[AlphaKilo]

Originally Posted by Gannu_1

A time-lapse video shot by the client:

http://www.Youtube.com/watch?v=IUQcC-XmbJM

Let me know if you guys have any questions. I’d be glad to answer them to the best of my knowledge.
.

Fantastic! I have a question.
How is the ship balanced during loading/unloading such heavy cargo using its own/external cranes? There will a huge shift of Centre of Gravity and while lifting the cargo using ship's own crane, will it not tilt slightly towards the side in which the cargo is? How is this compensated?

Thanks!

[vibbs]

Originally Posted by AlphaKilo

Fantastic! I have a question.
How is the ship balanced during loading/unloading such heavy cargo using its own/external cranes? There will a huge shift of Centre of Gravity and while lifting the cargo using ship's own crane, will it not tilt slightly towards the side in which the cargo is? How is this compensated?

Thanks!

Hi,

Although I am an ex Marine Engineer (sailed the high seas for close to 8 years), and cargo handling is typically done by the Navigating officers, I would in brief give an answer to your question.

Cargo loading and unloading on any vessel is a critical operation and a plan is prepared by the Chief Officer of the vessel giveing due consideration to the shift in center of gravity. However there is always a shift and during the loading and unloading the vessel does list slightly (defenitely within limits) for short durations. Similarly there is always a change in trim during the cargo operations. This is kept under control by the means of another operation - Ballasting/Deballasting.

There are huge Ballast Tanks in the vessel which are filled with water (ballasting) and emptied (deballasting) to compensate the added or removed cargo and also to maintain the vessel upright.

This was a simplified answer and there does go quite a bit of calculations to arrive at the ballasting plans. Probably the deck officers in the forum can give a detailed explanation.

Comming back to the Bhp giants, as Jeroen said inspecting a liner means entering into the cylinder liner itself. Similarly inspecting the crankcase means entering into the crankcase.

Quite a fascinating field this is. Engineers in Merchant Navy actually work with their hands. My wife on her first sail with me onboard one of the vessels was surprised at seeing my grease and oil stained white boiler suit (which was more brown than white) when I went to recieve her onboard at the embarkation deck at 4 AM. That moment she realised what it means to be an engineer on a ship

Overhauling a 20 MW engine is done by 3 or sometimes 4 engineers and 2 or 3 support staff and most of the job is done onboard by the crew itself. Long working hours are normal specially at port. The vessels nowadays stay at port for not more than 24-36 Hrs and the immobilisation permit for the main engine is seldom recieved for more than that time. If you get stuck it could mean a non stop work for 36 Hrs to finish off the job and then get ready to maneuver the vessel out. I remember an instance when we were renewing the Liner on a Cape Size Bulker. The engine was 22000 Bhp MAN B&W 6S70 MC and the liner refused to move out. To top it up there was bunkering to be done before sailing off.

It meant a very hectic 38 Hrs for the engine staff. Such issues are not limited to the engineers only. Even the officers have a very hectic time at port, with all the authorities coming onboard and the cargo operations. The Chief Mate is literally on his toes for the entire duration of the port stay.

With short port stays, increased international regulations and reduces work force, Merchant Navy has become a high stress field now a days. My last vessel was a 380 Meter long and 80 meter wide Cape Sizer and running it were just 17 crew. Arriving and departing from ports is a strenous activity for the entire crew from the Captain to the Stewards with so many operations going on. Long sailing however (20-25 Days at a stretch) is what we sailors really look out for. Things get settled down well with occassional parties onboard and a swim in the pool in the evenings or a game of TT followed by a few drinks, specially for engineers in todays UMS classed vessels where you dont need watch keeping engineers out at sea during the night.

Originally Posted by Jeroen

In my days nearly all merchant ships with these large two stroke engines also had an exhaust gas boiler. Typically fitted in the funnel. In the exhaust there are big doors that can divert the hot exhaust gasses to go through a boiler. Under full load exhaust gasses are upwards of 450 -500oC. Lot of energy. Sufficient to get a boiler going and to produce steam of 4-5 bars. The steam would be used, amongst others, to heat up the tanks and the fuel lines with the heavy fuel.

Nowadays, some vessels have Exhaust boilers fitted after Auxiliary engines too. This reduces the dependance on the Oil fired Boiler at port thereby reducing the Fuel costs. I know a couple of companies that have gone a big way into investing on these Exhaust gas boiler (which includes retrofits on their existing fleet) for AEs specially on the container vessels where the steam demand is typically low at port and the Auxiliary engines big enough to provide sufficient waste heat recovery.

