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Ships GM question.

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  #1  
Old 1st July 2019, 21:09
jbo jbo is offline  
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Ships GM question.

I’d like to know if anyone can tell me the size of GM they can remember from any vessel they have sailed on.
If you could also tell me the type of vessel ie Tanker, Container, General Cargo etc and the condition she was in ie Ballast, part or full load etc etc.
Thanks
JBO
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  #2  
Old 1st July 2019, 21:48
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Stephen J. Card Stephen J. Card is offline  
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There is one ship that almost everyone here on here in SN.

How many have sailed in M.V. MEXNA ?

Stephen
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  #3  
Old 1st July 2019, 23:33
saudisid saudisid is offline  
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Gm

It depended on [ General cargo ] what was loaded . A lot of steel and you were fighting to reduce it. Other times fighting to get a gm. remember when in City of Glasgow having to go into Jeddah homeward for bunkers to keep a + GM. We had about 12 inch gm then. When with UASC it was the other way always had about 1 M [ 39 inches ].
Too big and she was stiff to small and she was so tender.
Alan
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  #4  
Old 2nd July 2019, 13:47
rothesian rothesian is offline  
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gm's

Hustler class container ships (124 TEUs )were best sailing with a GM of .5 of a metre
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  #5  
Old 3rd July 2019, 08:27
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Harwich BR train ferries had a C of G somewhere up on the boat deck
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  #6  
Old 4th July 2019, 21:08
harry t. harry t. is offline
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Trim and Stability

This lady (see attached) was designed 30 feet shorter, at 431 ft. in length and 27 ft. loaded draft, than her two sisters. This made for a bit of a curse with the ships trim and stability when loading full cargoes from rail cars in St. John NB in the winter months. - Usually, the loading sequence would unexpectedly change on account of the rail cars and paperwork noting cargo weights going adrift. Therefore, if in doubt, i.e. when the final GM was calculated at less than a foot using only provisional figures on departing. We would have the tug stand by after clearing the port until we gathered speed and gave her the "dead man's roll" a couple of times with the wheel hard over each way - just to double check before setting off across the pond. This ship was by far the most tender and could give a new mate or master quite a fright hence a close eye on the weights. The chief would also take care with his daily oil transfers to the settling tanks when on a loaded passage. No one played silly buggers on that lady. Note; if the lady gives a double dip while on her beam-end, and takes about 25 or more seconds from the upright back to an upright position – you’ve got a problem.
The usual rule of thumb to maintain stability on the old tween deck type 10,000-ton cargo ship was to load one third of the weights in the tween decks and two thirds below, to avoid any worries.
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Last edited by harry t.; 5th July 2019 at 06:50..
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  #7  
Old 5th July 2019, 00:35
dannic dannic is offline  
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Quote:
Originally Posted by jbo View Post
I’d like to know if anyone can tell me the size of GM they can remember from any vessel they have sailed on.
If you could also tell me the type of vessel ie Tanker, Container, General Cargo etc and the condition she was in ie Ballast, part or full load etc etc.
Thanks
JBO
Stena Searunner class vessels, small roll-on roll-off, built in Korea had negative GM as built.
Early ones went in to have sponson tanks fitted, but still rolled like heck! Atlantic Prosper & Project an example. And we went across the Atlantic!
Dannic
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  #8  
Old 5th July 2019, 01:32
soccerover soccerover is offline  
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Ray Harrop

I sailed with BP Tankers in the 1950's - their 40,000 tonners had a loaded positive GM of about 60 inches if i remember correctly.

China Nav cargo ships 3,000 tonners (Shansi/Fengtien etc) loaded GM was about 16 to 18 inches (I think).

