Bachmann announce Class 90 (OO)

[Gordon H]

And furthermore, there's only one contact point for the current to flow! I wonder how long the enjoyment of working catenary would last once the wire gets dirty and needs cleaning...somehow...

 

I am guessing you have no practical experience of this aspect of operation, as a properly pivoted pan head has at least two points of contact.

As Andi has said, if anything the wiping action of the head on the wire tends to keep the wire clean anyway - far better than a rolling wheel which simply accumulates dirt.

[Gordon H]

Prices are getting steep enough without additional costs for things that cant be seen or have limited use

 

It shouldn't cost any more to have a working pan than non-working.

If anything, the pantograph is the most obvious feature of any OH electric, so certainly will be seen, and if it's there why not use it?

Not much point modelling electric outline if you don't do it properly.

[PaulRhB]

I am guessing you have no practical experience of this aspect of operation, as a properly pivoted pan head has at least two points of contact.

As Andi has said, if anything the wiping action of the head on the wire tends to keep the wire clean anyway - far better than a rolling wheel which simply accumulates dirt.

Worth noting that to add to what Andi and Gordon have said the wire zig zags deliberately on straights and as a result of tracks curving under a straight wire. This evens out the wear on the head and keeps it from building up deposits. Dcc supply through the overhead is a bit more tricky if you want to go scale as it can burn the wire through if you get a short as it's the smallest wire in the circuit, most manufacturers still recommend track power for dcc as a result even in G scale.

[PaulRhB]

I struggle to understand the benefit of working pantographs, if it looks right then I couldn't care less whether the power comes from rails or the overhead.

 

I'm sure it was mentioned in one of the magazine features recently where a club had found that when working with DCC and their electrics used overhead for power and commands that it was causing problems where the locos were presumably also getting the DCC commands through the rails and they ended up disabling the overhead because of it.

The DCC signal is more easily disrupted by an intermittent contact. I suspect they weren't using tensioned catenary so the contact was a bit soft resulting in it bouncing and causing interference. Decent contact can be made if the catenary is properly tensioned and pantographs are well sprung but that's difficult in portable layouts especially. Note this only really affects dcc as DC just reduces the supply to the motor for a moment and the flywheels and drive cover that up.

On my RhB layout I used track power because I had to have removable sections so couldn't rely on consistent tension or possible damage when in transport from only one end being pulled.

Edited March 5, 2016 by PaulRhB

[ClikC]

Not this debate again.

 

My stance is thus, working OLE would be lovely, but the implications of producing this to scale, make it impractical at best. If people want to do it off of their own back, excellent, we may all learn something from it. However, to dismiss someone’s 'layout' or 'modelling' because their OLE doesn't work, just smacks of (probably unfounded) elitism.

 

It shouldn't cost any more to have a working pan than non-working.

If anything, the pantograph is the most obvious feature of any OH electric, so certainly will be seen, and if it's there why not use it?

Not much point modelling electric outline if you don't do it properly.

 

I've highlighted my main issue here. Model trains, are an engineered product. By that I mean, the product (the model) will be developed using an Engineering Design Process (there are many types of design process, I do not know what model Bachmann employs). But, EVERY aspect of the product will have been evaluated, and tailored to meet the Product Design Specification (PDS). Certain solutions to various aspects of the PDS may be selected from a catalogue of existing designs, wheels, motors, aspects of the electrical system etc. Any individual aspect of the parts and assemblies that make up the model, which cannot be satisfied from an existing catalogue, will require its own PDS, and its own Engineering Design Process carried out, in the development of the part and/or assemblies. This is also true for changes, to any existing part or assembly, such as a pantograph.

