Traction - general discussion

"And to use or not use traction tyres has split the model railway community in 2. More so than any other topic possibly!"

2 DCC or not 2 DCC?

I think a properly weighted loco should have no problem maving a prototypical train of properly weighted coaches.

I tend to find that the layouts where people need traction tyres are the same layouts that cant run long enough train jo justiofy their use. or the layouts are not well designed and so have avoidable extreme gradients and curves.

i think the lack of gradient on the hornby demo layout is far more to do with ease of setting up than anything else.

You put the lack of tyres down to misguided lobying but note that when traction tyres were fitted as standard that there was a healthy market for more accurate wheels. there is no after market source for traction tyres. why? pecause people simply dont want them.
they responded to the customers wishes.

Traction tyres do have a tendency to pick up much off the track.

now to answer the last question, how many coaches can it pull is given buy tractive effort at standstill. its how much oomph it has to start a train.

Gradiet climbing is continuous tractive effort. its how much weight it can continuously pull.

if a layout is well designed then really there shouldnt be a problem with inclines.

"Diesels are better than steam and traction tyres are better than no traction tyres."
I think that is a matter for ACAS or the united nations to sort out!

Peter

QUOTE 2 DCC or not 2 DCC?

QUOTE I think that is a matter for ACAS or the united nations to sort out!

but how true!

Happy modelling
Gary

There really need not be any argument..it is down to individual preferences.

Perhaps we ought to clamour for the OPTION when opening the box?

we get bags full of detail parts, do we not?

For haulage capacity, this very argument raged over the US model scene 20 or more years ago.

No one doubted the haulage capacity of a mundane Athearn SW7 switcher.

disregarding whether this was down to what looked like cast steel wheels, and a washing machine motor?

maybe traction tyres are needed because of the material used by the makers for wheels?

Perhaps we like shiny things too much?

I dislike tyres for a several reasons....like, their tendency to make track dirty, or the fact that, no matter the quality, they still actually raise the wheel up a tad..and this has been noticeable with stalling on insulfrog Peco points..
Then from a personal viewpoint, many of my locos have to be 'shared' with an 8 year old.......using Hornby's 'Thomas' as an example....many young modellers like to simply push the engine along a bit...either to positon them better, or to give it a nudge.
The traction tyres resist this action...on 'thomas', to the extent of actually loosening the wheel on the axle!
The above is VERY important to a very young modeller.
After all, to encourage a youngster to take more than a passing interest in model trains, they have to be reliable, and work EVERY time, under a variety of conditions.....bit like an exhibition?

Another point, I feel it important that a loco's wheels be allowed to 'slip' on occasions.....if only to reduce strain on a motor ?

Over the years, modellers in all disciplines, railwise, have looked at the materials that wheels are made of.....and the amount of 'grip' provided?

perhaps there lies another issue?

There are several factors that improve traction, Traction tyres, weight and power of motor. Traction tyres are only one aspect of these and lack of them will contribute to less traction power but is not the overwhelming factor. Weight is. Regardless of how powerful your motor is, your loco will only pull in terms of what power can be transmitted to the track. Traction tyres assist in this process but if you do not have the weight or the power in your motor then traction tyres are useless.

I don't see the rivet counter approach to traction tyres as being particularly relevant as you can't see them when the loco is going round the tracks and most modellers tend not to spend too much time looking at the underside of their locos.

At the end of the day I don't really give a monkey's whether they have traction tyres or not as long as they work efficiently. While these problems can be sorted out by adding extra weight is it too much to ask that manufacturers build a ready to run product in the first place? I don't see why I should waste my time modifying a loco because some couldn't design it properly. Let's face it they're not cheap and a bit of extra lead isn't going to cost much.

In terms of Continental locos having them, the priority there is operational efficiency. They want their locos racing around without derailing and anything which assists in that process is good. Most Germans would be baffled by this staring at the underside of the loco business and to be honest so am I. In all fairness the German locos do not need really them as on average their locos would weigh double the UK equivelant, well the Brawa, Trix and Maerklin ones do anyway. They could probably do without them but it obviously has never been an issue there.

As regards dirtying the tracks, I hadn't really noticed. What was said by Alastair makes sense though.

At the end of the day as long as the loco functions well then I don't care whether it has traction tyres or not but if a loco is a poor performer and this is a contributing factor and it hasn't been included because of some whinger then I wouldn't be happy.

What I don't want is to spend close to a hundred quid on a loco which cannot do slopes and has it's wheels spinning wildly while it's inadequate motor and insufficient weight cannot get it to move through lack of traction.

QUOTE (Gofer @ 5 Mar 2007, 08:44) <{POST_SNAPBACK}>Magnadhesion?

This was actually quite effective, but only with steel wheels on steel track. There were some magnets mounted on the chassis close to the inside edge of the driving wheels. This had the effect of magnetising the driving wheels to the track, thus increasing the "grip".

