Discussion related to commuter rail and rapid transit operations in the Chicago area including the South Shore Line, Metra Rail, and Chicago Transit Authority.

Moderators: JamesT4, metraRI

  by Gilbert B Norman
Interesting Mr. Fan Railer.

The usual configuration for the non-powered idler axle for six wheel passenger engines' trucks is the center axle resulting in an A-1-A designation.

Wonder what prompted the change away from that traditional arrangement.
  by Fan Railer
Likely because the design architecture of the SD70 P4 locomotives are B1-1B.
  by Gilbert B Norman
Likely a point, Mr. Fan Railer.

However, If I correctly understand, these SD-70 engines were built and were used in freight service by a Class I prior to their sale to METRA. To my best knowledge, any such engines were C+C configured.

C+C engines used in passenger service could best be called "problematic" (remember E's and PA's were all A-1-A+A-1-A), and METRA was wise to call for de-motoring one axle on each truck. While ATSF, owing to their superior trackage, never had incidents with such with their fleet of SDP-45's, different story with those on "my MILW". While there are several photos in TRAINS with these engines leading, their "truck hunting" characteristics became evident, and they were quickly assigned as trailing units only, and post A-Day, to freight.

Nothing ever came to my attention regarding any such matters with those acquired by SP, GN, and SAL. If such made any difference, those were of the traditional "hood" design.

Now enter Amtrak and their debacle with such motive power. They ordered a fleet of 150 SD-40's and assigned them systemwide. They were AOK on the ATSF; elsewhere "mixed" with several roads having derailments arising from "hunting", and on all roads very bad lateral motion (know so first hand on the MILW where once I was on the head and the Engineer was not about to go authorized 70mph). Well that story ended with non-disclosures resulting in EMD taking those engines back as trade-ins on Amtrak's quite reliable F-40 fleet.
  by eolesen
Ah... the SDP-40 vs. FP45 debate. One of my favorites. MILW didn't have SDP's -- they had FP45's. Slightly different beast.

One school of thought on the Amtrak SDP's problems was the location of the boiler and boiler water storage tanks. They sat up high, and that extra tank sloshing could have been a factor. Other people blamed the early HT-C trucks.

I don't know that the location of the traction motors will be a concern. Certainly boiler water won't be.

I'd always heard that crews liked the FP45's in freight service. MILW didn't want Amtrak taking them, which is why they had their boilers removed.
  by Gilbert B Norman
Mr. Olesen, thank you for correcting the nomenclature of the various engines I previously noted.

Of interest if I may go off topic, I guess the MILW didn't know what to do with their "Management Trainees" most of the time. Having an Accounting degree, they had Internal Audit as a first stop on my career path. But nevertheless, I was out riding engines to become familiar with the property. I was "on the head" of Amtrak #8, Empire Builder between LaCrosse and CUS. Near Dells where the track speed was 70, I noticed we were only going maybe 55. The Fireman showed me the Orders and there was nothing about a restricted speed. The Engineer, not the friendliest guy I ever met in this life, realized I was questioning something. He then says "hey college boy, I run this thing at 70 then you will REALLY have something to write up when it spills!!!".

Finally, the lateral motion on those Amtrak SDP-40's was indeed "wild".
  by MetraBNSF
So when do we expect to see the SD70MACHs on the rails? This article sheds some great info.


More Metra MACs Arrive in Chicago

By Justin Franz

January 19, 2023

CHICAGO — Metra expects to begin testing its new SD70MACH locomotives this spring, the railroad tells Railfan & Railroad. As of this month, there are three of the six-axle passenger locomotives on the property and a fourth is currently in Colorado being tested.

Metra has purchased 15 and could eventually acquire up to 27 of the unique SD70MACHs. The locomotives are being rebuilt by Progress Rail from former Kansas City Southern/Transportación Ferroviaria Mexicana SD70MACs. This isn’t the first time Metra has used six-axle locomotives for passenger power. In the past, the agency has used former Burlington Northern E9s and Milwaukee Road F40Cs. When the SD70MACHs do enter service, they are sure to be some of the most unique locomotives in passenger service in country.