 

Bachmann has a design for the Brecknell Willis high speed pantograph. But I would be very surprised if any aspect of its design were considered as an electrical circuit. Almost (if not) all of Bachmann’s current range of model are designed to be, DCC compatible, if not DCC ready. So it would be a fairly safe bet to assume that any new product, would need to meet this requirements. So firstly, DCC utilises a bipolar form of DC, where in the current is alternated between positive and negative values as a type of square waveform, which is Pulse Width Modulated (PWM), (fundamentally producing pseudo Alternating Current) to encode digital information transmitted to model locomotives and static decoders. As any Electrical Engineer can tell you, components in AC circuit exhibit Impedance, be that Resistive ®, Inductive (L) or Capacitive ©, Combinations of these different types of component, their respective values of RLC and how they form the circuit can affect the overall or fundamental impedance of the circuit. At certain frequencies and in certain combination, the impedance can be so high as to completely block any voltage from passing, or even attenuate or amplify the power of the electrical signal.

 

Every aspect of the Bachmann's Brecknell Willis high speed pantograph would need to be explored, as part of the overall electrical circuit for the model. I don't have a pan or a Multimeter to hand right now, but I think it would be a safe bet to say it at least exhibits resistance, and that resistance due to the materials it is constructed from, and that resistance may change as the pan moves and metal components rub together, or the surface area of metal of metal contact changes, I'd also bet that each pan Bachmann produces has a slightly different level of resistance. That resistance would change the impedance of the models electrical circuit, which may cause the electrical circuit to deviate from the required electrical tolerances. In order to overcome this, Bachmann would need to measure a quite large sample size in order to work out the mean resistance, and then employ production and testing methods to ensure Pantographs were produced within acceptable limits of resistance. The increased impedance by use of the Pantograph may necessitate changing the protecting resistors on the main circuit board for ones of lower value. Worst case being, additional resistors of lower value may need to be changed out for ones of existing value, by means of a selector switch swapping between 'pan' and 'rails' pickup, in order to ensure the model can run correctly for both standard two rail, and overhead current collection. To be fair, electrical tolerances for model locomotives are quite broad (especially for DC only operation), so that case would be unlikely. BUT, my point here, is that is just one series of aspects which Bachmann would have to consider and explore, before producing a locomotive with a working electrical pantograph. The opinion that it "shouldn't" cost anymore, is utterly and demonstrably incorrect.

 

Worth noting that to add to what Andi and Gordon have said the wire zig zags deliberately on straights and as a result of tracks curving under a straight wire. This evens out the wear on the head and keeps it from building up deposits. Dcc supply through the overhead is a bit more tricky if you want to go scale as it can burn the wire through if you get a short as it's the smallest wire in the circuit, most manufacturers still recommend track power for dcc as a result even in G scale.

 

In addition to this. The prototype utilises high grade copper for the contact wire, and the pantographs have replaceable carbon strips which pick up the current from the OLE. The design exhibits low electrical resistance, and thanks to the carbon, low wear rates on the contact wire. In model form, replicating the carbon on copper will be highly impractical. Depending on what materials are selected for the model pan and OLE, some combinations may exhibit galvanic corrosion due to electrolysis, which despite the sliding motion of the pantograph, may cause poor electrical contact in model form.

 

These are just some of the issues which stand in the way of RTR OLE and model electric locomotives. But, they are pretty big factors. Which is why, working catenary layouts are very rare, even in rest of Europe, where electrical railway modelling has very much been in vogue, in comparison to here in the UK.

 

Regards

 

ClikC

Edited April 4, 2016 by ClikC

[Nile_Griffith]

Have to say that if somebody is going to run a flag up a pole and proudly declare that there is no point in modelling an OHLE layout unless you are going to power the models prototypically. Had better come up with a really good methodology for modelling an "N" gauge steam layout!!!!!!!! 

[Gordon H]

Not this debate again.

 

My stance is thus, working OLE would be lovely, but the implications of producing this to scale, make it impractical at best. If people want to do it off of their own back, excellent, we may all learn something from it. However, to dismiss someone’s 'layout' or 'modelling' because their OLE doesn't work, just smacks of (probably unfounded) elitism.

 

 

I've highlighted my main issue here. Model trains, are an engineered product. By that I mean, the product (the model) will be developed using an Engineering Design Process (there are many types of design process, I do not know what model Bachmann employs). But, EVERY aspect of the product will have been evaluated, and tailored to meet the Product Design Specification (PDS). Certain solutions to various aspects of the PDS may be selected from a catalogue of existing designs, wheels, motors, aspects of the electrical system etc. Any individual aspect of the parts and assemblies that make up the model, which cannot be satisfied from an existing catalogue, will require its own PDS, and its own Engineering Design Process carried out, in the development of the part and/or assemblies. This is also true for changes, to any existing part or assembly, such as a pantograph.

