Nope, only the PowerCab plus one extra cab in the basic PowerCab – so two trains at once max with the out-of-the-box PowerCab.
You can, however, run multiunit diesel consists (not uncommon on a diesel era layout), and get up to 7 locos running at the same time spread across two trains. For instance, on my Siskiyou Line, I typically have 3 units on the point and a 2-unit mid-train helper – and with two trains, that’s 10 locos right there.
COMPARISON OF STARTER SYSTEM EXTRA CAB EXPANSION OPTIONS
The Zephyr has the advantage with regard to cabs … it will take two additional cabs out of the box, and you can also connect two additional high quality DC power packs as throttles. You could run up to 5 separate trains with a fully loaded Zephyr. Not bad!
Either system can get more sockets for additional cabs with the purchase of additional UTP panels (universal throttle plug panels) for $15 each. Of course, then you have to foot the cost of the additional cabs.
NCE basic engineer cabs (Cab04p) costs about $70 street price … while the Digitrax basic engineer cab (UT4) costs about $65 street price.
The NCE full-featured throttle (ProCab) costs about $125 street price, and the Digitrax full featured cab (DT400) costs about $140 street price.
So the Zephyr out-of-the-box has a one-DCC-throttle socket advantage over the PowerCab – the Zephyr’s DC powerpack option is nice, but I view it as transitory and don’t recommend it as your long-term DCC throttle solution.
As to individual add-on throttle prices, the two systems are basically a wash.
P.S. It’s interesting how all these trade-offs can work – to me a lot of this is basically a wash, and you should just go with the system vendor yo