N Gauge Forum

General Category => N Gauge Discussion => Topic started by: Ontrack on August 23, 2020, 12:47:22 PM

Title: Locomotive weight vs traction tyres?
Post by: Ontrack on August 23, 2020, 12:47:22 PM
It is noted that nearly all new N Gauge Locomotives are generally lighter than the older models with the exception of Union Mills which have exceptional pulling power.
Perhaps it's because of needing space for dcc electronics so to compensate they are often now fitted with traction tyres.

Has the industry gone too far with lightweight locos and traction tyres or should they in your opinion make them more heavy like before?
Title: Re: Locomotive weight vs traction tyres?
Post by: ntpntpntp on August 23, 2020, 01:17:27 PM
I have nothing against traction tyres per se.

The need to allow space for electronics and decoders, fidelity to prototype meaning a desire to leave a clear view through windows or under the boiler, using plastic rather than metal bodyshells, not allowed to use lead for weights now, etc.  It all adds up to less opportunity to make the model with decent weight.

The best combination as far as I'm concerned are the old German made Arnold locos with metal bodyshells *and* traction tyres. They pull like a ...er...  train    :D
Title: Re: Locomotive weight vs traction tyres?
Post by: east anglian on August 23, 2020, 01:39:32 PM
Interesting  comment   about   the   use   of   lead  weights,   you   can  still   purchase  lead  and   find  it  the   best  to   cut,shape  and  form  to  fit  into  most  tiny  spaces,     
Title: Re: Locomotive weight vs traction tyres?
Post by: Train Waiting on August 23, 2020, 01:55:49 PM
I think one of the reasons Union Mills models have exceptional pulling power is because they have traction tyres.  Union Mills' view is, I understand, that weight is essential for electrical pick-up and the silicone rubber traction tyres give 'superb grip'.

As Nick helpfully points out - both weight and tractive tyres is an attractive combination.

Best wishes

John
Title: Re: Locomotive weight vs traction tyres?
Post by: Ontrack on August 23, 2020, 02:46:00 PM
Quote from: east anglian on August 23, 2020, 01:39:32 PM
Interesting  comment   about   the   use   of   lead  weights,   you   can  still   purchase  lead  and   find  it  the   best  to   cut,shape  and  form  to  fit  into  most  tiny  spaces,     

I also keep tropical fish and find the strips of lead weight sinks you get with plants very useful to increase a locomotives traction.
So far a whole strip fits in a dapol 68 roof, other strips bent into shape to fit into a farish J39 drive tender, another shaped folded strip into a 2MT ivatt cab and so on. Of course not suitable if you want true to scale unless old  heavy cab crew (made of lead) unsuitable for childen.
In my experience it's not always weight or more drive wheels that increases traction, big motors with large flywheels can have the same effect using less wheels like in a dapol 86.
Title: Re: Locomotive weight vs traction tyres?
Post by: Ontrack on August 23, 2020, 04:00:37 PM
Quote from: ntpntpntp on August 23, 2020, 01:17:27 PM
The best combination as far as I'm concerned are the old German made Arnold locos with metal bodyshells *and* traction tyres. They pull like a ...er...  train    :D

Yes i agree, one of my Arnolds had shed its traction tyres but still pulls very well :)
Just got a new maroon Kato "N Pocket line" with two black flyweight trucks,  no traction tyres and no pulling power, their old locos are far better.
Title: Re: Locomotive weight vs traction tyres?
Post by: Leon on August 23, 2020, 05:55:03 PM
I've been thinking that all rolling stock are being manufactured with materials that are far too light-weight. I've a lot of points where wagons and coaches frequently derail and my belief is that it's because of their weight - or lack thereof. Perhaps I'm wrong? I see a lot of attention to prototypical design, measurement, etc. but nothing suggesting that rolling stock should be prototypical with regard to weight.

Leon
Title: Re: Locomotive weight vs traction tyres?
Post by: njee20 on August 23, 2020, 06:53:22 PM
The NMRA define weight 'standards', which don't relate to prototypical weight, but do specify what stock should weigh, based on a few variables. More common among US manufacturers.

Dapol are consistently guilty of producing over light stock. Their 66s and 68s would definitely benefit from more weight, as would various bits of their rolling stock. Interestingly their Megafret container wagons have a cast metal deck in OO, whilst we get featherweight plastic for a similar price.
Title: Re: Locomotive weight vs traction tyres?
Post by: ntpntpntp on August 23, 2020, 06:57:31 PM
The majority of British N stock has always seemed a bit lightweight to me, compared to my Continental stuff.
Title: Re: Locomotive weight vs traction tyres?
Post by: njee20 on August 23, 2020, 06:58:34 PM
Absolutely. And modern stuff eschews traction tyres. Consequently haulage is usually poor.
Title: Re: Locomotive weight vs traction tyres?
Post by: Chris Morris on August 23, 2020, 07:22:40 PM
The worst thing is a light loco without traction tyres. Both Dapol and Farish have done this. I have been told that the Farish Castle doesn't have traction tyres so there are more pick ups for the sound version. If the power is lost even for a split second by the sound version it has to start  from zero with its inertia slow start. If this is correct then the model has been compromised for most users for the benefit of the high priced sound version.

