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STORES
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Hello, Can Someone Please Explain To Me How A Obo Functions, ? The Method Of Carrying 2 Very Different Cargoes, I Allways Understood Oil Was Carried In Tanks, And Ore In A Hold, Surely Oil Must Be In A Airtight Compartment, How Were The Cargo Spaces Cleaned Between Cargoes, And How Is Ore Discharged, Thanks, Stores.
 

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In a nutshell.
The oil is carried in the holds, which are cleaned manually.

Heating coils are then connected (they were stowed at the top of the hatch I think).

The hatches are batttened down and you have a tanker.

It has been a long time since I sailed on these and really had little to do with the preparation/changeover. I am sure there are others here who can and will explain in more detail.

This little snippet is just to satisfy your initial curiosity.
 

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I would gladly reply to you stores , but have spent more than 30 years
trying to forget about OBO's and have still not succeeded.
 

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Heigh ho...

The OBO was a Norwegian invention, see here:

http://en.wikipedia.org/wiki/Ore-bulk-oil_carrier

Not to be confused with the ore / oil carrier ("O/O") which is an entirely different beast, stucturally, having small centre holds and big wing tanks. An O/B/O is, structurally, a bulk carrier.

The Big Idea is to cut down on time spent in ballast by being able to carry a wider range of cargoes.

The problems with the OBO concept in practice are these:

1. BIG PROBLEM: The pattern of world trade is such that the OBO simply does not work, commercially. There are very very few places that import oil and export coal, for example. Consequently the owner finds that he has spent a lot of money building an expensive bulk carrier or an expensive tanker. Instead of switching between wet and dry cargoes every voyage, as Naess intended, most O/B/Os trade for a year or two "wet" and then a few years "dry".

2. As everyone who has ever had to do with them will attest, these ships involve a lot of very hard, very dirty, work (some use the word "nightmare").

3. These ships are very unpopular with the oil companies, and indeed are banned from some terminals.

4. There is a specific safety issue. Conventional bulk carriers have their bulkheads mounted on stools which connect to the tank top. This is necessary because the bulkheads are corrugated to give the necessary strength. The stool is a void space, but if a crack should develop (as is not unknown) in the stool it can part fill with cargo oil leaving an explosive atmosphere in the stool space... this has never really been solved.
 

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Andrew,

The Gotaverken built Seateam OBOs were exemplars of the stool cracking (my first trip as E/O was on one, "Norvegia Team").

Long after the last one had left Denholm's I visited "Trader" in Dunkirk. Close by one of the ex-Seateam OBO's tied up - the full length of every accommodation walkway had gas bottles lashed to the handrails. No need to ask what repairs were in hand (out of hand?).

David V
 

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The high water mark of O/B/O enthusiasm was reached with the series of nine PROBOS contracted by a complex syndicate of mainly Norwegian owners with Hynudai (three) and Korea Shipbuilding and Engineering (six) in the early 1980's.

These ships would in theory do just about anything from carrying bulk liquid caustic soda (s.g. 1.5 from memory) to carrying clean and dirty oil products to forest products and containers, and furthermore as designed they were meant to do this with a crew of, iirc, 14.

Unlike "normal" O/B/Os they had not side rolling split hatchcovers but massive pontoon covers handled by the two gantry cranes...this had an amusing moment when a US pilot could not find the ship as he was looking for a tanker not a geared bulk carrier...

Things did not go entirely according to plan...(Cloud)

I had altogether too much to do with the Probo Baro and the Probo Baoning.

The Probo Baoning after changing hands some years later achieved notoriety as the Probo Koala in the Trafigura waste dumping case.
 

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OBO Defense

Heigh ho...

The OBO was a Norwegian invention, see here:

http://en.wikipedia.org/wiki/Ore-bulk-oil_carrier

Not to be confused with the ore / oil carrier ("O/O") which is an entirely different beast, stucturally, having small centre holds and big wing tanks. An O/B/O is, structurally, a bulk carrier.

The Big Idea is to cut down on time spent in ballast by being able to carry a wider range of cargoes.

