Dapol Wagon Wheelset Gauge

[Olive]

I'm new to British OO gauge / scale but have a long history with other model railway scales and gauges, most noteably On30.

Its a real learning experience getting started with UK outline and so far I've purchased some Bachmann and Oxford Rail rolling stock locally as well as one of those beautiful Suttons Locomotive Workshop class 24 engines.

The bonus is that I can run the OO trains on my 16.5mm gauge On30 tracks and DCC to get up and running.

 

So, to the point of this :

I bought 6 Dapol LMS box vans this month from Rails of Sheffield and when I try to run them through my turnouts, they all derail or jump, indicating the wheelsets are out of gauge. My track is handlaid code 83 on timber ties and conforms to NMRA track standards. All my On30 equipment and SLW engine and OO rolling stock work flawlessly.

When I checked the back-to-back measurement of the Dapol wagons, every wheelset was set to about 14.3mm, whereas the NMRA standard indicates 14.55 (+0.05, -0.18)mm.

 

Search as I might, I can't find any internet references to a specific set of British OO wheel standards that might be different to NMRA practices.

Is there something different about OO standards that allows Dapol to set a narrower back-to-back? Or are the Dapol wagons known to be narrower?

 

Thanks.

 

 

[Darius43]

Hello Olive,

 

Looking at 00 gauge back-to-back gauges that are commercially available, the preferred dimension seems to be 14.5mm.

 

However, some say that 14.7mm gives better running on fine scale track such as Code 75.

 

The Double O Gauge Association website gives values for fine scale and intermediate track:-

 

Double O Gauge Association Standards

 

Irrespective of whatever the “official”  measurement is, the 14.3mm b-t-b on your wagons would appear to be too small for your track so some easing out of the wheel b-t-bs would be in order.  Whatever works for your track would be the “correct” b-t-b.

 

As for the Dapol wheels, quite often the wheels on RTR products have “incorrect” back-to-back dimensions that have to be adjusted to the “correct” values.  Not great, but there it is...

 

Cheers

 

Darius

 

Edited May 14, 2021 by Darius43

[Olive]

Thanks Darius.

That was very helpful, particularly details about the Double O Gauge standards.

It points to a back-to-back dimension of 14.4mm which is too narrow in my opinion and narrower than the NMRA standards at 14.55mm.

I'm loathe to purchase any more Dapol wagons if it means that I have to regauge every wheelset.

Would be better off sticking with those very smooth running Oxford wagons that I have.

 

Thanks again,

Rick

[Matabiau]

Am I the only one who consulted this thread after seeing the reduced title "Dapol Wagon Wheels...."? Following Rails of Sheffield's latest batch of limited editions anything is possible.

[GWR-fan]

Rick,

       if you have handlaid track then a simple re-gauging will be a doddle.  Not just Dapol,  but many "OO" manufacturers,  including both locomotives and rolling stock,  are a little lax with standards like back to back.  You will also find that Dapol metal wheelsets are considerably less expensive than say Hornby or Bachmann wheels.  I prefer to avoid Dapol wheels unless fitted to Dapol rolling stock as from my experience the axle length may be less than the standard 26.5mm used on Hornby and Bachmann rolling stock and wheels tended to drop out if Dapol wheels were fitted to other than Dapol stock.

 

If you are thinking NMRA standards then you are in the wrong arena.  Even simple things like conforming to NEM standards for couplers is very lax.  Dapol rolling stock also suffer from coupler droop,  so Dapol rolling stock does not always freely couple to other manufacturers' stock.  The pin on the coupler hook also droops so low that it hits the railhead on points (switches) and crossings.

[Darius43]

4 hours ago, Olive said:

Thanks Darius.

That was very helpful, particularly details about the Double O Gauge standards.

It points to a back-to-back dimension of 14.4mm which is too narrow in my opinion and narrower than the NMRA standards at 14.55mm.

I'm loathe to purchase any more Dapol wagons if it means that I have to regauge every wheelset.

Would be better off sticking with those very smooth running Oxford wagons that I have.

