Bulk Carrier Loading

Bill Davies
17th April 2009, 21:54
There was an article in the Nautical Institutes 'Seaways' (then named)magazine back in the 70s which I recall caused much embarrassement to the author on Ore Carriers arriving in certain ports 'by the head'. I will try and find a copy as I am sure it will cause concern re the standard of those engaged in these dangerous ships and possibly throw a different perspective on those serving in these ships.

Bill

Bill Davies
17th April 2009, 22:09
Thanks for re-assigning the post

Bill

K urgess
17th April 2009, 22:11
Moved this into it's own thread, Bill.
I'm sure you will agree that to have it in the Derbyshire thread would be wholly inappropriate.

jasmacpm
17th April 2009, 22:18
Bill,
can I ask you for more clarity in your posts, ie.,
what 'standard' you refer to?
Who are 'those' engaged in these dangerous ships?
Who are 'those' who will benefit, or not benefit, from the 'different perspective?'

Jimmy.

Bill Davies
17th April 2009, 22:45
Kris,
Quite agree. I was reading the 'Derbyshire 'thread when I wrote it.
Many thanks.


Jimmy,
Yes, you are right to ask as it does not appear clear.
The article I recall was named 'Does it move or dosn't it' . It was written by an individual who should have known better and it recall may help others on the 'thought pocesses' of senior individuals in these class of ships which I would describe as dangerous.
Leave it with me over the weekend and I'll locate it somewhere/somehow and make of it as will. I'm sure you will find it entertaining.

Brgds

Bill

John Cassels
18th April 2009, 07:53
First interesting thread in months !.

Bill Davies
18th April 2009, 08:14
I do my best John. It's not all hellfire.

Pilot mac
18th April 2009, 14:00
Bill,
many moons ago I sailed as Mate on bulk carriers and it bothered me that on occasions we would arrive by the head after a long ocean passage when it was required that we arrive even keel, (I'm not talking a great amount about 12cm springs to mind). At the time I was sailing with a Mate FG certificate (pre 1978 in case you ask!). I was not aware of change of trim due to change of density, either I had not studied it or it was not in the syllabus for Mate FG at that time. All became clear when sitting Masters as it was in that syllabus and I made sure that I indeed studied it!

regards
Dave

Bill Davies
18th April 2009, 14:13
Dave,
You stole the show! That was indeed the whole point of the article in the 'Seaways'. I'll try and post it tonight . It will be amusing but if I try and give it from memory it will not be the same.

Brgds

Bill

Bill Davies
18th April 2009, 20:46
JC, Jimmy & Dave, here it is!

The following article was place in the Nautical Institutes periodical (now know as Seaways) around the mid 70s. The article having the title ‘Does it Shift or Dosen’t It’
was written by a Ch.Mate on a British flag Panamax running between Narvik and Ijmuiden.

The Mate noticed that on arrival at Ijmuiden the vessel was always several inches or more ‘by the head’. Concern was also raised about the manner in which the Nories and Burton’s (must have had a BF man onboard) Tables seemed to develop a life of their own in their movement across the fore & aft Chartroom bookcase.

However, the following considerations were debated:

1. Were the cones of Iron Ore in each hatch actually moving forward by the induced vibration as the vessel was underway. This was discounted as highly improbable.
2. Were the several inches of stripping left in the TSTks and DBTks finding there way to the fore end of the tanks and actually changing the trim. This was discounted as the possible moments involved were not sufficient.
3. Was the ship trying to align itself in the earths magnetic field? A seventy thousand tonne compass needle?

4. There was some reference made to the shift in the position of ‘G’ but this was dismissed as irrelevant.

This was very embarrassing for me as I had onboard a Mate who lost no time in pointing out that the author carried the same UK qualifications as me.

The following month a German Master lost no time in pointing out the real reason for the vessel ‘going by the head’ and that was… let’s hear it Dave, Jimmy and John Cassel?

So gentlemen, was this typical of the type of Senior officer in Bulk carriers. I would like to think not.

Hoping that this style of post generates other similar posts.

Bill

Derek Roger
18th April 2009, 23:52
Bill the problem was more than possible that there was not a lot of fuel forward and that as all the aft fuel including the engine room bunkers were being consumed during the voyage ( hence a forward trim )
If the forward DB's were filled that would decrease the amount of cargo loaded ?? Not very good for a cost effective trip ?

Just a thought . Derek

John Cassels
19th April 2009, 08:53
Gentlemen , reading this at my oldest sons place in Rotterdam , will think
about the thread on drive back home later today.

One point seems clear , both Narvik and Ijmuiden must be pretty close
to SW...................

Bill Davies
19th April 2009, 10:22
Derek, this is not an operational issue (forget internal transfer) but rather a stability phenomena.

John, drive safely and concentrate on the road, not this problem.

Brgds to you both

Bill

randcmackenzie
19th April 2009, 15:52
Is this the old chestnut about a ship loaded Even Keel in salt water will always go by the head if she sinks in fresh(er) water because the afterbody is more full than the forebody?

Bill Davies
19th April 2009, 16:48
Is this the old chestnut about a ship loaded Even Keel in salt water will always go by the head if she sinks in fresh(er) water because the afterbody is more full than the forebody?

Your warm! Emboldened not correct.

randcmackenzie
19th April 2009, 22:02
OK, to be more precise, the Waterplane area of the stern is more than that of the bow, hence a sinkage imparts a trimming moment forward.

Aggavated in places like the first lock in Panama, because the bow is in fresh or super fresh water, and the stern is in salt.

Bill Davies
19th April 2009, 22:27
[QUOTE=randcmackenzie;313732]OK, to be more precise, the Waterplane area of the stern is more than that of the bow, hence a sinkage imparts a trimming moment forward./QUOTE]

OK.
'G' will not change appreciable on passage and will be the same on arrival as on departure. If one was to argue a change dy/dx would only be in the vertical and therefore would not affect our arguement.
The vessel arrives at Ijmuiden and on entering Brackish water increases her draft by an amount equal to DWA. If the vessel increases her draft she has an increased WP area. Now, when this happens then clearly 'B' changes longitudinally (this is where I said you were warm) and produces a 'trimming moment' BG 'by the head'.


