With a big lens you might try a shot from the billboards just off of Cass Ave. south of the tower. You can see them in the lower right corner of this screen cap from MS Live Search Maps. The coaling tower is in the upper left.
I'm not sure if this is private property or not. There's almost never anyone parked there.
You could also try viewing from the other side of the yard - there's a new subdivision on the south side with a long berm that gets you over the fences. Further north is the Oakland County Government complex, but there is high fencing all along that area and plenty of cops (which can be good or bad).
And by lunch I mean eat in the car and do slow drive-bys. I've yet to find a good parking spot with a view of switching action without feeling like I'm in someone's way.
CN issued 2 press releases this morning, one for the U.S. and one for Canada, saying CN police would be busily enforcing the railroad's zero tolerance policy on trespassing. I'll paste one of them below.
Rail Safety Week – ZeroTolerance for trespassers in the U.S.
HOMEWOOD, Ill, April 23, 2008 — CN invites media representatives to support Rail Safety Week, from April 28 to May 4, 2008. This year, during safety blitz operations conducted at about 150 highway/railroad crossings across the United States and Canada, CN Police will insist on its tough Zero Tolerance policy for trespassers.
The sustained increase in trespassing fatalities is totally unacceptable and CN pledges to enforce laws and regulations. Over the past decade, fatalities from railroad crossing incidents have been declining steadily while trespassing incidents remain very high.
As an ongoing part of CN’s All Aboard for Safety community education program, CN Police officers will be alerting motorists to the importance of safety at crossings as well as the deadly risks of trespassing on railroad property. They will also warn them about their uncompromising, Zero Tolerance policy for trespassers.