Model Tramways & DCC

[GoingUnderground]

I went to the Festival of Model Tramways last Sunday at Kew. It was a very enjoyable time.

 

I was surprised at the number of layouts using DCC, including one collecting from live overhead with both rails acting as the common return. Is DCC becoming more the norm in tramway modelling circles or was it just a coincidence?

[Balloon_726]

Hi, my N gauge tramway layout Thornton Gate, has been running DCC since 2012, I was one of the early adopters (in tramway circles), However as time as gone on others have switched over to the system.

Is it the norm?  Hard to say, maybe not yet as I still know of a large number of exhibition projects that use traditional DC methods.

The recent Totally Models show at Rigby Road depot (which I exhibited at) I think only had 2 or 3 DCC layouts (including my own) in a show with 25+ layouts. So its hard to draw a conclusion.

DCC has huge operational advantages, especially for trams where flexible line of sight running is required.

[RAF96]

Can some clever dicky please draw up the track and model wiring schematic for a DCC overhead power rig using both rails as return.

Thank you...

[rue_d_etropal]

If you want to operate, then maybe DCC has an advantage, but most tram layouts seem to run on auto pilot OK. Simple detection, start and stop works fine. Maybe some tramway modellers are just following a trend, but what many people feel is that DCC actually makes model railways at exhibitions much less interesting to watch, as the operators have to work all the time, and in practice prefer to stop and chat, so you can end up with nothing moving at all. Fine if you have enough operators, and even then, too many layouts have a big crowd behind layout, just chatting to themselves.

I was at Rigby Road. Both my layouts were analogue, one with a simple auto shuttle. For exhibitions it does not have to be over complex. What is more important is to make sure everything works properly, and when problems arise look at practical ways to fix them.

[Gordon H]

Can some clever dicky please draw up the track and model wiring schematic for a DCC overhead power rig using both rails as return.

 

Hardly requires a diagram of any sort. The description itself is quite sufficient.

[GoingUnderground]

Can some clever dicky please draw up the track and model wiring schematic for a DCC overhead power rig using both rails as return.

Thank you...

Nothing special is required. Just wire as for old-fashioned Hornby Dublo (or modern Maerklin) 3 rail.

 

If the truck/motor bogies are wired for 2 rail, cut the wire that runs from the insulated wheel pickups and connect the wire from the pickups to the chassis, and the wire from the insulated commutator brush to the pick up from the overhead, be it trolley pole, bow collector or pantograph. If you want to get clever, fit a DPDT switch in the tram to allow you to switch between standard 2 rail via track, or overhead with both rails as common return.

 

If you use normal 2 rail track with plastic sleepers don't forget to interconnect the running rails if you're using them both as the common return. That does make occupancy detection easier to rig up as you don't need current detection.

 

Fitting the decoder is exactly the same as for a loco. Make sure that both motor brushes are insulated from the chassis and from the pickups. If ordering new BEC style motor bogies or trucks, make it clear that you want DCC versions or you may find the white metal chassis soldered directly to a motor brush. It can be sorted, but takes time.

Edited July 27, 2017 by GoingUnderground

[RAF96]

I have bec trucks and the DCC instructions.

 

I was basing my tram overhead wiring on a Hornby Class 90 loco which has a live panto and a slide switch to divert from rails to overhead, but couldn't work out how to run it thus on a normal DCC track.

 

As my tram track is an end to end track driven shuttle on DC at present I thought it would look better with an overhead.

 

Thanks for the instructions.

Rob

[GoingUnderground]

I have bec trucks and the DCC instructions.

 

I was basing my tram overhead wiring on a Hornby Class 90 loco which has a live panto and a slide switch to divert from rails to overhead, but couldn't work out how to run it thus on a normal DCC track.

 

As my tram track is an end to end track driven shuttle on DC at present I thought it would look better with an overhead.

 

Thanks for the instructions.

Rob

[GoingUnderground]

I have bec trucks and the DCC instructions.

 

I was basing my tram overhead wiring on a Hornby Class 90 loco which has a live panto and a slide switch to divert from rails to overhead, but couldn't work out how to run it thus on a normal DCC track.

 

As my tram track is an end to end track driven shuttle on DC at present I thought it would look better with an overhead.

 

Thanks for the instructions.

Rob

To use the class 90 on DCC is exactly the same as using it on DC with the overhead/track switch in the track position. To use DCC wtith power via the overhead just connect the overhead to the same rail as is used by the insulated side of the motor.

 

If you have the tram shuttling back and forth, you will either need trolley pole reversers if you are going to use trolley poles, or if using a bow collector leave the overhead very slightly slack at each end so that the bow can flip over, or use pantographs as they're direction neutral.

[rue_d_etropal]

I have no problem with reversals, as my trams are based on London conduit system. No wires above, a lot simpler, and also a bit more different than most tram layouts. 

[GoingUnderground]

London had a mixture of conduit and overhead. The conduit was used by the London County Council for the vast majority of its system, whilst the 3 independent companies, the M.E.T., LUT, and SMET, that became part of the "Combine" all used overhead. The ex-M.E.T., ex-LUT, and ex-LCC systems north of the Thames were converted to trolleybus operation in the 1930s. So a London tramway layout doesn't always mean it won't have overhead. But the LCC system was one of the largest conduit systems.

 

There was a horse-drawn tramway model at the Festival, (it was one of those using DCC), which is another alternative to using overhead.

 

There is always yet another way, model a tramway that used the Stud Contact system. Just don't forget to model a stunned horse lying in the road after treading on a live stud. The LCC briefly experimented with using stud contact.

[rue_d_etropal]

I had thought of trolley bus wires(non operational), but my layout is based on a fictional street just to the north of Kings Cross. I am assuming the trams(and conduit) lasted a few more years, and it was a street not converted to trolley bus, hence no wires. Main reason for layout is to highlight the conduit system, which for me, having never fully appreciated it, as there are often troiley bus wires making it look to a non tram expert like other trams with wires.