Austrains C30 suspension defect

 
  NSWRcars Chief Train Controller


On another forum, I have raised an issue that I have identified with Austrains new C30 class pony truck springs, that affects tracking of the trucks and makes the locos prone to derailment. The pony truck suspension coil springs appear incorrectly sized and bind with the pony truck pivot slot. Here is an image that clearly shows the offending suspension spring on an Austrains C30:

http://users.tpg.com.au/bdayling/modelrail/C30defect.jpg

Note the angle that the coil spring is sitting. I believe that incorrect size springs are fitted, and they partially drop into the pivot slot, causing binding. The loco is unfit for service.



Comparing the Austrains C30 to their late run C36, the pony truck pivot and suspension, while not identical, is a similar design but the coil spring on the 36 is much larger diameter, and slides freely over the truck top without fouling the pivot slot. It looks to me like a larger diameter spring fitted to the 30 might solve the problem.



I’d like to refer the matter to Austrains for investigation and a fix, but the only contact details I have for Austrains is the PO Box number printed on the box. Can anyone help, or alert Austrains to the issue?



Brian Ayling.

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  steve_w_1990 Junior Train Controller

Location: Trying to fix something on the PTA Network
Public Relations have never been a strong point of Austrains, and, even if you did send them a letter regarding the issue, I wouldn't hold my breath for a response.

It took Austrains 18 months to be able to resend my dogbox cars after a useless post office returned them to sender when I was on holidays.

Unless you can chat to them at an exhibition about the issue, I fear you may be talking to a brick wall.
  Roachie Chief Commissioner

Location: Kadina SA (formerly NSW)
Brian, Whilst I agree the loco is not perfect, saying that it is not "fit for purpose" is probably a bit of an overstatement.

I don't know your age, but I'm old enough to remember when we paid a king's ransom to buy brass steam locos and then had to just about tear them down to correct defects, before they would run sweetly.

But, you know what, we did it because we wanted the locos to run properly and we knew that if we returned it to the importer there were a few possibilities:

1. We might (if we're lucky) get it back in 6 months
2. Even then there was no guarantee it would run as well as we'd like
3. We could roll-up our sleeves and do some "modeling" as opposed to "plonking".

Now, you've already done half the work.......you've identified the problem. That's great.

Now, try to imagine how much self-satisfaction you'll gain by FIXING that problem.

Here's a couple of clues or ideas in this particular instance.

1. As with MANY model steam locos, the front spring is clearly too long on your model. It is a simple task to remove the retaining screw, remove the spring and snip some off it. Looking at the photo, I'd say about half the length would be okay.

2. Place the spring back into position with the cut end facing upwards towards the smokebox. I'm assuming the other end of the spring is shaped such that it doesn't have an "open end"? Another alternative, if the original spring is too wide, try using the spring from an old retractable biro.....those springs are a narrower diameter and may, possibly, be a better alternative.

3. Find (or make) a small washer; one that has an inside diameter the same as the bogie pivot bolt. Place this washer between the bogie and the spring. It will (should!!) prevent the spring from working its way through the bogie's slotted hole.

The aim here is to have the spring just long enough to provide a MINIMAL amount of downward pressure on the bogie to prevent it lifting off the track and thus de-railing WITHOUT actually providing any upwards LIFT to the loco, thus robbing it of much-needed tractive capacity.

The same goes for the rear bogie.

If you feel like doing a bit more "modeling", why not add some small pieces of lead weight to the two bogies to aid them in their quest to stay out of the ballast?

So, getting back to my original statement, you have a couple of choices....you could whinge to the importer who may or may not be interested in your plight (he has your dough already so there's not much in it for him to go out of his way to keep you happy), or you can ....to use the good ol' Aussie vernacular.... "have a go" and feel the satisfaction drench your skin when you see it running sweetly.

If, per chance, you suffer from some incapacity that precludes you from doing this type of job, then maybe you could prevail upon a member of a model railway club to assist you or something similar. I'd be happy to assist you in that instance, but you probably don't live anywhere near me (I'm at Kadina, in country SA), so there will hopefully be better alternatives.

Cheers and good luck with this minor issue.

Roachie
  SA_trains Deputy Commissioner

Location: ACT
Hi Brian,

Sure, you can chase this with Austrains.... They have a website with an e-mail contact. I'd be interested in what response you get and over what timeframe.

Basically though, I would take the spring out and put some lead flashing on the bogie. Job done and will operate nicely. I usually take the springs out and replace with lead on my locos. Taking the spring off and replacing with lead is probably less than 15 minutes work. The job will be done before you can have a conversation with Austrains!

The springs are next to useless and can lift driving wheels off reducing traction or derailing issues like you are experiencing.

Like Bill's offer, if you are not able, I am happy to do it for you. I'm in the ACT.

Cheers
  NSWRcars Chief Train Controller

Hi Brian,

Sure, you can chase this with Austrains.... They have a website with an e-mail contact. I'd be interested in what response you get and over what timeframe.

Basically though, I would take the spring out and put some lead flashing on the bogie. Job done and will operate nicely. I usually take the springs out and replace with lead on my locos. Taking the spring off and replacing with lead is probably less than 15 minutes work. The job will be done before you can have a conversation with Austrains!

The springs are next to useless and can lift driving wheels off reducing traction or derailing issues like you are experiencing.

Like Bill's offer, if you are not able, I am happy to do it for you. I'm in the ACT.

Cheers
SA_trains
I’m OK with doing mods to the loco myself. However, as I figured there are going to be a lot of customers needing to fix these locos, it really ought to be addressed by Austrains.