The problems with the OBO concept in practice are these:

1. BIG PROBLEM: The pattern of world trade is such that the OBO simply does not work, commercially. There are very very few places that import oil and export coal, for example. Consequently the owner finds that he has spent a lot of money building an expensive bulk carrier or an expensive tanker. Instead of switching between wet and dry cargoes every voyage, as Naess intended, most O/B/Os trade for a year or two "wet" and then a few years "dry".

Hello Andrew .You were a broker, and may know better, but it wasn't entirely true:

North Europe to USA with residual fuel oil, and return with coal, grain or fertiliser,

Oil cargo to Chile, ore out,

Low Sulphur Waxy Residue from Indonesia to USWC, then coal Vancouver to Japan/Korea, and round again,

Oil PG to Australia, coal or ore out to Europe, load North Sea or Africa and on you go.

2. As everyone who has ever had to do with them will attest, these ships involve a lot of very hard, very dirty, work (some use the word "nightmare").

Agreed - especially the older ones, though it did get much better. I did several years in them, and actually quite enjoyed it - hard core crazy maybe

3. These ships are very unpopular with the oil companies, and indeed are banned from some terminals.

An OBO from dry was always a bit hard to fix on a poor market, but in oil they were better tankers than the real thing, in that they could discharge the entire cargo with miniscule ROBs.

4. There is a specific safety issue. Conventional bulk carriers have their bulkheads mounted on stools which connect to the tank top. This is necessary because the bulkheads are corrugated to give the necessary strength. The stool is a void space, but if a crack should develop (as is not unknown) in the stool it can part fill with cargo oil leaving an explosive atmosphere in the stool space... this has never really been solved.
A problem in some, but in the main could be designed out - there was always a hrd spot where stool and hopper tank met. More likely to be a case of knocked off manhole bolts or stool plugs.

Best Regards.
 

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STORES
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Discussion Starter · #11 ·
OBO,s

[/COLOR]Am glad i never sailed on one, i am not a ship designer or structural analyst, have allways said ships are too big now, size cannot keep increasing, rivetted ships appeared much stronger, welded hulls appear thinner,i dont think anyone now who designs ships really appreciates the stresses and strains imposed on a ship at sea, the bigger the ship the more stress, and with the massive tonnage of a cargo it carries welded steel does not seem to be strong enough, i saw avideo of a large container ship in heavy weather, a view from aft to fwd along center of main deck, have never seen a ship bend so much, was beyond belief, same as cruise liners now, too big, the criteria today seems to be one of huge ships and cargoes, minute crews to man them, at the expense of ship and human safety, it seems all the lessons and experience learned over time in ship safety and design have been forgotten, the Derbyshire was a classic example.(Scribe)
 

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Randmackenzie - I was never a broker; I rejoiced in the magnificent title of Tonnage Manager i.e. the person responsible for making sure we had the right ships and that they made money, by building, buying, chartering in and out and selling. Point being - I saw all the numbers, which a broker does not.

I do take your point that sometimes - just sometimes - these cargo combinations do work out, but by and large they don't, which is why these ships never became popular with owners and are now vanishing from the scene.

As an owner, you end up with a more expensive tanker or more expensive bulker and insufficient opportunity to make the money back.

I was responsible for a Capesize bulker that had honest to goodness hatch cleaning arrangements, in the manner of an O/B/O, with guns that self stowed and big eductors off the hatboxes, so we ran grain clean between cargoes, and that did work (and is still working, I believe) so a little bit of the O/B/O concept stayed with me.

Stores - remember that a container ship does not really have a deck, to speak of.
 

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Andrew, I have read your wiki article and am suprised that it does not mention the earlier vessel's that were capable of a dual cargo role, the vessel's concerned were built at the Craig, Taylor Yard on the Tees ( where my Paternal Grandfather was a Director). These vessel's 9 in all and the last one built in 1906 were built on Oil Tanker "lines", however, if required they could be used to carry dry cargo. One of the vessel's name's was the "Petrolea" and she was capable of discharging 3,500 tns of oil in 24hrs and be away in 24hrs. Sailing on an OBO was a challenge at the best of times, but the "facilities" on board were a world away from those on the old style Tramps.
 