Bill

Bill Davies
19th April 2009, 22:39
JC,
Apologies for not waiting for you response but randmackenzie was there already.
Brgds

Bill

Derek Roger
20th April 2009, 00:38
Derek, this is not an operational issue (forget internal transfer) but rather a stability phenomena.

John, drive safely and concentrate on the road, not this problem.

Brgds to you both

Bill

Bill ;
Remember that there is no such thing as a mystery ; either we do not have all the facts or we are interpreting the facts incorrectley. ( I will let you do the spell check )

Derek

Bill Davies
20th April 2009, 18:32
Bill ;
Remember that there is no such thing as a mystery ; either we do not have all the facts or we are interpreting the facts incorrectley. ( I will let you do the spell check )

Derek

Derek,

You have lost me!

Bill

John Cassels
20th April 2009, 19:24
Back home safetly . Busy traffic , everyone heading for the coast .

Yes , Roddy is correct regarding the effect of change of load waterline
coefficient due change in density. This will change the CB ( slight shift aft),
However Bill , I do not see that this could have an effect in the situation
as given. As far as I am aware , both Narvik and Ijmuiden are . if not salt
then very close to it. So close that I cannot see that any change in
dock density would have such an effect as was stated.

Roddy´s example of the P. canal is well known but Narvik/ Ijmuiden I´m not
so sure.

Bill Davies
20th April 2009, 19:42
Well John,
I can almost sense you being out of breath. Roddy is indeed correct although the Canal phenomena is unique in the differential.
Narvik from memory varied from 1025 to 1022. If we consider a Panamax loading up there then when she arrives in Ijmuiden say, 1000 - 1005 then one will experience a trim by the head.

Brgds

Bill

Bill Davies
20th April 2009, 19:52
What views do you gentlemen have on the Mean of Means and it's variables?
There is much to discuss and perhaps we can coax Hugh away from asking embarrassing questions.

Bill

jasmacpm
20th April 2009, 20:47
Hi, Bill, so far out my depth (and memory), I was beyond the Continental Shelf, but most interesting and I can just about follow the theory, too. I take it from your original post that you found a colleague/s much in dark like myself?

Regards,

Jimmy.

Bill Davies
20th April 2009, 20:56
Jimmy,

I think you are being modest. The author of the article should have known better and was not even gracious enough to admit that he got it wrong. Now, that is what worries me in the context of people working aboard this type of ship which are commonly referred to as the 'workhorses of the sea'.

Brgds

Bill

Derek Roger
20th April 2009, 21:26
Derek,

You have lost me!

Bill

Bill I was referring to your use of " phenomena " which in common use tends to indicate a mystery or something unexplained .

The correct definition is "an observable occurrence " which no doubt is the context you intended an as such you are totaly correct .

I take it that this phenomena is only observed in large vessels with a fine stern and full bow section .

On smaller cargo ships with a fine bow and stern there would be no appreciable change in trim when going from Ocean to Rivers for example .

Regards Derek

Ron Stringer
20th April 2009, 21:52
I have no idea what you have all been talking about but I do know that the word 'phenomena' is the plural of 'phenomenon' and therefore it is incorrect to write of 'a phenomena'.

Yours pedantically,

Derek Roger
21st April 2009, 00:18
I have no idea what you have all been talking about but I do know that the word 'phenomena' is the plural of 'phenomenon' and therefore it is incorrect to write of 'a phenomena'.

Yours pedantically,

A pedantic reply if I may ;
Phenomena has been used as singular for 400 years and its plural phenomenas for over 350 years .

The non standard is phenomenon which is used incorrectly( either in the singular or plural ) by most people who are not well versed in language .
Most use it to describe something which is an unsolved mystery . Hence my earlier post .

It appears that Brocklebanks had some scholars .

Derek

John Cassels
21st April 2009, 08:05
Bill I was referring to your use of " phenomena " which in common use tends to indicate a mystery or something unexplained .

The correct definition is "an observable occurrence " which no doubt is the context you intended an as such you are totaly correct .

I take it that this phenomena is only observed in large vessels with a fine stern and full bow section .

On smaller cargo ships with a fine bow and stern there would be no appreciable change in trim when going from Ocean to Rivers for example .

Regards Derek

Think you have it the wrong way round Derek. The phonomena is caused
by the difference in waterplane area at loaded draft forward and abaft the
centre of buoyancy. A fuller body abaft the C of B. will give a slight
change of trim by the head when in water of less density. The C of B
will actually shift slightly giving a small change in trimming moment.

Bill , I hate to keep on about it but are you sure Ijmuiden is so brackish ?.
It's very many years since I discharged there but knowing it's location , I
would have said it would be a lot more than 1000-1005. Could be wrong
though.
Off now to get our loat ready for the season. At least I know the water
in the marina is fresh !!!.

Bill Davies
21st April 2009, 08:35
John,
We are, in principle, talking about the 'Effect of Change in Density on Draft' and to be frank I do not know that the author used Ijmuiden (whats in a name). It seemed appropriate when I was recalling the story.
As a matter of interest I will call one of my colleagues over there and check.

Brgds

Bill

Ron Stringer
21st April 2009, 14:30
Well Derek, this is well off thread and was only intended as a light-hearted response to several very sniffy posts about supposed oversights by others. But, ever the pedant, I can't resist taking the bait and responding.

It appears that Brocklebanks had some scholars. Derek

However it appears that the Brocklebank scholars didn't own a dictionary.

I quote from Collins English Dictionary

'phenomenon [C16: via Late Latin from Greek phainomenom, from phainesthai to appear, from phainein to show.]

Usage. Although phenomena is often treated as if it were singular, correct usage is to employ phenomenon with a singular construction and phenomena with a plural: that is an interesting phenomenon (not phenomena); several new phenomena were recorded in his notes.

And that is the way that I was taught at school (but only half a century ago, not three and a half). Our English masters were always very insistent on correct usage as opposed to common usage.

Derek Roger
21st April 2009, 16:10
Well Derek, this is well off thread and was only intended as a light-hearted response to several very sniffy posts about supposed oversights by others. But, ever the pedant, I can't resist taking the bait and responding.