This loco isn’t quite so simple to weight the pony trucks, because of electrical pickups fitted. The suspension spring fitted by the manufacturer is clearly unsuitable for the application.
  kingfisher Chief Train Controller

Hi Brian,

Sure, you can chase this with Austrains.... They have a website with an e-mail contact. I'd be interested in what response you get and over what timeframe.

Basically though, I would take the spring out and put some lead flashing on the bogie. Job done and will operate nicely. I usually take the springs out and replace with lead on my locos. Taking the spring off and replacing with lead is probably less than 15 minutes work. The job will be done before you can have a conversation with Austrains!

The springs are next to useless and can lift driving wheels off reducing traction or derailing issues like you are experiencing.

Like Bill's offer, if you are not able, I am happy to do it for you. I'm in the ACT.

Cheers
I’m OK with doing mods to the loco myself. However, as I figured there are going to be a lot of customers needing to fix these locos, it really ought to be addressed by Austrains.



This loco isn’t quite so simple to weight the pony trucks, because of electrical pickups fitted. The suspension spring fitted by the manufacturer is clearly unsuitable for the application.
NSWRcars
The electrical wiring to the pickups on the front pony truck would probably also preclude the simple fix of removing the offending spring as many have done with other Australian outline steam locos.
  NSWRcars Chief Train Controller

I spent some time last night examining the suspension spring and front pony truck fitted to my Austrains C30. I haven’t yet examined the rear pony truck, but I suspect it uses the same pivot and spring.



The manufacturer’s fitted spring is a cylindrical coil with closed ends and here are its APPROXIMATE dimensions:

Wire diam 0.23mm

Coil outside diam 3.4mm

Number of turns 10 (11 counting the closed ends)

Uncompressed length 5mm

Compressed length 2.3mm

Despite the appearances of this photo

http://users.tpg.com.au/bdayling/modelrail/C30defect.jpg

I think the spring when fully compressed allows sufficient vertical movement of the pony truck.

A binding problem arises when the end of the spring partially drops into the 2.5mm wide pivot slot of the bogie frame, skewing the spring off-centre (as per the photo).



It may be possible to fit a larger diameter spring that entirely straddles the slot. For example a late-run Austrains C36 has a 6mm diameter spring. On the C30, the upper spring seat (under the smokebox) can accept a larger spring up to about 4.4mm diameter.

It may also be possible to fit a CONICAL coil spring with the top (narrow end) up to 4.4mm diameter and the bottom (wide end that bears on the bogie) somewhat larger.

It may be helpful to fit a shim or thin washer over the top of the bogie pivot slot to prevent the OEM spring from skewing into the slot.



Another option could be to dispense with the spring altogether, and fit weights to the pony trucks. Might be easier said than done, given that there are electrical pick-ups to clear.

I don’t see cutting the existing spring as an option. This would stiffen the spring, shorten its travel, and exacerbate the skewing and binding problem.



I am reasonably confident that a replacement spring and washer can be found, and fitting these should be a simple task that most modellers can manage.



Brian Ayling
  NSWRcars Chief Train Controller


An update on issues found with the Austrains 30 Class Tank Locomotive.

The problems seem to be exacerbated by the undersized pony truck wheels fitted to allow the model to transit 18 inch radius curves.

Details of my findings and some suggested solutions are here:

http://users.tpg.com.au/bdayling/austrainsc30.html


  c3526blue Deputy Commissioner

Location: in the cuckoos nest
Hello Brian,

Thanks for the effort you have put into solving this issue.  I have had similar issues with my two C30 tanks, mainly when running bunker first, but I believe that this problem is also an issue with the front bogie, although not to the same extent.  Others have these problems too.  Especially on our club exhibition layout which has some very rough trackwork.

My initial inspection was an observation that both bogies did not have sufficient vertical movement to follow all undulations in the trackwork.  With the small wheels fitted the bogie wheels had almost no travel beneath the plane of the driving wheels where they would rest on the rails.

Others have suggested the fix is to fit the larger driving wheels.  Obviously a simple fix.

I have resisted making any early changes for the following reasons
  • The larger driving wheels will raise the bogie height, putting more pressure on the bogie spring and reducing the weight on the drivers, hence reducing the load hauling capacity of the engine.
  • Changing the spring (as you have done) will help with the problem but if the spring stiffness is increased it will also reduce weight on the drivers, and hence its hauling capacity.

I like your bushing arrangement as this fully addresses the bogie ride height issue.

The club layout that I run on has extensive 1:50 (nominal) grades on all four main lines and the hauling capacity is just on the prototypical loading for a C30 of eight end platform or BOB cars.  Any extra reduction in tractive effort will reduce these trains by one or two cars.

I am planning some load trials to determine the effect of bogie suspension/wheel alterations and will advise further when these are available.

Is there a website or other contact details for Century Springs?

Happy hauling,

John
  NSWRcars Chief Train Controller

Is there a website or other contact details for Century Springs?

John
c3526blue
This morning I added a link to Century Springs at the foot of my web page. If you can't see that link, refresh the page.

The S-1093 was the softest spring of correct dimensions that I could find in the Century Springs catalogue. I had a small quantity of these imported. A spring with a few more turns would be better, but I think they'd have to be custom made. Century Springs will do this, but would have to be a quantity that I cannot afford!

My locomotive fitted with S-1093s and the undersized pony truck wheels has no problem hauling 4 mainline cars up a 1 in 45 on a sharp curve. That exceeds my requirements so I won't be pursuing other spring options.

Brian Ayling.

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