Catch a route 11 tram to the end of the line in Preston and you will find JS Grey Reserve, a nice if unremarkable neighbourhood park. There is plenty of grassy open space on which to fling a frisbee, trees for shade, kids' playground, a barbecue, even a small rose garden.

It's well used by locals, but in recent months they've watched on as a big chunk of it has disappeared behind temporary fencing and a hulking grey electrical substation has been built. Preston folk are not the only ones who have had to give up a bit of public space in recent times for new tram infrastructure.

About a dozen new substations have gone up across inner Melbourne, and while there is nothing pretty about them, and some communities have complained, it's clear the city needs them. They pump extra juice into the tram network, which is required to power the 70 large new E-Class trams that are being rolled into service at the rate of one a month.

The E-Class are the part of an investment of almost $1.4 billion in boosting the capacity of the tram system, without which Melbourne's public transport network would not have a hope of keeping up with the runaway pace of population growth. Melbourne's tram patronage surged 12 per cent to carry more than 200 million people last year, a figure that puts them in the same ballpark as the city's trains (which carried 233 million), and closer to becoming the backbone of the city's public transport system.