They have done a fabulous job with the Tipitaka website. With so many
books it would be easy for it to become so slow as to be almost unusable.
If one doesn't know the chapter, one just clicks on the Table of Contents,
which lists all suttas in the current book. A link from there will take
you straight to the first section of the Sutta:
http://www.tipitaka.org/tipitaka/s0203m/s0203m-frm.html
However, one will need to know which book to look in.
The site could do with an alphabetical index of suttas or a search
facility. Perhaps it will get done one day.