"guessing" ???I don't think it's a different track gauge (is it?) but certainly there was talk of it being 25,000 kV AC as we have here in South Australia. You don't need nearly as many sub-stations as you do with 1,500 V DC but yes, it ill be incompatible with the existing suburban network (without dual voltage trains).SRL won't share any tracks with mainline trains, so I'm guessing that it will be SG and 25kV AC, maybe even 3rd rail. Gonna be interesting to see.
We went thru all this last December.
Page 14 section 3.1.5 definitely 25kV AC
Even without knowing who will build the rolling stock, its certain that they will be built at Ballarat, Newport or Dandenong. All BG.
Can't rail anything on SG
So why on earth complicate the project by having to deliver every completed set, and return every set for major maintainence, on the back of a truck?
Delivery of HCMT and Xtrap show how it's done, without power (so voltage doesn't matter)
PS a fully equipped train carriage is too big for road travel anyways, without a very specialised route.