Alstom Pendolino get stuck at points and poor pick up from track

[Deem]

Hello everyone

I recently bought used Hornby Alstom Pendolino, body and exterior is very good.

I am having issue with front bogie going over points, I checked the wheel width which was 13.75 and corrected to 14.00 MM which helped, Cleaned the wheels with Isopropyl which improved further. But issue remained when Driven bogie goes over the points it get stuck and won't move.

This is a DCC ready model and I don't want to install Decoder until this problem is solved.

Another issue is when tested on rolling road one direction speed is less on the same throttle compare to other direction.

According to picture shown in Service Sheet (hss-302b-pendolino-380(1) Alstom Pendolino) traction tyres are on each axle, my loco have both traction tyres on same axle.

Looking at the picture of part number on Lendons of Cardiff - part number X9718M (which is newer or modified version) have traction tyre on each axle as well. Would I need to replace the wheels or need to something else.

Regards

[Going Spare]

I was going to suggest there may be a trapped wire from the pick-ups stopping the bogie pivoting freely, but this would also cause problems going round curves which you do not mention.

You refer to both the "front" and "driven" bogie - are both giving problems? One derailing (front) and one stalling or trapped (driven)?

I would set the back-to-back measurement at 14.5mm for Hornby points.

The more recent (X9718M) drive bogie wheelsets have both tyres on one wheelset as stated on the Service Sheet and shown on Peters Spares website.

[Deem]

Apologies for not being clear, you stated more recent (X9718M) Wheel set have traction tyres on same axle which is correct.

But Hornby own website is showing traction tyres on each axle.Picture 1 showing that, picture 2 showing from Cardiff of Lendons which shows traction tyres on each axle, picture 3 is from Peter Spares which shows traction tyres are on same axle as I have in my Loco.

[Deem]

Only the motor driven bogie is the issue. I will adjust the wheel width to 14.5MM to see if that solve a problem.

Regards

[Deem]

Just another twist to this issue,

I have tried Bachmann Class 170 DMU 2 car set and they work fine on same points or track.

Hornby Class 373 Eurostar EMU 4 car set used as well on same track and no issue's what so ever.

Only Alstom Pendolino with traction tyre on same axle get stuck and when it get stuck loco get lifted few millimetre in the Air before Loco will stall and need to have a push before it will move.

[Going Spare]

If it is the motor bogie that gets lifted a few millimetres (so that the wheels lose contact with the rails?), it seems to suggest that, the wheelsets on that bogie are not set to the correct spacing and get forced upwards when passing between the frog and the check rail because they are too wide or too narrow to fit through the gap, but I am puzzled that this causes the train to stall as the motor should still be getting electricity from the cab-end bogie to keep it running.

The fact that there are traction tyres on both wheels on one motor bogie axle should not stop current-collection from the other three wheelsets on the vehicle provided they are in contact with metal rail, the pick-ups on those wheels are clean and positioned correctly and the wiring between the cab-end bogie and the motor is undamaged.

Regarding the conflicting X9718M illustrations, I suspect those originally used for X9718 have been re-used by Hornby and Lendons. Peter's Spares' illustration accords with the Service Sheet description.

[mjb1961]

does it have the same issues in both directions or just the one .

[Deem]

First of all Thanks for your time and help, to answer both questions,

Yes it does both ways as I have points, 2 types - hornby R8072 /R8073 and R8077 / R8078. This Loco have problem on both points.

As for stalling, that is actual puzzling me as well, first thing I did after I notice the problem, I cleaned the wheels, cleaned the side walls of the rim so if there is any dirt causing any contact issue can be fixed with Isopropyl.

Did check if wheels have correct spacing, by the way which was 13.79 MM so I try to adjust them and now they are 14mm or tad maybe over.

I will check tonight when I have a chance, report back here to see if we can all solve this matter.

In the mean time I will place order for new wheel sets anyway so either replace them or have them as spare for future use.

To my very limited knowledge about this hobby, I thing either the the wheels have wrong traction tyres or fitted incorrectly because they are way to high from the rim for my liking. I could be wrong and I will try to upload the picture to show as well so maybe we can get to the bottom of this problem.

Regards

[Deem]

Further update

Wheel spacing is still actually 13.79 or 13.80 MM so what I was trying to do last night didn't work. As for jumping up from track when stopping at the points or even on plain track is really strange for me and can't get my head around to this problem.