 

Thanks again,

Rick

Hi Rick,

 

You should be able to adjust the Dapol wheels rather than replace them with wheels with the correct b-t-b dimension.

 

For a few wagons that shouldn’t be too much of an imposition.

 

Cheers

 

Darius

[Olive]

GWR-fan and Darius :

 

Thanks for the input. I have re-gauged the offending wheelsets to 14.5mm and they run better now, but still nowhere as good as the Bachmann or Oxford wagons. I can live with that.

It's not that its hard to fix the problem, but that the problem exists in the first place.

 

I've got a parcel coming from the UK that includes Kadee NEM coupler replacements for the Dapol tension locks. No issues with the Bachmann or Oxford wagons in this regard but it looks like you are warning me that the Kadees might be dragging in the mud with the Dapol wagons.  More fettling, eh?

 

In my modelling world, everything complies to NMRA and so its a bit of a surprise to find that the OO standards are laxly applied by UK manufacturers. It's only been the Dapol wagons that have caused concern at my end.

Just different worlds I guess.

 

So thanks again guys ... the education process continues. It's a lot of fun.

 

[NCB]

In practice, British OO track standards should be virtually the same as NMRA HO standards, and model commercial wheel standards conform to RP25/110. It sounds as though your Dapol wheels are way out.

[Dunsignalling]

6 hours ago, NCB said:

In practice, British OO track standards should be virtually the same as NMRA HO standards, and model commercial wheel standards conform to RP25/110. It sounds as though your Dapol wheels are way out.

By no means the only ones. I use a 14.5mm BTB gauge (SMP) and have to correct almost everything.

 

I've encountered both Bachmann and Hornby OO wheelsets that are as tight as 14.2mm. 

 

If you are running on Code 100 track, it seldom causes trouble, but Code 75 or handbuilt track isn't so forgiving.

 

I also found that, even after the BTB was corrected, vehicles with Dapol wheels still derailed much more often than others. They may have altered it on newer production (though Olive's recent experience suggests not), but the wheel treads appeared to have no coning.

 

The errant wagons were set aside. When they were test fitted with Bachmann, Romford or Gibson wheels, all immediately stopped misbehaving. I therefore obtained sufficient quantities to enable me to discard the Dapol type. 

 

 John

 

 

Edited May 15, 2021 by Dunsignalling

[Dunsignalling]

Re. Kadee couplers on British outline wagons.

 

I have found the application of NEM mounts to vary considerably, between and even within makes, and I wasted far too much time correcting the alignment.

 

I'm not overly keen on the look of them anyway, so now, unless they gauge perfectly first time, I remove them and fit Kadee #146 Whisker couplers instead. 

 

John

[BR60103]

Olive: The N in NMRA is National, not International.

You may also find that the flanges are fatter than standard and the back face of the wheels is not quite where you expect it.

I started with NMRA track about 60 years ago and found that British wheels did interesting things at the frogs, like getting wedged in them or climbing over the check or wing rails. Try to match your wheels to the NMRA standards gauge.

I find that I have to fettle/fiddle with most NEM coupling mounts. Usually I put a sliver of plastic strip in with the tail of the coupling. Sometimes I have to adjust the box itself. 

I have a lovely little 14.5mm back-to-back gauge. It's a rectangular block of brass, beatufully machines with a slot for the axle and a place for the gear. I don't know who made it. I often can force the wheels over it and spread them or push them onto the axle up to it.  Also NWSL gear puller.

 

[Dunsignalling]

4 hours ago, BR60103 said:

Olive: The N in NMRA is National, not International.

You may also find that the flanges are fatter than standard and the back face of the wheels is not quite where you expect it.

I started with NMRA track about 60 years ago and found that British wheels did interesting things at the frogs, like getting wedged in them or climbing over the check or wing rails. Try to match your wheels to the NMRA standards gauge.

I find that I have to fettle/fiddle with most NEM coupling mounts. Usually I put a sliver of plastic strip in with the tail of the coupling. Sometimes I have to adjust the box itself. 

