A very old video about the first gen M110 from the 1960's....you can see the drastic improvements on the previous picture of M110A2 that I had. This video kind of gives you an idea how it works. Note the 13 man crew and eventually we increased to 3 Battery's of 8 guns for a Battalion strength of 24 guns.
http://www.youtube.com/watch?feature=player_detailpage&v=TUs6q1VjauE
http://www.youtube.com/watch?feature=player_detailpage&v=TUs6q1VjauE