Grain Stabilty Calculation

It's a little more involved than that. Read Section 7 of the IMO Grain Rules.
The maximum heel due to grain shift is limited to 12 degrees max., but there is a residual righting area requirement which also must be satisfied. Also, initial GM after free surface correction for liquids in tanks must not be less than 0.30 meter.

 

thanks. i know the three criteria to fullfil. but from cross curves of stability, how to calculate the MAXIMUM PERMISSIBLE GRAIN HEELING MOMENTS ?

 

You've got to make sure the area under the righting lever curve but above the heeling arm curve is at least 0.075 meter-radian, from the intersection of the heeling arm curve with the righting lever curve up to the minimum of the angle at which the maximum difference occurs between the ordinates of the two curves, 40 degrees, or the downflooding angle.

This is where you have to take the cross curves for a particular displacement, correct for the assumed VCG of the vessel to produce righting levers, superimpose the heeling arm curve, and calculate the residual area according to the criteria above. The maximum grain heeling moment for which all of these criteria are satisfied is the Max. Allowable Grain Heeling Moment for that combination of intact displacement and vessel VCG. (in other words, you assume a series of trial grain heeling moments and check to see which ones satisfy the stability requirements.)

 

Is this still a problem of yours?

 

In the "old" days I believe they just loaded grain 15% less than max dwt. *7&th grade picture book with big words in it. (circa 1979)

 

The deadweight is the actual weight in tons that a ship can carry when loaded to the maximum allowable draft (including fuel, fresh water, supplies, catch and crew).
That is, a grain carrier, like any other type of vessel, can be loaded up to 100% of its deadweight.

 

This game of hit and miss guessing whether your vsl meets the reg7 of grain code is over.... there is a formula to calculate the GHM max permissible which is a function of KN 12 deg, KGv and displacement.

 

Well, I don't own a ship (yet), so its no matter to me to clutter my apparently fading memory with new formulae. You're telling me my book was wrong? I thought it made sense that because of possible of shifting weights and grain loads being taller than ore loads by weight that there was some type of adjustment.certainly I know what deadweight dwt is. Back whenever the book was written they still had general bulk carriers.

 

I do not say that your book is not correct, I have no reason to say it, but from what you say, it seems clear to me that you have not understood what your book says.

 

solved it already !