Bad Cropping

[NicTrain35]

These photos were rejected for Bad Cropping, but I'm not sure how to crop them. Can somebody please help me? Thank you very much! :)
http://www.railpictures.net/viewreject.php?id=80602
http://www.railpictures.net/viewreject.php?id=80606
http://www.railpictures.net/viewreject.php?id=80607
http://www.railpictures.net/viewreject.php?id=80611

[Lord Vader]

Nick, try to make them as close to 1024x768 as possible. The reason is that we are trying to make the photos on the site a uniform size. There is dead space in the oversized images that can be cropped and likely some space that can been added to the ones cropped too close.