Does anyone know which chassis this is?

[Andy Lowman]

I have a couple of tram locos that I want to change to a 0-4-0 chassis so that they can happily negotiate the 'tight' curves on one of my layouts. Please note that the screw at the rear does not hold the chassis in, at the rear this done by a couple of lugs that locate into the body. Does anyone know which chassis this is and which one could be put into the loco as an alternative? Thanks.

[B.Meldon]

It is a 1980's Graham Farrish N gauge 94XX chassis. These were sold as chassis only at one time.
If you file off the flanges from the center wheels these Graham Farrish chassis will go around tighter curves. I have done this several times myself.
You will have to dismantle the chassis and remove the central axle to do this job or the fillings will end up on the magnets in the motor, you will have to be careful not to damage the metal coupling rods and the plastic peg that they are permanently attached to on the central wheels. But it is only worth doing if the chassis runs well, they are known to have issues with the gear on the central axle.
However, regardless of the chassis the coupling overhang on the Peco GVT loco will cause issues on tighter curves.
(It is also worth knowing that in the real world these locos were turned to run cab first at both ends of the railway.)

[Hugh Norwood]

I have one of these under a white metal GVT loco. It's one of my best locos for reliability and pulling power. It goes round 9" curves fine (with flanges on all wheels!)

[B.Meldon]

I have one of these under a white metal GVT loco. It's one of my best locos for reliability and pulling power. It goes round 9" curves fine (with flanges on all wheels!)

There appears to have been variations in the chassis design over the years, some are fine on 9-inch curves and points and some are not. Some even have issues with the pre-2010 Peco 009 12-inch points. I think it is all about how much side play in the chassis there is for the axles as well as the shape of the wheel flanges. It is not at all obvious when looking at the chassis, it is very much hit and miss. Most, but not all, of the ones I have that date from the late 70's and early 80's with the three pole motor had issues.  But others may know more.

[Andy Lowman]

Thanks Brian, I hadn't thought about removing the flanges although until I looked closely at the chassis I was considering taking out the middle wheels (obviously not now!). Both loco's run really well and if I can't replace the chassis then removing the flanges is, at least, a solution.

[B.Meldon]

Whatever alternative chassis you use it will require modifications to the chassis and the body to get them to fit.
In the past I have used the Fleischmann track cleaning chassis in this body kit, however getting the body to sit at the correct height above the rails involves quite a lot of work that can be done when building the kit, but may well prove to be very difficult or even impossible with a completed body kit.
The Kato chassis could be an option, but again it is getting the body to sit low enough that may well be the issue.
There are far too many 009 locos that use the Kato chassis that are way to tall and are set too high above the rails.

As I mentioned in one of my previous posts, it is the coupling overhang that will give you problems on tighter curves with this loco.
Even on more generous 12-inch curves the narrow coupling face can cause issues when pushing rolling stock. This can be cured by changing the couplings for wider ones, Bemo couplings for example, or by fitting a section of single strand wire in a horizontal hole just behind the existing coupling face.

[B.Meldon]

Whatever alternative chassis you use it will require modifications to the chassis and the body to get them to fit.
In the past I have used the Fleischmann track cleaning chassis in this body kit, however getting the body to sit at the correct height above the rails involves quite a lot of work that can be done when building the kit, but may well prove to be very difficult or even impossible with a completed body kit.
The Kato chassis could be an option, but again it is getting the body to sit low enough that may well be the issue, that will require modifications to the body and chassis.
There are far too many 009 locos that use the Kato chassis that are way to tall and are set too high above the rails.

As I mentioned in one of my previous posts, it is the coupling overhang that will give you problems on tighter curves with this loco.
Even on more generous 12-inch curves the narrow coupling face can cause issues when pushing rolling stock. This can be cured by changing the couplings for wider ones, Bemo couplings for example, or by fitting a section of single strand wire in a horizontal hole just behind the existing coupling face.

[JulienW]

As others have said this is the Farish GWR 94xx pannier tank chassis that the Peco GVT loco kit was designed for.  It's also possible to upgrade them with a coreless motor from Tramfabriek (this is the right kit, it just fits a lot of different Farish chassis).

Just out of interest have you tried running the locos with their Farish chassis on the layout? Unless your 'tight' curves are ridiculously so you should be OK as Hugh suggests, and if not then take the flanges off the middle drivers as Brian suggests.

The most effective way to do this is to clamp the chassis, apply power direct to the motor and a file to the rotating flange.

The copper strip over the top forms one motor pole, though you could also use the nut on the top of the chassis where the plastic covered wire runs. The other motor pole is linked to the metal chassis block, so just clip a lead somewhere out of the way.

The main thing is to try to avoid the metal filings falling into the motor and gearing, so it may be best to clamp the chassis the right way up (motor at the top) and bring the file in from underneath.

The most common alternative chassis is to use one of the Kato 4 wheel tram chassis, either the older 11-103 or 4 or the newer 11-108 or 9.

You'd need to sort out some way of fixing the chassis within the body, but as it's a fairly common conversion I'm sure a google search will give lots of inspiration.  I also have a feeling that someone may have done a 3d printed adaptor  plate.

The only thing to bear in mind is that the bodies that the Kato chassis are designed for are comparatively light compared to the cast white metal kit body so wear on the chassis (particularly the newer ones with their inbuilt compensation) may be increased.

[Andy Lowman]

Thanks, Brian and Julien. Very useful comments, much appreciated.