THE October 1964 opening of the 552.6km Tokaido Shinkansen was a major news event not just in Japan but globally as the striking image of streamlined electric trains flashing past Mount Fuji captured the public's imagination. The term bullet train was quickly coined to describe this technological wonder.

While a maximum speed of 210km/h might not sound particularly fast by modern standards, the consistent operation of trains at this speed was a huge step forward, particularly in Japan where trains could only reach 110km/h on the conventional 1067mm-gauge network. The new standard-gauge double-track railway also doubled the capacity of the Tokyo – Nagoya – Kyoto – Osaka rail corridor, which was vital as the existing narrow-gauge line was operating at capacity.

The initial journey time of 4 hours was a huge reduction compared with fastest conventional train which took 6h 30min. The Tokaido Shinkansen journey time was cut to 3h 10min in 1965 making day trips by train between Tokyo and Osaka attractive for the first time.

The line connects Japan's four largest cities. Tokyo and Yokohama have a combined population of over 17 million, while Nagoya has 2.2 million inhabitants and Osaka 2.6 million. To put this in perspective, JR Central serves just 23.7% of Japan's total land area but this region is home to 59.9% of the country's population and generates 64.4% of national GDP.

This helps to explain the Tokaido Shinkansen's huge success. Traffic soared during the early years from 11 million passengers in the first year of operation to 118 million a decade later. Traffic fell back to around 91 million journeys per year during the late 1970s and early 1980s as economic growth slowed

By the mid-1980s traffic was starting to build again and grew strongly in the early years following the breakup and privatisation of Japanese National Railways in 1986 and the formation of JR Central in 1987. Traffic peaked at around 132 million journeys and remained at this level throughout the 1990s.

There was another growth spurt in 2004 following the opening of Shinagawa station in Tokyo and the ability to operate all trains at 270km/h for the first time. Traffic peaked in 2007 before the global financial crisis and recession hit, bringing journeys down from 151 million to 138 million by 2009.

"The majority of our passengers are travelling on business so the economic conditions influence our results," says Mr Yoshinori Hatta, general manager of JR Central's London office. "In the last 20 years the Japanese economy was not good, but it has been doing slightly better in the last couple of years."

ShinkansenThe Tokaido Shinkansen has carried 5.6 billion passengers since it first opened and daily ridership has soared from 61,000 in 1964 to around 420,000 today, making it by far the busiest high-speed line not only in the Japan but also the world.

"In fiscal 2013 passenger traffic reached 155 million journeys, so ridership has now exceeded the previous peak of 151 million journeys," Mr Yasuyuki Kudo, assistant manager with JR Central in London, adds.

The Tokaido Shinkansen cost Yen 380bn to construct. According to coverage of the opening of the line in the October 1964 issue of IRJ this equated to $US 1bn, or £377m at 1964 exchange rates.

The line was already profitable when JR Central was formed. Revenue on the Tokaido Shinkansen increased by 5.8% in fiscal 2013 to Yen 1.07 trillion ($US 10.5bn) which is 91.5% of JR Central's total rail passenger income and 67.5% of overall revenue. JR Central made an operating profit of Yen 426.1bn in fiscal 2013 and a net profit of Yen 199.9bn.

There have been a number of important milestones in the Tokaido Shinkansen's 50-year history. In 1972 the railway was extended 180km west from Osaka to Okayama with the opening of the first stage of the Sanyo Shinkansen. A further 442km extension was completed in 1975 taking the Sanyo line to Hiroshima and Hakata/Fukuoka.

In 1986 the maximum speed was increased to 220km/h and two years later three additional stations were opened.

In 1992 series 300 trains started running on Nozomi services ushering in 270km/h operation for the first time and cutting the Tokyo - Osaka journey time by 30 minutes to 2h 30min.

JR Central began test running with its series 300X experimental train in January 1995 and the train set a new Shinkansen speed record of 443km/h in July 1996.

In 1999 construction of the second general control centre for the Tokaido and Sanyo lines was completed and the first series 700 Nozomi trains entered service, while the last of the original series 0 trains was withdrawn.

In 2003 Shinagawa station was opened, and all trains were able to operate at 270km/h following the withdrawal of series 100 trains. "When we had mixed speeds it made it very difficult to plan the timetable," explains Hatta. "With a uniform operating speed we were able to provide a much better timetable."

In July 2007, the first series N700 trains entered service. This train was developed jointly by JR Central and JR West and can run at 300km/h on the Sanyo Shinkansen. The N700 is the first Japanese high-speed train to feature body tilting, enabling it to negotiate 2500m-radius curves at 270km/h compared with 255km/h for non-tilting trains.

This was followed last year by the N700A which, in addition to tilt is equipped with high-performance wheel-mounted brake discs, a bogie vibration detection system, and a fixed-speed running device. Work started last year to retrofit the 80 series N700 trains with the high-performance brake discs and fixed-speed running device to improve their safety and reliability. The work should be completed next year and by the end fiscal 2016 the series N700A will make up 80% of the Tokaido Shinkansen fleet.