The exciting example I recall of GM and GM change was the long voyage of the famous Ben Line Steamers - their early 1960's vessels (beautiful ships - Ben Cruachan class) - the voyage I refer to was the non stop (except for Suez) Hong Kong fully loaded to London - the vessels left Hong Kong with a positive Gm of about 30 inches but as they were steam turbines and burning about 75 tons per day at 20+ kts (fuel coming out of the double bottoms) the ships, by the time they were going up the English Channel, were as tender as could be with a positive GM reduced to about 4-6 inches.
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  #9  
Old 5th July 2019, 05:34
Kevin O'Neill Kevin O'Neill is offline  
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Ships data for JB)

Good morning JBO - just ted your request for information on GM - a Few years ago I managed an FPSO which started life as a tanker - Four Lakes of Premuda Group. I still have copies of the stability manual and from that details:

DWT 94255 on draft of 12.949 m
GM Ballast departure - drafts F5.04 A 10.204 - GM t 14.394m
As an FPSO Lightship GM 35.804m
As an FPSO full ballast ship GM 14.540m
AS an FPSO Fully loaded GM 6.632m (Draft 12.863 - displacement 99295mt)

Hope this is of use/makes sense - feel free to get in touch
Kevin
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  #10  
Old 5th July 2019, 19:41
harry t. harry t. is offline
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Stability

Quote:
Originally Posted by harry t. View Post
The usual rule of thumb to maintain stability on the old tween deck type 10,000-ton cargo ship was to load one third of the weights in the tween decks and two thirds below, to avoid any worries.

On one of the few tween decker’s then operating in the 70’s we had been loading at several ports around the coast of Japan and had finally arrived to load at the charterers home port. Requesting an urgent meeting with their senior cargo super who had sent us the loading plans weeks earlier, it was pointed out the 3,000 tons of general cargo he proposed to load in the tween decks was unsatisfactorily as this equated to 50% top deck weight. He begged to differ, explaining the 3,000 tons he proposed to stow in the tween decks was only one third of the 9,000 tons of cargo. The fact 3,000 tons was half, or 50% of the 6,000-ton bottom weight didn’t register, – insisting he must reduce the tween deck weights before we proceeded further. Out came the Abacus/Soroban and in a flash the chap maintained the 30% tween deck weight was correct. It took a little more time to convince the man it was 50% of the lower hold weights and thus, was too dangerous to proceed. He finally redrew the plans. Later, on several occasions we had to shut off power to the winches and the heavy derrick, so as to impress upon the stevedores we had wanted the cargo stowed right out to the ships sides, and not just back against the bulkheads and outwards over the tank tops to the edges of the bilges – they clearly intended shoring everything off to the ships side with thousands of feet of 2x4 inch timbers or heavier – not much good for a Pacific crossing. Otherwise, a great trip, a long trip, later, the wee woman stated - ‘any more trips like that, don’t bother coming home’. Six months earlier, the owner wearing his 1946 demob suit, was pleading poverty on account our daily rate for the charter to south and east Africa was only £530 daily. Now, things had improved somewhat, £1850 daily plus £100 daily for the heavy derrick, until then, just a big ornament. In those days no travelling by land to or from any of the restricted ports by foreigners was permitted. George, the 4th officer was in his element when I met him at the station, relating how after he was stopped from boarding the train bound for Tokyo had found himself surrounded by a large party of giggling schoolchildren. The braver amongst them, just like little fish nibbling, pinching the dark hairs on his arms. He was a hairy curiosity in the land of the smooth skinned and clearly had enjoyed the experience.
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  #11  
Old 6th July 2019, 16:49
Avraham Ariel Avraham Ariel is offline  
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Gm

