The limited haulage capacity of modern RTR models

[34theletterbetweenB&D]

Well, per title, do you find this is a problem?

 

For a discussion to make sense we do need some standards, and there are three I would particularly suggest.

 

I suggest this thread is confined to OO in order that valid comparisons are made, and seperate threads are started for other scales if there is interest in doing so.

 

As for what is hauled, it needs to be understood what the load's starting and rolling resistance characteristics are like. Personally I use a minimum standard of 'at least keeps rolling once started on a 1 in 100 incline' which means that trains need at most 1% of their total weight to be available as drawbar force from a loco if it is to start and haul that train on straight and level track. But something different might be more to others liking?

 

Traction tyres should also be considered in a seperate thread, it's happily now an uncommon item on RTR OO product.

 

FWIW, my own feeling is that the immediate practical answer is DIY with lead when the manufacturers don't oblige with sufficient built in ballast weight. There could be some better design, all of internal layout, constructional methods and materials choices, and if enough of us can achieve concensus that might be worth registering as a suggestion?

 

 

 

[Robin Brasher]

My model railway club has a level test track with 3' radius curves so I could use this to test the haulage capacity of new locomotives. So far I have not tested locomotives to their limit but my Hornby T9 had no problems with 6 Hornby Maunsell coaches. On the other hand my Hornby M7 could not cope with 5 Bachmann green Mk1s and a 00 Works Devon Belle Observation car whereas the prototype had no problem with this load. Perhaps we need to standardise on the make and type of coach.

 

I don't think the new models have the haulage power that Hornby-Dublo did.

 

The Model Railway Constructor usually included the maximum load pulled without slipping and Model Rail often continues in this tradition.

[Rowsley17D]

In my experience steam outline models don't keep their feet very well. On my old layout I had rather steep gradients and my Bachy Jub was additionally weighted with liquid lead and performed much better and would easily take nine bogies. Never got round to doing more as I had a house move.

[davidw]

My 16' x 13' round roundy is ECML based very gentle gradients. All pacifics (including early A1 models) will handle 16 mk1's I typically place 9 -11 vehicles behind such motive power. As a mater of course all Mk1's have had their weights removed - with no detrimental affects to running, or introduced wobble.

 

Thompson tend to rub and Gresley coaches are extremely free running though heavy -like wise Hornby Pullmans.

 

Only loco that at the moment disapoints is a Bachmann K3 

[Baby Deltic]

The Bachmann Peak's have got some grunt.

[Torr Giffard LSWR 1951-71]

Evenin' all,

 

Bear in mind that the combination of nickel-silver rail and wheels doesn't help...there is a better coefficient of friction between steel and steel or steel and nickel-silver.

 

Also, ensuring that all stock is free running and doesn't have unnecessary weight...combined with removing severe radius curves and ensuring that track is well laid helps to improve haulage capability.

 

Dave

Edited April 3, 2014 by Torr Giffard LSWR 1951-71

[andyram]

Well last night I was running a few of my 4-6-0 models around the Mickleover Club's layout. The train was made up of 5 Mark 1 coaches. 2 were the latest Bachmann TSO's and the remaining 3 were slightly older, and lighter, Hornby models.

- The old "Mainline" Jubilee struggled to maintain its pace on the bends even with the controller set to almost full power.

- The similar model by Bachmann was a little better,but certainly seemed be working too hard.

 

Then came the Hornby Black 5 -no problem!

In fact the latter model managed to shift a 6 coach made up by adding another of the heavier Bachmann models.

 

In this case more modern was certainly better!

[34theletterbetweenB&D]

...Only loco that at the moment disapoints is a Bachmann K3 

... 4-6-0 models...

Just snipping those two out (and granted that the nickel-silver rail and tyre combination is not optimal, but that's what is produced RTR, and has also been the usual 4mm finescale choice for fifty-some years) I would only add eight coupleds (which currently means 2-8-0s) and that's where the majority of the traction trouble in RTR OO lies in my experience.

