Thank you for downloading this upgrade for the Union Pacific Challenger.  This upgrade is for the Challenger that was made available for Steam after the release of Sherman Hill back in Train Simulator 2013.  If you own any previous versions of the Challenger this upgrade will not apply without some teaking.

First off thanks to theoldessauer for beta-testing this mod!  Just a note to him that there are a few more changes that I've made to this mod since the beta test so you will want to download this as well :)

Changes include:

-adjusting the weights for all 3 versions of the Challenger

-adjusting the tractive effort in the simulation file and the associated dcsv files

-adjusting amounts of fuel in the tenders (now displayed in imperial figures)

-enabling the cylinder cocks for manual operation (for some reason the handle in the cab does not move but the cylinder cocks do open now; best to open them with "c")

-fixing the particle emittors so that steam comes out of the cylinder cocks, turbo generators, whistle and sand comes out of the sander (unlike the Big Boy this does look like sand)

-fixing the headlights based on the fix by wopflyer

The loco now can achieve a top speed of 70mph like its real-world prototype and can definitely hold its own with a full load in either direction over Sherman Hill (be generous with the sand coming out of Laramie!).

FYI: you can indeed mix and match tenders with the Challenger pack.  Water and coal/oil will enter the loco just the same as with any other tender.  You can even use the Challenger's coal tender with the Big Boy if you'd like (I prefer doing that myself - it looks better) and you can put the Challenger's oil tender behind the Big Boy to more appropriately model the likely operations of #4014 when her restoration is complete and she's converted to burn oil.  All you'd need to do is change the number on the tender in the scenario editor and *voila* you have a new Big Boy tender.

To install open the Railworks Utilities app and install the included .rwp file.  It may be best to uninstall and install the upgrade again if you verify your cache or completely re-install your game.

If you want to try applying the actual physics part of this upgrade to the Challenger available before TS2013 you can contact me either on the forum or at my address at dtrainBNSF1@gmail.com for instructions.  I fear putting the steps for that here would cause a lot of headaches and it would also be highly experimental because I don't have the older Challenger from TS2012 T_T .  It would include changing a line in the associated engine files.

As always I take no responsibility for any negative side affects this upgrade may have on your computer or your copy of TS2015.  Install at your own risk.  I don't anticipate any problems but I have to say that.

While making this mod I became very interested in the versions of the Challenger with smoke-lifters and came across this page that contains plenty of historic information about these unique Challengers.  You can find it here: http://utahrails.net/up/ttg-challengers.php

Have fun :)

-David Whiting (dtrainBNSF1)