Milwaukee Road

[IA and eastern]

Where is Michael Sol's web site? Gary

[Overmod]

blue streak 1

However your post made it sound that Aluminum has less resistance per circular mill than copper.  Is not so.

Is certainly not so, in my understanding at least, and connection area and surface prep of connections to aluminum feeders are also a critical point.  But this is a discussion of cost, and the conductive area of an aluminum feeder of equivalent cost per foot installed would give superior conductivity over copper even at comparatively low-voltage DC where less of the energy can be carried outside the metal of the conductor.

[Overmod]

IA and eastern

Where is Michael Sol's web site?

Start here:

https://www.yumpu.com/user/milwaukeeroadarchives.com

[Erik_Mag]

blue streak 1

Aluminum has less resistance per circular mill than copper.  Is not so.  Aluminum house service entrance wire has diameter of twice copper  house wire for same current carrying capacity.

If you look at my post, I specifically said "larger". The Milwaukee had several places where 700mcm copper feeders, the intent was to replace those with 1650mcm aluminum or 2250mcm aluminum with the former roughly equivalent to 1000mcm copper and the latter roughly equivalent to 1400mcm copper.

Keep in mind that a pound of aluminum wire of a given length will have less resistance than the same length of copper wire and that for more than 50 years a pound of aluminum cost less than a pound of copper. This is one reason why100+kV transmission lines almost always aluminum cable, often with steel reinforcements.

Aluminum wire in houses has issues. Most of these are traceable to aluminum oxidizing very rapidly when exposed to air and aluminum oxide makes a very good insulator. In fact there had been a fair amount of work done using bare square shaped aluminum wire for motor windings, by encouraging the growth of the oxide layer to act as the insulator.

[rdamon]

When I was working for a power company that was putting ground wire that contained fiber optic cables (OPGW)  We built on a line installed in the early 1900s in central GA that still had copper conductors.  I bet a fair about of the salvaged copper ended up in the workers trucks.

 

I am sure that if they tried to replace the Cu trolly wire with Al that that would have created all sorts of redesign as Al likes to sag.  An upgrade of a 220kv line to operate at 100 degrees C required raising the structures several feet and breaking up longer spans

 

[Overmod]

rdamon

I am sure that if they tried to replace the Cu trolley wire with Al that that would have created all sorts of redesign as Al likes to sag. 

There would be far more problem than that, with wear.

I am still not quite sure how Al2 HV cabling sags as much as it does with the steel core, but it certainly does.  I wouldn't expect aluminum anywhere in a modified 3000V catenary structure unless perhaps if it were built, or modified, to constant-tension.  And I don't think constant-tension would be easy to retrofit to the pole structure on much of the MILW installation...   

[jeffhergert]

Overmod

 

 

IA and eastern

Where is Michael Sol's web site?

 

 

Start here:

 

https://www.yumpu.com/user/milwaukeeroadarchives.com

 

I have a different link that can be found on Overmod's link but requires a few more whoops.

http://milwaukeeroadarchives.com/IndexPage.htm

Going to the individual topics can provide more links to specific topics, such as the 1977 bankruptcy.

Jeff

[SALfan]

CSSHEGEWISCH

The N&W/VGN merger was completed in 1959.  When you consider that N&W started dieselization in 1955, I seriously doubt that the merger had any effect on the end of steam operations.

 

There was an article in TRAINS a few years ago that said the planned purchase of Virginian sped up N&W's dieselization.  They had already started the process, but they had a lot of modern or modernized steam locomotives, and the process would have taken a number of years.  N&W sped up the dieselization because the operating savings from dieselization would pump up the stock price, thereby making it necessary to issue fewer shares to swap for Virginian stock.  If you remember, the last part of N&W's dieselization went at a frenzied pace, to the point that they leased passenger diesels from Atlantic Coast Line (in all their eye-scalding purple glory).