pins flush and made them blend in well with the weathered surface texture of the antique columns.

For the work to be carried out, a section of the canal had to be drained
For the work to be carried out, a section of the canal had to be drained
The width of the cracks required pins with a large diameter to length ratio
The width of the cracks required pins with a large diameter to length ratio
Installation of stitching pins
Installation of stitching pins: Close to 1'000 were used for this project
In many locations, the cracks were wide open
On some of the columns, the cracks had caused a gap of up to 12 mm
Our specialists stitched over 7 meters of cracks
On this restoration project, our specialists stitched over 7.4 meters (25 feet) of cracks
Once completed, the repair blends in very well
The completed repair blends in very well
Stitching in progress
Metal stitching in progress: Stitching pins installed in an overlapping pattern
Locks were added for extra strength
Metal stitching in progress: Adding of locks, perpendicularly to the crack, for extra strength

Nuclear Power Plant Emergency Diesel Generator Block Repair

The operational requirements for emergency diesel generators (EDG) installed in nuclear power plant are very strict and demanding. In case of an emergency event leading to the loss of off-site power, a nuclear power plant’s EDGs are meant to supply independent, redundant power. From this follows that they have to start reliably and quickly  under any condition and must be able to take on load almost instantaneously, which generally means within about 10 Seconds. This is tested regularly under real-life conditions, according to the prevailing nuclear codes, standards and regulations.

This testing regimen of sudden load changes puts an enourmous thermal loading on most of the EDG’s internal components and on its auxiliary systems. Excessive wear and tear is therefore to be expected and is indeed a small price to pay for ensuring plant safety.

For years, QuantiServ has been supporting nuclear power plant operators and contractors serving them with specialist services throughout the long service life of the plants. We are happy to play a small, but nevertheless important role in ensuring safe and reliable electricity supply from whatever source.

The enclosed pictures show the machining of an impressively large, 20-cylinder engine with a rated output of 4000 kw, a cylinder bore of 240 mm and a stroke of 230 mm. It suffered from a small internal defect, caused by wear and tear, that we successfully remedied in our workshop in The Netherlands in 2020.

Metal Stitching Repair of Two-stroke Engine Bedplates

This post introduces metal stitching as an attractive solution to repair cracks in two-stroke engine bed plates.

Background

The term “metal stiching” is most commonly associated with the repair of cast iron parts, as an alternative to welding, to which cast iron does not lend itself easily. Due to its brittle nature, cast iron tends to fail again rapidly after welding, unless the welding takes place at very elevated and uniform temperatures. These conditions are hard, if not impossible, to achieve in most workshops, let alone at site.

It is less commonly known that metal stitching is also an increasingly often used process for the repair of steel parts, where welding actually would be possible. There are good reasons for chosing stitching over welding, even in steel.

First and foremost, metal stitching is a cold process and thus does not lead to deformation or latent heat-induced stresses in the part being repaired. Post-repair (in-situ) machining to correct these deformations is therefore rarely required.

Second, as we have shown through independent labaratory testing, a metal stitched junction that has been made by a qualified operator using Lock-N-Stitch tools and stitching components, exhibits a tensile and fatigue strength that is equal to, or better, than that of a welded junction.

During the last few years, QuantiServ have gained extensive experience in applying the metal stitching process to crack repairs in two-stroke engine bedplates and columns. Two instructive cases are discussed below, both involving container ships with 96-bore engines.

On the first vessel, the stitching was carried out in stages, during successive port stays. On the second, the repair was carried out during a regularly scheduled dry docking in China.

Case 1: Bed Plate Metal Stitching During Successive Port Stays

In the course of a crank case inspection, a 800 mm long crack was found in the main engine bedplate on board a 15,500 TEU container vessel in 2019. Contacted by the ship owner, we carried out an assessment. It revealed that the crack would propagate quickly if the engine, a 14-cylinder, 96-bore one, would continue to operate at, or near, its nominal speed.