I have a lovely little 14.5mm back-to-back gauge. It's a rectangular block of brass, beatufully machines with a slot for the axle and a place for the gear. I don't know who made it. I often can force the wheels over it and spread them or push them onto the axle up to it.  Also NWSL gear puller.

 

The description of your gauge matches my SMP one to a tee.

 

John

[NCB]

I believe the NEM standard mount doesn't have the height above rail specified, hence ...

[Dunsignalling]

6 hours ago, NCB said:

I believe the NEM standard mount doesn't have the height above rail specified, hence ...

DOGA have a copy of the NEM 362 specification sheet on their website, and that quotes the correct alignment of the inner top face of the pocket as 8.5mm above rail height.

 

Symoba produce a useful and inexpensive gauge for setting up the adjustable pockets on their CCUs, which conforms. 

 

John

 

 

doga couplings.pdf

Edited May 18, 2021 by Dunsignalling
Typo

[ERIC ALLTORQUE]

This is an interesting thread,its something ive wondered about as i have been having axle sets made to replace and re engineer the Hattons 66 axlebox issue. ive set the prototype to 14.5 with the DCC concepts gauge and all seems well but looking before i started they were smaller at around 14.4 and notice all the Accurascale models are set to this at manufacture.I first was going to set them at 14.75 and theres a 14.85 gauge for Ho/OO available also,all a bit confusing it seems,if the wider track is best why are they setting them at 14.4............

[Dunsignalling]

17 minutes ago, ERIC ALLTORQUE said:

This is an interesting thread,its something ive wondered about as i have been having axle sets made to replace and re engineer the Hattons 66 axlebox issue. ive set the prototype to 14.5 with the DCC concepts gauge and all seems well but looking before i started they were smaller at around 14.4 and notice all the Accurascale models are set to this at manufacture.I first was going to set them at 14.75 and theres a 14.85 gauge for Ho/OO available also,all a bit confusing it seems,if the wider track is best why are they setting them at 14.4............

Basically, the r-t-r standard has historically been14.4mm to go through the points that come in sectional track systems.

 

Setting them wider helps reduce the tendency for them to jump or drop when negotiating finer points.

 

Usual b-t-b for "OO fine" is 14.7mm, which I worked to on a group layout that I was formerly involved with (SMP track with hand-built points). That said, I have a Lima GW railcar with Ultrascale wheels that I just assembled so the axle ends were flush. It ran perfectly everywhere but when it got measured to be approved for an exhibition outing, the b-t-b turned out to be 15.1mm. It runs OK through Streamline points apart from the shortest ones too!

 

John

[BR60103]

Back around 1960, I was starting American HO and my friend was into Triang OO. We found that my NMRA standard wheels would go down the far side of the frog on his Triang points.

I didn't have any problems with Dublo 2-rail points. Triang really didn't like NMRA points.

 

[Dungrange]

21 hours ago, ERIC ALLTORQUE said:

This is an interesting thread, its something I've wondered about as I have been having axle sets made to replace and re engineer the Hattons 66 axlebox issue. I've set the prototype to 14.5 with the DCC concepts gauge and all seems well but looking before I started they were smaller at around 14.4 and notice all the Accurascale models are set to this at manufacture. I first was going to set them at 14.75 and there's a 14.85 gauge for Ho/OO available also, all a bit confusing it seems, if the wider track is best why are they setting them at 14.4............

 

The desired back to back setting is a function of the both the wheel flange thickness and the checkrail gap in the point work used on a layout.  The flange thickness is important, because it's not the back to back dimension that is critical, but the back to front dimension.  That is, it's the back to back dimension plus the flange thickness that should be constant.  Therefore, if using wheels with a thicker flange, then the back to back dimension should be less.  Similarly, if using closer to scale flanges, then the back to back dimension should be increased. 

