Modules

General

This section includes information on the layout and its different modules. The modules can be categorized into two types: overground modules and underground modules. 

Overground Modules


Length: A combination of C-tracks. The standard length is 1080mm, which is the resultant length of three 24360 straight track pieces.
Width: 520mm
Construction: A wooden box-structure with track and scenery elements on a kapa-sheet and layers of styrofoam sheets.

The overground modules include stations as well as scenery modules depicting the track between stations. These include modules with turnouts as well as normal straight and curved modules. All of the modules have a double-track line with one of two different track spacings.


Underground Modules

Length: 1000mm (2 x 24071 + 5 x 24172)
Width: Not specified, ca. 200mm
Construction: Balsa wood with a kapa-sheet bottom layer for support

The underground modules depict metro stations that are located below the surface in tunnels. These modules too have a double-track line with two different track spacings depending on the platform arrangement. The underground modules are not self-supporting but are designed to be placed underneath the overground modules on a separate support. The tunnels between underground stations are not modelled but are instead kept hidden from view.


Construction & Standards


I've made some of my own standards considering the modules. The current idea is that the layout will consist of overground modules made of a wooden box-construction with a double-track line running in the centre of the module. The modules are 9cm deep and stand on their own legs. Their height from the floor will be adjustable.

The track used is Märklin C-track that is screwed on the module. Every module has a length equalling a combination of C-tracks, with the nominal length being 1080mm (3x 172mm+188mm). Curves will be of R9 (1114,6mm) on the visible sections whenever possible to make the running trains look nice. The C-track will be located at "level -1cm" so that the actual ground level is 1cm above to make up for the high trackbed of the C-track.

The underground section is still under more detailed planning but currently the idea is to only model the stations and leave the tunnel sections so that they are not visible to the viewer, giving the appearance of trains coming from "somewhere" and disappearing there again. This also makes up for the short distances between two underground stations. The underground modules will be situated underneath the overground modules so that the track runs about 20cm below the overground tracks.

As the track will run on both sides of the module as opposed to one center-located track overground, the layout will always have twice the amount of underground track than overground track. For example, if a module includes a 108cm double-track line, under it on both sides will also be a 108cm double track line. That makes 6 x 108cm = 6,48 meters of track in a single area of just 108cm, saving space and allowing for as much of distance to be covered as possible. The downside is that at least two underground stations won't be visible to the viewer if the layout is situated along a wall. This is why I will possibly also want to add some small video cameras to monitor these stations and other important underground areas from a single place. The idea is to have as simple trackage as possible on the wall-side to avoid any problems, with all switches and more tight curves situated in the front side. Some hatches and openings will of course still have to be made in case of derailments etc.

The idea in terms of realism is that the underground track is not "actually" situated under the modules. It is just a means of saving space and a necessity to be able to model underground sections. Imagine a real-world metro line, take a strong grip from the place the track goes underground and then fold the whole system in half so that the end stations meet each other. That's the idea!

The layout has two different "standards" in terms of track spacing:

Standard A
- Track spacing of 64mm
- A nominal spacing on the whole line
- Defined by the standard spacing of the wide radius turnouts 24711 & 24712 with the 24071 pieces in between

Standard B
- Track spacing of 120mm
- Allows for island platforms on stations and to make a X-crossover between tracks
- Defined by the spacing of a X-shaped crossover area constructed from the normal-radius switches 24611 & 24612 with the 24649 crossover in the centre

Electrics, Control System & Signals

This section is still under further planning since I haven't yet figured out all the details of the upcoming electrical and control system I'm going to use. The options range from a fully-automatic computer-controlled layout to a manually controlled one, or a mix of both of them.

What I do know by now is that the layout will use Märklin's three-rail system and will be partly digital and partly analog. The tracks are supplied with digital power through a transformer and all rolling stock will have AC-compatible motors with pickup shoes for the third rail. The trains will be controlled via Märklin's control devices. I currently own a Central Station 2 and will use it for the time being at least, maybe adding a Mobile Station to the mix if needed. I plan to operate the switches using digital technology to reduce the amount of wiring, making cuttings to the bottom of relevant modules to allows for easy access to the turnout motors and decoders when needed.

The analog part in the layout will be the signals, which are there for decorative purposes only and do not control track power. They will be powered by a separate transformer and the control boxes will be integrated into the modules. All stations (at least the overground ones to start with) will have working color light signals. Other modules will also have appropriate working block signals (with no real function) and possibly some non-working dummy signals like distant signals or the emergency stop signals before a platform, for instance. 