We proposed to the customer to carry out the repair while the ship remained in service. As the thirteen year old vessel was engaged in a “high-rate/less-time” trade, the customer of course jumped at the opportunity to get the crack repaired without any vessel off-hire. Following a review of the vessel’s trading pattern, we decided to carry out the repair during successive port stays during the vessel’s Northern European loop.

Our specialists commenced their work as soon as the vessel was alongside in port and did not stop anymore until the engine had to be restarted. They then rested during the short voyage to the next port, where they continued in the same manner.

While working, our specialists discovered that the crack in fact was about 300 mm longer than had previously been reported by the crew. This meant that the time in Europe was insufficient to repair the crack in its entirety.

Our specialists revisited the vessel a few months later, again in Europe, to repair the previously unreported section of the crack. All in all, it took seven port stays of a few hours each to repair the bedplate.

Attendance Voyage Number of port stays
First Antwerp – London 4
Second Bremerhaven – Antwerp 3

In total, we repaired on this bed plate over 800 mm of crack in steel plates with thickness ranging from 18 – 50 mm, without a single day of off-hire or otherwise interfering into the vessel schedule.

To repair this bed plate, metal stitching was chosen over welding because it has the following advantages:

  • The vessel stayed in operation throughout the repair. The stitching was done in stages during port stays, a few centimeters at a time. With welding, this would not have been possible. The vessel would have had to be taken out of operation for around three weeks.
  • Lower costs, compared to welding. A competitor proposed to carry out repair by welding in 20 days. We repaired it by stitching in 12 days. Less time spent means less costs.
  • For metal stitching, a hot work permit is not normally required. Such a permit would be very difficult to get in container terminals, meaning that welding would not have been possible from a safety point of view.
Crack runs from the girder side plate down into the oil sump
The crack runs from girder side plate down into the oil sump
Metal stitching repair in progress
Crack without the sealing compound that was temporarily applied
View of the crack without the sealing compound that was temporarily applied
The completed repair, prior to cleaning and painting
The completed repair, prior to cleaning and painting

Case 2: Bedplate Stitching During Dry Docking

The second case discussed here concerns an 8-year old, 13,000 TEU container vessel with a 12-cylinder, 96-bore main engine. The crack discovered on this engine was quite similar to the one described above.

Since the crack was discovered shortly before the vessel was scheduled to undergo a routine dry docking, it was decided to repair it during the docking period in China in 2020.

The crack extended over a length of 750 mm in steel plates with thickness ranging from 18 – 50 mm. Repairing it took our specialists eight days, working in single shifts.

Crack runs from girder side plate down to oil sump
The crack runs from the girder side plate down into the oil sump
Stitching of the crack in progress
Metal stitching of the crack in progress
The completed repair prior to repainting
The completed repair prior to repainting

The first two-stroke diesel engine that we have metal stitched has meanwhile accumulated 77,000 hours. We repaired a 600 mm long crack in the gear column (A-frame), in 2006. The repair is still in perfect condition today.

04 January 2021

Read more

The two repairs presented above were carried out using stitching components from the American company Lock-N-Stitch. We would like to stress that we have labaratory-tested other products available in the market and that we have found their strength to be insufficient for demanding applications like these.

Read more about metal stitching

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.

Jaw Crusher In-situ Machining, 700 Meters Underground

In November 2018, our in-situ specialists carried out machining work in one of the world’s most modern underground mines, located in central Sweden. The mine processes about 2.5 million tones of ore annually and produces gold, silver, zinc and lead.

The assignment lasted about a week and consisted of milling, drilling and tapping work on a large jaw crusher located at a depth of 700 meters. There, the ore is crushed before it is hoisted to the surface for further processing.

Our specialists machined the upper section of both the stationary and the moving jaw. On each jaw, they milled off about 26,000 cm3 of steel and then drilled and tapped them so that a newly fabricated section could be bolted on.

Brand New Light Surface Grinding Tools Now Available for Sale!

