Fast Tracking

It’s easy enough to make a train go fast but much harder to make it stay on the track and to give passengers a comfortable ride.

The 0 Series Shinkansen

These are the ones Japanese remember most fondly and which so amazed the world when the Tokaido Shinkansen [東海道新幹線, lit. New Arterial Line; a.k.a. Bullet Train] connecting Tokyo and Osaka opened on 1st October 1964 just in time for the Tokyo Olympics. These first trains didn’t have any name other than shinkansen and were only called 0 Series when it later became necessary to differentiate them. 0 Series trains ran at speeds of up to 200 km/h (125 mph), with later increases to 220 km/h (135 mph). More than 3,200 cars were built but by 2008 none remained in service. 

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The buffet car was always a special treat.

The Series 0 shinkansen wouldn’t have been possible without various 1950s innovations that raised bogie performance and reduced weight and vibration so the trains could run safely and comfortably at faster speeds.

• incorporating springs and oil dampers into the bogie suspension to significantly reduce vibration
• mounting traction motors on the bogie frame and using flexible couplings and gears to transmit power to the wheels
• using a press-welded structure to reduce the weight of the bogie frames
• using disk brakes to increase braking power at greater speeds
• using air springs in the carriage suspension to increase passenger comfort

 [Refer to this document for more about the early technical innovatoins.]

The 200 series

In 1982 the Tohoku Shinkansen Line and the Joetsu Shinkansen Line opened with 200 Series trains that resembled the earlier 0 Series trains but were lighter and more powerful for mountain routes with steeper gradients. They had small snowplows to handle snowfall and exposed equipment such as the motors and compressors beneath the train was enclosed in sealed cowling to protect it from snow. Another innovation were the special air intakes designed to remove snow from the air. The first 200 trains had a top speed of 210 km/h (130 mph) but later ones could do 240 km/h (150 mph), and some were converted to be capable of 275 km/h (171 mph). By 2007 none remained in service.

The 100 series

The naming system for new train series gave new trains running east of Tokyo even numbers and those running west of Tokyo odd numbers. [Having 100 come after 200 defeats the purpose of numbering, but not of naming. This post will therefore order the various series according to their chronological date of first introcution and irrespective of any implied numerical value. G.] The 100 Series trains began service in 1985 and had a more pointed nose as well as two double-level cars in the middle and that were not powered, most likely because there wasn’t sufficient space left between the bogies to do so. By 2012 none remained in service.

The 100 Series prompted a remodelled front car for the earlier 200 series. Apart from the livery, the only obvious difference is the snowplow.

The 400 series

The first mini-shinkansen series was introduced in 1992 on the Yamagata Shinkansen route branching from the Tohoku Shinkansen route at Fukushima. The mini-shinkansen concept involved regauging existing 3 ft 6 in (1,067 mm) gauge lines to standard gauge and linking them to the shinkansen network to allow through-running. [W.] In order to negotiate local rail networks, the 400 Series was designed to have lower clearance and to be narrower. Steps projected from below the doors to bridge the gap between the train and the platform.  The 400s had a maximum speed of 240 km/h but all were withdrawn by April 2010.

The 300 Series

The 300 Series was introduced in 1992. They could carry about 1,300 passengers at a maximum  speed of 270 km/h (170 mph). The 300 Series abandoned the bullet-like nosecone for a more automobile-like styling with wider windscreen and lowered headlights, and also had flared panels protecting the front bogies from snow. It also had bolsterless bogies for greater stability at high speed, higher running performance on curves, less vibration and greater ride comfort, smaller size and lower weight to reduce track wear. All these improvements are to do with issues fundamental to rail transportation. 

A 300 set the 1991 Japanese speed record of 202.3 mph (325.7 km/h). A total of 69 were built. All were withdrawn from service by March 2012. 

The unusual shape of the nose of 300X was designed to minimise noise.

Another 300 X variant pursued aerodynamic advantage. Changes such as these and the incrasingly flush window frames and headlight casings reveal increasing attention being paid to air movement at the leading edges of the train. 

The 300X research project involved two test runs per week at night on track between Kyoto and Maibara on which revenue-operating trains ran during daytime. Testing covered rolling stock, tracks, overhead lines, and signal communications and involved simulations, constituent technology, and test runs, or combinations of the three. The simulations made it possible to predict situations that up till then could only have been checked with on-track tests, and provided insight into “boundary” problems that span a number of technological fields.

For example, it was found that lightening the unsprung mass affected running stability and ground vibration along the tracks.

