A lot of switch engines have a sloped section of the hood, just in front of the cab.
I have always assumed that’s for improved visibility. But I was thinking about this: since the engineer’s position is outboard enough that he can look straight forward alongside the hood (a sightline that is above the walkway), I don’t see how that hood slope makes any difference.
Also, road switchers don’t have the slope, and neither do many (other types of) yard switchers. If the slope is so valuable, why do so many engines NOT have it?
What am I missing? Is the slope there for some other reason altogether?
Still in training.
Are you talking about EMD switchers?
I would assume that he means the slope on the short hood of various genset switchers. The slope would be to improve visibility since in switching operations, the view across the nose and right in front of the end platform would be less obstructed.
If he means the downward slope near the cab on the hood of 567-powered EMD switchers, I'm not sure what purpose is served. Also note that 645-powered EMD switchers don't have that downward slope.
Sorry. I should have been more specific. I am talking about EMD switchers, like the SW9. I am talking about the downward slope towards the cab, on the top of the hood in the area just forward of the cab. (I am assuming that the hood end is the "forward" end of the locomotive on this sort of yard switcher.)
https://en.wikipedia.org/wiki/EMD_SW9
I just don't see how that would improve visiblity to any significant degree. The engineer would be able to see a brakeman/conductor at the front right steps area (or on the ground) anyway, without the slope, so I'm not sure why it's there.
Apparently other builders saw no need for the slope.
I don't know if current-model switchers of any builders have the slope, but I think not.
I'm sure dozens of you folks could enlighten me on this!
I always thought of the 'waist' as serving the same general purpose as a Draper taper, improving the potential sightlines out of the cab. The top slope matches the taper of the sides. Note that it gives a view of the exhaust from the cab. An analogue is the presence of the two little windows in the top of an Alco RS3-style cab (which on CNJ in the early '60s were used explicitly to monitor the stack during running).
Remember that it may be important to keep 'situational awareness' even when not sitting on the seatbox running the engine.
The EMD switcher hood slope was introduced in April 1949 at EMD Plant Number 3 in Cleveland as a production cost savings measure. Before that there was a level area extending from the cab to a pronounced rise in the hood to get to the level of the exhaust. Data from Extra 2200 South's "All About SW's" by Don Dover with research by Don Strack and Ed Skinger. See X2200S July/August 1973 issue No. 41 pp 20-25.
OvermodI always thought of the 'waist' as serving the same general purpose as a Draper taper, improving the potential sightlines out of the cab. The top slope matches the taper of the sides. Note that it gives a view of the exhaust from the cab. An analogue is the presence of the two little windows in the top of an Alco RS3-style cab (which on CNJ in the early '60s were used explicitly to monitor the stack during running). Remember that it may be important to keep 'situational awareness' even when not sitting on the seatbox running the engine.
I always thought it was to check verticle clearence signs as you approach overhead structures with the long hood forwards. Never thought of the exhaust stack.
The New York Central eventually plated over the middle windows on EMD switchers and did the same to the middle windows on Alco RSs.
Does anyone currently manufacture traditional diesel switchers, with the cab all the way to one end?
AFAIK not only does no one currently produce end-cab diesel switchers, I don't believe any have been produced for some time...perhaps not since EMD discontinued the SW-1500 in the 1970's? Once railroads decided to go with high-horsepower six-axle road diesels (SD70s, AC4400s etc.), it left them with a lot of four-axle road-switchers (like GPs) that could be moved into yard work. Cheaper to use what you already have rather than buy new.
The last EMD endcab switcher was Dow Chemical 957, an MP15T built in 1987.
http://utahrails.net/ajkristopans/SWITCHERS645.php
Thanks, guys.
It turns out that Knoxville Locomotive Works builds new end-cab switchers.
http://www.goklw.com/switchermodels
wjstixAFAIK not only does no one currently produce end-cab diesel switchers, I don't believe any have been produced for some time...perhaps not since EMD discontinued the SW-1500 in the 1970's?
There have been some with limited success:
MK1500 and 2000s, GP15D and GP20Ds, even the green goats and Gensets.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
Those are more road switchers than true end cabs, though. Which is why the end cab model died. The number of secondary jobs was shrinking, and railroads wanted something that could work switching, transfer and road local jobs.
EMD understood that railroads wanted a roadworthy unit, hence the MP series.
Of course, cascaded road power has filled most of this role.
What's the distinction between an end cab and road switcher? FRA blue card gives you a choice of road or yard unit. Pretty sure the genstes had "y", but it's been a while since I've been on one.
I'm sure more knowledgable people than I can answer better, but to me an end-cab engine has no short hood at all.
I think the hood is irrelevant. In my mind, it's top speed (trucks and suspension) and intention (including 'does it have a toilet for road service?' that make the difference. Switcher trucks are limited to 45 MPH and ride pretty roughly at that speed. I'm guessing the gensets are designed for a higher speed than that.
That's not to say that you can't classify things with the FRA however you want.
What a given railroad classifies as a switcher can appear quite arbitrary. In the 1970's, SP classified its remaining C628/C630's as switchers since they were used primarily as hump pushers and in transfer service.
Do I not remember correctly that the 'yard' vs. 'road' distinction is made for union-related compensation purposes?
I for one would like to see what was on the blue cards for those UP TR units bought in the early '50s to be road pushers. (The ones subsequently equipped with DB only so they could be operated downhill 'light' fast enough without wearing out their switcher-truck brakes...)
sw1 designer was on crack
One of the only railfans who gives a crap about the MMA, despite not living IN the northeast.
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