Light weight and traction issues.

[Old Crow]

I'm new so please excuse if this subject has been covered.
I'm just beginning "N" gauge and my last experience was with Hornby Dublo years ago, where the stock was made of "iron!" I note the very light weight of my GF coaches that given half a chance would like to raise a wheel on curves. I'm also intrigued to find the use of tyres on some locos, I guess because of adhesion problems? My query is how in heaven's name do you fit tyres when there's all that delicate watch-like valve motion in the way? I'm thinking you have to be aware of electrical conductivity - so just one set of driving wheels? My loco will be a pre-owned GF Coronation Pacific - original version.

Regarding the light weight. Why not add weight where possible? Has anyone tried roughening the track on inclines or maybe even the driving wheels - or is that total heresy?

[daffy]

Having no steamers I will leave the tyres problem to others, but on no account should you roughen the wheels or track surfaces IMHO as you will give yourself problems with electrical conductivity, with the probability locos won't run well or at all due to the bad connection.

What adhesion problems are you experiencing?

[ntpntpntp]

Definitely NEVER consider roughening track or wheels, that will simply ruin the track or loco.

On steam locos, to fit traction tyres you usually have to remove the crank pin or screw holding the rod to the wheel, then you can slip on a new tyre.  Not all wheels have tyres otherwise there would be insufficient electrical pickup.  The wheels that are intended to have tyres will have a groove in the tread.

Some people do add weight (to simulate the weight of a real coach or wagon), and find it can make models run with less "wobble" but it depends on the model and how much weight is added.  Too much and you're simply adding more load for the poor loco to struggle with.  I'd say don't bother unless you need to. Just because the stock is light doesn't mean it will climb out of curves.  As long as the wheels are free running, the bogies turn easily and the track is well laid you should have no problems.

[jpendle]

Remember, 'it's just like the real thing'.

On some inclines kettles will need to be double headed or banked, think Lickey Bank or Shap.

But diesels and electrics will be able to handle the same load with no need to bank or double head.

In our miniature world we have a tendency to use tight curves and very steep inclines, which when scaled up, most full size loco's would struggle with.

Regards,

John P

[PLD]

I note the very light weight of my GF coaches that given half a chance would like to raise a wheel on curves.
Regarding the light weight. Why not add weight where possible?

It is a fallacy that adding weight improves track holding... The critical factor is the interface of the wheel and rail. i.e. that the track is reasonably well laid to the correct gauge, and the wheels are the correct gauge and profile.
Adding weight to a Loco will improve tractive effort provided it is evenly spread so as not to unbalance the loco (which could reduce haulage capacity!) Adding weight to rolling stock does little other than reduce the number of wagons a loco can move...

I'm also intrigued to find the use of tyres on some locos, I guess because of adhesion problems? My query is how in heaven's name do you fit tyres when there's all that delicate watch-like valve motion in the way? I'm thinking you have to be aware of electrical conductivity - so just one set of driving wheels? My loco will be a pre-owned GF Coronation Pacific - original version.

they are indeed for traction, and yes it is a trade-off between tractive effort and electrical pick-up...
Do not attempt to fit tyres to a loco that is not designed to have them (the original GF Coronation Pacific is not). it will increase the diameter of the wheels so fitted and result in other wheels being lifted off the track. Locos that are intended to have traction tyres are designed for the valve gear to be detached in the event of needing to change a tyre.

Has anyone tried roughening the track on inclines or maybe even the driving wheels - or is that total heresy?

Not recommended... dirt tends to collect in the grooves created.

[PLD]

On some inclines kettles will need to be double headed or banked, think Lickey Bank or Shap.

But diesels and electrics will be able to handle the same load with no need to bank or double head.

What utter biassed rubbish...   

The need for double-heading is not about Steam vs Diesel. There are steam and diesel locos that can deliver the required horse-power and other steamers and diesels that can't...
Over Shap (to use one of your examples), no diesel was able to take the 12-14 coach loads a Duchess could take unaided until the class 50s came along and even the early electrics (AL1-4s) tended to double up...