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If you want to see a truly mental ship then you should go and have a look into the vessel that started life as the LNG/C El Paso Cove Point and eventually became the STL type FSO Apollo Spirit - but in between it got converted to a OBO called the Jade Phoenix(EEK)


This sort of thing should really not be allowed in a sane and caring society.
 

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I ended up having considerable experience on O B Os including three new buildings.
The concept was good however no one seemed whether to but bulk carrier men on or tanker men on the new type of vessels with sometimes dire consequences and some times amusing ones also.
We had folk who could not open hatches and others sucking them in or blowing them some feet in the air.
Other chaps new nothing of the instrumentation and other remote control gear fitted. Engineers didn't either!. One chap got a much better vacuum with tank vents shut but after the alotted time the tank must be empty. End result laying against Ras Tanura sea island at an alarming angle. Fortunately the vessel was brand new and therefore quite strong. I was 4th Engineer taking bunkers so it was thought that I had caused the problem. The Ship was FULLER ballast.
Another nightmare was an idiot on the bridge watch complaining about inert gas oxygen content being way to high with black smoke pouring out of the funnel. This is a cracker, it was found out much later on by an exasperated Chief he was measuring the oxygen content of the control air pressure gauge marked as IG pressure.
On older vessels well they were just plain dangerous and I was glad to get off them altogether at the expense of a job though as redundency from Denholms came with the collapse of CAST.
O B Os good concept but!!!

regards

Malky
 

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OBO's , an abberation to all mankind.

Almost as if they were invented in Tokyo as payback .

And Andrew , having said the above , I know of lots of OBO.s which made
piles of money for their owners over many years.
 

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I had the misfortune of sailing on one once and it was not an experience I ever want to repeat! It was my first trip with Shell as 3/E on the Rapana, a V.L.O.O as Shell called it. The trip got off to the worst of starts possible as I was sat on the jetty at Tubarao, waiting for them to lower the gangway so I could get onboard. They where having problems lowering the gangway as the two pieces of the telescopic ladders became jammed with iron ore dust. The mate and the chief engineer were in the process of freeing it, when it suddenly freed itself due to the strain it was under. Unfortunately it caught both men trapping them by the feet, their screams turned my legs to jelly! once freed they had to be rushed to hospital as both had suffered nearly complete amputations of one foot each.
The trip never got any better, ship was a disgrace. fortunately it only carried iron ore on my time onboard as I said that if they loaded it with oil. I would not sail out of port on it and would be sat on my suitcase waving goodbye to them!
Later events proved me right! after a long drydocking the Rapana loaded oil again and had just discharged the first part of her cargo at Brofjorden and was on her way to Tranmere when she suffered a pumproom explosion and fire killing 3 of the crew. Shell sold her and her sister ship shortly afterwards! A lesson learnt the hardest of ways!
 

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How much volume did they loose compared to an equivalent size only dry or only liquid cargo ship?
Esentially none, in liquid, unless one counts in the lost deadweight that would have been available had the ore holds not been built as such. In practical terms, none.

In dry, an awful lot, as they were built around the s/f of iron ore, 0.74 or thereabouts.

I can remember when I had to tell junior officers who had to do with Shell expediters "Don't mention the RAPANA" in much the same terms as "Don't mention the War!"
 

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1. BIG PROBLEM: The pattern of world trade is such that the OBO simply does not work, commercially. There are very very few places that import oil and export coal, for example. Consequently the owner finds that he has spent a lot of money building an expensive bulk carrier or an expensive tanker. Instead of switching between wet and dry cargoes every voyage, as Naess intended, most O/B/Os trade for a year or two "wet" and then a few years "dry".

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I've seen pictures of Ore-Bulk-Container ships, namely the Cast ships with alternate Ore/Bulk and Container holds, do they work commercially and are OBC's usually like this with alternate holds or are some with holds that can hold all three types?

I've also seen references to Bulk carrier/Car-Carriers with demountable suspended car deck but i'm not sure if that was just a suggestion rather than an actual ship.
 
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