APROBATORIO PUNTAJE MÁXIMO Evaluación Ficha, CV documentado +

(PLEASE SEE NOTE MARKED **** IN CASE 1)

Present trim is 15.6 cms by stern - we require to finish 38.6cms by stern - Therefore change in trim should be 23 cms by stern.

First tackle this - loading in #8.

To trim by stern by 23cms = Trim required in cms x 100 = 23 x 100 = 807 MT Trim caused by 100 MT 2.85

Therefore (2451 - 807) = 1644 must be distributed in #4 & #8 without any further change in trim

To load in #4 without any change in trim we load

Weight to load x Change of trim caused by #8 = 1644 x 2.85 = 1025.3 = 1025 finish with the required drafts - you can check this

Ford Aft

really is, if you are careful and know what you are doing - remember that the change of trim values per 100MT in the trimming tables assumes that the weight is loaded or discharged from the middle of the hold and you know that it would be impossible to load all the cargo for trimming in the centre of the hold - what you should ensure is that the cargo for trimming is distributed evenly across the hold - in the athwartship and fore

& aft directions. You should then be able to get the trimming as accurately as in the formula.

Remember that the vessel is almost always hogged or sagged and hogs or sags under the effect of cargo loaded or discharged in different holds - always play safe - if your maximum draft is to be at midships assume she will sag a bit due to the trimming cargo, i.e. if the sag before trimming is about 3 cms, assume that after trimming it will sag further, if the maximum draft is aft assume she will hog a bit after trimming, i.e. if prior trimming you are sagging 3 cms, after trimming, she will sag 1 cm. Of course once you are comfortable with the way your v/l behaves, you can estimate whether she will hog or sag depending which holds you are using.

In Case 3, even tho max draft is to be at midships, I am confident that on the Cape-size, trimming with 3 & 8 will produce a hog effect - but please do remember that the ship is not a violin and the hog & sag effect is not always instantaneous - if you load at #1,2 or 9 on the Cape-size you will probably see the hog effect come into play almost instantaneously. However, should you load in 3 or 8 it will be much more gradual - similarly the sag effect will be much slower when loading in 4 or 7 and much faster when loading in 5 or 6.

Remember it is not always instantaneous - an example to illustrate -

Voyage 8 on SILC - loading coal at R/Bay - about 3500 MT for trimming at the stop for trimming - trimming with #4 & #8.

Voyage 9 similar situation.

On Voyage 8 the loading sequence was such that the run before the trim stop called for loading 5450 MT in #6 hold - #6 is just abaft midships - we were sagged at this point - after trimming at #4 & #8 we ended up with a sag greater than at the trim stop.

On Voyage 9 the loading sequence was such that the run before the trim stop called for loading 6600 MT in #2 hold - at the trim stop we were sagged - after trimming at #4 &

#8 with almost the same quantities for 4 & 8, as in Voyage 8, we found that the sag had decreased.

This seems to support the idea that the v/l hogs & sags over a period of time - what my conclusion is, is that in Voyage 8, the run in #6, was causing the v/l to sag & this sagging does not stop immediately you stop loading at #6 - the v/l takes some time to complete this sag effect. Conversely the v/l was undergoing a hog effect when loading at #2, in Voyage 9, and this does not stop immediately on stopping loading at #2.

compound that you probably will be trimming with #3 & #7 which means that at the trim stop, with loading complete at the end holds - 1 & 9 - you will be even more hogged at the trim stop than at completion - after loading the trimming cargo at #3 & #7 you should be able to reduce this hog - but the difficulty you encounter is that it is extremely difficult to predict what amount this hog effect or any sag effect actually is - however if you trim as suggested below you should be able to eliminate any estimation errors.

This is the 2 drop method for trimming to which I will refer to a little later.

In all the cases I have explained - I have shown you calculations right down to the absolute maximum - i.e. if the max.draft was 17.50 metres - the calculations were right down to 17.50 metres - there is absolutely nothing wrong with this method & you should be able to get right down to the absolute maximum but prudence would suggest that you always have a little in hand - let s say about 1 cm at least on the Cape - size which translates to abt 100 tonnes & about 1.5 cms on a Panamax which also translates into 100 tonnes.

In my early days as a Chief Officer, after I was comfortable with this trimming calculation method, I would reach the trimming stage, keep the required safety margin in hand, and do the trimming in 1 drop, i.e. if I was trimming with #3 & #7 - I would calculate the quantities to load in #3 & #7 & load them - was later advised & realised that it is much better to do the trimming in 2 drops -

i.e. stop for trimming - make your calculations for #3 & #7, then remove a total of about 700 tonnes from the figures - do ONE drop in #3 & #7, do another draft check, then do a final drop in #3 & #7. This method is infinitely better - this small amount of cargo in the 2nd drop eliminates any error caused by the error in the loader - when the shore side is required to load a certain quantity, very unlikely you will get that exact figure.