Do I have a GM story for you!
In 1970, Maritime Fruit Carriers’ (MFC) m/v Alaskacore was on her maiden voyage with full cargo of refrigerated seed potatoes from Saint John (NB) to Montevideo. Just out of Drammen Slip & Verkste of Norway, she was the fourth in a series of abt 10 reefers of ca 4900 GRT. I think MFC later on had acquired 6 of them. Alaskacore was their first, and as I said, it was her maiden voyage.
Soon after departure she was hit my moderate SW’ly winds and although her double bottom (DB) tanks were filled to capacity with bunkers and ballast, she developed a slight port list, which was increasing as a result of the wind and consuming bunkers.
When the list reached about 6 degrees, the (German) master became pretty nervous and ordered to pump ballast out of a port DB tank. The immediate result was a heavy fall to starboard, where the vessel settled at 12 degrees of list. The major casualty was the starboard gangway, which immediately found it’s way to Neptune’s palace. Luckily there were no human casualties. Immediate topping up all DB tanks saved the vessel.
I was Operations Manager for MFC at the time. The master reported the GM on departure from Saint John was 22 cm. I did not bother to ask him if it was positive or negative, I just fired him on the spot.
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  #12  
Old 7th July 2019, 00:16
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Stephen J. Card Stephen J. Card is offline  
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Remember being told about the stability problems with that class. The worst condition was when full load bananas and the No. A Deck was the problem. See the photo. Quite obvious! Funny... in the attached photo shows the ALASKACORE with the missing starboard gangway. How many did she loose? !!!!

Joined LOCH MAREE in Panama after voyage from NZ bound Helsinki. Apples. The mate I was relieving told me that the stability was not that great and that on arrival Cristobal we were bunkering and also drums of lub oil on deck. Next morning the mate left and the boat with the lub oil arrived first. The care picked up the first two drums and the ship went a nice roll. Can't remember how much, it did not feel nice at all! I put the drums back down in the boat and told them to come back when we have full bunkers. No problem after that.
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  #13  
Old 7th July 2019, 20:51
harry t. harry t. is offline
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The last two posts Re the gangways, brought to mind an incident on a loaded passage from Belle Isle in Labrador to Inistrahul in the north of Ireland. The mate had arrived on the bridge to relieve the 2nd mate to find the weather freshening fast and her awash in a following quarterly sea. Altering course, another point off, riding it nicely, he left her there until relieved by the 3rd mate at 8 am. But, whatever possessed the 3rd mate, before the old man got to the bridge, he decided to bring the lady back onto the original course. In doing so a couple of big seas caught her coming around, taking away the amidships gangway, stove in the surrounding fashion plates and carried away all of the port side hand rails on the prom deck. The ships main gangway stowed on the after deck beside a submarine periscope being returned to the Clyde for repair, both went overboard along with four refrigerated containers. All of this after-deck paraphernalia taking a passage caused considerable damage to the hatch coamings and bulwarks abreast Nos.4 & 5 hatches – all, in less than a minute. In the cold weather conditions in those latitudes, mild steel becomes brittle, hence so much structural damage.


This lady (see below) ‘took the biscuit’ stability wise, and boy, could she roll after being lengthened by 60 feet. She then went on to take her first cargo of newsprint and paper products homewards from Port Alfred to Glasgow. The resulting damage and subsequent claims after discharge took the wind out of everyone’s sails, tho’ fortunately, the owner held onto newsprint contract. With the deep tank ballast in No.1 hold, trim was always a problem, nor was it unusual to have to stop loading, when she’d suddenly fall over to be held-up, fortunately, by the quay. On more than one occasion the Technical Director had showed his displeasure with the master for the anticipated ‘unnecessary expenditure’, i.e., tank cleaning, that would be incurred, because he’d instructed the chief, against his wishes, to harden up his oil tanks and flood those empty, with sea water ballast. Of course, there never was any need to clean the tanks afterwards, the man had somehow conveniently forgotten oil and water don’t mix.
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  #14  
Old 10th July 2019, 14:16
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Quote:
Originally Posted by Stephen J. Card View Post
There is one ship that almost everyone here on here in SN.

How many have sailed in M.V. MEXNA ?

Stephen
Or for us oldies - mv Exna! All downhill after it went metric!
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  #15  
Old 11th July 2019, 23:04
IRW IRW is offline  
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|After loading various lumber products from shingles to long 12x12s around Vancouver and Vancouver island. We Finished off at Crofton.. Deck timber was loaded to just under crane bases. When completed the stevedore had on a whistle all (4) cranes lift a load then land same. the time of the roll gave a GM. Mind you the sailing pilot had a a good laugh at our expressions as we left.
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  #16  
Old 12th July 2019, 01:24
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Or for us oldies - mv Exna! All downhill after it went metric!