We are asked frequently, whether we are selling the in-situ machining tools that we have developed and manufactured and that our specialists use in the field. While such requests are of course flattering and while we appreciate that other companies find our tools appealing and would like to purchase them, we have up to today always politely declined such request. The reason is that we first and foremost see ourselves as a top-notch in-situ machining company and not as a tool manufacturer. Our tools are thus a means to end – the more accurate and efficient they are, the better the result of our machining assignment that our customer comes to enjoy.

Our very newest Light Surface Grinding machine (LSG) has now proven to be so popular, that we have decided to break with tradition and to make it available for sale.

The machine was designed to be as compact and portable as possible. It has an adjustable base, no heavy adapter plates are therefore necessary. Its total weight is 30 kg (66 lbs). This is significantly less than any comparable machine currently on the market and means that it does not have to be sent as cargo to a ship or power plant, but can be brought along as checked-in luggage.

The tool’s main purpose is to quickly and accurately skim the cylinder liner landing surfaces at the top of medium-speed engine blocks. It can be used to machine diameters of 360 – 670 mm, which makes it suitable for engines with a bore size of 260 – 500 mm. Additional accessories to also skim the landing surface on the cylinder liner are also available.

The advantages of the Light Surface Grinder (LSG) are many:

  • High accuracy
  • Fast to set up and easy to use
  • Compact design
  • No adapter plates are necessary as the machine’s base is continuously adjustable
  • A single machine covers the range from ⌀ 360 – 670 mm
  • Total weight = 30 kg (66 lbs)

Contact us for more information, or to order one.

Contact us

 

 

Four-stroke Cylinder Head Valve Seat Bore Repair

Our reconditioning centre in Vancouver has just carried out furnace brazing of 13 pieces of 32-bore four-stroke engine cylinder heads for Canada’s premier ferry operator.

The valve seat bores were seriously damaged by cavitation and corrosion. Machining to over-size was not possible anymore because this had already been done during past overhauls and the maximum diameter had already been reached.

QuantiServ’s unique process starts with the generous removal of any damaged material around the valve seat bores. Thereafter steel sleeves are soldered in in a vacuum oven before finishing off the heads by NC machining of the valve seat bores. Standard-size valve seats can then be installed, followed by pressure testing of each cylinder head.

QuantiServ’s furnace brazing process is applicable to four-stroke cylinder heads of any engine type with a cylinder bore diameter of > 200 mm. It is patented word-wide and classification approved (LR / ABS). Classification certificates are available on request.

Condition of the cylinder heads before reconditioning:

 

Condition of the cylinder heads after reconditioning, before installation of the valve seats:

Read more

 

Two-stroke Bedplate Line Boring in Mexico

When a six year old bulk carrier suffered main bearing failures on its Japanese-made main engine, QuantiServ was called in for an initial inspection and for discussions on how to arrange the repair in the fastest and most economical way. The inspection in Veracruz, Mexico, showed that main bearings # 7 and 8 failed and that the crankshaft as well as the main bearing pockets were damaged.

The crankshaft was beyond repair and had to be replaced by a new one. The bed plate, on the other hand, could be recovered by line boring. With the engine frame lifted up, QuantiServ’s in-situ specialists carried out

  • a thorough inspection of the bedplate, including NDT crack detection and hardness measurements
  • laser alignment checks before line boring
  • line boring of main bearing pockets # 7 and 8
  • laser alignment checks after line boring
  • blueing checks

The work was carried out successfully while the vessel was alongside in the shipyard in Mexico.

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.

Reconditioning of Fourteen 96-bore Cylinder Covers

In November 2017, our Reconditioning Centre in Shanghai carried out reconditioning of fourteen cylinder covers for a major European ship owner. These covers came from one of the world’s largest container ships, equipped with a 14-cylinder, 96-bore main engine.

All fourteen cylinder covers and all fourteen exhaust valves were reconditioned within a period of less than one month, while the vessel was undergoing steel work at a shipyard in Qingdao.

This was the third vessel out of a series of similar vessels for the same customer. QuantiServ carried out the reconditioning work for all these vessels.

