This medium sized Z-Scale model railroad is set up in the typical European approach. Two of the transformers control the outer loop of track (one for a locomotive using both rails for power and the second using one rail and the catenary wire for power). The second pair of transformers control the inner loop, rails and overhead both. Note that all four transformers have their throttles in the same position. Train control is primarily through the use of the signals, which are controlled by the three small light blue boxes on the left side of the control panel. Further, locomotives are stored in the engine house and on an adjacent siding by turning off short segments of track through one of the larger dark blue control boxes. This control box is connected to the transformer controlling both rails of the inner loop of track. In practice, the transformers’ speed controls are left in one position and rarely are used except during switching. Larger layouts would have even more transformers, each controlling their own loop of track.
In comparison, a typical American layout would have two transformers and a series of single-pole, double-throw (center off) toggle switches which would let the operator choose to control a specific section with one of two transformers.
It’s an interesting matter with outcomes that show up in interesting places. For many years, the Märklin Z-Scale transformers had very coarse speed controls because it was felt that this was unnecessary. In America, speed control became a big issue, with throttles having finer speed control and momentum features so that the engineer would gain the feel of handling a real train. Americans were first to use walk-around throttles, and when the Europeans finally got onto the idea, they chose infrared walk around throttle, which were fine when used singly but were impossible when used with a second infrared throttle. In the early days of digital command control of trains, it was felt that 14 speed step were more than sufficient for a model railroader. This was true for the Europeans, but the Americans demanded much finer control, which led to 128 speed steps.
In any case, the arrival of serious command control has brought the two groups together because the technology allows for either approach within the command control environment. Advanced decoders have load compensation features which further enhance train operation, and command control allows for the operation of signals and such. The only problem remains that command control has yet to enter the Z-Scale market. There are indications that this is about to change, but that’s what I said in the Greenberg book in 1988.....
There are indications that things are changing a bit. The newer Märklin 67271 transformer has finer speed control.