In brief, this is one of the very best switching scenarios I have ever played.
Background: Railworks Scenario Shop ( http://railworks3scenarios.com/ ) is selling "Heavy Hauling Freight A Scenario Pack for Ohio Steel 2 Dover to Massillon. Their price is a mere $3.99 Canadian.
Details: There are a lot of freight switching scenarios available for RW3, both freeware and payware. This one takes place in the complex Philadelphia Finishing Mills yard and exploits all of that yard's challenges. You begin by breaking up an incoming train that just arrived (in fact, you delivered it in the previous scenario of the set) and end by assembling an outgoing freight. I won't give away any more than that, but be prepared to keep busy, probably for more than the scenario's listed time of 70 minutes.
Moment of truth: I received an X at the end of this one, probably because of my habit of reaching for the speed limit and then braking too hard when I realize that my destination is so near, which leads me to shove the throttle into the emergency braking range.
About the package: As I've mentioned in other threads, the full versions of the 5 scenarios contained in this pack require a rather hefty number of downloads that you won't find listed on the website pages, except for the payware Dash 9 DLC. Rolling stock "collectors" may already have some or all of the freeware requisites and the Dash 9 can be avoided by playing the "Default" versions included in your purchase.