The N700A will replace the series 700 trains, which are less powerful than the N700 and N700A trains as only 12 of their 16 cars are powered compared with 14 out of 16 on the other two trains. This means the total output of the series 700 is only 13.2MW compared with 17.08MW on the newer trains, and its maximum rate of acceleration is only 2km/h/s compared with 2.6km/h/s for the N700 and N700A. The series 700 has a maximum speed of 285km/h which means it cannot reach the 300km/h line speed on the Sanyo line.

When the transition to full series N700/N700A operation is complete, JR Central will have an entirely uniform fleet with the same performance, capacity and internal layout. This will give it maximum flexibility in rostering trains to any service.

JR Central has been able to achieve a steady improvement in energy efficiency with each successive generation of trains. The series 300 trains consumed about 30% less energy than the original series 0 trains operating at 220km/h, while the series N700 and N700A trains use around 25% less energy than series 300 trains and about 19% less than series 700 trains running at 270km/h. This is one of the reasons why JR Central has already started to withdraw series 700 trains even though they were only introduced in 1999.

The Tokaido Shinkansen has maintained a flawless safety record throughout its half century of operation with zero fatalities or injuries to passengers caused by train accidents such as derailments or collisions. There are several reasons for this. Having a dedicated high-speed passenger railway without any level crossings obviously reduces the risk of collision with other types of train or road vehicle. The line has been fitted with an automatic train control (ATC) system without lineside signals from the outset which is designed to prevent a train from getting too close to the train in front. The renewal of the ATC system was completed in March 2006 and the old multi-step brake control system was replaced with a one-step system which ensures smoother braking from maximum speed to a complete stop.

JR Central is already well prepared for natural disasters especially earthquakes through the reinforcement of structures and an advanced earthquake detection system. A faster and more accurate earthquake alarm system called Terra-S was introduced in 2005. Last year the responsiveness to vertical and interlocking-type earthquakes was improved together with better backup systems to improve reliability and safety.

In 2009, JR Central started to install derailment protection guards inside the running rails in response to the Niigata Chuetsu earthquake in 2004 which derailed a Joestsu Shinkansen train. Initially they are being installed in areas predicted to suffer strong earthquakes or locations where a high-speed derailment would cause considerable damage. The modification is being done in conjunction with measures to prevent ballast spillage, embankment sinking, and displacement of elevated track supports. The work is expected to continue until 2020.

JR Central currently operates 323 trains per day with a staggering annual average delay of just 0.9 minutes per train including delays caused by things beyond JR Central's control such as natural disasters. This exceptional level of punctuality is attributed to having a highly reliable operating system, very reliable infrastructure and rolling stock, comprehensive staff education and training, and vertical integration. "A railway is a total system," Hatta says, with each element focused on maintaining safety and reliability.

In March JR Central introduced its "10 Nozomi Timetable" with up to 10 Nozomi trains per hour in peak periods to help reduce overcrowding.

JR Central is currently preparing for another increase in maximum speed on the Tokaido Shinkansen to 285km/h, which will take effect in spring next year. While the railway is being coy about what effect this will have on journey times, there are only limited opportunities to raise the speed on the line due to the prevalence of curves and the line's proximity to buildings where noise is an issue.

In 2002, JR Central started to set aside funds each year for a 10-year project to renovate many of the structures on the line which are beginning to show their age. Research has been underway concurrently, mainly at the new Komaki research facility which opened in 2002, to find a less-disruptive and more cost-effective way of carrying out the work. JR Central says the research has resulted in a method of working which will not only substantially reduce interference to train services but also drastically cut construction costs, so much so that JR Central has been able to advance the start of the work by five years from 2018 to 2013.

The Tokaido Shinkansen is vitally important to the future success of JR Central as it generates such a high proportion of its revenue, but JR Central recognises that it has entered a time when "we must think of drastic ways to deal with feared future aging and large scale disasters" as it takes a very long time to plan and build a new railway. This, together with a realisation that there is a limit to how much extra capacity can be squeezed out of the existing high-speed line, is the background to JR Central's bold decision to build the Chuo Shinkansen superconducting maglev line entirely with its own funds and as quickly as possible.

Environmental protection measures have already been approved and JR Central will start construction later this year. The first phase will link Shinagawa in Tokyo with Nagoya and will incorporate the Yamanashi maglev test line which is currently being extended from 18.4km to 42.8km at a cost of Yen 355bn. A maximum speed of 581km/h has been reached so far during test running.

When the maglev line opens in 2027 the journey from Tokyo to Nagoya will take just 40 minutes saving about one hour on the current rail journey time of 1h 35min. JR Central plans to eventually extend the maglev line to Osaka.

This project is a massive commitment by JR Central as a private company both in terms of the risk it is taking in funding such a huge project from its own resources and by adopting a radically new technology. It will certainly be another cause for celebration when the first commercial maglev train departs in 2027.