[Gansan]

Tanker ships will have ballast tanks, in which sea water will be taken in / expelled according to the loading / un-loading of cargo tanks to keep the ship in trim. Same technique in bulk carriers as well, perhaps?

[Jeroen]

Originally Posted by Gansan

Tanker ships will have ballast tanks, in which sea water will be taken in / expelled according to the loading / un-loading of cargo tanks to keep the ship in trim. Same technique in bulk carriers as well, perhaps?

correct. All ships, big or small, tend to have ballast tanks. Sometimes, you can use the fuel as well. Some of the fuel tanks must be empty of course, otherwise you can't pump back and forth.

Dutch engineering officers are taught as part of their formal training how to do the load and ballast calculations,

I've sailed on a small container vessel and our ballasting system could be operated fully automatic. You might have seen these huge crane barges, they have advanced ballast system as well.

Jeroen

[Gannu_1]

Originally Posted by vibbs

in todays UMS classed vessels

For those who are wondering, UMS means Unmanned Machinery Space which means the ship can be entirely controlled from the ECR (engine control room) without a personnel being physically present in the Engine Room. Sometimes they can be controlled from the Bridge as well. But yes this happens in a cuckooland where no alarms ring or no sensors report incorrect values!

Originally Posted by AlphaKilo

Fantastic! I have a question.
How is the ship balanced during loading/unloading such heavy cargo using its own/external cranes? There will a huge shift of Centre of Gravity and while lifting the cargo using ship's own crane, will it not tilt slightly towards the side in which the cargo is? How is this compensated?

Thanks!

I guess you've got your answer by now. The term ballasting refers to filling the tanks of the ship with sea water, fuel or sometimes even sand or lead shots permanently in order to counter the moment caused due to the excess load.

When the load is taken by the cranes, the tanks at the opposite ends would be automatically filled with sea water by the ship's ballasting systems sometimes referred to as anti-heeling systems. Heeling means the ship tilts to one side - port or starboard. As the load is taken, the anti-heeling system kicks in and the water is pumped in, into the tanks and distributed as the load is kept on the cargo hold. If this isn't done or fails, the ship begins to heel to the heavier side and may even capsize!

This video of a anti-heeling system by the manufacturer explains it in a simple way. Have a look:

http://www.youtube.com/watch?v=BWcZrFlmAgs

The Happy Sky has a permanent ballast consisting of a byproduct of polymerisation which looks very similar to leadshots. These have been filled on 2 tanks in the Port side exactly opposite to the ones where the cranes have been installed on the Stbd side.

What happens when the anti-heeling system/ballast system fails? MV Cougar Ace happens!



She was a car-carrier carrying approx. 4700 Mazda cars from Japan to Canada. A sudden instability caused the ship to capsize to the stbd side. A Dutch rescue time was sent in to salvage the ship and they successfully did it, although they lost their naval architect in the process.

Here's an interesting article (albeit slightly lengthy!) by Wired:
http://www.wired.com/science/discove...urrentPage=all

Salvaging a ship is as good as winning a lottery. You get insane returns if the ship is successfully salvaged, which generally goes in millions of $. Of course, Mazda had to publicly announce the VIN of the cars onboard the Cougar Ace and all of them were completely destroyed by crushing them.

Not a healthy sight to see all the 4700 brand new cars waiting in the yard only to be crushed under a shredder!













Mazdas 247

[Gansan]

Originally Posted by Jeroen

I've sailed on a small container vessel and our ballasting system could be operated fully automatic. You might have seen these huge crane barges, they have advanced ballast system as well.
Jeroen

I have one doubt. Why can't the Master or navigating officers themselves operate the engine in ships, like the captain or co-pilot of an aircraft do? Why should it be through the commands relayed to the engine room by them? Are there any vessels like that in existence?

[vibbs]

Originally Posted by Gansan

I have one doubt. Why can't the Master or navigating officers themselves operate the engine in ships, like the captain or co-pilot of an aircraft do? Why should it be through the commands relayed to the engine room by them? Are there any vessels like that in existence?

Although the question is not directed at me, I ll jump the gun here.
On all modern vessels, they have bridge maneuvering. The engineers are standby in the engine control room to monitor all the parameters and also manage the other auxiliaries. Maneuvering a vessel requires many movements which include start/stop of engines and also reversing. This itself depends on many other auxiliaries working well in tandem. So the engine room needs to be manned for this purpose. The engine itself is however directly controlled by the bridge unlike in older days where in the movements are relayed using a telegraph and the actual controls being done from the engine control room.