 

The back-to-back figure of 14.4 mm is correct for a combination of 'intermediate' standard wheels running on 'intermediate' standard track.  The DOGA intermediate wheel standard is close to the NMRA RP25/110 wheel profile and the intermediate track standard is close to the ready to run track that many people use in the UK, such as the Peco streamline range, which isn't dissimilar to the NMRA track standards, although the tolerances are specified differently.

 

However, many individuals and some manufacturers use wheels that conform to other 'standards'.  Wheels such as those produced by Alan Gibson, etc, tend to be slightly closer to scale than RP25/110 (or DOGA intermediate) and are closer to the RP25/88 standard, so for such wheels, a back to back dimension of 14.5 mm has traditionally been used.

 

The minimum back-to-back figure of 14.8 mm is correct for a combination of 'finescale' wheels running on 'finescale' track.  In this context, finescale track is track built with EM standard flangeway gaps (1 mm), so this DOGA standard is only relevant to those who build their own track. As far as I am aware, there is no commercially produced track that meets the DOGA finescale standards.  Finescale wheels are those that are effectively to EM standards, but with the position of the wheel on the axle adjusted to the narrower track gauge of 00.

 

Wheelsets with a wider back to back may work okay on commercial track, but it means that the checkrails in point work won't be performing the job that they are there for, which is to stop the wheel flange hitting the crossing vee.  If stock derails because the wheel flange hits the crossing vee, then its probably because the back to back is too wide (or the checkrail gap is too wide).

 

Unfortunately, the DOGA standards don't carry the same weight as the NMRA, so whilst in the States, manufacturers tend to want to claim that their products conform with the NMRA standards, UK manufacturers never highlight that they comply with the DOGA intermediate standards and seem to think that they can adopt their own.  Accurascale specifying that they are using the 14.4 mm recommendation set out in the DOGA Intermediate standard is positive, in my opinion.  We just need to hope that one day, all manufacturers will agree to use one consistent standard for UK models, but I won't hold my breath.

[Dungrange]

On 17/05/2021 at 23:55, NCB said:

I believe the NEM standard mount doesn't have the height above rail specified, hence ...

 

No the NEM standards for coupling mounts do state the dimensions of the coupler pocket, its height above the rail head and how far back the coupling pocket should be placed relative to the buffers.  Kadee have therefore designed their NEM couplers to work with all models that fully comply with the NEM-362 standard.   

 

The problem is that the NEM standards are produced by MOROP, which is effectively the European equivalent of the NMRA.  They produce a whole range of standards which are translated into French, German and English.  You can see the list of standards translated into English at https://www.morop.org/index.php/en/nem-the-norms.html

 

I can't find a link to the NEM-362 standard in English, but you can see it in French at https://www.morop.org/downloads/nem/fr/nem362_f.pdf.  This was adopted by the Double O Gauge Association (DOGA) as the recommendation for UK outline models back in 2007.

 

However, as the NEM-362 standard relates to the fitment of pockets to H0 models (which is obviously the norm across Europe) and doesn't specifically mention 00, many UK manufacturers initially chose to adopt the pocket dimensions, but ignore the rest of the standard on the basis that their models are 00, so therefore they can place the pocket wherever they like and still call it a NEM pocket.  Thankfully manufacturers are now understanding that they need to fully comply with the NEM standards, not just the bits that they want to, if we are to actually have the ability to interchange couplings.

 

The NEM-362 standard has the same mounting height for both H0 and S, so since 00 fits between these two scales, why did UK manufacturers choose to ignore the recommended mounting height and adopt their own model specific values?  It seems very much like the typical British attitude that we don't like following what we perceive to be other people's standards.

[Dunsignalling]

There is an English version of the NEM 362 standard on the DOGA website, pdf attached to my post of Tuesday.

 

Unfortunately, the customary Bachmann/Dapol non compliance seems to have spread.

 

I've just spent about an hour fitting a Kadee coupler (#141 in a #262 draft box) to the tender of my new Hornby MN, the pocket was so far back under it that even the longest NEM Kadee wouldn't reach..... 