 

Bachmann has a design for the Brecknell Willis high speed pantograph. But I would be very surprised if any aspect of its design were considered as an electrical circuit. Almost (if not) all of Bachmann’s current range of model are designed to be, DCC compatible, if not DCC ready. So it would be a fairly safe bet to assume that any new product, would need to meet this requirements. So firstly, DCC utilises a bipolar form of DC, where in the current is alternated between positive and negative values as a type of square waveform, which is Pulse Width Modulated (PWM), (fundamentally producing pseudo Alternating Current) to encode digital information transmitted to model locomotives and static decoders. As any Electrical Engineer can tell you, components in AC circuit exhibit Impedance, be that Resistive ®, Inductive (L) or Capacitive ©, Combinations of these different types of component, their respective values of RLC and how they form the circuit can affect the overall or fundamental impedance of the circuit. At certain frequencies and in certain combination, the impedance can be so high as to completely block any voltage from passing, or even attenuate or amplify the power of the electrical signal.

 

Every aspect of the Bachmann's Brecknell Willis high speed pantograph would need to be explored, as part of the overall electrical circuit for the model. I don't have a pan or a Multimeter to hand right now, but I think it would be a safe bet to say it at least exhibits resistance, and that resistance due to the materials it is constructed from, and that resistance may change as the pan moves and metal components rub together, or the surface area of metal of metal contact changes, I'd also bet that each pan Bachmann produces has a slightly different level of resistance. That resistance would change the impedance of the models electrical circuit, which may cause the electrical circuit to deviate from the required electrical tolerances. In order to overcome this, Bachmann would need to measure a quite large sample size in order to work out the mean resistance, and then employ production and testing methods to ensure Pantographs were produced within acceptable limits of resistance. The increased impedance by use of the Pantograph may necessitate changing the protecting resistors on the main circuit board for ones of lower value. Worst case being, additional resistors of lower value may need to be changed out for ones of existing value, by means of a selector switch swapping between 'pan' and 'rails' pickup, in order to ensure the model can run correctly for both standard two rail, and overhead current collection. To be fair, electrical tolerances for model locomotives are quite broad (especially for DC only operation), so that case would be unlikely. BUT, my point here, is that is just one series of aspects which Bachmann would have to consider and explore, before producing a locomotive with a working electrical pantograph. The opinion that it "shouldn't" cost anymore, is utterly and demonstrably incorrect.

 

 

In addition to this. The prototype utilises high grade copper for the contact wire, and the pantographs have replaceable carbon strips which pick up the current from the OLE. The design exhibits low electrical resistance, and thanks to the carbon, low wear rates on the contact wire. In model form, replicating the carbon on copper will be highly impractical. Depending on what materials are selected for the model pan and OLE, some combinations may exhibit galvanic corrosion due to electrolysis, which despite the sliding motion of the pantograph, may cause poor electrical contact in model form.

 

These are just some of the issues which stand in the way of RTR OLE and model electric locomotives. But, they are pretty big factors. Which is why, working catenary layouts are very rare, even in rest of Europe, where electrical railway modelling has very much been in vogue, in comparison to here in the UK.

 

 

Difficult to know where to start with this lot.

I did 'learn something from it' as you put it when our group decided to give it a go back in the early 80's. It can be done, and made to work, and shown extensively at exhibitions - and has even appeared on TV.

A bit much going to the lengths of describing what electrical engineers need to consider in such a design, then following it with a reference going to 'protecting resistors on the main circuit board'. If that is what you think they are, we need go no further.

