I have started noticing, on the UP AC4400s The ones with high number boards always have ditchlights mounted above the walkway, and units with low numberboards are mounted under the walkway, but there is not any difference in relation to the nose/headlight. Why is this? Is there any reason (or existing unit) that has high numberboards and low mounted ditchlights?
Where is the headlight?I think that there are some specs concerning the relationship between the headlight and the "ditch"lights.
The older units all had the ditch lights under the anti climer when the first wide cabs came out. GE did a nice job of integrating the ditch lights into the design and most of the roads purchased their units in the standard position that GE started with. The UP purchased their first units with the lower number boards for some reason but all of the first group including the Dash nines had the nose number boards and the standard lower ditch lights.
After the UP purchased the SP railroad, they inherited about three hundred of the AC4400’s that had high number boards like the EMD units. It turns out SP also purchased their 300 AC4400 units with the ditch lights on the deck for some reason. After the UP integrated these into the pool, the orders started to change and the high number boards seem to be the normal practice.
If you think about it, the number boards being near the nose headlight probably are hard to read on a moving train. That is probably the reason they now have the high number boards on the newer GE’s. I have noticed this at night with the bright headlights on, the lower number boards are really hard to read. I am guessing again, but I have seen many pictures of diesels in the snow and ice type of weather and the lower ditch lights sure take a beating in that weather.
Snow packed around them and the bulbs might have failed due to cracks with the heat and ice at the same time.
The concern here is they form a triangle so you can judge the train distantance and speed at night. That gives you some depth perception. The rule does not limit any railroad to nose or cab mounted position.
&nb
Without anti climber
http://pinpuller718.rrpicturearchives.net/showpicture.aspx?id=559276
With:
Guys,
To the best of my knowledge, all Dash-9’s and AC’s and every American freight engine since are anticlimber equipped. Anticlimbers have been standard equipment on all GE and EMD freight locos since the advent of the Dash-8 and the 2nd. generation SD40-2’s.
Spokyone,
your photos offered comparison of an EMD GP38-2 to a SD70MAC which while one has an anticlimber and one doesn’t, still fails to aid in this particular case.
miniwyo,
An anticlimber is basically a reinforced extension of the forward and rear decks on the locomotive that extends beyond the face of the pilot to prevent objects such as cars from “climbing” up in front of the cab when struck by the train. It’s purpose is to protect the train crew in the event of the inevitable grade crossing accident. Older locomotives such as the 1st. generation SD40-2’s and Dash-7’s didn’t have this feature, or at least it wasn’t standard equipment as I believe that anticlimbers had already existed at that time. Instead they had a hinged “pulpit or gangplank” (they have several names) which served as a draw bridge span of sorts to step from the platform of one locomotive to the other.
I recall reading recently that there are FRA specific specs related to the distances between headlights and ditch lights when the above mentioned triangle is formed and that is no doubt the issue with light placement mentioned in the original post on this thread.