SBB/BLS catenary masts & spans in N gauge

[Gordonwis]

And the now moribund single track on the Bielersee at Twann - Ligerz

 

 

[Frutigen]

Progress with the catenary masts was delayed for various reasons but I'm back on the case and have some progress. After tweaking the arms and painting a number of masts I've now got about 2/3 of the single track section sorted. I even made one of those anchor structures for the buffer stop (don't know the proper term for them) out of bits of mast and plastic rod. I wasn't following any particular prototype here and it's a bit short on detail but I feel it does help to finish off the scene.

 

Although they are lit to stand out in the photo, in the room the masts blend into the scenery because of their finished colour, which I think is a good result. The paint is Halfords Wheel and Wheel Trim Steel, which gives a much finer finish and better shade than the silver hobby paint I tried on a test piece. Details are picked out in acrylic applied with a fine brush. 

 

Again, huge thanks to @JimFin for developing and printing these pieces.

 

 

[njee20]

Quite a few print artefacts on those, are they FDM printed? That'll yield a stronger, but coarser, print. I assume they're not, given the registration arms look fairly fine.

 

FWIW the gap between the catenary and the contact wire is called the encumbrance. In the UK, mk1 systems have a 6' encumbrance and mk3 (as per the Dapol masts) have a 3' encumbrance. I don't know what is standard in the rest of the world, but I'd have said much of Europe tends to be nearer 3'.

[JimFin]

48 minutes ago, njee20 said:

Quite a few print artefacts on those, are they FDM printed? That'll yield a stronger, but coarser, print. I assume they're not, given the registration arms look fairly fine.

 

FWIW the gap between the catenary and the contact wire is called the encumbrance. In the UK, mk1 systems have a 6' encumbrance and mk3 (as per the Dapol masts) have a 3' encumbrance. I don't know what is standard in the rest of the world, but I'd have said much of Europe tends to be nearer 3'.

They are resin prints -  but single pieces. I use a mix of 2 different types of resin to give them some flexibility. This is the RhB version but same principle.

 

[Frutigen]

Here's a wider view in normal lighting. It's what I had hoped for and at this more normal viewing distance I'm happy to accept any detailed blemishes - or dodgy finish work on my part. I think I might need to tone down some of the concrete bases a bit, though.

 

 

 

Edited August 8, 2022 by Frutigen

[njee20]

Nice! I assumed they were resin, as you'd not get that level of fidelity on the registration arms on FDM, just a bit thrown by the layering on the base, but I think that's just the cruel close up given they're only a couple of mm high!

 

I've been playing around with printed OHLE myself, I'm trying to make them less flexy so there's a chance of stringing wires!

 

They look great Keith - they blend in well to the surroundings, which is the best complement! 

[Frutigen]

17 hours ago, njee20 said:

I've been playing around with printed OHLE myself, I'm trying to make them less flexy so there's a chance of stringing wires

 

I’d like to see that.
 

For my current layout, the masts and spans are a cosmetic layer to help create something of the right atmosphere for the scene, but I’m beginning to see that it’s a massive subject if you want to model a catenary system correctly. For instance, I’ve wondered just how many extra masts I would need for an actual wire to even pretend it’s in the right place over the middle of the track. Probably not a problem on a straight layout, but more challenging with the 180 degree ~200mm curves on Obermatt. 

[njee20]

Yeah, it needs more work to get to that stage; it's all a compromise, making the masts (or the registration arms) stiffer will inevitably mean making them thicker, which I'd sooner not do. In a lot of ways 3D printing is perfect for OHLE - lots of template parts you can print by the dozen. Your point about wires is definitely valid particularly if you want the pantograph to actually ride the wire, which in turn needs overscale wires. Back to the compromise point.

It's interesting that the OHLE on the GWML is all made by Swiss firm Furrer+Frey, and is very similar to a lot of new SBB stuff. Very modular too, which is ideal for modellers!

 

 

[Frutigen]

Here are the basic components for a span - this is the longest one at 210mm.

 

 

I'm thinking maybe I can use single masts at the ends to create outriggers. These masts are slightly shorter but just about allow enough depth to accommodate the span on top. 

 

 

And here's my first attempt (yes, I failed to prepare the ground levels properly). I've also grafted some arms on in an attempt to mimic the arrangement you can often see on the real thing but I'm not sure if that's going to be robust enough for long term use.

 

 

All the other spans in the background are just resting on their posts - they need to be trimmed to length, have their hangers and arms added and then painting. 

 

As with an earlier post, the close-up photography here is cruel and highlights small blemishes that are much less noticeable at normal viewing distances.

 

Edited August 17, 2022 by Frutigen

[Frutigen]

I chose this catenary system, in part, because of reports that the most realistic commercial product is extremely fragile and almost impossible to repair. Well, this 3-D print system isn't totally bob-proof and I've broken a few of the more delicate parts, but I'm getting much better at handling them and haven't broken anything recently. I've got a few spare parts just in case, though.

 

The lattice spans, in particular, need careful handling. I've noticed that they are particularly vulnerable at the point where I've glued them to the posts, where any twisting or impact is liable to snap them off. Here's one that has already been repaired, you can see the fillet of glue holding it back in place. However, I've discovered that if you just rest the span on the post (there's a little ledge for it so sit at the right height), then the whole structure will flex and spring back to shape if it gets an accidental nudge. Unless any problems emerge, this is the approach I plan to take with the ones I'm still working on. It also makes them removable, which could be useful for track cleaning or for moving the layout.

 

 

I like the way the spans will stack so you can daisychain them, as they do on Swiss railways. In the photo above, the top span is unpainted and is just resting on its mate. You can see some pips on the bottom edge - I'll remove the bigger ones carefully with a sharp blade before spraying but smaller ones are effectively invisible once painted.

 

I also like being able to place the second span at an angle. I discovered that if you round the edges of the post very slightly with a flat file, then the spans will rotate freely without stressing either part. I did originally just fit the span over the post and then twist it gently to its new angle, but this tended to distort the overall shape of the structure and also felt much less resilient to accidental movement.

 

 

 

 

Edited August 19, 2022 by Frutigen

[Frutigen]

Progress has been slow as I’ve been busy with other stuff, but I finally got most of the pieces sprayed and set up. There’s still some detailing to do but that will have to wait until after the half term madness. 

 

Photos often reveal things you don’t see for yourself, like the bendy mast on the left. Looks like I need to shorten the span slightly. 

[Frutigen]

Progress remains slow due to life getting in the way but I think I’m on the last leg of detailing. Even the trains look happier running under real fake catenary. 
 

Edited November 24, 2022 by Frutigen

[Frutigen]

I think I’m going to declare the catenary project finished, all that remains now is tweaking and maintenance. 
 

A massive thank you to @JimFin for making this possible and also to everyone whose comments in the early stages of this thread helped me decide which system to go for. 
 

 

 

I should add that the end structures in the 2nd photo above are something I cobbled together from Jim’s uprights and some old rail, so please don’t blame him for their clunkiness. 

[Nutbrook]

The catenary looks great Keith. I too have masts by Jim on my railway and found them excellent.