Also quite useful for collecting all forms of metal debris from around the track !

Only the older Triang modeller will remember it.

QUOTE The Hornby ones with loco drive are a lot better as there is more weight in the loco to keep it down but the two three year old ones still had tender drive and little weight in the loco to keep it on the tracks. The newer ones are definitely better. Bachmann ones tend to be better weight wise too. I haven't had any problem with Bachmann locos only Hornby but they do seem to be sorting this out.

The Hornby GNER 225 can't pull any more than five coaches on the level which is annoying as I have eight and it just sits there with it's wheels spinning out of control!

Most people will recognise this as a fair description of old generation Hornby and Lima mechanisms - 3 pole pancake motor bogies , fitted with traction tyres,lightweight and picking up from a handful of wheels each side

QUOTE I do admit to replacing the tractioned tyred wheels fitted to my 'Ark Royal' more as an experiment than anything else (albeit with replacement wheelsets from the Hornby stable and not from Ultrascale). The loco will still start 10 Bachmann MkI's on a 1 in 36 gradient effortlessly.

Most folk will recognise this as the sort of performance we now expect from a new release British OO diesel - 5 pole centre motor driving both bogies by shafts/gear towers, 8 or 12 wheel pick up , widely spread , lots of weight (and no traction tyres)

Comparing this with the real world, the 1 in 36 gradient is comparable with the bank from Exeter St Davids up to Exeter Central. I'm not sure what the official load limit for a 50 was at this location but they regularly hauled 10 coach Mk2a sets up this incline on Waterloo-Exeter trains in the 1980s . So model performance is in line with what the real thing pulled in service

By contrast there was an episode a few months back where a steam special doubleheaded by a Bulleid Pacific and a BR Standard 4-6-0 stalled on the same bank . I can't remember whether it was a 4MT or 5MT Standard , or whether the load was 12 or 13 coaches, but it was said at the time that the load was 1 coach more than would have been permitted for those locos on that bank in steam days(although there were questions about the handling of the smaller loco on the grade). I think the official limit for the 4-6-0 without assistance was quoted as 5 Mk1s and for the Pacific as 7 Mk1s

For Hornby the "new era" models started with their rebuilt Merchant Navy in 1999: this was when they switched to loco drive with 5 pole motor and lots of weight. Bachmann's first high spec mechanism was the earlier version of their 46 , about 1991-2 , which stuffed an existing drive train from their US Spectrum range under a Peak bodyshell but gathered pace from about 1997. They don't have any motor bogie driven locos (unless you could the 108), and they're now replacing the old locos with split chassis

Lima never really got into the centre driven mechanism era - their only attempt was the abortive 67 where the drive train was apt to break up during shipment. Heljan started in OO in 2000 with their 47 which is a big heavy centre-motor mechanism and no traction tyres . It's very well regarded for performance

For British 4mm D+E modellers , the whole thing has been driven by direct comparison between Lima/Hornby OO models and US HO diesels from the likes of Athearn , Kato, Lifelike etc, rather than something like the Rivarossi Big Boy. Many British diesel modellers are heavily involved with US outline HO as well and the cry has always been - "This is what I can get from any basic Athearn HO diesel for £45 - why should I have to pay £60 for a British diesel that doesn't have x/y/z and needs extensive work before it will run slowly across points without stalling and struggles to pull the skin off a rice pudding"

Or to quote Neil QUOTE While these problems can be sorted out by adding extra weight is it too much to ask that manufacturers build a ready to run product in the first place? I don't see why I should waste my time modifying a loco because some couldn't design it properly. Let's face it they're not cheap and a bit of extra lead isn't going to cost much.

One particular gripe with traction tyres was that on OO locos they were generally fitted to all wheels on one side of the motor bogie .That meant you only had pick up from 2-3 closely spaced wheels on each side - hardly a recipe for good pickup (I notice Vi-Trains have fitted just one wheel on each bogie with traction tyres , meaning they can still have 8 wheel pickup)

Now we actually have the sort of mechanisms in OO diesels the Yanks have had for years I really wouldn't want OO to go back to the mechanical Dark Ages of 15 years ago

QUOTE (dbclass50 @ 5 Mar 2007, 10:14) <{POST_SNAPBACK}>This was actually quite effective, but only with steel wheels on steel track. There were some magnets mounted on the chassis close to the inside edge of the driving wheels. This had the effect of magnetising the driving wheels to the track, thus increasing the "grip".

Also quite useful for collecting all forms of metal debris from around the track !

Only the older Triang modeller will remember it.

Hi dbclass50. Sorry for any confusion I may have caused. I do remember magnadhesion very well and the pros and cons of it. My question mark was with respect to Alastairq's term 'magnetraction' - a term I'm not familiar with.

QUOTE (BRITHO @ 5 Mar 2007, 13:35) <{POST_SNAPBACK}>I seem to remember my "Hiawatha" was fitted with it.

Regards

John

You admit to having one of those !