[Old Crow]

Thanks for the advice guys, yes I thought roughing up the track was a no, no! But I was talking very slight.
And, from the photos, that original Coronation pacific indeed does not use tyres. So - this means that the newer ones actually have a reduced diameter wheel to cater for them? That they are fitted as standard when new? I am thinking of buying a newer one as well.
I want my loco to pull a reasonable load - any one used five or more coaches with one of these?

Talking of Shap - that's the region I used to live in and watch the big pacifics there and the area I would like to model. Not thinking of huge inclines but I could build a straight run of about four feet plus that I'd like to raise to the height that would clear another track say 50- 55mm- is that excessive?

[jpendle]

On some inclines kettles will need to be double headed or banked, think Lickey Bank or Shap.

But diesels and electrics will be able to handle the same load with no need to bank or double head.

What utter biassed rubbish...   

The need for double-heading is not about Steam vs Diesel. There are steam and diesel locos that can deliver the required horse-power and other steamers and diesels that can't...
Over Shap (to use one of your examples), no diesel was able to take the 12-14 coach loads a Duchess could take unaided until the class 50s came along and even the early electrics (AL1-4s) tended to double up...

Oh Dear 

I stand corrected 

John P

[Delboy]

Hi Old Crow,
DCC Concepts do an aid to traction on slopes involving steel plates that go under the track and magnets that you attach underneath your loco chassis. The magnet can also double up if you are using reed switches at various stages of your layout. See the link below:-
https://www.dccconcepts.com/product-category/specialised-model-accessories/dccconcepts-powerbase/
Dennis.

[Old Crow]

Thanks Delboy, Interesting stuff and looks like an answer. Magnets and steel seem intriguing. Have heard reports of burning out motors if you stress them??? 
I'm new to all this and just realising that with the whole lightweight issue, tolerances are much finer than I'd thought. Seems the world prefers to be largely flat! Just learning you need sensible curves and well laid track.
Still having problems with my Farish Mk1 coach. Seems that one bogie at least has a lot of horizontal play and coach can wobble enough to lift a wheel. Found it runs far better with a little weight (a nut ) over the offending area. Would like to place this inside perhaps, so can you open these coaches?
On the other hand, My original spec pre-owned Duchess behaves beautifully.

[ntpntpntp]

..I could build a straight run of about four feet plus that I'd like to raise to the height that would clear another track say 50- 55mm- is that excessive?

That works out about 1 in 25, so yes rather steep to be honest.  I think 1 in 40 is a more usual rule of thumb.

[ntpntpntp]

DCC Concepts do an aid to traction on slopes involving steel plates that go under the track and magnets that you attach underneath your loco chassis.

Modern day Magnadhesion for users of non-ferrous track!

[mattycoops43]

..I could build a straight run of about four feet plus that I'd like to raise to the height that would clear another track say 50- 55mm- is that excessive?

That works out about 1 in 25, so yes rather steep to be honest.  I think 1 in 40 is a more usual rule of thumb.

Yes, but also bear in mind you can get away with less than 55mm depending on thickness of the bridge. If you don't need to get hand under for access, and can make it strong enough a train will go under a much lower opening.

[zwilnik]

What about a battery powered banker?

[daffy]

Be aware that differnet locos, even ones that are apparently identical, can have differing abilities when it comes to inclines. If you are running different locos, or will in the future, it is best to err on the side of caution with how much grade you go for. Many believe 1:50, or 2% is a workable limit, but you need to run all your locos in a test with them loaded to the maximum you perceive them being normally used. Some of my Kato electrics will happily take a rake up 3% or more (in tests).
You mention a four foot straight. Is it possible for you to begin the incline before the straight, giving you a longer distance to make the ascent, and thus the ability to reduce the gradient? If so, note that gradients on curves can have a marked negative effect on a locos climbing ability due to increased drag.
Another way to achieve your desired clearance is to look at the problem from both sides - where one track goes uphill, while the one it is crossing is slightly depressed, say at just 0.5% or 1.0 %.