Comment 10 for bug 1492515

The activity calls for two pickups after dropping the player's train in the yard. The pickups are in no specific order, but both need to be completed in order to complete the activity. A popup appears telling you to return to the engine service area to refuel your engines and to replenish your sand supply, which was diminished earlier in the run. The sand tower and the fuel tower are on two separate tracks, and require two separate pickups. While completing the activity, I chose to replenish my sand supply first, then backup and switch to the refueling track. This is where the activity should end. Unfortunately, pressing "T" at the sand tower causes OR to fail.

I noticed in the notes above that "Sand" appears to be a freight pickup type, and not a fuel type. While there may be instances where a player is required to pick up sand as a freight item, this is not the case in this instance. In this case, the sand is not a commodity being carried, but a supply that is used on American locomotives to assist with braking. This particular activity has a long, steep downgrade prior to reaching the yard, which, if you are braking correctly, will diminish your sand supply.

In MSTS, the sand supply in a locomotive is usually infinite, which obviously is not realistic. I'm not sure is OR is even programmed for sanding (as I usually find other ways of slowing the train), but if it is...it may have different parameter for computing sand usage and refilling. I'm sure that in MSTS, this "pickup" is strictly aesthetic, meaning it doesn't really affect the sand level in the locomotive. Without having more knowledge of route development and how pickup items work, I can't tell for sure.