However it appears that the Brocklebank scholars didn't own a dictionary.

I quote from Collins English Dictionary

'phenomenon [C16: via Late Latin from Greek phainomenom, from phainesthai to appear, from phainein to show.]

Usage. Although phenomena is often treated as if it were singular, correct usage is to employ phenomenon with a singular construction and phenomena with a plural: that is an interesting phenomenon (not phenomena); several new phenomena were recorded in his notes.

And that is the way that I was taught at school (but only half a century ago, not three and a half). Our English masters were always very insistent on correct usage as opposed to common usage.

Ron you are correct that we have diverged from the thread ; my reference was from Webster- Merriam . Wiktionary however supports you position . There seems to be a dissagreement between the minds on the correct usage . I will submit to your Collins version for future use .
Now back to the thread.

Regards Derek

Derek Roger
21st April 2009, 16:29
Think you have it the wrong way round Derek. The phonomena is caused
by the difference in waterplane area at loaded draft forward and abaft the
centre of buoyancy. A fuller body abaft the C of B. will give a slight
change of trim by the head when in water of less density. The C of B
will actually shift slightly giving a small change in trimming moment.

Bill , I hate to keep on about it but are you sure Ijmuiden is so brackish ?.
It's very many years since I discharged there but knowing it's location , I
would have said it would be a lot more than 1000-1005. Could be wrong
though.
Off now to get our loat ready for the season. At least I know the water
in the marina is fresh !!!.

John you are right I had it **** backwards .The stern has to be fuller than the bow to get a foward trim . The TPI aft would be greater than forward and as the weights have not changed the bow has to sink relative to the stern .
An equation that still sticks in the brain is that for salt water Tons Per Inch immersion is the WPA / 420 .

Cheers Derek

Pilot mac
21st April 2009, 16:44
Bill,
I dont recall any in depth study for draft surveys whilst doing my tickets its probably down to who you worked for as to what format you used. I came across some weird and wonderful methods during my time but I always used Mean of the Mean of the Means. I can only speak from practical experience but it seemed to usually work out alright when compared with a reliable shore weight.

bregards,

Dave

Bill Davies
22nd April 2009, 08:39
Dave,

I too favoured the Mean of the Mean of Means. There were several others methods used of a more academic flavour which were both cumbersome and unreliable. Looking back these necessary skills were nowhere to be seen on the syllabus

Brgds

Bill

Bill Davies
22nd April 2009, 09:28
Water density at Ijmueden:
Before the locks: 1018.00
Inside the locks : 1010.00
Let us not hang on to a name, the principle is the same, SW to FW.

Brgds

Bill

Pilot mac
22nd April 2009, 13:00
Bill,
I joined my first bulk carrier as second Mate with a Mates ticket and I did'nt even know what a draft survey was! Not a sniff of it for Mate FG. Steep learning curve as it is of course bread and butter stuff to Bulk Carrier Mates.
Draft surveys used to vary between a cursory half hour to six or more hours with a gaggle of surveyors. Some of them used to arrive with all kinds of elaborate claptrap for 'accurate' reading of the drafts, perspex tubes etc etc. I favoured the mark one eye ball and usually managed to pull the wool over their eyes!

bregards
Dave

John Cassels
22nd April 2009, 19:42
Think we had a very interesting thread on draft surveys a while back.

Like all the best threads though , it died a death after we all made our points
of view.

Bill , I won't press my point re Ijmuiden.

When you think about it , it should be possible to calculate what the change
in trim should be when passing from salt to fresh.

Difference in centre of boyancy at loaded draft and at loaded draft plus
FWA. This times Displ. will give a trimming moment , divide by MCTC will
give a trim which applied to the centre of flotation will give a change of
trim at fore and aft.

It's so long since I thought of this , is my thinking correct ?.

R58484956
22nd April 2009, 19:53
Bill another interesting thread you have started and for once no animosity, some of the antagonists must be getting soft in old age.
Keep the threads coming, better than watching TV.

Bill Davies
22nd April 2009, 23:06
John,

You are thinking too deeply into this. The calculation is quite simple and is volumetric.

The ship on departure will, in practice, be a little by the stern and in any case for equilibrium B and G will be in the same vertical line. Throughout the passage, the position of G will not appreciably change. The ship now arrives at the discharge port and the aim should be Even Keel (SW). However, the berth is a little upstream and the water is brackish ( say 1010). The ship now settles deeper in the water (the draft increases). This extra volume (slice) will have its own b (the COG of the new volume…slice).
Clearly, with this new volume of displacement B will move to a new B1 which is in the direction of b (aft). The force of buoyancy now acts up through B1 and down through G ( a clockwise moment)....by the head!!


Finally, BB1 , Sinkage, BML / MCTC are found in the usual way and thus COT.

Brgds

Bill

R58484956
23rd April 2009, 09:18
Bill ten out of ten, you have passed and you can go home early today.

John Cassels
23rd April 2009, 11:00
John,

You are thinking too deeply into this. The calculation is quite simple and is volumetric.

The ship on departure will, in practice, be a little by the stern and in any case for equilibrium B and G will be in the same vertical line. Throughout the passage, the position of G will not appreciably change. The ship now arrives at the discharge port and the aim should be Even Keel (SW). However, the berth is a little upstream and the water is brackish ( say 1010). The ship now settles deeper in the water (the draft increases). This extra volume (slice) will have its own b (the COG of the new volume…slice).
Clearly, with this new volume of displacement B will move to a new B1 which is in the direction of b (aft). The force of buoyancy now acts up through B1 and down through G ( a clockwise moment)....by the head!!


Finally, BB1 , Sinkage, BML / MCTC are found in the usual way and thus COT.

Brgds

Bill


Thought that was more or less what I said - or tried too anyhow .

Bill Davies
23rd April 2009, 14:01
Clearing the Belt.
How many were caught out 'clearing the belt'? Probably a good reason not to finish forward

Bill

Ian J. Huckin
23rd April 2009, 21:33
Clearing the Belt.
How many were caught out 'clearing the belt'? Probably a good reason not to finish forward

Bill

Plus most ships trim by the head when they get up to FSS.....