Secondly, your estimation of the sag or hog caused cannot be far wrong with the final drop of abt 700 tonnes - also if you have underestimated the effect of hog or sag at the first trimming drop you can still make a correction - besides that if you have erred the other way with your hog/sag estimation - i.e. on the safe side - you will be able to load a little more - for eg if you had estimated that the v/l would sag 3 cms more during the first drop & reduced your quantity in line with that, & you actually sagged only 1 cm more, you could then load a little more cargo -

However, in ports where they will absolutely not allow you to sail even with 1 cm excess, such as Hay Point or Richards Bay I would strongly advise that you keep something in hand even at the 2nd drop.. There are still many possibilities that will cause you to be overdraft - chief among them is that even though you do your very best to ensure there is absolutely no list you are 1 cm in excess on 1 side & have no sinkage available to correct this - always play safe - REMEMBER nobody gives you a medal for loading extra cargo - but you will face all sorts of trouble if you are over draft.

Choosing which holds to use for trimming is a matter of personal preference but I will

9 on the Cape-size and 1,2 & 7 on the Panamax - loading in these holds definitely cause the v/l to hog - the problem is that it is impossible to predict how she will or how much she will hog - i.e. if you are loading at #1 this will cause the ford draft to increase more than the trimming tables suggest, but the decrease in the aft draft due to the hog effect will be much less & it is impossible to predict how much at each end.

When sagging the effect is at one point - midships.

Also because loading in #5 & #6 on the Cape-size or #4 & #5 on the Panamax would cause the v/l to sag I would not trim with these holds if I could help it.

On the Cape-size would prefer to trim with any combination of #3 & 4 ford & #7 & 8 aft.

Ideally if loading at alternate holds would trim with #3 & #7.

On the Panamax would prefer to trim with #3 & #6, at a push would trim using #2 &

when loading alternate holds would probably trim with #3 & #7 but in no event would I trim with #1.

Examination of the trimming tables would show that almost all vessels have ONE hold ford of midship where loading would cause a very negligible change in the aft draft - and also ONE hold aft of midships where loading would cause a very negligible increase in the ford draft - on Panamax size (7 holds) the likely holds are #3 & #6 - on the Cape size (9 holds abt150,000 dwt) it is likely #4 & #7 & hence I would prefer to do my trimming with these sets of holds, if circumstances permit.

Considering the Cape-size - Trimming with #4 & #7.

You have reached the draft check stop prior trimming - you read drafts and make you calculations to load quantities in #4 & #7. Let us say that these figures are 1500 MT in

#4 & 2000 MT in #7.

I would then load abt 1200 MT in #4, then 1600MT in #7 and keep the loader at #7.

Then I would read the drafts and make calculations to load certain quantities in #7 & #4 to reach the final required drafts.

Assume these quantities to be 440MT in #7 & 320 MT in #4.

Now the trimming tables tell us that for every 100 MT loaded in a) #4 the ford draft increases by 1.81cms & aft draft increases by 0.09cms

Therefore for the 320 MT to be loaded in #4 the increase in ford draft would be 5.8 cms and there would be no increase in the aft draft.

b) #7 the ford draft increases by 0.07cms & aft draft increases by 1.79cms

Therefore for the 440 MT to be loaded in #7 the increase in ford draft would be nil and the increase in the aft draft would be 7.9 cms.

At this final drop I would have someone ensuring the v/l is to be upright, we would load first in #7, with the Mate watching the aft draft on the shore side. The Mate is kept informed all the time about the quantity remaining - when the loader states that there is 300 MT to go, the Mate reads the draft.

Knowing that the remaining 300 MT is going to cause an increase in the aft draft of = 5.4 cms, he can then monitor if all is well - if the reqd aft draft is 17.00 mts and he reads the draft to be 16.946 with 300 MT to go, all is well - if however the draft is 16.966 then he knows that he is going to finish over draft so he can stop the loading and make adjustments. By trimming with #4 & #7 he knows loading in #4 will not change the aft draft so at this stage - when loading at #7 - he only has to bother about the aft draft.

When the 440 MT is complete at #7 and you have reached the reqd draft of 17.00 metres aft - this now removes the problem of the aft draft.

Immediately loading at #7 complete - the Mate would make his way quickly forward and read the ford draft - if all is going well the ford draft should be 17.00 - 0.054 = 16.942 metres - he would then make his way to the midship draft on the shore side, with one person on the offshore side on the ladder, checking the midship draft.

Now all you are to worry about is the midship draft - you have people checking on either side with one person in contact with the loader to ensure you complete absolutely upright.

