Great question.

I've never seen the need. Having a variety of tech sites usually gets the larger mechanical projects as everything is leading to Mechatronics anyway.

Exactly what kind of Mechanical engineering specialisation are they looking at?

Well they are more in the traditional mechanical engineering fields, namely petro-chemical, mining, transport, hvac etc. Or rather lets say heavy industrial.

Usually these industries are serviced by trade magazines, usually you can only get a hard copy, so very little online presence, and very little community participation (forums, user submitted content etc.)

OK, Heavy Engineering (Construction and Production)

The first few that come to mind... (some are paid subscription)

http://www.rigzone.com/

http://www.upstreamonline.com/

http://www.gulfpub.com

http://www.lngworldnews.com/

http://www.manmonthly.com.au/

http://www.eng-tips.com/ (all engineering forum)

http://www.australianmining.com.au/news/

http://www.hydrocarbonprocessing.com/

Thank you very much, I'll pass the links on to my colleague.