Pilot mac
24th April 2009, 13:08
I had trouble in Vancouver loading Sulphur when we could not get the 'operative' to stop the belt as he was asleep. Cargo ended up peaking above the coaming. Thankfully we were geared and could shift it about with our own cranes otherwise somebody would have been in deep mire. Struggled with the ballast as well that load, ah, the joys of loading! Always nice to get to sea.

regards
Dave.

Bill Davies
24th April 2009, 13:41
That's interesting Dave, as there was a similar incident in the early 70s in Dampier on a Gearless Cape Size vessel.

Ian J. Huckin
24th April 2009, 21:27
That's interesting Dave, as there was a similar incident in the early 70s in Dampier on a Gearless Cape Size vessel.

Bill & Dave,

That's why bulk Sunnies (sunflower seeds) were the preferred cargo out of the Lakes, plenty of time alongside because of the volume, but no draft worries because of the light stowage factor.....

Bill Davies
26th April 2009, 09:52
How often has your ego compromised your professionalism?
Loaded more cargo than your predeccessor!
Uncovered irregularities?
Overloaded?
DWT 'K'
No names of ships or individuals (Ships names can easily lead to individuals) please, just the incident.

Bill

slick
26th April 2009, 19:11
All,
On several occasions the Bulk Carrier I served on , left a port only to have the Upper Wing Tanks (one set) topped up to ease the rolling and this set of tanks was then pumped out prior to the Channel, nobody was any the wiser, as for loading sometimes we left by the head the argument going along the lines that she'll trim by the stern when we are underway.
Yours aye,
Slick
Esse quam videri

Bill Davies
26th April 2009, 19:14
Slick,
Use of the TSTks was quite common. I do hope you waited to discharge the Pilot before utilisation of same.

Brgds

Bill

trucker
26th April 2009, 19:22
discharge the pilot.hopefully not the sameway as discharging the ballast.(Jester)

Ian J. Huckin
27th April 2009, 17:36
All,
On several occasions the Bulk Carrier I served on , left a port only to have the Upper Wing Tanks (one set) topped up to ease the rolling and this set of tanks was then pumped out prior to the Channel, nobody was any the wiser, as for loading sometimes we left by the head the argument going along the lines that she'll trim by the stern when we are underway.
Yours aye,
Slick
Esse quam videri


G'day Slick,

Re the highlighted above - check Post #44

It would be interesting to get some more opinion here as from my time (as an engineer so it is more hear-say to me) the 10,000 to 42,000 ton bulkers I sailed on all trimmed by the head up to 1.5 m when loaded and approching FSS.

Ian

Pilot mac
27th April 2009, 18:44
Independent upper wing tanks were very useful as you say slick for knocking out some stability when loaded, also very useful whilst loading as they didnt need stripping and they would literally 'drop out' .

Dave

John Cassels
28th April 2009, 08:31
Independent upper wing tanks were very useful as you say slick for knocking out some stability when loaded, also very useful whilst loading as they didnt need stripping and they would literally 'drop out' .

Dave


As long as you weren't by the head !.

Pilot mac
28th April 2009, 09:36
Slick and Ian,
I dont think there are any hard and fast rules about squat, one of the mysteries of the sea! I think that very generally speaking then fuller form vessels will trim by the head and finer form vessels will trim by the stern. Throw in a few variables like shallow water, and anything can happen.
I was Mate on one ship for three years and I had a patent trim indicator which was never wrong. Whilst loading I would leave my bathroom door off the latch and as soon as it 'self closed' then I knew she was by the head, time to move the spout aft.

regards
Dave

greektoon
28th April 2009, 10:30
Never submerge the appropriate marks

Never load by the head

Ian J. Huckin
28th April 2009, 16:48
Slick and Ian,
I dont think there are any hard and fast rules about squat, one of the mysteries of the sea! I think that very generally speaking then fuller form vessels will trim by the head and finer form vessels will trim by the stern. Throw in a few variables like shallow water, and anything can happen.
I was Mate on one ship for three years and I had a patent trim indicator which was never wrong. Whilst loading I would leave my bathroom door off the latch and as soon as it 'self closed' then I knew she was by the head, time to move the spout aft.

regards
Dave

I believe you have it, because I spent my last four years at sea on Lauritzen and Chiquita reefers and I do not recall them trimming by the head once underway.

Re trim and draft restrictions imposed up the Great Lakes: when I was with Boltons we (engineers) all got very experienced with cargo work in that C/E planned for the least amount of D.O. and H.O. to do the Montreal/Montreal part, also minimum F.W. and ballast tanks DRY. We did all we could to keep bilges dry and drink as much beer as possible to enable a heavier lift. The more we lifted out of the Lakes the better our cargo bonus.

So, here is the problem; Loading Lake Head in say April the water temp was about 36F and air temp about 40F. We would load and trim exactly to the allowable draft. Then head down the Lakes...after about 48 hrs the water temp would still be in the 30s but day temps could be up in the 70s. The deck would heat up and 'hog' the ship therefore putting us over our marks for 'n aft.

There are video cameras at each lock trained on your draft marks so everything was critical. Worst case you would be put on a lay-by berth and would have to discharge cargo. That never happened to us because we rigged a deck cooling system on our bulkers to keep the deck cool and keep the 'hog' out of the ship. Not many ships about with a deck cooling system eh???

Ian

Flixtonian
28th April 2009, 17:12
Hi Ian

TMA ships all had "home made" deck cooling sprinkler systems, and not only were they effective, but also essential, to stop the vessel being over draught in the locks.
One time in Detroit on the Achilles, after loading scrap and swarf cargo, we had to wait on the berth for about 10 days to allow the swarf cargo temps to show a downward trend before the Coastguard would give us clearance to sail. It was in May, and I used to read the draught every morning at 0800 when the ship was even keel. I then read it again at 1600 and the ship would be hogged 4", with nothing having changed on board.
This was a good opportunity to see this "bi-metalic" type effect in action, particularly in May, as the water temp. was just above freezing.

Steve F.