[vaisakhr]

Originally Posted by Gansan

I have one doubt. Why can't the Master or navigating officers themselves operate the engine in ships, like the captain or co-pilot of an aircraft do? Why should it be through the commands relayed to the engine room by them? Are there any vessels like that in existence?

+ to what vibbs sir has told. Maneuvering is a very big task for the machinery. Frequent stopping and reversal can lead to many problems. So all the parameters of the machinery to be monitored and proper watch should be there in the engine room. Like the ships in our company, most of them are not able to do bridge maneuvering due to many reasons.

Originally Posted by Gannu_1

For those who are wondering, UMS means Unmanned Machinery Space which means the ship can be entirely controlled from the ECR (engine control room) without a personnel being physically present in the Engine Room. Sometimes they can be controlled from the Bridge as well. But yes this happens in a cuckooland where no alarms ring or no sensors report incorrect values!

During UMS the engine room including the ECR will be unmanned. All the controls will be given to bridge. There will be alarm panels in the accommodation which will give an audible as well as a display of the alarm activated. Then the duty engineer will attend the alarm. All the alarms will be frequently tested and maintained properly.

[Jeroen]

Originally Posted by Gansan

I have one doubt. Why can't the Master or navigating officers themselves operate the engine in ships, like the captain or co-pilot of an aircraft do? Why should it be through the commands relayed to the engine room by them? Are there any vessels like that in existence?

In fact, most, if not all ships, these days are operated directly from the bridge!

Only on older ships you will still find this system with what they call telegraphs. The bridge would "ring" for half ahead and the engineers would start the engine and ensure it would run at whatever the RPM necessary for half speed.

I have had the pleasure of sailing with both systems.

These days the engine room is mostly unmanned. Marine engineers will work during normal "office hours", but outside the office hours, everything is run automatically. There will always be an engineer on duty. He or she will receive any alarms from the engine room in her/his cabin. Also, even whilst on full automatic you would do occasional inspections. So every so many hours the engineer on duty would go down to the engine room and do a full inspection.

Even fully automated engine rooms tend to be manned during maneuvering and for instance if you're in very busy shipping lanes. If anything happens you can't afford to wait for an engineer to wake up and make it down to the engine room.

I worked a lot on ocean towage tugs, salvage operations and Anchor handling tugs. Even though nearly all these ships had a fully automated engine rooms as per our standard operating procedure, it was always manned. The nature of the work for these ships is such that you just can't take the risk. This was quite a while, so would be interested if that is still the case these days?

Jeroen

[Mad Monkey]

Originally Posted by Gannu_1

Alright, I stumbled upon this thread some time back. Here’s my bit of contribution to the thread.

I design ships for a living, have been in this industry from the start of my career spanning 5+ years and we rolled out a multi-purpose vessel for a Dutch heavy-lift company (Biglift) earlier this year, sometime during May. We did two more previously which were more or less similar but this one was on a different scale altogether, I couldn’t help but share it here! But first some blah-blah.

Let me know if you guys have any questions. I’d be glad to answer them to the best of my knowledge.

PS: Jeroen Sir - Glad to have a marine engineer onboard! Some insightful information there.

@Gannu 1 ..... i guess you work for L&T ?

were you involved when L&T built their first ship which was for RollDock ?

The vessel for Rolldock was really a superb engineering feat by the dutch designers

Semi-submersible ,height adjustable decks and ramp for RO-RO operation and two 350Mt cranes

Not sure if you know about the common history behind ROLLDOCK and BigLIFT

[Gannu_1]

Originally Posted by Mad Monkey

@Gannu 1 ..... i guess you work for L&T ?

were you involved when L&T built their first ship which was for RollDock ?

The vessel for Rolldock was really a superb engineering feat by the dutch designers

Not sure if you know about the common history behind ROLLDOCK and BigLIFT

Yes I do. And I was involved in Rolldock's ships. To be specific the design part. And honestly, Rolldock was nothing compared to Biglift's designs esp. the foldable weatherdeck hatch covers and 2 900 t cranes.

Regarding the common history part, are you referring to Mammoet here? I believe the crew from Mammoet split and formed Rolldock BV. Are you aware of a more recent advancement?

Hint - Bigroll

[Jeroen]

Originally Posted by Gannu_1

Regarding the common history part, are you referring to Mammoet here? I believe the crew from Mammoet split and formed Rolldock BV. Are you aware of a more recent advancement?

I have no idea what happened to Mammoet but I know the company from the past. Mammoet was originally a Dutch firm that specialized in heavy road transport and lifting big things. It was three big Dutch firms that merged, Goedkoop, van Wezel and later also Stoof. I believe somewhere along the line the whole group got bought by KNSM, a Dutch shipping firm, that got bought by NedLLoyd, yet another Dutch shipping firm.

