Re: Draft Survey Questions
Dear huywi,
Manipulating ballast figures is a well-known phenomenon of creating cargo or let cargo disappear.
The unloaded cargo is increased on paper, while the freight is paid on the out loaded cargo, or the loaded cargo is more than the out loaded cargo on paper and the difference is vanished.
The ships’ draft tables are ruling, as they have been for the last 12 years that the ship exists.
Did the chiefs officer gave a reason for his request? 
Take care
Teus ■
Teus
Re: Draft Survey Questions
Thanks for your reply Teus.
The cheif officer did not give reason for his request. I suspect that because ship is under new ownership with new crew, he set the constant at 350 previous voyage and now it would reflect bad on him for constant to suddenly jump to 444.
The ships (Panamax) at this port usually arrive with No. 4 hold with ballast, so to get a truly accurate figure of ballast with trim and list is difficult. ■
Hello Sailor
Originally Posted by Teus Tuinenburg
Manipulating ballast figures is a well-known phenomenon of creating cargo or let cargo disappear.
The unloaded cargo is increased on paper, while the freight is paid on the out loaded cargo, or the loaded cargo is more than the out loaded cargo on paper and the difference is vanished.
The ships’ draft tables are ruling, as they have been for the last 12 years that the ship exists.
Did the chiefs officer gave a reason for his request?
Take care
Teus
Wonderfully put! Shakespearean. ■
Re: Draft Survey Questions
Dear huywi,
Cargo officers often ask to increase or to reduce constant.
The reasons may be very different. ■
Constant Remarks
Dear Huywi,
As a collegue Draft Surveyor I can advice the following :
When a C/O doesn't accept the constant, he probably doesn't agree with the outcome. A Draft Survey can be influenced on different fields (Ballast/Draft Readings/Bunker details/Density of the ballast water). It is very important to check all those items in detail to get a good result. On capesize Vessels you almost must be aware that when the water is running out of the sounding pipes, those tanks are not full when Vessel is having trim. Altough 0,8 is a small trim.
It is definitely in the C/O advantage to have a lower constant as the discharged weight increase in this case.
In case the C/O doesn't agree with the constant, it is always useful to propose to recheck all the tanks and in most of the times they will agree with the original soundings.
Good luck with your future drafts,
Dave Chanet ■
Draft Survey
a newbie here, best regards to everyone.
please refresh myself on the formula about draft reading which i happened to forget.
situation:
ship alongside stbd side
as per example:
mid draft port: 7.50
mid drat stbd: 7.45
fwd draft stbd : 4.50
aft draft stbd: 8.45
what i am asking if you would help me is the usual quick formula as per estimate in getting the draft fwd port and draft aft port.
thank you ■
Re: Draft Survey Questions
Dear Carmelo,
To begin with.
StbMid =( StbAft + StbFwd) / 2 = (4.5 + 8.45) / 2 = 6.48 m
In your example, the draft StbMid = 7.45 m
Difference between a straight ship and the floating situation is 7.45 – 6.48 = 0.97 m sagging.
(Seems a lot to me, although depending on the ship’s length).
From the midship draft readings, the calculated list of the ship is 7.5 – 7.45 = 0.05 m to port.
If the forward and aft marks are on the parallel ship section, you can ETIMATE the same list for forward and aft. (Unless the ship is distorted, which is not unlikely, due to the high sagging situation).
You can also use a lifeboat to get to the port draft marks.
If you start calculating with those figures, do not forget the trim correction.
Nowadays, a modern ship uses the computer for these calculations.
Have a nice day
Teus ■
Teus
Re: Draft Survey Questions
dear sir teus,
thank you for your quick reply.
your are orrect with that idea and explanation.
i am a chief officer on a handy size bulk carrier, it usually happend that you need a estimated draft reading every now and then. this can be done of you've got the draft reading on midship p/s side and the fwd and aft draft on the side where the vessel is along side.
by that draft reading you with the formula i am asking you will be able to calculate easily the estimated draft at fwd and aft on the sea side of the vessel, this will help us a lot you know reading draft on the vessels sea side while along side takes time especially when she is in ballast.
got any idea sir,
carmelo ■
Re: Draft Survey Questions
sharing about draft survey calculation here http://www.rulyabdillah.com/2010/06/...n-program.html ■
Re: Draft Survey Questions
The explanation is great and really helpful. I too agree with the explanation. I am too having a small confusion in this. Now I got it solved.
Thanks for sharing the link rulyabdillah..
strategic export controls ■
Re: Draft Survey Questions
Originally Posted by Carmelothank you for your quick reply.
your are orrect with that idea and explanation.
i am a chief officer on a handy size bulk carrier, it usually happend that you need a estimated draft reading every now and then. this can be done of you've got the draft reading on midship p/s side and the fwd and aft draft on the side where the vessel is along side.
by that draft reading you with the formula i am asking you will be able to calculate easily the estimated draft at fwd and aft on the sea side of the vessel, this will help us a lot you know reading draft on the vessels sea side while along side takes time especially when she is in ballast.
got any idea sir,
carmelo
Dear Carmelo,
To calculate easily the estimated sea side fwd/aft drafts you will need to know exact sea side Mid draft - to reduce time for it you can use new draft survey equipment "Alexx", which will allow you to read offside draught marks from the screen of your mobile phone staying on the deck and without going down by the rope ladder. I've seen it on site:: http://draftequipment.weebly.com/ ■
Draft Survey Questions
I am new to draft surveys so would be grateful for advice.
Say I work out ships weights before loading of cargo and after determining amount of ballast with ship at 0.8 trim and 0.06 list, find a constant of 444mt and the chief officer asks if we can lower the constant to around 350mt.
On this particular vessel, all the crew are new because ship has changed to a new company so there are no previous draft survey records. The ship is Panamax size and 12 years old.
Question: Is the chief officer concerned with accuracy of the constant? In general, is it in the chief's interests to have a larger or lower constant and why would that be??
Thanks ■