Just a couple of shots for visual examples.
http://www.rrpicturearchives.net/showPicture.aspx?id=78793
a Hawker Siddeley 3800 cu ft hopper
http://www.rrpicturearchives.net/showPicture.aspx?id=1651255
One of two later style 4550 cu ft hoppers, this an H-S.
Rainer