 

Where there is the layout space and the desire to do so these models should be able to take a full size load, which means at least a dozen coaches or sixty plus wagons, but most struggle or straight up refuse, even with free running stock.

 

My bete noire (the current model if there are earlier incarnations) are:

K3 and V2 - well balanced but too light

BR Std5 - poorly balanced, oversprung carrying wheels, too light

Castle and 7P Patriot  - too light

Stanier 8F - too light.

 

None of these models are a problem due to inadequate volume to contain sufficient ballast, it just needs to be installed.

 

Do we suppose the designers actually consider the weight that will bear on the driving wheels as needing to be proportional to power rating during the development? Sometimes they appear to, the Bach 9F and Hornby Britannia among the more striking examples. But many medium sized locos do seem to 'miss out' in this respect.

[davidw]

Curiously,  of the two K3's i have one runs fine the other is light footed. The V2 I have is - latest  chassis the top end is insufficient. Though it'll pull fine

[mark axlecounter]

I have had the Hornby 8f's pull 40 wagons with ease the black 5's can only manage about 7 Bachmann mk1's

The most i got with the Bachmann mogul's are about 5 mk1's and the Hornby brits the most they can cope with is 12 mk1's

I have not added weight in any loco they are as they are when they come out of the box.

The track I use is code 75 I have been happy with how they run

 

mark

Edited April 4, 2014 by mark axlecounter

[Miss Prism]

Do we suppose the designers actually consider the weight that will bear on the driving wheels as needing to be proportional to power rating during the development?

 

They probably consider it, but realise there's little they can about it with their current chassis technology.

[bike2steam]

I still think the way that the loco is run-in has a lot to do with it, I spend a lot of time running mine in, first without, then with load. Maximum loads without slip, as an example, are Hornby 8F - 60 wagons (minerals), Black 5 - 10 coaches, Bachmann Crab - 40 wagons, WD - 50 wagons, and a St 5 - 11 coaches ( but that's cheating, the standard Bachmann motor has been changed for a Mashima 1426). My best are Model-Yard conversions ( now about 12 years old) of Hornby 9F's, from tender to loco drive, I have loaded them to 100 minerals.

[TheSignalEngineer]

Doubt if many were as bad as the Hornby Mickey Mouse 2-6-0 of about 30 years ago. Mine would manage to take about 3 coaches with pin-point bearings but steadfastly refused to budge on curves with one Hornby Dublo coach.

[34theletterbetweenB&D]

...Do we suppose the designers actually consider the weight that will bear on the driving wheels as needing to be proportional to power rating during the development? ...

They probably consider it, but realise there's little they can about it with their current chassis technology.

But is that really so?  It seems to me that there are four weighting options that are under-exploited in OO:

• Consistently filling the body interior with ballast. Sometimes a clear effort is made to really fill the interior for maximum weighting, other models, not so much.
• Good internal layout placement of the motor, gear train and decoder socket and void, to leave maximum volume for weight over the coupled wheels.
• When a little shy of space because the prototype is smaller or has an awkward layout,  additionally use metal bodywork.
• When really desperate for space, cast the chassis block and other weight blocks in a higher density metal such as a tungsten based alloy.

None of these techniques are rocket science, all proven in model railway manufacturing.What is noticeable is the uneven application of what is the simplest technique: filling the available interior space with ballast. Some models practically solid inside with metal, others left with much 'airspace' inside, and no discernable reason behind the why. The airy interior loco is inevitably lighter and thus fails to pull as well. As a result one has the daft situation that a loco with a class 5 to 8 power rating struggles to pull anything like its normal service load, but the class 3 rated 0-6-0T that does the shunting will move the same train with traction to spare.

 

As already written in the OP, it is fixable by the purchaser; but it does strike me that odd decisions are made at the design stage in the development of the models.