Goedkoop brought in the maritime part which at that time was limited to harbor towage in Amsterdam and some very large floating crane barges.

When I was a little boy / teenagers they had the biggest cranes in the world! My dad was their lawyer. At the time he was one of the very few lawyers that specialized in European Transport Law, so all the the big transport firm hired him. Got me a holiday job working on one of the Goedkoop harbor tugs in Amsterdam harbor. The rest is history as they say. Ten year laters I was Chief Engineer on an ocean going salvage tug.

Later on Mammoet got taken over by van Seumeren, another Dutch heavy lifting / road haulage company. They became famous with the salvage of the Kursk.

Today they have their headquarters near Rotterdam. Their headquarters is in the shape of a huge bollard, and is quite a landmark. http://en.wikipedia.org/wiki/Mammoet

Although they are heavily profiled with the Kursk salvage, their headquarter is shaped like a bollard and near Rotterdam on the river the Nieuwe Maas, entrance to Rotterdam harbor, I believe their main business is still road haulage and heavy lifting onshore.

I'm familiar with some of the ships of the Mammoet fleet in the early 80's. In particular their single ocean tug, the Happy Hunter. I've been on her a few times.

Can only find pictures/videos of the RC model not the real one!

Still, its pretty cool:

http://www.youtube.com/watch?v=5wnmhK3lK1I

The happy hunter later became Smit Hunter as part of the Smit group.

Smit another true Dutch company was, for many decades, the worlds largest operator of ocean going tugs, AHT, and was famously known for many salvages the world over. They were involved in the Kursk salvage as well, although it was fronted by Mammoet. Word of mouth had it that Smit bid for this project at a much higher price than Mammoet. Mammoet won the contract, but ended up subcontracting a lot of the actual work to Smit. So Mammoet's name is for ever attached to this remarkable salvage.

I worked for several of their companies and sailed on many of their tugs and AHT.

http://en.wikipedia.org/wiki/Smit_International

Nice time, very enjoyable all this memories!

Jeroen

[Gannu_1]

Since we mentioned RORO, sharing a few snaps of the Rolldock ships we built before the Biglift one. This ship had a stern ramp just like the ramp of a car carrier over which cars would roll out of the ship.



The ramp can be positioned over various heights to suit the land height and any object could roll over it into the cargo hold. Or alternately, the ship can submerge itself in water and any floating object (like a smaller boat for instance) can float itself into the cargo hold.

This ship had 2 engines (albeit smaller, 6035 hp, 9 cylinders inline, 320 mm bore, 400 mm stroke) and thus 2 propellers (again CPPs) both of which would rotate in opposite directions w.r.t. each other at 175 rpm.



The ECR (engine control room):



The HFO (heavy fuel oil) and LO (lube oil) purifiers:



The bridge:



One of the cargoes laden into the hold (the person standing below can be used for reference ):



The owners later repainted the ship with a lighter shade of blue:



It was the same ship that transported ill-fated INS Sindhurakshak which sunk due to an explosion at Bombay recently.

Originally Posted by Jeroen

Smit another true Dutch company was, for many decades, the worlds largest operator of ocean going tugs, AHT, and was famously known for many salvages the world over.

Smit International is regarded as the pioneer (or as we Indians say, baap meaning father) of the marine salvagers. Their professional reputation precedes them! These guys have salvaged some of the most insane wrecks from the ocean including the Mighty Servant 3, Cougar Ace (refer my previous post for snaps) and the more recent Costa Concordia ocean liner.

I mean, how the hell can something like this:



be salvaged back to this:



Complete respect to these guys! One of the superintendents of the Biglift ships who was here for surveying was onboard the Mighty Servant 2 which sunk and couldn't be salvaged!

Originally Posted by Jeroen

Nice time, very enjoyable all this memories!

I totally understand. Do you have any memorable experiences to share Sir?

[DrPriyankT]

@Gannu1 and @Jeoren..I have a question for you guys.
How do the 7, 9, 11 and other odd numbered engine cylinder combinations maintain their balance on ships? Won't the unequal vibrations produced increase structural wear and tear?

[Thad E Ginathom]

How do they do it in cars? I suspect something like an asymmetrical flywheel might be involved, so that the entire system is balanced even if the sum of the pistons is not.

Also, a really small RPM was mentioned for the propellers. is that geared down from the engines? what RPM do the engines run at? My hunch is it a lot less than the small motors that we are used to. I've notice that with fishing-boat diesels you can sometimes hear the duh duh duh duh individual explosions when the thing is only ticking over.