The 1950s Modernisation Plan changed British railways forever, ending steam and bringing in the use of diesel power. In 1957, British Railways introduced two new classes of trains; the Type 1 and the Type 2.

Read on to learn about the different Type 1 trains, and their role in the railway’s past and future.

The need to modernise the network

By the late 1940s, travelling by train across Britain had become increasingly difficult. The railway network had fallen into disrepair after years of neglect, compounded by extensive damage from World War II. As a result, the infrastructure was outdated and in desperate need of an overhaul.

Adding to the strain, road haulage had emerged as a strong competitor. Lorries offered a cheaper, more flexible way to transport goods and raw materials across the country and seaports.

Faced with these pressures, the government recognised the need for action and introduced the 1955 Modernisation Plan. The plan aimed to overhaul the railway system by replacing outdated steam engines with diesel and electric trains, upgrading infrastructure, and improving efficiency. It was an initiative designed to transform the nation’s railways into a modern, competitive, and sustainable mode of transport.

Moving away from steam

The government committed to phasing out steam locomotives entirely. Many passengers had grown fond of these soot-stained giants, but they were outdated technology. Though the decision was unpopular, it was deemed necessary for progress.

The 1955 Modernisation Plan was a massive undertaking. It required not only replacing old steam engines with more efficient models, but also upgrading the entire rail infrastructure. This also meant retaining staff to manage and operate the new locomotives and technology.

The birth of the Modernisation Plan

The Modernisation Plan became more than just an effort to upgrade Britain’s railways - it was seen as a crucial step in rebuilding a country weary from war and years of austerity.

However, such an ambitious transformation came at a high cost. To finance it, the government made significant sacrifices, including the centralisation of freight services and closure of unprofitable branch lines. A decade later, this approach was echoed in the Beeching Report (1963), which recommended widespread cuts to underused routes and stations to improve efficiency and financial viability. As a result, thousands of miles of railway lines were closed, fundamentally reshaping Britain’s rail network.

For leisure travellers, the Modernisation Plan was a doubled-edge sword. While they benefited from faster, more reliable trains that could reach remote destinations quicker, there were now fewer remote destinations accessible by train due to the widespread closures.

The Type 1 locomotives

British Railways (later British Rail) required a new generation of diesel and electric locomotives, eventually classified as "Type 1." These engines produced between 800 to 1,000 of horsepower, marking a significant shift from steam-powered trains.

Let's explore the Type 1 locomotives that transformed UK rail travel, including their development, operational history and ultimate fate.

 

Class 15 (1957-1971)

The Class 15 was one of the first diesels ordered in the big move from steam to diesel. British Thomson-Houston, Paxman, Clayton, and the Yorkshire Engine Company built these big engines.

The single cab design was unusual for a British locomotive as it looked more like a North American road switcher.

Road switchers have a single-driver cab seat in the middle so they can move other railway vehicles from one track to another. You can still see them in most train yards.

Only 44 Class 15s were built, but these were quickly scrapped because the engines were unreliable and the cab's position made for poor forward viewing. BR converted four of the scrapped trains into pre-heating units.

They supply warmth to stationary trains so they don't have to switch their engines on; a clever reuse of retired stock.

Today, D8233, the only surviving Class 15, is under restoration at the East Lancashire Railway.

Class 16 (1958-1968)

The North British Locomotive Company (NBL) built the Class 16, launched in 1958. They modelled it on an earlier prototype (No. 10800) they'd already designed for branch and secondary line work.

The NBL were great at steam engines but lacked experience in diesel and electric which led to many issues such as the Paxman engine. It was a powerful, compact, and lightweight engine, but overheated in confined spaces with poor ventilation.

Only ten Class 16s were created, all of which ended up at the scrapyard. Today, the only way to experience it is through photographs and written records.

Class 13 (1965-1986)

The Class 13 is one of the most unusual engines in British railway history. It wasn't a single locomotive - it was two Class 08s coupled together.

The Class 13 tackled the heavy work at Tinsley Marshalling Yard. Tinsley was a heavy-load and shunting-intensive yard and engineers decided one Class 08 shunter was not enough.

They worked together in a "master and slave" formation to tackle the heavy work. This means that the controls of one of the Class 08s handled the operation of both units.

