Why are cab units preferred for passenger service?

[TinGoat]

Hi Mike,

Let me answer your question with another question...

Why are hood units preferred for freight service when it comes to diesels?

Because of better visability front and rear.

The Cab Units were developed for main line freight. The "F" in F-Unit is for freight. But the bad rear view made switching difficult. Some F-Units were equiped with a rear window, but it didn't help very much.

EMD tried to fix the problem with the BL-2

EMD switched to Hood Units for freight, but continued to build Cab Units for Passenger Service and some long-haul freight service.

You are partially correct that the Cab Units are for appearance in a passenger train and to a lesser degree for Aerodynamics.

I think that it is more of a weight issue.

Cab Units are lighter because they are built with an open lattice or Monocoque frame. Also, there is a lot more room for steam or other head end power [HEP] for heating the passenger train and providing electricity for lights etc...

However, there are plenty of examples of Hood-Units in Passenger Service. HEP is in the short hood.

Here's a good webpage on Cab-Units Exotic Diesel Locomotives = <!-- m --><a class="postlink" href="http://exotic.railfan.net/">http://exotic.railfan.net/</a><!-- m -->