Ian J. Huckin
28th April 2009, 22:08
Hi Ian

TMA ships all had "home made" deck cooling sprinkler systems, and not only were they effective, but also essential, to stop the vessel being over draught in the locks.
One time in Detroit on the Achilles, after loading scrap and swarf cargo, we had to wait on the berth for about 10 days to allow the swarf cargo temps to show a downward trend before the Coastguard would give us clearance to sail. It was in May, and I used to read the draught every morning at 0800 when the ship was even keel. I then read it again at 1600 and the ship would be hogged 4", with nothing having changed on board.
This was a good opportunity to see this "bi-metalic" type effect in action, particularly in May, as the water temp. was just above freezing.

Steve F.

Hello Steve,

On Astart we discharged Gypsum at Thurold and actually left the Lake system light ship...I was heartbroken. Felt for sure we would hit Duluth/Superior/Thunder Bay etc but never did...the ladies were heartbroken too..(Thumb) So never put the deck cooling on.

I used to load swarf on the Rebeka Oma up the Rouge River, Detroit for Passajes in Spain, what a tedious affair when you had a hotspot and the USCG would hold you up.

Did you ever discharge it while it was burning? made for a terrific fireworks display at night....

Ian

Bill Davies
28th April 2009, 22:39
Dave,
Gravity discharge TSTks were always handy and could be utilized to your advantage but you had to watch close as JC points out.
The squat phenomena is of course linked to reduction in UK clearence and 'bank effect'. I seem to remember that there was an arrival draft of 55' at Redcar (Tony Crompton will know) and we used to notice substantial squat in the English Channel with the North Sea Pilot reporting us as being 60' (10%.. bodily sinkage + trim by the head)

Bill

Ian J. Huckin
29th April 2009, 06:20
Dave,
Gravity discharge TSTks were always handy and could be utilized to your advantage but you had to watch close as JC points out.
The squat phenomena is of course linked to reduction in UK clearence and 'bank effect'. I seem to remember that there was an arrival draft of 55' at Redcar (Tony Crompton will know) and we used to notice substantial squat in the English Channel with the North Sea Pilot reporting us as being 60' (10%.. bodily sinkage + trim by the head)

Bill

Bill,

Would squat be similar to "ground effect", like a low pressure boundary under the hull?

Ian

Bill Davies
29th April 2009, 19:44
Ian,
They are similar but there is a subtle difference.
Squat is a phenomena which happens when a ship sinks bodily in the water and trims according to her Cb. ‘By the head’ on a bulk carriers (full form) and ‘by the stern’ in a ‘fine formed ‘ passenger ship or reefer vessel. The same argument here as used when increasing draft when going from SW to FW (movement of ‘B’). The water displaced (pushed ahead)causes a vertical drop (increase in draft) and is caused by the displaced water flowing at an increased speed under the hull(thoughts of Bernoulli). Thus, squat varies directly with the speed squared ( approx). It manifests itself in reduced UK Clearence.

Bank Effect is when we here of a vessel in a narrow channel ‘smelling the bottom’ and the vessel will swing towards the closest bank. Squat has already taken effect before Bank effect cuts in.

Ian J. Huckin
29th April 2009, 20:59
Ian,
They are similar but there is a subtle difference.
Squat is a phenomena which happens when a ship sinks bodily in the water and trims according to her Cb. ‘By the head’ on a bulk carriers (full form) and ‘by the stern’ in a ‘fine formed ‘ passenger ship or reefer vessel. The same argument here as used when increasing draft when going from SW to FW (movement of ‘B’). The water displaced (pushed ahead)causes a vertical drop (increase in draft) and is caused by the displaced water flowing at an increased speed under the hull(thoughts of Bernoulli). Thus, squat varies directly with the speed squared ( approx). It manifests itself in reduced UK Clearence.

Bank Effect is when we here of a vessel in a narrow channel ‘smelling the bottom’ and the vessel will swing towards the closest bank. Squat has already taken effect before Bank effect cuts in.

I do understand what you are saying, I remember enough of my studies to relate to it.

Bank effect was a bugger up in the Lakes, especially just after you cleared Montreal up-bound...that long cut played havoc, especially if a ship was downbound coming past you.

And that brings up another weird effect: ships that close are also attracted to each other, so to minimise that effect on a close approach you actually steer towards the other ship, for a brief period. This would swing your stern away from that ship and, although the bows were the closest point of approach the majority of the hull stayed well away and reduced that "suck together!" effect.

lakercapt
29th April 2009, 23:40
I do understand what you are saying, I remember enough of my studies to relate to it.

Bank effect was a bugger up in the Lakes, especially just after you cleared Montreal up-bound...that long cut played havoc, especially if a ship was downbound coming past you.

And that brings up another weird effect: ships that close are also attracted to each other, so to minimize that effect on a close approach you actually steer towards the other ship, for a brief period. This would swing your stern away from that ship and, although the bows were the closest point of approach the majority of the hull stayed well away and reduced that "suck together!" effect.

Yes Ian
For an engineer (Not belittling) you certainly have the concept of close water ship actions and reactions. Frightens the bejesus out of you when you first do some of these maneuvers. Meeting another ship in the South Shore canal you met in certain places (not under the bridges) and steered directly towards the other boat until a boat length away then both altered to starboard. The interaction pushed the bows apart and when the bows were level you put the wheel to port until both boats were parallel then steered until the sterns cleared and port the wheel again as the sterns sucked towards each other. When clear std again to steer down channel.
It is not possible to overtake in a narrow channel as the bow and stern suction causes the overtaking boat to sheer towards the stern of the other boat.
Bank suction is when the stern of the boat gets too close to one bank and the stern gets sucked towards that bank. Used to use this effect when canaling and there was an offshore wind. To break it apply more speed.
Hope that is not too technical but doing this so often most of the time we left it to the wheelsman to do the necessary wheel movements.

Ian J. Huckin
30th April 2009, 02:12
Yes Ian
For an engineer (Not belittling) you certainly have the concept of close water ship actions and reactions. Frightens the bejesus out of you when you first do some of these maneuvers. Meeting another ship in the South Shore canal you met in certain places (not under the bridges) and steered directly towards the other boat until a boat length away then both altered to starboard. The interaction pushed the bows apart and when the bows were level you put the wheel to port until both boats were parallel then steered until the sterns cleared and port the wheel again as the sterns sucked towards each other. When clear std again to steer down channel.
It is not possible to overtake in a narrow channel as the bow and stern suction causes the overtaking boat to sheer towards the stern of the other boat.
Bank suction is when the stern of the boat gets too close to one bank and the stern gets sucked towards that bank. Used to use this effect when canaling and there was an offshore wind. To break it apply more speed.
Hope that is not too technical but doing this so often most of the time we left it to the wheelsman to do the necessary wheel movements.