[Miss Prism]

I don't disagree with any of that, and there have been some obvious absurdities in D/EMU land, notably Bachmann's early paranoia about the tractive ability of a single drive bogie, and as a consequence deciding to rip out the interior of its initial 150 and fill it full of metal. Heljan's 128 will pull about 10 times what the prototype could.

 

On the steam front, the biggest problem area is probably 4-6-0s, and I think until motors are put in tenders and better bogie suspensions are incorporated, then the current approach will prove problematic in terms of reasonable loco balance and adequate weighting over the drivers. It would also help enormously if the drivers were held in or suspended with a more resilient material, but manufacturers seem to be reluctant to recognise that avenue. These are after all, just toys, and I don't think manufacturers lose too much sleep over the inability of a 4mm model Castle to work 12 coaches up a gentle grade, because the majority of the marketplace hasn't got nor expects to have room for that scenario.

[APOLLO]

I've too many locos to list, both old and new, but here are my best, excellent and hopeless.

 

Best / Excellent = 12 coach trains / 40 wagon goods, slight inclines, 3rd rad max curves. Note new = last 5 years or so models)

 

Best

 

2 Triang Hornby "Silver Seal" 1975'ish Tender Drive locos - An original 9F Evening Star & a Black 5. The reason being both sides of loco wheels electrically pick up, 2 wires to ring field motor in tender, large weight in there and traction tyres (still original) to the 4 driven tender wheels. Superb haulers, slow & quiet runners, never stall on peco insulfrogs, 1970's design, still going strong - what more can I say - bring them back into production !!!!!!!!!!!!!!

 

Excellent

 

All my Heljan & Bachmann large diesels. (Don't have any recent Hornby diesels)

All my old Lima diesels (I have lots of em, good haulers when brass wheels cleaned & who needs sound chips !!)

Hornby Brittania's (new), O1, Bulleids, both spam can & rebuilt (new)

Ancient Hornby Dubblo "City of London"

2 x pairs of old Hornby Class 25's. Lovley runners when 2 coupled together

1 x pair of Wren class 20's (even 1 pulls OK, but stalls on points so I coupled both together electrically & permanently)

Bachmann WD 2-8-0 & 9F 2-10-0

Hornby Railroad (new) Black 5 and 9F, both after weight added, which is easy to do with these 2 locos.

 

Hopeless

 

Most of my new Bachmann steam locos, size up to/including 4-6-0 (Jubs, K3, etc) - They run nice, don't stall, look nice but won't pull the skin off a rice pudding. Hence I double head, 2 Bachmann Jubs OK on a 10 or 12 coach train. One will only pull 7 max.

All of my old Tri-ang locos, both steam /diesel. I tend again to couple 2 together electrically & permanently, I.E. Jinty with a 3F, becomes a useful "loco" and no stalling on point frogs.

Most tender drive Hornby locos. (although a couple run & haul very well for some reason)

New, small Hornby steam locos (Q1 etc) - run nice but no weight, won't pull.

 

I have quite a few "in betweeners" too many to list.

 

It's all about WEIGHT - new (and some of my old) models need MORE.

 

Brit15 (Hornby Apollo, OK with 12 on !!)

Edited April 4, 2014 by APOLLO

[TheSignalEngineer]

As for the best I ever had, it would have to be my Dublo 3-rail 2-6-4T. It would take 10 Dublo SD coaches round 15" radius curves.

[ZiderHead]

Doubt if many were as bad as the Hornby Mickey Mouse 2-6-0 of about 30 years ago. Mine would manage to take about 3 coaches with pin-point bearings but steadfastly refused to budge on curves with one Hornby Dublo coach.

 

My Ivatt ran really well after it loosened up a bit, it hauled 3 coaches and all my wagons (inc ?10 opens heaped with fine sand) round my 8x4', although it required some driving to get it going and avoid it slipping. Not bad for a prototypically underpowered class II My Hymek (iirc same motor?) just pulled away with no problems.

