The logic behind GP9's

[Sawtooth500]

Look at: http://upload.wikimedia.org/wikipedia/commons/7/71/DGVR40_Staunton_WJGrimes.JPG You will see a GP9, with a forward hood, I'm not completely sure what it's called but it's that hood so that you can't really see forward, only a little window on each side. Why was it built like that with only 2 forward windows on the sides and the middle blocked? It seems to make much more sense for there just to be 4 windows in the cab all looking forward - much better visibility for the crew.

[creepycrank]

Sawtooth500

Look at: http://upload.wikimedia.org/wikipedia/commons/7/71/DGVR40_Staunton_WJGrimes.JPG You will see a GP9, with a forward hood, I'm not completely sure what it's called but it's that hood so that you can't really see forward, only a little window on each side. Why was it built like that with only 2 forward windows on the sides and the middle blocked? It seems to make much more sense for there just to be 4 windows in the cab all looking forward - much better visibility for the crew.

First the GP9 is a revision of the GP7 and externally they look much the same. The GP7 is a product in response to the success of the Alco RS1 and a bare bones locomotive for branch line service. In that service it should be bi-directional and some were equipped with 2 control stands. The view ahead would be the same as the steam locomotives they were replacing. The high short hood also allowed room for steam heater for passenger service. They have platforms at both ends so that a brakeman could ride short distances comfortably and be seen by the engineer. The low short hood design used universally now only started to make sense when these locomotives started to replace F and E units on line-haul service.

[BLS53]

Probably a carryover from steam engines, and the designers didn't put much thinking into it at the time. Obviously it was corrected with the next generation of Geeps.

[samfp1943]

Remember,

    N&W RR, and some Southern RR locomotives were bought to run long hood forward, even to having the Frame with a direction designator on the long end "F", and in many cases two control stands.   Those engines lasted quite awhile  before they were changed to the more conventional cab configurations, and the high, short hood 'chopped' and a center window added.

I think I remember, the rationale for that change was the increasing interchange with other railroads, who prefered the low noses,etc.

Hopefully, some can correct me where I am in error or add to what I posted. Thanks!

[ndbprr]

why does a 57 Chevy have drum brakes instead of discs? Or try why didn't the Wright brothers just use a jet engne on their plane at Kitty Hawk? The answer to both questions is the same as the GP9. Improvements are a result.of time and enlightenment, some come fast others slow.

[SSW9389]

Low short hood GP9s were built for Phelps Dodge and Southern Pacific. The Phelps Dodge units ran long hood first and the low short hood was for observing back over the train. The 20 Southern Pacific units were set up short hood first and were built in 1959.   

[XRAY]

I do not know how much truth there is to this, but I read in one of my books that the EMD designer ( Mr. Dillworth IIRC) designed the GP series with the high short hood because of union labor rules that required a fireman in the cab at the time. And that he did not the engine to be cause of labor disputes between the railroads and the unions. 

[creepycrank]

Although its seems logical that the GP7 should have been originally designed with a low short hood forward for the same visibility as the F and the BL2 having to peek around this obstruction was not any worse than steam locomotive. I think that EMD considered it a branch line bi-directional locomotive and they were marketing the F exclusively for main line service. Of course GP stands for General Purpose so it didn't take the railroads any time to figure out what that means. Eventually the GP displaced the F design for all service. The other thing is that the low nose gives the locomotive an obvious front end. The first successful diesel locomotives were all box-cabs where they have outstanding visibility forward but no collision protection. I think that some experimental locomotives built by either Westinghouse or GE in the 30's did have a low stubby nose. A diesel locomotive is fundamentally a electric locomotive with a diesel generator on board some place and in the beginning followed electric locomotive design practice.

[ndbprr]

 

Everything undergoes evolution.  Since the Geep 7 & 9 were developed in the passnger era I suspect the need to house the boiler for heat is a major reason for the high hood,  There just wasn't any place in the long hood.  If you overlay a scaled GP7 or 9 on and F unit they are basically the same length with much less area under the hood.  Where else could you put it? 

[daveklepper]

I worked a EMD the summer of 1952 when the GP-9 was designed and made a small contribution to the changes in load regulator control of the GP-7 for the GP-9.  These changes were applied in two versions to GP-7's 1567 and 1568 or the B&M delivered in the Autumn of 1952.  They were compared running alternately on weekdays on the regular 4pm passenger run to Portsmouth returning on the night frieght with the same engine crew to Sommerville Yard.  During the winter 1952-19532, while a Senior at MIT, I was a test engineer on these for Ernie Bloss, B&M SofMP.   No thought was given at EMD to changing the basic design of the succesful GP-7, just incremental improvements.   The failure of the BL-2 marketwise (mechanicaly just fine) may have also been a factor.

[zugmann]

 To be honest, when running short hood forward in a high hood, you really don't lose much visibility at all.  I (and I suspect many others) barely look through the middle windows.  You look through the window in front of your seat.