 

John

Edited May 22, 2021 by Dunsignalling

[The Johnster]

I have a pretty low opinion of Dapol wagons' running and coupling, having had nothing but trouble with them in in the past.  I now avoid their products and have none on my layout.  You can 'rescue' them to some extent with Hornby or Bachmann wheels, which have a better tyre profile, and since they will run through code 75 turnouts should be fine on your code 83 spiked track.  The NEM coupling mounts screw to the wagon floor, and can be easily removed and replaced with Parkside PA34 mounts glued in the correct position to the floor. 

 

Coupling bar height with 00 NEM couplings should be a standard above the rail head, but it isn't in practice; Dapol's droopy couplings are the worst but they are by no means the only offenders.  I've had Bachmann loco with different coupling bar heights above the rail on each end of the loco.  I use tension locks, but Kadees need a standard height above the rail to operate reliably as well.  At least with Kadees you get a standard profile!  To some extent it doesn't matter what this standard height above the rail is, so long as it is standard across your layout. 

 

British (and European) outline rolling stock presents a problem in that a variety of coupling mounting situations are encountered, rigid wheelbase wagons and loco tenders, bogies, and steam loco mounting on chassis, bogies, or trailing axles that may be pivoted, radially mounted, or 'floating'.  For wagons and tenders, the PA34 mounts can be packed or trimmed so as to be set at a height above the upturned wagon floor (or is that a depth, with the wagon the right way up?) that will provide a standard height above the rail for your couplings.  They and not expensive, enough for 5 vehicles for less than ten beer vouchers Sterling, but of course you will have the postage to Oz unless you can find a dealer down there somewhere.  Parkside are a Peco subsidiary so a Peco dealer should be able to order them for you.

 

My recommendation for your Dapol LMS vans is to save the bodies, which are not at all bad (better than Bachmanns' short fat representations) and ditch the chassis, especially if they are the older type with moulded handbrake levers.  Parkside will be your saviour again, as they do a range of kit chassis which are easy to assemble and run very well with Gibson (IIRC) wheels in brass bearings if you take care to assemble them flat and square.  I use Lego bricks to assist in this!

[BR60103]

13 hours ago, Dunsignalling said:

I've just spent about an hour fitting a Kadee coupler (#141 in a #262 draft box) to the tender of my new Hornby MN, the pocket was so far back under it that even the longest NEM Kadee wouldn't reach..... 

 

I put a #20 on the front of Duke of Gloucester.  The coupler is just barely in front of the buffer beam and the knuckle well behind the buffers.

I never tried the Triang coupler on it.

 

[Dunsignalling]

15 hours ago, The Johnster said:

I have a pretty low opinion of Dapol wagons' running and coupling, having had nothing but trouble with them in in the past.  I now avoid their products and have none on my layout.  You can 'rescue' them to some extent with Hornby or Bachmann wheels, which have a better tyre profile, and since they will run through code 75 turnouts should be fine on your code 83 spiked track.  The NEM coupling mounts screw to the wagon floor, and can be easily removed and replaced with Parkside PA34 mounts glued in the correct position to the floor. 

 

Coupling bar height with 00 NEM couplings should be a standard above the rail head, but it isn't in practice; Dapol's droopy couplings are the worst but they are by no means the only offenders.  I've had Bachmann loco with different coupling bar heights above the rail on each end of the loco.  I use tension locks, but Kadees need a standard height above the rail to operate reliably as well.  At least with Kadees you get a standard profile!  To some extent it doesn't matter what this standard height above the rail is, so long as it is standard across your layout. 

 

British (and European) outline rolling stock presents a problem in that a variety of coupling mounting situations are encountered, rigid wheelbase wagons and loco tenders, bogies, and steam loco mounting on chassis, bogies, or trailing axles that may be pivoted, radially mounted, or 'floating'.  For wagons and tenders, the PA34 mounts can be packed or trimmed so as to be set at a height above the upturned wagon floor (or is that a depth, with the wagon the right way up?) that will provide a standard height above the rail for your couplings.  They and not expensive, enough for 5 vehicles for less than ten beer vouchers Sterling, but of course you will have the postage to Oz unless you can find a dealer down there somewhere.  Parkside are a Peco subsidiary so a Peco dealer should be able to order them for you.