Hey there lakercapt,

If it has anything to do with ships then I'm interested so I appreciate your explanations.

I was probably sitting back down below with a cuppa rosy totally unaware.....

Part of that canal goes through an Indian Reservation doesn't it? we used to get our funnel shot full of holes for a while...did you ever hear of that happening on any ships?

Ian

lakercapt
30th April 2009, 02:43
Part of that canal goes through an Indian Reservation doesn't it? we used to get our funnel shot full of holes for a while...did you ever hear of that happening on any ships?

Ian

Yes Ian
the South Shore canal runs through the Kananakwe Indian reserve and there were times when there were disputes about land claims etc and they took some of their frustrations out on ships passing through.
Never was shot at but had rocks and ball bearings shot at us from catapults but mostly by kids as they did not have AK47's!!!!
Was tense on occasion.

Dave Edge
30th April 2009, 11:03
The more I read about squat the more I become convinced that nobody actually knows what they are talking about (SN members excepted) or can quantify it. Okay, it exists - we all remember the QE2 - but even the 'experts' don't seem to know of what they speak.
In the July 2006 issue of 'Nautilus Telegraph' a scientist, Dr Barrass,FNI, contributed an article entitled 'Don't Fall Victim to Ship Squat Perils' in which he contended that vessels with high block coefficients squat up to 2 metres at 10 knots.
Houston pilot representative Louis Vest pointed out that they regularly took such vessels with a 13.7 metre draught and UKC of 0.6 metres up the Houston Ship Canal at 10 to 12 knots without difficulty and without squat.
Dr Barrass replied that it was impossible; Captain Vest replied that they did it every day.
The full article appears in the UK Maritime Pilots Magazine, brilliantly edited by John Clandillon-Baker, and may be accessed on line at www.pilotmag.co.uk ; on the menu click on back issues and go to pilotmag 292 Spring 08.
Regarding stuff ups on bulk carriers; we arrived at the Atlantic end of the Panama Canal in company with a 'Panamax' bulky belonging to a very well known European company which had been up the Mississippi with us. She had loaded grain for Japan and the master had asked of his agent the maximum Panama Canal draught at the time he would be transitting. This he obtained and she arrived exactly on it - but in salt water. As she was gearless there was no way to discharge so she eventually proceeded via the Cape - after the master and mate had been relieved.

James_C
30th April 2009, 13:26
Dave,
As I recall there was quite a series of letters exchanged in the letters page of the Telegraph between the Scientists and the Seamen, it all got a bit acrimonious towards the end.

ROBERT HENDERSON
30th April 2009, 13:33
Dave,
As I recall there was quite a series of letters exchanged in the letters page of the Telegraph between the Scientists and the Seamen, it all got a bit acrimonious towards the end.

I followed the same article, I believe it was in more than one issue of the Telegraph, I also remember it got as James C said. a bit acrimonious.

Regards Robert

Bill Davies
30th April 2009, 18:17
The more I read about squat the more I become convinced that nobody actually knows what they are talking about (SN members excepted) or can quantify it. Okay, it exists - we all remember the QE2 - but even the 'experts' don't seem to know of what they speak.


Dave,
There are no shortage of experts and while Bryan Barrass has made his name on this topic there is much that he says which I do not agree with. Similarly, there will be no shortage of Pilots who will have a contrary view to the so called experts. I have experienced squat on all the ships I have sailed from the 'Ore' ships running between Puerto Ordaz and Baton Rouge (Both good testing grounds) to +400k ULCCs. Quantifying it is very much an academic exercise but it certainly is directly proportional to speed. In the 'Mariner' class we invariably smelt the bottom on departing Jebel Dhanna which was suficient to instill my belief. I have always had a rule of thumb that the bodily sinkage plus the trim may account for approx 7%/10%) depending on SG as if you were approaching a river berth you would have the FW to consider.
Bill

Dave Edge
2nd May 2009, 06:58
Bill,
Not disputing that squat exists or that it increases with speed, what I find problematic is the apparent inability of anyone to accurately quantify it. At Bluff we have a rock bottom in the channel so go for the worst case scenario and allow 1.2 metres UKC at 9.7 metre draught, equating to about 12.5%, and try to keep the speed below 5 knots on deep draught ships. I wonder what margins bulk carrier ports utilising DUKC work to, however, given that draught is tonnage = money.
Regards,
Dave Edge.

Bill Davies
5th May 2009, 19:31
Dave,
My own posts on this topic reflect the size of ships I have sailed in, the smallest being a Panamax. However, I have been reliably informed that the phenomena manifests itself in all sizes and Jebsens lost a ship (a 6k vessel) in the Drogden Channel about twenty years ago due to her tearing the bottom out of herself through xs speed resulting in squat.

Bill

trucker
5th May 2009, 19:35
is that how the q.e.2 scraped the bottom ,i believe some where off florida.a couple of years back ,i believe it was because of the x.s speed pushing her down or squat.

Bill Davies
5th May 2009, 20:10
Squat was given as the cause of the grounding but I think there was much more which is better left unsaid. Incidentally, trucker, due the Queens fine lines she would have 'trimmed by the stern'.

trucker
5th May 2009, 20:22
bill ,they certainly kept pushing the theory of squat.but then they would if it had been anything untoward.(Thumb)

Bill Davies
14th May 2009, 21:40
How many of you rigged up 'water tubes' to ensure you were upright on completion or did you rely on lights or similar.

Bill

John Cassels
15th May 2009, 08:40
Sounds a bit silly Bill , but used to have an apprentice standing by on the
monkey island at the heeling indicator at the standard compass !.

