I was fortunate enough to have time to see the giant Big Boy steam engine when it spent the weekend in West Chicago. When the subject of your image is that large (132 feet long), the camera may add too much light to brighten up the scene. Don’t let it happen. Use exposure comp (+/-) to reduce light while adding just a bit. I’ve included both pictures to prove a point.
Too Bright Picture: ISO 80, 35mm focal length, f4 @ 1/25, exposure comp +1.67, Just Right Picture: ISO 80, 35mm focal length, f4 @ 1/60, exposure comp +.3