Modern Hornby Class 43 HST Dummy Car causing derailments

[redixon]

Hi,

 

I've slowly been building up a full length 11 car GNER Mallard HST (2 PCs + 9 Mk3), I have one R4323 mk3 left to buy but they're rather rare (and pricey) on eBay.

 

I recently ran the train (2 PCs + 8 Mk3) on a large rectangular/oval test circuit using 3rd radius set track and at standard set track straight between the 2 90 degree turns at either end of the 180 rectangle/oval. As the train exited the 180 degree turn the coaches derailed caused by, what i imagine anyway, drag from the dummy power car pick ups. Since then I've removed bogies to check for any fouling material but found nothing. I've also purchased a new trailing dummy bogie and compared the roll resistance against the original tailing bogie to see if the issue lays with my dummy power car bogies or if its just atypical. They both roll the same distance so my original dummy bogies appear to be ok.

 

Has anyone else experienced this issue? I've seen videos of full length 11 car ECML HSTs on Youtube running through curves without issue and also HSTs doubling over themselves as they climb the Helix on Chadwick Model Railway's YouTube account (albeit shorter West coast 7 coach unit climbing 4th radius curve). I'd really hate to finally complete the Train and then not be able to use it when i build my layout.

 

Appreciate any feedback on this, thanks.

 

Ryan

[Stephen O]

Hi, I know there is drag from the dummy cars not freewheeling because mine (an original Hornby with the ringfield motor can't get around my garden circuit because of a steep hill and the drag of the dummy, without the dummy its fine, ive also had the train tip over caused by the dummy dragging on another hill and the path of least resistance changing to flip the train on a transition bend so I am looking to add a motor to my dummy. I find personally that (my) coaches are too light and longer trains suffer poor rail riding from intermittant coach wheels. check to see if on the apex of the bend your coach wheels are being lifted up. All I can suggest, which is something ive got to do myself is to try and ease the curves for the longer trains.

 

hope this helps

 

every day is a school day on my railway.

 

Stephen 

[phil-b259]

If the intermediate coaches are lifting themselves then try adding weight. Logically if the heaviest vehicle is at the front and they get progressively lighter towards the rear chances are that there won't be an issue cornering.

[The Johnster]

Assuming that the test track concerned is well laid, level, and without doglegs, and given that the train is derailing exiting the curve and entering the straight, I would also check that the dummy's bogies are free to swing and have a reasonable amount of fore/aft 'pitching' play.  The issue may be being caused by something fouling on the bogie as it returns to the straight position coming off the curve. 

 

It is also worth checking the behaviour of the couplings at this point on the test track.  A stiff hook, or a hook catching on crud on the opposite coupling's bar, could be pushing the vehicle sideways as it returns to the straight position, causing the derailment.  Both these causes will result in the bogie being deflected off the road in the same direction each time.

[steviesparx]

On 01/05/2021 at 20:25, redixon said:

Hi,

 

I've slowly been building up a full length 11 car GNER Mallard HST (2 PCs + 9 Mk3), I have one R4323 mk3 left to buy but they're rather rare (and pricey) on eBay....

 

Has anyone else experienced this issue? I've seen videos of full length 11 car ECML HSTs on Youtube running through curves without issue and also HSTs doubling over themselves as they climb the Helix on Chadwick Model Railway's YouTube account (albeit shorter West coast 7 coach unit climbing 4th radius curve). I'd really hate to finally complete the Train and then not be able to use it when i build my layout.

 

Appreciate any feedback on this, thanks.

 

Ryan

 

Can't say for certain, but possibly the full rake videos on YT have a driven car at each end ??? 

 

I have a couple of Bachmann Pullmans, they both have driven power cars from the box, and are only 6 cars long....

 

Not a cheap option I know, but for such a long rake maybe you should look into it.

[89A]

I always propel my sets. Better with the older large non swivel couplings on the coaches to match the power cars but still possible with the newer swivel couplings. With those usually have to fit a large coupling to both end coaches and fixed straight between coaches (eg Roco type or Bachmann pipe type.)

[Phil Mc]

I’ve got a LNER 9 coach set, a FGW 8 coach set, and a GWR 8 coach set.

All of which will happily run around 3rd radius curves, either being ‘pulled’ or ‘pushed’ by a single powered PC and a dummy at the opposite end.

BUT, only after the coaches had some weight added to the chassis.

There’s a convenient space under the metal strip weight to add liquid lead type material.

 

cheers,

Phil.