I'm very happy with the pulling power of fairly light locos with traction tyres. I'm not at all happy that Dapol can't be bothered to supply spare traction tyres. I'm pleased that the Farish 2-8-0 Austerity tyres fit the Dapol 28xx.
Title: Re: Locomotive weight vs traction tyres?
Post by: ntpntpntp on August 23, 2020, 07:41:05 PM
Quote from: Ontrack on August 23, 2020, 04:00:37 PM
...one of my Arnolds had shed its traction tyres but still pulls very well :)

Treat it to some new shoes, it will thank you for it  :D
Title: Re: Locomotive weight vs traction tyres?
Post by: tunneroner61 on August 23, 2020, 07:51:56 PM
My two Dapol 28xx came with spare tyres. Can't comment on other Dapol locos.

Title: Re: Locomotive weight vs traction tyres?
Post by: Chris Morris on August 23, 2020, 08:11:10 PM
Quote from: tunneroner61 on August 23, 2020, 07:51:56 PM
My two Dapol 28xx came with spare tyres. Can't comment on other Dapol locos.

Yes and mine but they got used on my locos. My locos have to work hard for their living!  It could easily be coincidence  but I haven't had to replace a traction tyre since I stopped using track magic a few years ago. Track magic is very good at doing what it says but it seems to leave a greasy covering on the rails. I'm not going to start using it again.
Title: Re: Locomotive weight vs traction tyres?
Post by: Dorsetmike on August 23, 2020, 09:05:16 PM
A lot depends on the loco, there are a few that are too light and don't have traction tyres, the Dapol M7 is a good case in point, very light and no tyres, if it had tyres (assuming you could make the necessary grooves to hold them) then current colection is compromised so weight is the only option.
Three of my Dapol four are fitted with push-pull pump and reservoirs etc, all are metal, brass tube stuffed with "Liquid Gravity" by De luxe, there is also some sheet lead on the cab floor and under the front frame extension (push pull M7s were converted from a batch of locos with longer front frames than others.)
My first M7 was hacked from an ABS white metal Highland tank kit on a 14xx chasis so weight was no problem. The modified Dapol M7s will all pull 9 Dapol Maunsell coaches plus 2 Farish Bogie vans so I can safely say weight can make a big difference as this video shows.

https://www.dropbox.com/s/s23ryqnij2whacj/M7%2B11fwds.mp4?dl=0 (https://www.dropbox.com/s/s23ryqnij2whacj/M7%2B11fwds.mp4?dl=0)
Title: Re: Locomotive weight vs traction tyres?
Post by: east anglian on August 23, 2020, 09:49:26 PM
Dorset   Mike,   Its   a   very  impressive   video   for   such   a   small   tank   engine   to  haul  as   many    coaches,  but   being  realistic  in  real  life   I   doubt  if  they   ever   hauled   more  than  4.   
Title: Re: Locomotive weight vs traction tyres?
Post by: Train Waiting on August 23, 2020, 10:12:57 PM
Certainly impressive haulage power.  'M7s' were powerful locomotives and this was put to good use on the Waterloo ecs trains.

Many thanks for the video.

Best wishes.

John
Title: Re: Locomotive weight vs traction tyres?
Post by: Dorsetmike on August 23, 2020, 10:34:32 PM
@east anglian (https://www.ngaugeforum.co.uk/SMFN/index.php?action=profile;u=1114) 
QuoteI   doubt  if  they   ever   hauled   more  than  4.   
as John says they were employed on empty stock workings between Waterloo and Clapham carriage sidings, typical loading would be around 12 bogies, and in that area lines were very busy with suburban electrics as well as main line services so they couldn't dawdle.
Title: Re: Locomotive weight vs traction tyres?
Post by: Les1952 on August 23, 2020, 11:05:24 PM
Quote from: Chris Morris on August 23, 2020, 07:22:40 PM
The worst thing is a light loco without traction tyres. Both Dapol and Farish have done this. I have been told that the Farish Castle doesn't have traction tyres so there are more pick ups for the sound version. If the power is lost even for a split second by the sound version it has to start  from zero with its inertia slow start. If this is correct then the model has been compromised for most users for the benefit of the high priced sound version.

I'm very happy with the pulling power of fairly light locos with traction tyres. I'm not at all happy that Dapol can't be bothered to supply spare traction tyres. I'm pleased that the Farish 2-8-0 Austerity tyres fit the Dapol 28xx.

ALL of my Dapol tender locos have a goody bag of traction tyres in the box.  Having said that when a tyre starts to go out of round I treat it as time to send the loco off to DCC Supplies for a service.  But then again my locos lead a hard life.

Les