If you had any practical experience of using model pantographs for real, you would know that a full metal design works best. My very first scratchbuilt cross-arm pantograph head was made using a carbon strip from a propelling pencil. Although it worked, it clearly suffered from the effects of self heating, so that experiment was abandoned. Thereafter all metal designs have been used. Thus, the impedance of that particular component has never been in question, and with the low forces involved, wear has never been an issue either. Rolling wheels, on the other hand, to this day cause all sorts of problems with intermittent and variable contact. That said, I do wonder how much effort manufacturers put into the testing of their pick-up systems generally, because it still seems to be a major issue on many loco designs. Whether the signal is DCC or not makes no difference either, other than the issues already identified.

The intention is not elitism - but trying to get across to people the kind of things that can be done if sufficient effort is made to include certain design features in the first place. Over 50 years ago the Triang 81 and EM2 had pantographs that could (just about) be used, so if anything, things have gone backwards since then.

As mentioned, European and Japanese manufacturers have been producing locos with (potentially) working metal pantographs for years, it just seems a shame that it doesn't happen here too. If you can buy a working cross-arm pantograph for an N Gauge Japanese loco (even as a spare part!) surely the manufacturing tolerances can't be the limiting factor.

 

 

Have to say that if somebody is going to run a flag up a pole and proudly declare that there is no point in modelling an OHLE layout unless you are going to power the models prototypically. Had better come up with a really good methodology for modelling an "N" gauge steam layout!!!!!!!! 

 

<controversial mode> All the more reason not to try... </controversial mode> :-)

[jjb1970]

I think it is more a cost - value issue than a technical one. I have no doubt that a realistic, fine scale working pantograph could be made for the Class 90, the question isn't so much whether it can be done but whether the number of people who want to run the model from an overhead power supply would justify the added costs when many buyers will not even have an overhead system and the majority of those who do have overhead lines will not use it for powering models. If most customers do not need a working pantograph then it is probably more sensible to offer the model as standard with a dummy sprung pantograph.

[Gordon H]

I think it is more a cost - value issue than a technical one. I have no doubt that a realistic, fine scale working pantograph could be made for the Class 90, the question isn't so much whether it can be done but whether the number of people who want to run the model from an overhead power supply would justify the added costs when many buyers will not even have an overhead system and the majority of those who do have overhead lines will not use it for powering models. If most customers do not need a working pantograph then it is probably more sensible to offer the model as standard with a dummy sprung pantograph.

 

If it is a cost issue, why does it not have the same effect on equivalent European and Japanese outline models? Are the expectations of modellers in those fields different?

Sommerfeldt and Veissmann, to name but two European manufacturers, have complete ranges of catenary and pantographs which can be used conductively.

Ironically, whilst looking around for other manufacturers, I now find that Bachmann themselves have produced DCC fitted models with working pans - and a switch to select the option:

http://www.spookshow.net/loco/bachmanhhp8.html

The case rests...

[YesTor]

If it is a cost issue, why does it not have the same effect on equivalent European and Japanese outline models? Are the expectations of modellers in those fields different?

 

Ironically, whilst looking around for other manufacturers, I now find that Bachmann themselves have produced DCC fitted models with working pans - and a switch to select the option:

http://www.spookshow.net/loco/bachmanhhp8.html

The case rests...

 

Maybe the overseas models that you highlight have a comparatively higher price tag than equivalent UK models?  Or perhaps there are compromises made elsewhere, such as less detailing components?  Just a possibility.

 

Either way, there is undoubtedly going to be an additional cost involved in incorporating any additional feature; and I would have thought it unlikely in the current climate that any manufacturer would remotely consider introducing yet another addition to any model that will impact price in the upward direction, in what is clearly an already highly price-conscious UK market?  With the retail price for the Class 90 yet to be announced, the only electric locomotive in the current Bachmann range to draw an example from is the Class 85, which is currently listed at £134.95.  What will the equivalent retail price be in 3 or 4 years time when the 90 hits the stores?  So factor in any inflationary increase, plus an additional £20, at a guess (or more?) for working pantograph, and I can hear the cries of woe already as the final price maybe hits closer to the £200 mark?

Edited April 5, 2016 by darkjunglemung

[ruggedpeak]

Obviously the Hornby 90 for all its faults has had the option of running via OHL for some time, with a chunky switch on the roof.

