Frame and Walkway Height Difference - NS GE Dash 8's vs. Dash 9's - Trains Magazine
Frame and Walkway Height Difference - NS GE Dash 8's vs. Dash 9's
At lunch today from about 1:00 PM to 1:15 PM, I had an opportunity to walk pretty close to a pair of road diesels - a WB NS freight on the Reading Line had stopped at about MP 32 - presumably for a red signal ahead - which is paralleled about 30 ft. away on the south by Industrial Ave. Specifically, they were NS 9509, a GE D9-40CW leading, back-to-back with NS 8760, a GE D8-40C, trailing.
What I noticed right away was that the entire frame and perimeter walkway of the D8 was a good 9 or 10 inches higher than that of the D9 (perhaps Kootenay Central's recent post with the links to the FM Trainmaster photos and comment about how high their vertical ladders were, was still on my mind). It wasn't just a temporary or one-end-only thing such as unusual trucks underneath, either - at both ends, the D8 had a single step-down and notch cut into the walkway so that it matched at about the same height as the D9's entire walkway and top of frame. After further study, it seemed to me that the hood sections were all about the same relative height and 'steps' up and down, so it is likely that the D8's overall height difference is that much higher than the D9's. And that is compounded by the air conditioner unit on top of the D8's cab, which the D9 didn't have - althogether, then, the D8 might need about 2 ft. more vertical clearance than the D9. Of course, my wife has the camera today, so no photos of that to accompany this . . .
Anyway, I'm wondering if anyone else has noticed that difference - and why it is that way ? What was GE able to do from the Dash-8's to the Dash-9's to lower the frame that much - and why ? Or, why are the Dash-8's that much higher ?
Somewhat related to this - now that a lot of routes are or shortly will be capable of accomodating/ clearing much taller double-stack container and multi-level auto-rack trains - will there next be a trend towards taller locomotives to take advantage of those bigger clearances somehow ? Is there anything about a modern locomotive that could benefit from being taller, such as piston stroke, airflow over the radiators and/ or dynamic brake grids, etc. ?
Finally when they got the ''Proceed'' signal, those 2 locos moved out right smartly with their train. I didn't get a car count and don't have a scanner, but I'd estimate about 80 cars, and they were up to about 15 MPH within 10 car-lengths - and that's on/ against an average 0.5 % ascending grade, too. By the time the tail went past, I estimate it was at 35 MPH or so.
- Paul North.
"This Fascinating Railroad Business" (title of 1943 book by Robert Selph Henry of the AAR)