[newbryford]

One thing often forgotten with comparing model with prototype is that we have much sharper curves and gradients which are killers when it comes to rolling resistance. Unless we have similar grades and curves then we cannot compare easily, if at all.

With regard to curves (which are the big drag IMO), anything less than about 8feet radius should have a checkrail - so that's a sharp curve!

 

My experience is limited to RTR diesel traction and most will cope with what is put behind it as long as the stock is free rolling. Exceptions are a Bachy 66 with 20 hha hoppers on a curved 1 in 60 grade that haven't had the axle bearings cleaned out.

 

Cheers,

Mick

[MJI]

One thing often forgotten with comparing model with prototype is that we have much sharper curves and gradients which are killers when it comes to rolling resistance. Unless we have similar grades and curves then we cannot compare easily, if at all.

With regard to curves (which are the big drag IMO), anything less than about 8feet radius should have a checkrail - so that's a sharp curve!

 

My experience is limited to RTR diesel traction and most will cope with what is put behind it as long as the stock is free rolling. Exceptions are a Bachy 66 with 20 hha hoppers on a curved 1 in 60 grade that haven't had the axle bearings cleaned out.

 

Cheers,

Mick

 

Do what they do in real life bank them with a 60 on its own train

[westerner]

My Hornby Castle and a friends Bachmann Compound happily took 8 coaches round our mutual friends large roundy-roundy.

 

Diesels Dapol Class 22 8 coaches

 

Heljan Western we gave up after 16+ coaches

 

The same with the Bachmann Warship

Edited April 14, 2014 by westerner

[Andy Reichert]

http://www.youtube.com/watch?v=8AWOfqW0oXk

 

I didn't know there was limited haulage capacity. I found  Bachmann Mk1's to be amazingly free running compared to most US model cars, and my quite recent Horby 2-6-4 tank just rolls 10 along on my mostly level layout, almost as though it is running light.

 

I do remember the "Triang" (?) Southern L1 4-4-0 as being very poor puller, but all the new stuff seems to be remarkable capable.

 

In case of severe problems, with say steep gradients, any one with pulling problems can just lay some thin inexpensive steel shim under their track and mount some equally inexpensive neodymium magnets to the loco chassis. Just watch for overheating.

 

Andy

Edited April 13, 2014 by Andy Reichert

[andyram]

I must admit I have been quite pleased with some of the Bachmann models I have run this evening. The Director class easily shifted a 6 coach train made up of Hornby 4 Stanier coaches and 2 of the Hatchette magazine offerings. Yes I know it was hardly an authentic mix but it was all I had with me in the stock box. The Bachmann Crab made light work of the set as well.

 

 Most impressive was the efforts of the Bachmann Midland 3F which shifted a 20 wagon mixed freight without a hint of wheel slip. Whilst the Bachmann Super D also managed the same freight there was a little wheel slip at the beginning.

[JZ]

My Bachmann 5MT's give me the most hassle. The present layout has a section of 1 in 80 and they struggle with 7. Can't say any other loco has problems with what I would expect them to handle on it. Bachmann 3F/4F will happily take 24 wagons up this and my 7F and Super D will start on the gradient with 35 on.

Edited April 19, 2014 by JZ

[andyram]

Had a very nice surprise today whilst running stock at the Mickleover club. A rake of 7 Mark 1's was formed. These were made up of 5 x Hornby and 2 x Hatchette magazine offerings. In recent weeks some of the Bachmann Jubilees have found similar size trains difficult to handle. This evening I pressed a Bachmann Hall into service. This had no problem hauling the above train and even managed to restart the set on a curve. The Bachmann Manor ran equally well. Then came the smaller locomotives. The Hornby Large Prairie and Bachmann Standard 3 showed similar prowess.

 

Surely the rake of coaches would prove too much for a Bachmann Pannier! No, not a bit of it. The little 0-6-0 was more than a match for its bigger stable mates. So not all ready to run models are poor!