She was renamed MEXNA!

I sat Masters up at Glasgow, but I could not do orals because I still needed another nine months sea time. I was thinking about joining Uiterwyk Line and their vessels were Liberian flag. I went to Reston Va, to sit their ticket and my sea time was good for them. I had done the Glasgow ticket and it was only about three weeks before the Liberian exam. I thought it would be breeze. The problems started when doing the stability papers. Everything was in Imperial! Oops! I told the examiner with the problem. He told me to 'convert' the measurements metric, do the calculations and then give the answer back in Imperial. No problem.

Next problem was the Business & Law. Most was 'normal', but the Liberian Law was a bit different. No problem, you are not expected to know their rules. A copy of the book was on your table.
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  #17  
Old 12th July 2019, 07:39
Engine Serang Engine Serang is offline  
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Stephen, are you qualified?
I've always had my suspicions.
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  #18  
Old 14th July 2019, 23:01
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Stephen J. Card Stephen J. Card is offline  
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Stephen, are you qualified?
I've always had my suspicions.

Yes. :-)

Master Class 1. Class of Glasgow College of Nautical Studies. Best in the UK!

Last edited by Stephen J. Card; 14th July 2019 at 23:03..
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  #19  
Old 15th July 2019, 10:08
Engine Serang Engine Serang is offline  
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Yes. :-)

Master Class 1. Class of Glasgow College of Nautical Studies. Best in the UK!
Best indeed!
Could you say which other Colleges you compared Glasgow with and what criteria did you use to come up with your conclusion.
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Old 15th July 2019, 10:40
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Best indeed!
Could you say which other Colleges you compared Glasgow with and what criteria did you use to come up with your conclusion.
Hear Hear! Stephen, I suspect many people will give you an argument - me included! (Warsash Cadet and Certificates at Hull Nautical College).

Howard
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Old 15th July 2019, 10:51
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Varley Varley is online now   SN Supporter
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I am impressed E-S is agreeing with you Stephen although asking you for you data suggest he is bound on plagiarising.

Of course you are both wrong, despite my allegiances to Glasgow, Saudi Shields takes all biscuits.
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  #22  
Old 15th July 2019, 12:16
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Best indeed!
Could you say which other Colleges you compared Glasgow with and what criteria did you use to come up with your conclusion.

Well, they must have been good to get me through!

We know that results from the examinations are either PASS or FAIL. You don't know if you had 70% or 100% or in the 69% or 0%. What I did not know was that DoT does give one result, they tell which college had the highest marks for Master's for the whole year and through the country. 1980, I won a prize from GCNS. I had the highest marks for that year. The prize? Two £10 vouchers from Boots.

Sure, unless you tried every college in the country you have no idea which is the best. I only went to two of them. I made a mistake to start Master's at the Tower Bridge Poly. I stayed for three weeks. Walked in the first day and the lecturer sat reading his Telegraph or Sun. Completely confused. The lecturer says your timetable was 'Tutorial'. So first day, nothing to do. You never saw a printed piece of paper. Everything had to be taken down in longhand from dictation. Took a whole hour to get one paragraph done! If you were checking for say, a stability calculation, go to the huge 'STABILITY'.... find your question number 1/78/65/7654. Then check your own work until you could see the result. Too ages and if any of the other 24 students, you had no chance. Three weeks were wasted. I called J&J and asked to go back on the ship. Eight months later, back to GCNS. 8 of us in the class. The course was 6 months. Two of us wanted to sit earlier so we stepped up the pace. The lecturers bombarded us with paper. Anyhow, we went up after 3 1/2 months and went up for the exam. So, for my experience, GCNS was a fine establishment and the lecturers were outstanding. Fine gentlemen. As far as Glasgow, well, I lived a total of almost 3 years there and loved every moment. Beautiful city and great people.

