After some research, the rig in the link posted by Monrovia1 was originally assigned to E 209. When the department went through the cuts in July '11, a lot of rigs were shuffled around. When Engine 209 closed, and became Engine 89, which in turn, bumped the '06 Seagrave, which had been Engine 89 to Engine 289, forcing the '96 Seagrave into reserve. So, when E-89 gets their new KME, their current '06 Arrow XT will become E-278.
Hope that clears things up some what.
Hope that clears things up some what.