This standard-gauge line was completed in 1939 to export grain to Europe. Once in Churchill, the grain is loaded onto ships that sail across the Atlantic Ocean. Today the track also carries passengers, for it remains the only land transport link between Churchill and southern Canada.

As the train pulls out of Winnipeg, the world opens up, flat and brown. The crops have been harvested and the land is dead and silent. The sky, stretched between unbroken horizons, is grey and laden with drizzle. The snow has not yet arrived, with Canada experiencing an alarmingly warm autumn.

The ride is deafeningly loud. There is none of the swoosh of smooth rail and woosh of compressed air that European high-speed trains emit. This train sways and clacks as it trundles down the track, averaging less than 40km/h. They call it 'the slowest train in the world', and they might be right. The track is built on permafrost, permanently frozen ground, which makes a rough, unsteady track bed. The motion and pace of the train are similar to those of a yacht at sea.

The cabins are moulded from chrome, aluminium and green-painted steel. Innovative and clever, but built sturdily, to stand the test of time, like everything from the 1960s. My cabin has a fold-down bed with a small reading light. On the other side is a toilet, covered by padding, to turn it into a regular seat when not in use. The sink folds up into the wall, spilling it contents into a hidden drain as it is put away. The room is completed with a fan, luggage rack and large window. It makes me feel like a child in a treehouse.

This is a unique trip for my 82-year-old father and me. We are travelling through our home province and he points out towns and grain elevators he remembers from his childhood.

I have dreamed of riding this train for many years. Everything I have heard has buttressed my idea of the North as the place where men go to make money and find adventure. In The Idea of North, one of three radio documentaries exploring the theme of solitude, by Glenn Gould, the Canadian classical pianist rode what he called the 'Muskeg Express', the rattle and groan of the train nearly drowning out his interviews.

'This flat, flat country frightened me a little,' says a woman's voice at the opening of the piece. 'Because it just seemed endless. We seemed to be going into nowhere.'

In the dining carriage we spread maps out on tables to trace our fingers along the faint black line that crosses northern Manitoba. The province has more than 110,000 lakes, with water accounting for about 16 per cent of its area. Manitoba is the size of Afghanistan, or nearly two Vietnams, but there are only 1.2 million people in this wide space, and more than half of those live in Winnipeg.

Occasionally the train rolls through a town, announced by a few outlying buildings and converging power and telephone lines. Some towns are invisible from the train. Ponton is only a signpost, leaning into the wind beside the track. The train stops at Thompson and The Pas, and passengers step out into the snow, sucking on cigarettes and going for quick walks before returning, shivering and wet-nosed, to the warmth of their cabins. And then the train dives back into the tangled wilderness.

It is a flat wilderness, with patches of scraggly spruce and tamarack that ring boggy lakes. Sometimes the rail climbs onto higher ground, where birch and poplar trees sprout, but for many hours the windows show only the hardy but diminutive specimens of the taiga forest.

On the second day the train reaches the Barrens, a vast and remote part of Canada that was lionised by Farley Mowat's 1956 novel Lost in the Barrens, the story of two boys struggling to survive a winter in the frozen north.

'The dark jack-pine forests began to swallow up the prairie farmlands and the train rolled on, more slowly now, over the rough roadbed leading to the frontier country,' Mowat writes of the ride north.

In the darkness, a flash of light from the swaying train illuminates brilliant snow, dark trunks and the untamed shadows of the unending parade of trees outside.

The train stops in the middle of the night, in the middle of the forest. The steward told us that the train would stop if waved down, and that trappers living in the forest would occasionally hitch a ride into town. Peering out of the window, dreaming of a man in buckskin, carrying a rifle and a bundle of furs, I see only snow and trees.

When the sun rises on the last morning of the journey, the forest is gone. The land is wide open, with frozen sloughs separated by brown march grass and the occasional spindly tree.

We pack our bags and look out over the emptiness for signs of Churchill. There is still time for breakfast and I walk, swaying and grasping for support, towards the food. Snow has blown into the corridors between the carriages, making small drifts and frosting the glass. The warm smell of bacon and coffee greets me as I stumble into the dining carriage.

Soon the train crosses a rough coun- try road and there are signs, vehicles and buildings. Civilisation. As the train rolls into Churchill, an excited twitter passes through the carriage. A bear!

There, far from the tracks and barely visible, is a polar bear, snuffling at the ground beside the road. The bear is rather undramatic from a distance, but that's all right. I have already found what I was looking for.