ATSF/BNSF GP30u front light

[faraway]

I did scan <!-- m --><a class="postlink" href="http://www.rrpicturearchives.net/">http://www.rrpicturearchives.net/</a><!-- m --> for pics of ATSF GP30u and BNSF GP30u. I expected to find little to no differences except new numbers.
To my surprise all BNSF GP30u pics have the front light in the nose while I found lots of ATSF GP30u with the front light still in the upper cab position.

It was my understanding the front lights have been moved into the short hood when the GP30 to GP30u conversion happened at ATSF time. Looks like that is wrong but the BNSF did do the relocation of the front light in the GP30u.

If the location of the front light is not a save indicator for a GP30/GP30u conversion, what is left beside a new road number? Is the over plated rear road number and the air condition on the cab roof a save external indicator?

Could someone explain who and when moved to front lights?

[Justinmiller171]

This link may help: http://www.qstation.org/EricGoodman/eric...gp30u.html

[faraway]

This link may help: http://www.qstation.org/EricGoodman/eric...gp30u.html

Thank you. An excellent source of information!

[faraway]

May I add another question that pops up with the GP30u related text "The Blomberg trucks were modified by removing the clasp type brakes and converting to a single shoe."

I did notice that on GP40-2 vs. older GP38 engines too. How does that work? If the brakes are not on both sides the bearings of the axis have to manage the full load of applied break shoes of many tons.
Can someone explain the background and implications of that design change?

[Green_Elite_Cab]

May I add another question that pops up with the GP30u related text "The Blomberg trucks were modified by removing the clasp type brakes and converting to a single shoe."

I did notice that on GP40-2 vs. older GP38 engines too. How does that work? If the brakes are not on both sides the bearings of the axis have to manage the full load of applied break shoes of many tons.
Can someone explain the background and implications of that design change?

The Blomberg B trucks are older models. the Blomberg "M" is the newer type. I suspect that 8 brake pads were not necessary, and that more modern locomotives have greater control over their own operation (such as -2 modifications on EMD locomotives), saving the railroad money in brake pads. I think the "M" type is also lighter and less complex to maintain.

That said, both of either type tend to show up on locomotives even today, some being rebuilt with the old types.