Hello everyone,
I'd like to buy this beautiful locomotive, but I only have a 5-foot radius (LGB R2) available. I'd like to ask if this locomotive can drive through it, even though the instruction says 6.5 feet. Does anyone have experience with this?
I think with a 24-inch length, it should be possible, right?

Thanks

Thomas111

I am from Germany and not perfect in English, so I used google translator

Quote from: Thomas111 on May 04, 2025, 01:32:12 PMI only have a 5-foot radius (LGB R2) available. I'd like to ask if this locomotive can drive through it, even though the instruction says 6.5 feet

Thomas, your translator seems to have confused radius and diameter.  The loco needs 6.5 ft diameter curves.
Google says the R2 track is 5.4 ft diameter.

google is wrong, R2 is 5 foot, 1.25" in diameter, but even LGB published wrong data for years.

In any case, way too tight...

Well, I see the GP-40 is a two-axle loco and I see no reason why a two-axle truck (as opposed to three-axle) wouldn't work fine on a 4' DIA curve.
Unless, the trucks have limited rotation, but they usually have pretty wide swing.
So my guess is the real issue is coupler length/swing radius.
Depending on distance from truck to body-mounted coupler determines how far coupler extends outside the outer rail in a curve.
If the coupler can't rotate enough then the force direction pulls the trailing car off the track.
Currently running a USA Trains 2-axle GP-30 and this is exactly the problem I encounter, the loco's coupler pulls the trailing car off the track.

You do know that the USA Trains F3/F7 units will not run on R1 curves?

1. the main issue is the TRUCK swing limitation... they just don't swivel enough to accept this radical curve
2. yes for a TRAIN on a R1 curve, COUPLER swing is an issue, but many solutions
3. the spacing between the 2 trucks is also of import.

So, the coupler swing issue is the LEAST of these 3 on a 4' diameter curve, and the most easily "remedied".

Greg

Agreed and as I was saying the GP-30 has enough rotation to handle R1 so it then becomes a coupler issue.
As to FAs they must not have enough rotation in their trucks to handle R1.
So the first question for OP to answer is does the new GP-40 trucks have enough rotation to handle R1?
If yes, then his next inquiry will be to how well the body mounted couplers will work off-the-shelf on R1.

the GP-30 actually negotiates 4' diameter curves? Not a challenge, but have you seen this in person?

I don't have one, but like I said the F3/F7 from the same manufacturer does not. I have personally tested and observed this.

USA trains says that the minimum for the GP30 is 5' diameter, the same as the F7 on their site...

But I have gotten myself off the OP's target, sorry!

R2 should be do-able... extended coupler shanks, or the car hooked to the loco is a truck mounted coupler, or very short car...

(dunno why I was drawn down your mention of R1 curves, the OP states R2 curves, I should have ignored the R1 reference)

Greg