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Monday, November 11, 2019

The Alstom GM4000 - It's a Fake!

Excuse the click-bait-y title, but I just discovered something the other day that I wanted to bring to everybody's attention.  In North America there are effectivly two families of electric point machines,  The Union Switch and Signal M3 family and the General Railway Signal Model 5 Family.  You can order these in a variety of variants, single control, dual control, low profile, high profile, etc.  These two families have been around for so long that in the case of the M3 a variety of third parties are offering legit off-brand examples at a lower price point and without the US&S trademark.   Back in the 60's, GRS decided to get ahead of the copycats by designing a brand new point machine with a new set of associated patents and trade secrets.  Known as the Model 55, this cheap looking rectangle was relegated to North American transit systems, although it did kind of become the closest thing to a standard point machine that the UK has (so like I said, transit systems).

GRS Model 55 on the TTC's Scarborough Rapid Transit.

Needless to say the Model 55 was never very popular and even some of its enthusiastic early adopters, namely the Washington Area Metro and South Jersey's Port Authority Rapid Transit, eventually ultimately their Model 55's for US&S M3's.  I don't know why this was the case, but I suspect a lack of support was part of the reason as GRS had a new European parent in the form of Alstom and daddy Alstom was intent on making its own new M3 "killer" along with the associated patents.

Low profile US&S M3 on the NYCTA (7) Line at Queensboro Plaza
Backtracking a few decades, to take on the GRS Model 4 and GRS Model 55's electric transit switch machines, US&S had developed a low profile version of is venerable M3 because third rail shoes are a thing on transit. Basically it looks just like a regular M3 only flattened down by an inch or two.  So when the following appeared at Amtrak's rebuilt CORK interlocking in 2005, I thought they had opted for some sort of off brand low profile M3.


However something always bugged me about that shape and style and my instinct was indeed correct as that is not a low profile M3, but an Alstom GM4000A switch machine.  The spiritual successor to the GRS Model 55 and, apparently to some comments I got, just as failure prone.  Nevertheless a bunch of railroads bought GM4000s about 15 years ago and I happened to run into some of the survivors for the first time last December at Conrail's CP-JOHN in Morrisville, PA.


Outwardly presenting as a US&S low profile M3, the GM4000A is given away by having just two segments on top instead of three,  However if you check out the manual for the original model GM4000, it does indeed have the three segments.


I'm not here to speculate about why this inferior modern replacement of tried and true 1930's technology is an inferior modern replacement of tried and true 1930's technology.  That's a question for a C&S purchasing officer.  What I want people to take away is the knowledge that GM4000 family point machines are a thing, how at first glance they may resemble low profile M3's and that they might soon vanish from the scene so go take some photos while you can.  In this day and age every bit of diversity is a plus. 

2 comments:

  1. We have several GM4000A machines here in Detroit, some as recently made as 2015. The GM4000A has a fair amount of electronics in it, so it's nothing like the predecessor. The failure point for these is high water ruining the electronic controller box inside the "big" lid, the small lid covers the point detector and lock rod and connections for the cable to the CIL.

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  2. Is there a heater in the machine ?

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