Ruby & SWIG: recommended technique?

I compiled a C++ SWIG interface. It works fine from irb (interactive
Ruby). But, I’d like to embed this Swig module into a Rails
application. (I did not write this particular Rails application and
know very little about Rails per-se.)

I know that, to start WEBrick, you say

ruby script/server

I looked at script/server and it does not look like the right place to
stick the “require” line needed for loading the Swig module.

Is there a standard place where initial loading of modules should
happen? What is the recommended method in this case?

Thanks!