(DNV) Deck Girder Design question

Hi all...

I was working in a college project and I need to design the deck girder scantlings using DNV rules. But I have some doubts about it and I hope you can help me out. In Pt.3 Ch.1 Sec.8 - D 100 (Girders) - of DNV Rules, there is a statement that the thickness of girder web plates is not to be less than:
t = 12 s + tk
My question is: What this "s" stands for, it wasn't very clear to me on the rules. Would it be the girder transverse stiffener spacing or the deck longitudinals spacing? Or neither?

Another question:
In the same section, but on D200 - Simple Girders, there is the following formula for section modulus:
Z = (100 x S^2 x b x p x wk) / sigma

It wasn't clear to me the S and b. Could you clarify?

Thanks a lot

 

I ansvered your other post.

http://www.boatdesign.net/forums/showthread.php?p=143612#post143612