The Pennsylvania Railroad GG1: Why do some GG1's have large vents in the hood and some don't?
In February 1958, a snowstorm with high winds and very low temperatures created
a very fine snow that penetrated the intake vent filters of the GG1. Once
inside it melted and shorted out the traction motors. Every GG1 in the fleet
was disabled causing chaos for days. As the GG1s failed the P5as were sent to
tow them in and throughout the storm none of them failed. The P5as intake air
vents were located much higher than the GG1s and it was concluded that this
condition occurred only at the level of the GG1 intake air vents. In order to
prevent a re-occurrence the original louvered vents were removed and new steel
was welded in place to close the opening and new vents were installed in the
hoods just below the pantographs. This modification was made to 40 of the GG1s.
There were two styles of vents used. One style was rather large with square
corners and was used on 28 of the locomotives (see photo of surviving PRR
number 4903) and the other was rather small with rounded corners and installed
in 11 GG1s (see photo of surviving PRR number 4876). Two GG1s, numbers 4890 and
4900 actually had both styles of the vents installed (see photo of surviving PRR
This modification was made to the following locomotives:
* 4890 and 4900 had both types of louvers.
|GG1 Road Number||Large Square Corner Vents||Small Round Corner Vents|
|4893 - 4996|| ||x|
|4901 - 4903||x|| |
|4904 - 4905|| ||x|
|4906 - 4908||x|| |
|4910 - 4912||x|| |
|4924 - 4926||x|| |
|4928 - 4929||x|| |
|4931 - 4934||x|| |
|4936 - 4937||x|| |
Much thanks to Richard Duley who has
helped to provide a great deal of the information found on this page.