#1 U in the beginning (for Universal), or -7,8,9, (for decade that it was introduced, ie. -7 for 70's, -8 for 80's ect., and also to set them apart, from the U's as they (-es) had upgraded electronics, like the -2's)
#2 B is for 4 axles, C for 6 axles.
#3 is the number in the midle. For example B30-7. The 30 is for 3000 HP.
First off is the loco that started it all for GE. The U25B. The best way to tell it apart is by the steps, on the rear of the walkway, below the raidator section. Also that there is no step (bulge), or overhang in the raidatior section on the top of the long hood. The hood is compleatly flat or smooth. Here is a U23B.
Next was the U28B. Early ones looked exactly like a U23B, later ones you could tell the diffrence by the fact that the steps on the walkway dissapeared, and also you start to notice that the raidator, at the top of the long hood, is starting to develop "wings" (overhang above the walkway), and there is starting to develop a wider secton of body below the raidatior, that is starting to run down the side of the long, to inclued the air intake. Here is a later production U28B.
From the colection of Joe Hughes.
Then came the U30B. The next step in carbody design, is also the best way to tell these units. Notice how the air intake section, now runs all the way down the side of the long hood, to the walkway, below the raidatior. Once again the early units were impossable to tell from the later U28B's. Also in the early 70's just before the introduction of the -7's, Ge released the XR series of the U boat. It was the beginning of the upgraded electronics. You can see the spotting feature, of the XR's in the photo of the Frisco unit. It is a water sight glass, just below and to the right of the F in Frisco (the bottom of the F is about half way down the glass).
Collection of Jonathan Guy
Collection of Joe Hughes.
Up next in the magical book of GE's is the U33B. The major spotting feature of the U33B's was the fact that the raidatior section has finally grown the true "wings" that GE's have become famous for. After this GE become hard to tell apart for a while, unless you want to count doors.
Collection of Ken Roble
The next in the series is the U23B. It is identical to the U30B, except for the fact that it has a 12 cylinder prime mover, vs. the 16 used in the rest. GE put a 12 cylinder in for those railroads looking for better fuel consumption, by using 2 fewer cylinders. The only way to tell a U30B from a U23B, is by counting the tall hood doors. The U30, has 8 doors, the U23, has 6. The area you are looking for has the CM logo on it, it is those 6 doors. Here is a U23B.
Collection of Alan Gaines
Ooops helps if the doors are there, dosen't it.
Next time I will go over the - series.