Bill Davies
15th May 2009, 12:49
Not silly at all. If it works for you, that is all that matters.
I distrusted the lights which were in vogue in the 70s. The men in the ship loaders used them and that was fine but, for completion I used a water guage. Gave some reassurance in places like Sepitiba when the offshore midship reading was very much a guessing game.

Brgds

Bill

Bill Davies
27th May 2009, 19:51
How many times have you found that the loading plan 'as tendered' was not adhered to. What I am getting at here is that much is written about homogenous/alternate/block loading and we all now the pro's and Con's here.
Are there any recent experiences where a terminal has somewhat of a 'colly wolly' attitude to the plan and go right ahead and do it their way.

Bill

lakercapt
27th May 2009, 20:56
On "lakers" as loading to a restricted draft there were list lights at the for'd end and aft so the mates/trimmers/loaders could see them when completing the load.
One flashing red light meant you had a !/2 degree list to port.
One fixed red 1 degree
two red lights 2 degree etc
On occasions it was possible to have the for'd and after lights show different which meant the boat was twisted!!!
White light indicated that the boat was upright

John Cassels
28th May 2009, 08:57
How many times have you found that the loading plan 'as tendered' was not adhered to. What I am getting at here is that much is written about homogenous/alternate/block loading and we all now the pro's and Con's here.
Are there any recent experiences where a terminal has somewhat of a 'colly wolly' attitude to the plan and go right ahead and do it their way.

Bill

Can't give any "recent"experience Bill , but do not remember ever having
problems with the loading sequence. Amount of tonnage dropped in each
run sometimes left a lot to be desired though.

Bill Davies
28th May 2009, 22:09
On "lakers" as loading to a restricted draft there were list lights at the for'd end and aft so the mates/trimmers/loaders could see them when completing the load.
One flashing red light meant you had a !/2 degree list to port.
One fixed red 1 degree
two red lights 2 degree etc
On occasions it was possible to have the for'd and after lights show different which meant the boat was twisted!!!
White light indicated that the boat was upright

I never felt comfortable using lights for that very reason.
A good set of midship figures was what I was after.

Derek Roger
28th May 2009, 23:39
I never felt comfortable using lights for that very reason.
A good set of midship figures was what I was after.

Bill the system as described was very accurate and a lot of time was spent on calibration .
The system I was familar with was designed by a division of Port Weller Drydocks ( Canal Electric ) in St Catherines Ontario.

It was most important on the Self Unloaders specially the vessels with a Reclaimer system .
Not only did the vessels twist but tended to sag in hot weather ( even when correctly loaded ) at ambient temperatures .

There was a system of deck cooling using sprays from the main fire pump system to cool the deck and allow it to contract and maintain drafts fore ; aft and midships to allow the vessel to pass the canal in the maximum loaded condition .
I think the chap who designed the system was Casey Oppdam ( originally from Holland )

Regards Derek

lakercapt
29th May 2009, 04:05
Having a responsible person outboard on the gangway reading the draft and another on the dockside could work well but that changes could be so rapid that it was difficult to keep up. The lights gave instantaneous indication.
Transiting the Welland Canal and St.Lawrence seaway draft restrictions were strictly enforced and woe betide you if you were overdraft. You were secured until it was remedied. Not a situation the shipowners relished especially when time constraints were in there very important
That was the reason in spring And summer when water and air temeratures differences were the most marked water was sprayed on the decks to stop hogging. The air temperature being much greater than the water temperature and the coefficient of linear expansion of differant areas was quite considerable as to cause sufficient fore and draft increases and get you beyond permissable limits

Bill Davies
12th October 2009, 18:33
The Deadweight Constant

Can any of you remember carrying a DWT 'K' that bore no relationship to that shown on the T/C. I can recall several Cape Size /Panamax Bulk Carriers which had been on T/C for a period of time and the out-turn was 'whittled away by an ever increasing 'k' which was in fact mud in the tanks. The out-turn was of course 'masked' by many ingenious ways.
What was the largest 'k' you experienced?
How did you remove/reduce it?

Bill

sparkie2182
12th October 2009, 22:23
" 'masked' by many ingenious ways. "

That i can believe.

:(

johnb42
12th October 2009, 23:15
lakercapt
very much liked your #80 and #84. I only did the lakes a couple of times in my time at sea and did in fact get "pulled" in the Welland, for being overdraft. We were a couple of inches out of trim and the situation was easily rectified. It was still unwelcome at the time as we were all tired and a little short on humour, but rules were rules.
I remember reading about the spraying of "laker" decks to prevent hogging, didn't some lakers have a fixed "spraying" system?
Off topic, but I also remember no "monkey fists" being allowed on heaving lines in the lakes. If one landed in the boat or on the lock a magic knife (hopefully a Green River) would appear and the offending mass would be swiftly removed and condemned to the deep.

lakercapt
13th October 2009, 04:03
lakercapt
I remember reading about the spraying of "laker" decks to prevent hogging, didn't some lakers have a fixed "spraying" system?
Off topic, but I also remember no "monkey fists" being allowed on heaving lines in the lakes. If one landed in the boat or on the lock a magic knife (hopefully a Green River) would appear and the offending mass would be swiftly removed and condemned to the deep.

I don't recall any of the boats I was on having fixed spray systems are they would have been tough to drain in cold weather and that was essential for the fire main. They would be blown out with compressed air after every use.

Heaving lines could not have weighted end as you say as the lock personnel would cut the end off.

A ship with the sprinklers on would be a constant source of questions from shore side people viewing the transit in the Welland canal.

John Cassels
13th October 2009, 09:00
Cannot now remember how the constant was described in a C/P. If it was
"said to be " or fixed.
Seems to come to mind that most of the panamax's I was on used a magical
K of 750 mt. and am sure this bore no resemblance to the actual.

As you say Bill , there were many methods to adjust the outurn , some already posted. My favouite was playing around with the ballast main.