[Gordon H]

Either way, there is undoubtedly going to be an additional cost involved in incorporating any additional feature; and I would have thought it unlikely in the current climate that any manufacturer would remotely consider introducing yet another addition to any model that will impact price in the upward direction, in what is clearly an already highly price-conscious UK market?  With the retail price for the Class 90 yet to be announced, the only electric locomotive in the current Bachmann range to draw an example from is the Class 85, which is currently listed at £134.95.  What will the equivalent retail price be in 3 or 4 years time when the 90 hits the stores?  So factor in any inflationary increase, plus an additional £20, at a guess (or more?) for working pantograph, and I can hear the cries of woe already as the final price maybe hits closer to the £200 mark?

 

Given that the manufacturer will be obliged to fit something to the roof, it can hardly be considered an additional feature. The only cost consideration should only be the incremental difference between fitting one that can never work and one that could. For their 85, Bachmann clearly went to some effort getting the dimensions of the Faiveley pantograph right, but then spoilt what could have become a useful item, even as spare parts for other applications, by moulding most of it in plastic.

[Pandora]

The  class 90 and the 86, does anyone have the diagrams and headcodes for their runs over the North London line through Canonbury etc?  I'd like to look them up on Real time Trains and pay a few visits to see them pass through the station

[Pandora]

Working electrically conductive pantographs on the Triang overhead locos  permitted the independent control and  runniing of  two 12V DC trains on the same track,  one drawing power running entirely from the running rails and the other the overhead plus the negative return on a single running rail.

 

Surely such a technique is obsolete due to modern  DCC controllers and decoders.

[45568]

Working electrically conductive pantographs on the Triang overhead locos  permitted the independent control and  runniing of  two 12V DC trains on the same track,  one drawing power running entirely from the running rails and the other the overhead plus the negative return on a single running rail.

 

Surely such a technique is obsolete due to modern  DCC controllers and decoders.

And my dad and I had such a lot of fun with it! The 'steeple cab' loco. (never got 'Electra'), really added another dimension to the train set.

 Ah well. it's all so much more serious now isn't it?!

Cheers from Oz,

Peter C.

[Legend]

Maybe the overseas models that you highlight have a comparatively higher price tag than equivalent UK models?  Or perhaps there are compromises made elsewhere, such as less detailing components?  Just a possibility.

 

Either way, there is undoubtedly going to be an additional cost involved in incorporating any additional feature; and I would have thought it unlikely in the current climate that any manufacturer would remotely consider introducing yet another addition to any model that will impact price in the upward direction, in what is clearly an already highly price-conscious UK market?  With the retail price for the Class 90 yet to be announced, the only electric locomotive in the current Bachmann range to draw an example from is the Class 85, which is currently listed at £134.95.  What will the equivalent retail price be in 3 or 4 years time when the 90 hits the stores?  So factor in any inflationary increase, plus an additional £20, at a guess (or more?) for working pantograph, and I can hear the cries of woe already as the final price maybe hits closer to the £200 mark?

Probably quite close to the mark , depending on when models finally appear of course.

 

As to manufacturers remotely considering introducing an addition to the model impacting the price of the model upwards, this is the company that's adding passengers to coaching stock for £10 -£12 more, increasing the cost of a coach by around 25%. Assuming original price in the £40 region, which is already steep. Also the company bringing you a DBSO DCC fitted , no price announced yet, but if an Autocoach is £70 and this coach has working lights etc it's going to be well North of that.

 

It is interesting that Bachmanns analysis of the market is clearly that people will pay more , although they may sell less of the models. Oxford (generally cheaper, maybe as they introduce themselves into market) and Hornby (I'm thinking of the introduction of TTS as people weren't spending nearly £200 on full fat sound) clearly think there is a limit. It just might be that Bachmann are aiming top end market where a small number of people have large amounts of disposable income, in which case you just might get that operating panto.

[ruggedpeak]

I don't think a working panto will make any great difference to the cost of the model, especially when set against the initial costs of design and tooling. If designed in from the outset it will be negligible.

 

Hornby has a working panto in a model at sub £70 so it does not have to expensive. Also bear in mind it was Bachmann who made clear they wouldn't offer double packs of locos with one as a non-motored dummy as the difference in cost between motor and non was not enough to make it worthwhile.