[What About The Bee]

Hi Deem

Your Back To Back [this is the proper term, not 'wheel spacing'] is entirely too small at 13.8mm

The means that the inside surfaces of the wheels must straddle the wing rail and check rail at the points. If the points are made to the intermediate OO standard, that is 14.1mm

So think this through. The gap between the wheels is smaller than the two rails which must simultaneously fit betwixt them. So of course the loco hops upwards.

Please set your Back to Back for all axles to a minimum of 14.2mm. The Intermediate OO Standard demands that the Back to Back be 14.5mm, but we need not be so rigid.

Further, I would recommend you search out the Intermediate OO standards and understand what they specify.

Bee

[Deem]

@What about the Bee, thanks for your time and explanation, will try to find Intermediate OO Standard and try to understand.

As for "Back to Back" I try to pushed the wheels out without any success at the moment, is there a specialist tool I need to buy just for this particular model. As this axle have gear in the middle so logically I won't be able to use DCG - BB145 back to back tool. Or would the gear is small enough that it will fit in gap between the tool.

Regards

[Deem]

[What About The Bee]

POINTS:

https://doubleogauge.com/intermediate-track/

WHEELS:

https://doubleogauge.com/intermediate-wheels/

[atom3624]

I would be very careful just considering B2B!!

This is assuming the flanges are the same thickness / fineness on all wheels. What if you set the B2B to 14.4mm, but the flanges are actually twice as thick - heavier duty wheels 'to take a punishing'? The outsides of the flanges could be almost grinding against the rails if you're not careful!!

Is there much front / back movement of the bogie - might be momentarily losing contact over the dead areas on the points, then regaining, as GS mentioned, partially lifting the bogie, the tyres gripping, partially twisting the bogie and thus derailing ...

My own Pendolino runs just fine - which doesn't help you!!

Al.

[What About The Bee]

Hi Atom Al

You are correct. Considering only the back to back would be a procedural error.

The system of wheel profile, back to back, back to front, back to front plus tread width, flange width, flange depth, rail gauge, stock rail to check rail gap, check rail to wing rail width, wing rail to frog rail gap, frog depth, frog width right at points are just a few points of the system you need to consider. The inter relationship of ALL of them will decide if the locomotive will pass through the points or not.

The issue for Deem is that his back to back, at 13.8, is far smaller than the check rail to wing rail width, at 14.1, of any commercial set of points I am aware of for OO. My Peco points are indeed at 14.1 and would certainly pose issues for his locomotive.

Bee

[What About The Bee]

Deem,

While your image does indeed illustrate back to back dimension, it appears that your image is for FINE SCALE back to back. This would be the inappropriate dimension for your locomotive.

Please do follow the links I have provided you for INTERMEDIATE SCALE, which is what most Ready To Run is set to.

Fine Scale is the next level of realism, but all the locomotives and track in the system must conform.

Again, 14.8 is not the dimension you should be using.

You also mentioned being unable to set the B2B with your tool, because there is a gear in the way. There are B2B tools with a gap, used to straddle that gear. You can, of course, simply set the gap and measure it with a caliper.

Bee

[Deem]

[What About The Bee]

Hi Deem

The drawing you just posted is the correct one! 14.4mm Back to Back is the correct dimension.

While there may be subsequent and further issues as others correctly point out, your locomotive must conform to basic point geometry specifications. Fixing the geometry issue permits you to tackle other issues, knowing that this geometry issue no longer affects you.

There is the corresponding points specification. In your minds eye think of the wheel set moving side to side. Now with a piece of paper, do the sums. Consider where each wheel will be in relationship to the pieces of track.

Example: Place the wheel against (touching) the check rail. Traverse the axle, and see where the back if the other wheel is. In your case, the other wheel does not clear the wing rail. But what if your B2B was bigger than specified? The flange of the other wheel could pick the point, striking those rails, OR if entirely too big, end up in the diverting flangeway!

Now try that thought experiment with the wheel touching the stock rail. Does the opposing wheel clear the wing rails?

Points are fascinating to me, and were the subject of early patents.

Bee

[Deem]

Hello

Update, I have spoken to previous owner, shown him the video, showing what's happening with Loco, so he has agreed to accept the return and I will be sending it back.

Just wanted to say thanks for everyone for their support and advice.

Regards