Now the midship draft is 17.01metres - you are going to load 320 MT in #4 which will result in a sinkage of 3 cms & assuming this will cause a sag of 1 cm you will finish with 17.05 metres.

In the example of the trimming operation above, I have again finishing to the absolute maximum - if you are loading at one of the extremely strict ports would as before suggest you keep something in hand.

In the above example I have shown the situation when the vessel is finishing even keel, but you maybe finishing with a trim, say by stern, of 50cms.

Now we know that on SILC

Ford trim correction = Trim x 0.004 = 0.50 x 0.004 = 0.002 which is negligible Aft trim correction = 0.50 x 0.042 = 0.02m

No problem at the ford draft but

the draft at the aft perpendicular is 0.02m more than at the aft draft mark, which means that the Mate monitoring the aft draft should ensure that the read draft aft should not be more than

17.00 - 0.02 = 16.98 metres.

In the example on the previous page have shown a situation where you are trimming with 4 & 7 which do not change the draft at one end.

However you may be trimming with #3 and #8 with say, 320MT in #3 & 440MT in #8 Trimming tables tell us that for every 100MT

a) in #3 the ford draft increases by 2.35cms & the aft draft reduces by 0.48cms

therefore loading the 320 MT in #3 would result in the ford draft increasing by 7.5cms and the aft draft would decrease by 1.5 cms.

b) in #8 the ford draft decreases by 0.50cms & the aft draft increases by 2.34cms

therefore loading the 440 MT in #8 would result in the ford draft decreasing by 2.2cms and the aft draft would increase by 10.3 cms.

Now when you are doing the final drop the Mate at the aft draft mark would, if you were finishing even keel, allow the aft draft to reach 17.00 + 0.015( the decrease in aft draft caused by loading at #3) =17.015 on completion at #8.This would result in the aft draft being 17.00 m as required on completion of loading at #3.

If the vessel was to finish with a 50 cms trim then he would ensure that the aft draft, would on completion of loading at #8, be

17.00 + 0.015 - 0.02(diff between read draft & draft at perpendicular) = 16.995

This would result in the aft draft (at the perpendicular) to be 17.00 meters on completion of loading

at #3.

Each of the combination of holds you would use for trimming would have it s pros &

cons

#4 & #7 by virtue of changing the draft only ford and only aft respectively make it easy for monitoring the draft during trimming. However both 4 & 7 would cause the vessel to sag so your sag caused by the trimming cargo would be quite a bit. Also, 4 & 7 change the trim only very slightly - about 1.8cms per 100MT - therefore you would have problems if you reach the trimming stage with a trim far different from what you require to finish with. For eg: in Case 7A when you had to change the trim by 36.4 cms at the trimming stage you had to load 1277MT in #8 to achieve that - were you trimming with

#7 you would have to load 2034MT to achieve the same.

#3 & #8 would both work to slightly hog the vessel & it would be easier to correct any trim using #3 & 8 rather than 4 & 7.

When possible, i.e. when not loading alternate holds a combination - such as 4 & 8 sometimes works best - but the choice is yours.

Also have found that about 2000MT, on the Capesize, is quite sufficient for trimming - it is not too large, such that the hog or sag caused becomes a very big factor, also not so large as the shore loader error begins to make a big difference & also large enough to make any changes of trim you might require.

On the Panamax I would be happy to trim with about 1400-1600 MT.

Also, I would advise that you make your cargo plan such that in the pre-calculation when you reach the trimming stage you have the same trim as when you complete loading - it is a pipe dream to think that when you actually make the stop for draft check

& trimming that you will have the trim you desire - but this way you only have to make the correction in trim caused by the loader. If however you plan to finish with 50 cms by stern and your plan calls for you to reach the trimming stage with 25 cms of trim - then during trimming you would be not only trying to change the trim to the 50 cms but also making the correction to the trim caused by the loader which would be so much more difficult if, say, you reached the trimming stage with 5cms trim.

Also, it is not necessary that should you ,say, make a plan to trim the v/l with #4 & #8 and plan for 2000MT for trimming, that in your plan necessarily you need to have 1000 in #4 & 1000 in #8.

It s quite okay to have, say, 1200 in #4 & 800 in #8 even in your plan.

Probably the most important part of trimming is to make absolutely sure that each time you stop loading at a hold during trimming you are absolutely upright.

Say, you are trimming with #4 & #8 using the 2 drop method. At the first drop you load at (a) #4 then (b) at #8. Then after a quick draft check and calculation in the 2nd drop you load at (c)#8, then at (d) #4. Be sure that at the end of each one i.e. at the end of (a), end of (b), (c) & (d) you are absolutely upright.

A list of 0.25 degrees translates into almost 25 cms difference in the midship draft.