The Class 13 was specialised, and its limited use beyond Tinsley Marshalling Yard (a yard dedicated to sorting and arranging freight wagons into trains) meant it had a short life from 1965 to 1985. Only three were ever built, so their rarity and short life make them an interesting example of bespoke railway engineering.

None of the Class 13s still exist. However, enthusiasts still remember these unique machines fondly. The Class 13 reminds them of a period of trial and error in British railway history when bespoke solutions were the answer.

Class 14 (1964-1965)

Thanks to its unique design, the BR Class 14 is instantly recognisable. It has an offset cab flanked by bonnets at each end and a 0-6-0 wheel configuration.

A bonnet refers to the raised section at either end of the locomotive, which contains the engine and controls. The 0-6-0 wheel configuration means the locomotive has six powered wheels without any leading or trailing wheels, providing excellent traction and stability at low speeds.

Because of its looks, a Swindon Works foreman nicknamed it "Teddy Bear." If you like unusual trains, Class 14 is one you won't forget.

The "Teddy Bear” was also a pioneer. It had a Paxman engine and a Napier turbocharger to boost power. It also boasted a Voith hydraulic transmission which smoothed out the power to the wheels. The key to its success was its heavy buffer beams - thick plates at each end to improve weight distribution.

Despite being a reliable and much-loved workhorse, the Class 14s retired due to the Beeching Cuts and a decline in the industries using the engine caused its demise. However, many did find new homes in industrial settings, where they powered on for many more years. Today, several survive in preservation, including D9555, which still runs on its original route, now part of the Dean Forest Railway.

Class 17 (1962-1965)

The Class 17 is instantly recognisable thanks to its central cab perched like a watchtower between two long, sloping bonnets. Many think it looks like a sturdy tugboat on rails.

The cab gives drivers excellent visibility. That's unlike many of the Type 1s, whose visibility was more like peering out from a narrow porthole at one end.

In the Class 17s, Clayton Motors extended the hood space by splitting power between two locomotives, each equipped with a smaller Paxman diesel engine. While innovative, this design ultimately led to its downfall, as the twin engines proved unreliable in service. Additionally, the decision to use electrical transmission instead of hydraulic further contributed to performance issues.

By the early 1970s, BR scrapped all 117 locomotives. This made it one of the shortest lifespans for a mainline diesel-electric locomotive.

One lone representative, D8568, survives in heritage railway service. Your best bet to see this oddball locomotive in action is at a themed railway event.

Class 20 (1957 and still going)

Many consider the British Class 20 locomotive to be one of the most successful classes among Type 1 trains. Many of the early British diesel locomotives were unreliable and short-lived. The Class 20, on the other hand, was a success from the start and is still in operation today. It  is also a star attraction at many railway museums.

BR built 228 of these locos that can run up to 75 miles per hour and generate 1,000 horsepower. It has a straightforward and practical design and a powerful 8-cylinder English Electric engine.

Originally intended for light freight duty, the Class 20s, nicknamed "Chopper" because of its distinct engine sound, did so much more.

They were workhorses and were often coupled up with other locos to move heavier trains or navigate steep gradients in a process called "double-heading". During the summer, they'd haul passenger chargers or act as short-distance diversions of electric trains.

This British classic went global, too, inspiring locomotives in Portugal and Australia. The Class 20 may have been the most successful Type 1 locomotive ever made.

Later developments

The legacy of the Type 1 locomotive remains with us today. In the 1980s, a proposal to develop a new Class 18 - a proposed diesel-hydraulic locomotive - never made it past the drawing board.

Decades later, Clayton Equipment Company brought back the idea. They wanted to build a battery and diesel-powered loco to reduce emissions and improve efficiency. Designed for use at industrial sites like Tata Steel and Sellafield, it's a sign the railway values sustainability.

The new Class 18 is testing regenerative braking. These are two technologies that future train builders can use when manufacturing mainline locomotives.

Railways may be a 200-year-old technology but there's still plenty of room for innovation.

The legacy of the Modernisation Plan and Type 1 locos

The Type 1’s tell a story of experimentation, innovation and survival in a time of great change for British railways. Their legacy will continue to inspire railway enthusiasts and the future of rail transport.

Every train running on the network today has a story. Learn more about the trains we operate and the trains we've named to find out more about Avanti and what we believe in.