Significant Reconditioning and Field Service Job in Shanghai

In September our Reconditioning Centre in Shanghai carried out a a major reconditioning and field service order for an Iranian-owned tanker that was docked in a Chinese shipyard. This example shoes well the breadth of QuantiServ’s offering.

The following components were reconditioned:

  • 8 piston rods
  • 7 piston crowns
  • 7 cylinder covers
  • 6 exhaust valves
  • 7 crosshead pins
  • plus a number of smaller, related components

We also sourced for the customer a couple of new crosshead and crankpin bearings while we re-babbitted others, such as for example guide shoes.

QuantiServ engineers also carried out the overhaul work on board, supervised the oil flushing and attended the seatrial after the docking. We also replaced the stern tube shaft seals and in-situ polished some of the crankpin journals.

All the work was completed in 32 days.

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.

 

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.

Flywheel Teeth Dentistry on a Container Ship in Hong Kong

 

Our in-situ specialists from QuantiServ Dubai have just completed another flywheel repair. This time it was for a very large European owner, on one of their large container ships with a 12-cylinder, 96-bore engine while on anchorage in Hong Kong. Our specialists machined off two damaged teeth and installed an insert, which they had pre-fabricated at their workshop before boarding the vessel and which they sent on board jointly with the in-situ tools.
The total work took 42 hours – three long days of work – and the result is something that they can be very proud of!

Damaged flywheel with two severely damaged teeth

Damaged flywheel with two severely damaged teeth

Removal of the damaged teeth by in-situ milling

Removal of the damaged teeth by in-situ milling

Pre-fabricated insert installed, repair completed

Pre-fabricated insert installed, repair completed

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.

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

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.

 

In-situ machining of lateral surfaces on 20V32 engine block in Bangladesh

Lateral surfaces before and after in-situ machining

Lateral surfaces before and after in-situ machining

In-situ machining of lateral surfaces on a 20V32 engine block in a power plant in Bangladesh

In October 2016, QuantiServ received an urgent request to carry out in-situ machining on a 20-cylinder 32-bore engine block in a power plant in Bangladesh. During the replacement of the crankshaft it was noticed that both lateral surfaces of main bearing cap number 5 showed signs of severe fretting and were in need of machining.

Immediately, in-situ machining equipment was prepared at QuantiServ’s Dubai workshop and was sent to site. Once the equipment had arrived at site, QuantiServ’s engineers from Dubai performed in-situ machining on the engine block to achieve a clean surface that was free from damage. The in-situ machining process was constantly monitored by laser to ensure perfect alignment and adherence to very tight machining tolerances.

The main bearing cap was sent to a local workshop in Bangladesh for machining and installation of compensation plates. This process was supervised by QuantiServ’s engineers. Once the machining was completed, all mating surfaces for the main bearing cap were checked with marker blue to ensure a perfect fit.

Once the work was completed, a final check by laser on the assembled bearing cap showed that both the bore alignment and diameter fully conformed to the engine maker’s specification.

In-situ flywheel repair on a 3400 TEU container vessel in Mombasa, Kenya

milling-and-tapping-quantiserv

Milling and tapping, preparation for the teeth inserts to be installed

In-situ flywheel repair on a 3400 TEU container vessel in Mombasa, Kenya

QuantiServ received a request from a customer to repair the serration on a main engine flywheel. The vessel called Dubai, where QuantiServ engineers carried out an inspection. They found that five teeth were missing; an isolated one and four in a row.

While the vessel continued her voyage to Africa, our technicians manufactured new teeth and fitted bolts at our workshop in Dubai. They then brought these jointly with the required in-situ machine tools to the vessel, which had meanwhile reached the port of Mombasa in Kenya. There, the machining and installation work was carried out by four engineers in two shifts, around the clock, while the vessel was undergoing cargo operations.

Prefabricated teeth and fitting bolts

Prefabricated teeth and fitting bolts

The work was completed successfully within a tight time window of 72 hours without delaying or otherwise interfering with the vessel’s normal sailing schedule.

The final result, five missing teeth replaced

The final result, five missing teeth replaced