RS-1 vs RS-3

[CBQ Fan]

RS-1 & RS-3 trucks?  Same or different?  Variations?

[Hornwrecker]

Friction and roller bearing.

(I haven't had mine apart in awhile, so I don't know if they're interchangeable. Will be doing this soon as I'll be doing DCC conversions to them.)

[kornellred]

 Alco road switchers were shod with "so-called" AAR Type B 2-axle trucks with an axle spacing of 9'4" and using General Electric traction motors.  The overwhelming majority of them were produced by General Steel Castings.  Adirondack also produced these trucks.  They were equipped with either friction bearing or roller bearings.
Incidentally, these 2 axle trucks required an axle spacing of 9'10" when equipped with Westinghouse traction motors, as on Baldwins, for example.  I believe Alco used GE traction equipment exclusively.

[johnh35]

Friction and roller bearing.

(I haven't had mine apart in awhile, so I don't know if they're interchangeable. Will be doing this soon as I'll be doing DCC conversions to them.)

Yes, they are interchangeable (at least on the China runs)

[kalbert]

Don't forget about the Blunt truck. I believe Skytop35 has posted some pics of his MILW RS3 wearing some sideframes from somewhere on Shapeways.

[jmlaboda - RIP]

"Alco road switchers were shod with "so-called" AAR Type B 2-axle trucks..."

The problem is that there is no such truck and to call them such is inaccurate to say the least.  AAR-A trucks are the switcher type and it is the only AAR type.  The B 2-axle trucks are properly referred to as ALCO B trucks since AAR never developed a road truck... at least not according to the documentation I have seen.

[johnh35]

"Alco road switchers were shod with "so-called" AAR Type B 2-axle trucks..."

The problem is that there is no such truck and to call them such is inaccurate to say the least.  AAR-A trucks are the switcher type and it is the only AAR type.  The B 2-axle trucks are properly referred to as ALCO B trucks since AAR never developed a road truck... at least not according to the documentation I have seen.

What are the ones on the GE U25B and the FM units called?

[jmlaboda - RIP]

Unless it was the signature FM trucks (which curved on the bottom) I assume that they were still referred to as ALCO trucks.  I would expect GE to use the same name.  BLW trucks of a similar design but with a foot longer wheel base likely were referred to as Baldwin trucks.

Here is an interesting discussion about these trucks... more appropriately called Commonwealth or GSC swing bolster truck...
http://www.railroad.net/forums/viewtopic.php?f=6&t=18691

[johnh35]

"Alco road switchers were shod with "so-called" AAR Type B 2-axle trucks..."

The problem is that there is no such truck and to call them such is inaccurate to say the least.  AAR-A trucks are the switcher type and it is the only AAR type.  The B 2-axle trucks are properly referred to as ALCO B trucks since AAR never developed a road truck... at least not according to the documentation I have seen.

AAR never developed the "A" truck, that was a Martin Blomberg design:

http://www.google.com/patents?vid=2137074

This design was apparently designated an AAR truck by the employees of Alco, which received the "recommendation" of AAR to adopt it for their switchers. Since it was not an Alco design, calling any of then an Alco truck would not be accurate either.

[jmlaboda - RIP]

"RS-1 & RS-3 trucks?  Same or different?  Variations?"

I got to thinking about this question last night and it dawned on me that there is another aspect to these trucks and their usage that has not discussed... the fact that friction bearing trucks were used on some RS2s and RS3s (small numbers compared to overall production).  Typically ordered by shortlines and terminal operations that had tight purse strings (though on occasion chantged out to roller bearings later on) and often not considered...
http://rr-fallenflags.org/eje/eje804dsa.jpg
http://farm4.staticflickr.com/3500/4011191352_7182d9f12c_z.jpg
http://rr-fallenflags.org/brc/brc450jpa.jpg
http://www.railarchive.net/vintagediesel/rut207.jpg
http://cencalrails.railfan.net/kcc2prm.jpg

This is something not often modeled yet it was a part of the real world... I will need to keep this in mind myself if I shift my modeling period by just a few years...