Crossing the Northern Territory by road is one of those things that sounds better than it is. The main route links Darwin with Adelaide across the continent, and much of the journey is hundreds of kilometres of straight line with very little between one service and the next.
There is an alternative that does the same route and solves the problem at the root: a train that takes a little over two days to go from one end to the other.
01 Two thousand nine hundred and seventy-nine kilometres
The service is called the Ghan and it covers 2,979 kilometres between Adelaide and Darwin, with stops at Alice Springs and Katherine. The scheduled timetable, including the long halts for passengers to go on excursions, is around 53 hours.
The train itself gives an idea of the scale involved. A typical formation is some 28 stainless steel carriages, around 774 metres in length, hauled by two locomotives. Seen side on across an empty flat, the line does not end.
Frequency is low and worth knowing: there is at least one weekly service, and a second only between May and September, which is the northern dry season. This is not a train you catch on the spur of the moment.
02 A line that took a hundred and twenty-six years
The history of the line explains why the journey has the character it has. Work on the branch to Alice Springs began in 1926 and finished in 1929; the first service left on 4 August of that year.
There it stayed for generations. The extension from Alice Springs to Darwin, completing the crossing of the continent, did not open until January 2004, a hundred and twenty-six years after the plans began, at a cost of 1.3 billion dollars.
The name comes from the Afghan cameleers who moved goods through the interior before any railway existed. It is a nickname, not an official name, and it was given in the twenties.
A hundred and twenty-six years between the first plan and the last rail: the line took longer to build than most countries have existed.
03 What you see through the window
The real interest of the journey is that it crosses, in order and without breaks, all the climates of the territory. You leave the tropical savanna of the north, where more than 1,800 millimetres of rain fall a year, and arrive in the central desert, with 274.8.
The transition is not abrupt and that is the point. You spend hours watching the woodland thin, the eucalypts get smaller, spinifex appear and the earth shift from ochre to red. There is no line: there is a thousand-kilometre gradient.
Then comes the part that surprises anyone expecting only sand. In the centre, the train passes between folded ranges, with strata drawing parallel and curving bands. They are the same folds that left Uluru's beds standing on edge.
04 The pace, which is what you buy
It is worth saying plainly: nobody takes this train for speed. A flight between the two ends takes a few hours. What you buy is the fifty-three.
And there is a concrete reason those hours are worth something. The scale of central Australia is hard to grasp on a map and trivial to grasp from a window: when you have spent six hours looking at the same thing, and the train has not stopped, the inhabitants-per-square-kilometre figure stops being an abstraction.
The rest of the appeal is logistical and should not be dismissed. You unpack once, there is no driving, no hunting for somewhere to sleep or eat, and the long halts along the way are organised as excursions from the train itself.
05 What the train does not give
One has to be clear about what this trip is not, because it is sometimes sold as if it covered everything. The train does not pass Uluru or Kata Tjuta, which lie some four hundred and fifty kilometres from the line and require a separate journey from Alice Springs.
Nor does it allow improvisation. It stops at very few points and on fixed times, so anyone wanting to break off and explore has to plan it as an interruption of the ticket, not as a stop along the way.
And since July 2016 there is no economy class: all economy seats were removed and the journey is sold only with cabins. It is an expensive trip compared with flying, and that is probably the main barrier.
06 How to build the trip
The first decision is the direction, and it has consequences. Going down from Darwin to the south you leave the humid tropics and enter the desert, which is the order in which the transition makes most sense. Going up you arrive at green, which is a more rewarding ending.
The second is the month, and here there is little room. From May to August the north is in its full dry season, with between 0.8 and 20.7 millimetres of rain a month, and that is when the second weekly service runs. Between December and March the far north receives more than a metre of water.
And the third is treating it as the spine of the trip and not as a transfer. The sensible thing is to give a few days to Darwin and the north before boarding, come down to Alice Springs, do the trip to the red centre from there and carry on afterwards. The train works better as a backbone than as a shortcut.
What makes this journey different is not the train, which is a train. It is that it crosses without breaks a continent that any other means covers in hops: you go in through the tropics, come out through the desert, and in between there is no cut, only a thousand kilometres of ground changing very slowly.