I use Roco N-scale signals, which I have modified to somewhat resemble the real Helsinki Metro signals. They even use the same code/abbreviation system than the real-life counterparts. N-scale signals are big enough so that the top of the signal mast is about as high as the roof of the train so they are perfect for modelling metro signals, which usually are a lot smaller than railroad signals.

When I have progressed further with the layout, I will look into automatic train control possibilities with a block system and a system that stops the trains at stations, lets them wait there, and then accelerates them towards the next station. What I do know is that this will not be made using Märklin's signals and braking modules because of the extreme costs, but will most likely be handled by a computer software with the signals being there just "for show".


Track & Third Rail

The track type used in the layout is Märklin C-track, which has a snap-together mechanism and a plastic, grey roadbed. The locomotives get the positive power from small studs in the center that protude from a hidden third rail that's underneath the track piece. Both actual rails serve as the negative/ground. Märklin C-track comes in five different radii, R1 to R5 respectively. I previously considered using R4 and R5 on the overground modules but since the metro units are quite long, they don't look very nice even on them. This is why I'm now aiming to only use a visible radius of R9 (1114,6mm) on the layout, if possible. The minimum radius required for the trains to run reliably is R1 (360,0mm) so I will use that in hidden sections.

Now don't be confused! My layout has two different "third rails". One is of course the studs in the Märklin C-tracks that actually supply power to the trains. Additionally, I have modelled a dummy third-rail that actually resembles the real-life counterpart. The third rail in Helsinki Metro is usually yellow-colored and runs on the side of the track. The trains have power pickups on both sides so the position of the third rail may vary. I first thought of going without the third rail but then realized that there's no excuse not to model it other than laziness. The third rail is made of a painted hollow square-shaped plastic pipe that comes in 1 meter length. Now the trains don't anymore look as if they are powered by a means of the holy ghost and that's very nice!


Stations

One can't have a metro layout without some stations! Therefore the stations are in a very important role on the layout and I plan to include as many of them as practically possible. Due to the arrangement of the trackage I am able to always include at least two underground stations for every overground station. The current plan is to construct seven stations all in all, with two being overground and five underground.

Every station has a platform height of 23mm and length of at least 1000mm to be able to accommodate a four-part multiple unit. The platform length has been compressed from the exact scale, which would be about 1550mm due to practical issues. Therefore I am not able to run six-car trains that could be seen on the prototype during rush hours. However, with the opening of the West Metro in real-life, the maximum train length is now limited to four cars anyway. Also, the new M300 train only comes as a four-part unit. That means my layout will become more prototypical in the future!

Even though the layout depicts a Finnish system, the station names are in English. I don't want to have real-life names since the stations are visually a product of imagination and don't closely resemble any real-life counterparts. Secondly, the order and number of stations wouldn't be the same than in real-life and it would look quite dumb in the layout map. Thirdly, it's somehow very hard to come up with fictional Finnish names that sound right for a metro station and that would satisfy me. 

My solution is that the station names are in English and all of them are playful and freeform translations of the real-life Finnish stations. For example, the station "Siilitie" literally means "Hedgehog Road" and thus the station is called "Hedgehog Avenue". The station "Kulosaari" comes up from the words "kulo" that means either the purposeful burning of wood to enrichen a forest area or just a forest fire, and the word "saari" which means "island". Thus, we come up with a station called Flamewood Island.


Tunnels

Tunnels in the New Helsinki Metro layout are not modelled. The idea is that the trains appear from the unmodelled area to underground stations and then disappear back to the "tunnel". The underground tracks will run on the underside of the modules and will include unsightly-but-necessary tight curves and also hold all necessary wiring and such that is best to be kept out of sight.

One idea to soften the transition from a modelled underground station to an unmodelled area is to incorporate a piece of black cardboard or other similar material in the shape of a rectangle around the tracks leading to stations. This way the viewer can't see the unmodelled plywood-area right where the station platform ends. I have also thought about adding a piece of very light cloth or such to the end of these pieces so that the train could "disappear" behind a curtain. Of course the material should be very thin and smooth as to not damage the trains.

Before I decided not to model tunnels and before the whole idea of the layout had evolved to the shape where it now is, I made some tunnel modules from balsa wood. Two straight 100cm long tunnel modules and two curved R3 & R4 modules were made but they have been scrapped already, partly because I wasn't satisfied with their quality but mostly due to their redundancy.

So, that's about it when it comes to background and technical information!
If you want to see more, click here for a tour around the layout!