Last edited by Stephen J. Card; 15th July 2019 at 14:33..
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  #23  
Old 15th July 2019, 12:36
MMA MMA is offline  
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Originally Posted by Stephen J. Card View Post
She was renamed MEXNA!

I sat Masters up at Glasgow, but I could not do orals because I still needed another nine months sea time. I was thinking about joining Uiterwyk Line and their vessels were Liberian flag. I went to Reston Va, to sit their ticket and my sea time was good for them. I had done the Glasgow ticket and it was only about three weeks before the Liberian exam. I thought it would be breeze. The problems started when doing the stability papers. Everything was in Imperial! Oops! I told the examiner with the problem. He told me to 'convert' the measurements metric, do the calculations and then give the answer back in Imperial. No problem.

Next problem was the Business & Law. Most was 'normal', but the Liberian Law was a bit different. No problem, you are not expected to know their rules. A copy of the book was on your table.
I did Masters at Ashley Down Tech College, Nav Dept in Bristol (exam in Cardiff) and one of my fellow 'students' worked for Tradax under Liberian flag. He too sat the Liberian Master's ticket at Lloyd's Register head office in London, then followed that with sitting the UK version. Tradax said he'd get the Master's job whichever one he passed - he passed both but the Liberian one seemed to consist entirely of written papers with some multi-choice thrown in, including Rule of the Road. He never mentioned the law side of things though.
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  #24  
Old 15th July 2019, 14:24
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I did Masters at Ashley Down Tech College, Nav Dept in Bristol (exam in Cardiff) and one of my fellow 'students' worked for Tradax under Liberian flag. He too sat the Liberian Master's ticket at Lloyd's Register head office in London, then followed that with sitting the UK version. Tradax said he'd get the Master's job whichever one he passed - he passed both but the Liberian one seemed to consist entirely of written papers with some multi-choice thrown in, including Rule of the Road. He never mentioned the law side of things though.

Right. All written answers with some multiple choice. The thing is the vast amount of questions. On a DOT paper you might have seven or eight questions and you must answer four or five. The Liberian 'paper' might only one question on the paper. If multiple choice there have several questions. The big difference, there were a stack of papers.... about 150 papers and you had to answer all. There was no time limit. The stack of papers were mixed between subjects. The papers sat on the examiners desk. You could no look through them. Go to the desk, pick up the paper, turn it over and proceed to answering. After three our four hours you might want to take a break, your choice. Finish the paper and you could leave. Come back an hour or more or even come back tomorrow. Your choice. I was told that the usual exam might take five days. If you wanted three weeks, that was fine too. I started in the morning at 9 and I stopped at 5. Back to the hotel, right next door, and bright in the morning to start again. I finished the work at the end of the second day. Three would have been easier, but I wanted to get away and fly home.

Thinking back, DOT papers might be hit or miss. If you could not answer a question you would loose a lot of marks. Liberian exam, when you went over perhaps 400 questions, the examiner could tell if you were good or just wasting time. Orals... say for Rules of the Road, you make a mess on one question and you might get thrown out. The Liberian method might be the most useful way to test your knowledge.

Have a look at the US Coat Guard examinations. They are all multiple choice and by LAW, ALL of the questions that might be asked in the exams MUST be published! You can find a huge book with all of the questions. You can study the book and then take a chance. I am not certain is the system work well or not. Perhaps some of the SN gang will tell what they did.

Stephen
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  #25  
Old 15th July 2019, 14:42
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My Liberian Cert shows the EXAM number. If you had a UK cert and you want to have a Liberian you could and their certs are required on their ships. Everyone knows this. Say if, and I sure hope not, have a mishap, grounding or collision. It is come to an inquest and you have a UK certificate, the DOT will be advised and you might end up loosing BOTH tickets.

If you have done your Liberian ticket by Liberian examination, you might loose the Liberian ticket but they will not search you out from the DOT.

Didn't the Second Mate in the ELWOOD MEAD loose his Liberian ticket (with Liberian exam) and was able to go back to sea with his UK ticket? Or something along these lines.

Last edited by Stephen J. Card; 15th July 2019 at 14:50..
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