Bill Davies
13th October 2009, 21:00
Well John,

You are of course quite right. The book constant bore no relationship to the actual.
I seem to remember the book ‘K’ on Panamax to be about 570.00 mt but then I was only on half a dozen of those vessels. The Capesize was about 1100.00 mt.
However, getting back to the actual. I noticed on Capesize vessels that had been on T/C to the likes of BISCO that the actual ‘K’ was several thousand on top. Clearly, this was attributed to ballasting in the likes of Redcar, Immingham or Port Talbot.
Was in several Cape Size which had constants of inxs of 4k which of course required much manipulation of ballast. I preferred using TSTks discharging by gravity.
I remedied this problem (XS ‘K’) by leaving half a metre of ballast in the DBTks on both loaded and ballast passage when the vessel was rolling. Surprising how much you could remove. You needed a good conscientious Mate. The problem could have course been minimised if a little thought was given to ballasting by gravity and stage of tide.
I can't ever claim to attaining the book 'k' but I came fairly close by the method above.

Bill

Derek Roger
14th October 2009, 01:37
Bill ;
You seem to be more interested in Midship than in the Bow and Stern lists ?? You would not have got up the Welland Canal with that perspective and you seem to have neglected the hog and sag which would have more than given you problems .

chadburn
14th October 2009, 18:20
The main problem with the lakes is that the wave heights are somewhat larger in proportion to their lengths, the usual ratio of 1/20 can vary to 1/15. Two sets of calculations need to be done depending on ship length one with the crest and one with the hollow at the bow, a vessel uniformly loaded tends to sag and it is common practise to add additional cargo at the forward and afterends. Lakes vessels tend to be built stronger than similiar ocean going types.

lakercapt
15th October 2009, 02:45
Geordie Chief
I hate to spoil your paresis but any lake vessel I was on had lesser scantlings than an ocean ship.
When the weather got inclement we went for shelter as quickly as possible.
When you see a lake boat bending in what salt water sailors would consider only slight/moderate seas you would understand that logic.

They are built to carry as much cargo as possible and heavy steel plating restricts that capacity.

I was surprised when I went from deep sea to lakes to notice the differences and I soon discovered all the safe anchorages or steaming slowly back and forth in the lee of an island when no anchorage was available.

Not too long ago a well known wreck occured when a more prudent mariner would have sought shelter.

chadburn
15th October 2009, 14:16
Lakercaptain, no wonder Smith's did not get the order for a new build as that was the paresis it was based on, all though they did build later on for Manchester Liners. I have a whole host of info and diagrams from my time in the Drawing Office, unfortunatly it is just not possible to tranfer them on to this site. The info concerned stresses on vessels due to varying wave length's and height's appertaining to the Great Lakes, but I bow to your own PRACTICAL EXPERIENCE on sailing those waters(Thumb) rather than the some of the obvious theory only explanations that have been put forward.

joebuckham
15th October 2009, 16:15
Lakercaptain, no wonder Smith's did not get the order for a new build as that was the paresis it was based on, all though they did build later on for Manchester Liners. I have a whole host of info and diagrams from my time in the Drawing Office, unfortunatly it is just not possible to tranfer them on to this site. The info concerned stresses on vessels due to varying wave length's and height's appertaining to the Great Lakes, but I bow to your own PRACTICAL EXPERIENCE on sailing those waters(Thumb) rather than the some of the obvious theory only explanations that have been put forward.

chadburn and laker captain, i have been following this thread with great interest but you use a word, that i have highlighted, which is a word new to me. am i going mad( not from paresis) or is there a meaning other than the one given below.(Thumb)

Quote;General paresis usually begins about 15 - 20 years after the syphilis infection. Risks include syphilis infection and infection with other sexually transmitted diseases, such as gonorrhea (which may hide symptoms of syphilis infection)Quote

chadburn
17th October 2009, 17:06
Joe, I just carried on with what I thought was a bit of a joke(Jester) , thinking lakercapt possibly mistyped parenthesis(Thumb). Only he knows the correct answer to your query.

lakercapt
17th October 2009, 17:57
chadburn and laker captain, i have been following this thread with great interest but you use a word, that i have highlighted, which is a word new to me. am i going mad( not from paresis) or is there a meaning other than the one given below.(Thumb)

Quote;General paresis usually begins about 15 - 20 years after the syphilis infection. Risks include syphilis infection and infection with other sexually transmitted diseases, such as gonorrhea (which may hide symptoms of syphilis infection)Quote

Opps wrong word but I was not intending it in the STD category.
Glad so many observant members are ready to keep us honest.
That and spell check are wondrous restraints.

Bill Davies
17th October 2009, 19:52
Bill ;
You seem to be more interested in Midship than in the Bow and Stern lists ?? You would not have got up the Welland Canal with that perspective and you seem to have neglected the hog and sag which would have more than given you problems .

What specific post are you referring to?

chadburn
19th October 2009, 10:08
After all the info was gathered by Smith's in regards to the wave pattern's of the Lake's they did eventually (after I had left) in 1963/64 build the Manchester(s) Commerce, Renown, City, all 6cy Sulzers with twin side by side "Woodbine" stacks as well as the conversion of the Manchester Quest (1970) to carry containers. Still have most of the info which I kept concerning loading in regards to lakercapt's part of the World, the "Primary" trading route being an important factor for new build's just the same as it is between the build spec of Ocean Liner's and Cruise ships.

Bill Davies
21st October 2009, 05:04
Bill ;
You seem to be more interested in Midship than in the Bow and Stern lists ?? You would not have got up the Welland Canal with that perspective and you seem to have neglected the hog and sag which would have more than given you problems .

Another JC!

chadburn
21st October 2009, 11:03
[QUOTE=chadburn;369547]After all the info was gathered by Smith's in regards to the unusual wave pattern's of the Lake's they did eventually (after I had left) build in 1963/64 the Manchester(s) Commerce, Renown, City, all 6cy Sulzers with twin side by side "Woodbine" stacks as well as the conversion of the Manchester Quest (1970) to carry containers. Still have most of the info which I kept concerning loading in regards to lakercapt's part of the World, the "Primary" trading route being an important factor for new build's.

Andrew Craig-Bennett
8th April 2010, 15:57
Much of interest in this thread and I hope this is the right place to ask a question:

Does anyone know whether loader operators in Australian ports are on piecework or on a bonus system?

Same for Brazil.

You can see why I'm asking!

Octavius
11th April 2010, 15:36
Piece work or bonus? I imagine piece work as you needed eyes in your **** during loading.