[FT] Heavy Pulse Torps

I seem to remember seeing a write up for 'Heavy' pulse torpedos
somewhere, either in the list archives or IIRC on a web site somewhere.
However, I havn't been able to find it again on any search engine -
does anyone else remember such a web-site?

Alternatively, has anyone produced, and hopefully tried out, rules for
heavier (and lighter as well) pulse torpedos?

I'm thinking that they would make a reasonable spinal mount for some of
the UNSC ships - ie. resonably balanced game mechanics _and_ based on
existing (FT) human technology.

Charles