 

A robust metal panto, wire, small switch is all that may be required, with possibly a replacement high detail non-functioning panto in the box.

 

Whether Bachmann deliver a working panto remains to be seen.

[Gordon H]

Working electrically conductive pantographs on the Triang overhead locos  permitted the independent control and  runniing of  two 12V DC trains on the same track,  one drawing power running entirely from the running rails and the other the overhead plus the negative return on a single running rail.

 

Surely such a technique is obsolete due to modern  DCC controllers and decoders.

 

Yes, it permitted that method of working with two independent controllers, but it was by no means compulsory to use it that way. You could just use the wire supply and rail return if you wanted to.

It isn't just a matter of wanting to allow more trains to run simultaneously.

[No Decorum]

It is interesting that Bachmanns analysis of the market is clearly that people will pay more , although they may sell less of the models.

Bachmann is probably reluctant to reduce quality, having seen the mess Hornby got into by doing just that. A few compromises are creeping in, such as unsprung buffers, no etched nameplates and no driver or second man figures in the cab. Irritating to have to sort these out when prices have risen anyway, not to mention the bother sourcing and paying postage for the stuff.

[Removed a/c]

I don't think a working panto will make any great difference to the cost of the model, especially when set against the initial costs of design and tooling. If designed in from the outset it will be negligible. Hornby has a working panto in a model at sub £70 so it does not have to expensive. Also bear in mind it was Bachmann who made clear they wouldn't offer double packs of locos with one as a non-motored dummy as the difference in cost between motor and non was not enough to make it worthwhile. A robust metal panto, wire, small switch is all that may be required, with possibly a replacement high detail non-functioning panto in the box. Whether Bachmann deliver a working panto remains to be seen.

I think that only works on DC so for a DCC user it still isn't any good. 

[Pandora]

If it is a cost issue, why does it not have the same effect on equivalent European and Japanese outline models? Are the expectations of modellers in those fields different?

Sommerfeldt and Veissmann, to name but two European manufacturers, have complete ranges of catenary and pantographs which can be used conductively.

Ironically, whilst looking around for other manufacturers, I now find that Bachmann themselves have produced DCC fitted models with working pans - and a switch to select the option:

http://www.spookshow.net/loco/bachmanhhp8.html

The case rests...

i think the continental modeller does have greater expectations than we Brits, look back at the high quality products of Fleischmann  the DB V200 Warship etc, they were simply unaffordable to us in the late 1960s/1970.

Today look into the camera locos from Roco,  a small digital camera mounted up front and relaying an image to the operators screen for a drivers view of the layout.  We have a long way to go to catch up!

[jjb1970]

If the pantograph can be made as a working model without adding to the cost and with no compromise in appearance then nobody will object to the model having a working pantograph. If a working pantograph will add to the cost or result in a less realistic pantograph then it is for Bachmann to make the decision whether the majority of customers will be willing to pay more for the working functionality or whether most customers would rather pay less and accept a dummy pantograph. I think that is a decision for Bachmann to make.

[MGR Hooper!]

If the pantograph can be made as a working model without adding to the cost and with no compromise in appearance then nobody will object to the model having a working pantograph. If a working pantograph will add to the cost or result in a less realistic pantograph then it is for Bachmann to make the decision whether the majority of customers will be willing to pay more for the working functionality or whether most customers would rather pay less and accept a dummy pantograph. I think that is a decision for Bachmann to make.

Hornby's forthcoming Class 71 has a working pantograph (working = power collection). And I don't think it has added much to the cost because the Class 71 is still cheaper than other locos

[ruggedpeak]

I think that only works on DC so for a DCC user it still isn't any good. 

Any reason why it wouldn't work?

 

http://www.trolleyville.com/tv/school/lesson5_3/index.htm

[Removed a/c]

Any reason why it wouldn't work?

 

http://www.trolleyville.com/tv/school/lesson5_3/index.htm

Sorry I meant out of the box. I am sure there is a way to anything if you know how. Making it work is beyond me and frankly not something I have an interest in doing.