 

My recommendation for your Dapol LMS vans is to save the bodies, which are not at all bad (better than Bachmanns' short fat representations) and ditch the chassis, especially if they are the older type with moulded handbrake levers.  Parkside will be your saviour again, as they do a range of kit chassis which are easy to assemble and run very well with Gibson (IIRC) wheels in brass bearings if you take care to assemble them flat and square.  I use Lego bricks to assist in this!

Just a few points:

 

1. All the Dapol LMS vans I've seen came with their standard 10' wb underframe. I think the brown plastic attempt at the clasp brake sort probably died with Airfix/GMR. If Dapol ever did use it, it must have been very early on.

 

2. If using Kadee couplers, having removed the original NEM mount, why on earth would anyone replace it with another when they could fit "proper" Kedees (#146 for UK wagons) for no extra effort. 

 

3. You are a bit out-of-date on the prices of Parkside underframe kits (you definitely wouldn't get five for a tenner now*) and they don't (and never have) come with wheels or bearings. Only the complete wagon kits include those.

 

John

 

* Current price on H&A Models website is £3.75 or £4.75 each, according to type. 

Edited May 23, 2021 by Dunsignalling

[Olive]

On 15/05/2021 at 11:32, Dunsignalling said:

Re. Kadee couplers on British outline wagons.

 

I have found the application of NEM mounts to vary considerably, between and even within makes, and I wasted far too much time correcting the alignment.

 

I'm not overly keen on the look of them anyway, so now, unless they gauge perfectly first time, I remove them and fit Kadee #146 Whisker couplers instead. 

 

John

 

I've replaced all the tension lock couplings on my 6 Dapol vans with Kadee NEM #18 medium couplers mounted into the Dapol pockets. Photo #2 below shows one of the vans so fitted.

 

Following on from your post I purchased new Kadee #146 whisker couplers to try them out.

Photo #1 below shows the result and, together with a photo of the same 12T Dapol van with Kadee NEM #18 for comparison, show the difference between keeping with the Dapol NEM system and replacing all of that with a Kadee #146 metal whisker coupler in its own gear box.

 

The conversion from the NEMs to the Kadee #146 involved removing the Dapol coupler fittings, cutting off the leftover van's protruding coupler mouldings and fitting the Kadee gearbox flush to the underfloor of the van with a drilled and tapped hole for a #2-56 screw. Easy.

 

The #146s are at exactly the correct height when tested against a Kadee #205 height gauge and they are hanging straight compared to the Dapol NEM pocket-mounted couplers. PHOTO #3 shows the difference by comparison.

 

My only concern now is the length of protrusion of the Kadee #146 coupler head past the buffers. They look to be too far out for my liking, so I have ordered some Kadee #148 metal whisker couplers which are shorter than the #146s by 2.8mm. I think that the #148s will closer resemble the NEM #18s and the #146s will be similar to the NEM #19.

 

We'll see.  Lots of fun.

Thanks again John for the idea of using the Kadee #146s.

 

Rick

Edited June 18, 2021 by Olive
clarify photos by number

[Dunsignalling]

Hi Rick,

 

Neater job than the NEM set-up, isn't it, and keeps things under more control.

 

I overcome the protrusion by removing the top lip from the draft box so I can fit it further under the wagon. That way I can set the couplings up to exactly the length I want, and the box "vanishes" even better.

 

Using the #148 usually means having the box sticking out more, except on wagons with extremely short buffers. The Dapol tar tank is the example that springs most readily to mind. 

 

Attached photos show what I mean. The van pic shows how little of the box can be seen, though the angle isn't quite low enough to see the position fully. The one of the Bachmann mineral chassis shows it better, and illustrates how I file out the back of the box to retain the original body fixing screws. When using whisker couplers, that area is unoccupied so there's no danger of anything fouling.

 

Regards

 

John

 

 

Edited June 18, 2021 by Dunsignalling