This week, Chris is in the Republic of the Congo to experience one of the greatest surviving African railways of the colonial era. Built by French colonists at a cost of tens of thousands of African lives, this railway connects the capital of Brazzaville, far inland on the Congo River, to the coast 310miles away. It has remained a vital lifeline for both people and freight in a country with few roads and thousands of square of miles of jungle. Since its opening in 1934, the Congolese have done everything in their power to keep the railway open, even during the civil wars of the 1990s when the railway was deliberately targeted by guerrillas. Chris sets off from the overcrowded station at the port of Pointe-Noire to travel through the jungle to Brazzaville. With a few stops along the way, Chris is prepared for a gruelling two-day journey. Six days and a whole series of setbacks later, he finally arrives at his destination. Along the way, Chris experiences the best and worst of this jungle railway, including the beauty of the narrow gauge line snaking through the dense forest and the macabre carnage at a notorious accident black spot. He discovers ingenious engineering that is over 100 years old, but suffers a rude awakening in the heart of a tunnel in the middle of the night, before enduring a white-knuckle ride on a disused section of line where thousands of construction workers died.

In this episode, Chris crosses the Australian Outback on an amazing railway. The 2,000 mile long Adelaide to Darwin railway is commonly known as ‘The Ghan Line’. It is named after the main service that runs on it and the name ‘Ghan’ is said to derive from the Afghan-run camel trains that ferried people and goods across the Outback in the 19th Century. Building the line proved to be a huge engineering challenge that took over 100 years to complete. In his quest to uncover the extraordinary story of this railway, Chris travels from Adelaide to Darwin, following the original ill-fated route of the line. After cruising out of the city on the luxury modern Ghan train, he quickly transfers to one of the line's surviving steam trains before hitting the Outback for real. Dating back to the Afghan days, this remains camel country, but Chris quickly concludes that a modern 4x4 is a more practical means of crossing the Outback. He passes through ghost towns and explores abandoned railway relics before uncovering why most of the southern section of the line eventually had to be abandoned. At Alice Springs the old route and the newline converge. But Chris has now missed the twice weekly luxury passenger service, so he hitches a ride on a mile-and-a-half-long freight train headed for Darwin. After nearly 24 hours in the cramped cab, making friends with a succession of drivers, Chris finally makes it to Darwin.

In the last instalment of his interesting travelogue of extreme railway journeys across the world’s toughest terrains, presenter Chris Tarrant takes a trip through India on the Konkan line. The Konkan railway runs down the west coast of India, connecting the port cities of Mumbai and Mangalore. While the British built 40,000 miles of track across the vast sub-continent, they stayed clear of this narrow, boggy strip of land as it was deemed too treacherous and difficult to build on. As a result, western India remained undeveloped, until a brave Indian engineer took on the daunting task. Known as ‘The People’s Railway’, the line opened in January 1998, finally connecting the remote villages along the route to the outside world. Chris starts his journey at dawn in Mumbai, India’s financial capital and home to Bollywood. The ‘Mandovi Express’ is the first of many trains he catches along the 472miles of track running through the states of Maharashtra, Goa and Karnataka. As he travels through the stunningly lush scenery, Chris is struck by the engineering challenges that this extreme environment must have presented. To keep the line straight, 92 tunnels and 2,000 bridges had to be built in one of the wettest areas of the country. The monsoon rain continues to create havoc. In the last 10 years there have been two fatal accidents due to landslides derailing the trains. Chris joins the monsoon team who patrol the line daily to ensure that it is free from obstructions. He is amazed at the work and commitment going on behind the scenes to prevent further incidents. However, on ‘The People’s Railway’ it is his fellow passengers that provide the real enjoyment on the journey. Chris throws himself into his trip, inspired not only by the engineering miracle of the railway but by the community it serves.