Series 300 rolling stock was about 25% lighter than 100 Series, with a 30% lighter unsprung mass.  This led to 1998 track maintenance expenses being only 85% of those in 1993, despite a 50 km/h increase in speed. [ref.]

Boundary problems aren’t uncommon in railway transportation as they depend upon civil engineering, mechanical, electrical, and information systems that need to be designed and administered as a total system in a unified manner. It’s easy to see how boundary phenomena can be difficult to spot as a change seemingly insignificant in one field might have (good or bad) consequences for another.

The E1 Series

This was originally going to be designated the 600 Series. E1 trains were introduced in 1994 to alleviate overcrowding on the Tohoku and Joetsu routes. They had 3+3 seating in standard class and also had double-deck carriages. The first four upper deck non-reserved cars had 3+3 seating without individual armrests and did not recline. All E1 trains were withdrawn by September 2012.

The 500 series

These entered service in 1997 and had an operating speed of 300 km/h (185 mph). Innovations included the use of computer-controlled active suspension for a smoother and safer ride, and yaw dampers fitted between cars to prevent excessive sway. 

It had a revolutionary wing-graph pantograph.

In the case of the pantograph noise, air rushing over the struts and linkages in the mechanism was forming into so-called Karman vortices, also known as a Karman vortex street, and this turbulence was causing most of the noise. Karman vortices are created at all scales, from islands in the ocean to car aerials, and are manifested wherever a single bluff body separates the flow of a fluid. Alternate and opposite eddies swirl downstream of the obstruction, swinging back and forth as the force of one dominates and then the other. 

Vortex streets are a basic dynamic and some animals such as bees are thought to take advantage of it in their flight. Eiji Nakatsu is the bird-enthusiast and engineer credited with applying this physics to train aerodynamics. He studied the owl and its noise-dampening feather parts (fimbriae) that are a comb-like array of serrations grown on the leading edge of the primary wing feathers. They break down the air rushing over the wing foil into micro-turbulences that muffle the sound that typically occurs in wings without this feature. From 1994 a new “wing-graph” replaced the traditional pantograph and was a great success. The train could now run at 320 km/hr and meet the stringent 70dBa noise standard set by the government. [ref.]

There was also the more intractable problem of trains entering tunnels creating sonic booms at the other end of the tunnel. Japan’s rail tunnels are somewhat narrower than their European counterparts and often begin and end vertically, so when the shinkansen enters a tunnel at speeds above 200 kilometres per hour, the sudden increase in air pressure can cause a loud “boom” at the other end of the tunnel. In some cases, such shock waves are thought to have damaged tunnels in Japan, ripping chunks of material from tunnel ceilings.

It’s counterintuitive at first for the boom to happen at the exit when the train enters the tunnel.” [It seems to suggest the piston effect can’t be sustained. G] This German video gives both the boom and the train later leaving the tunnel.

The other way around is tweaking tunnel portals to the same considerations. Victor

Nakatsu once again searched for an answer in nature when a junior engineer observed [uncredited, as is the Japanese way] that the test train seemed to “shrink” when it was traveling through the tunnel. Nakatsu reasoned that it must be due to a sudden change in air resistance, from open sky to closed tunnel, and wondered if there was an organism that was adapted to such conditions.

From his birdwatching experiences, Nakatsu remembered the kingfisher, a bird that dives at high speed from one fluid (air) to another that is 800 times denser (water) with barely a splash. He surmised the shape of its bill was what allowed the bird to cut so cleanly into the water. The design reduced the sonic boom effect, and allowed the train to run at higher speeds and still adhere to the standard noise level of 70 dBa. It also reaped further benefits immediately. The new Shinkansen 500 had 30 percent less air resistance than the preceding 300 series. A measured actual train run (maximum 270 km/hr) showed a 13 percent reduction in energy consumption. [ref.]

Sadly, this wonderful story dumbs down to this.

The unhappy ending is that each train cost approx. 5 billion yen and only nine were ever built. Although technologically innovative, the cost-peformance was poor and so the 500 Series thus went the way of the Sukhoi SU-47 and the F22 Raptor [c.f. Architectural Myths #8: Clean Lines].

The E4 series

These dual-level 8-car trains were designed as the second mini-shinkansen to replace the E1. They also began service in 1997 and had a maximum speed of 240 km/h (150 mph). 

The E2 Series

The E2 was introduced in 1997 and had a maximum speed of 275 km/h (170 mph). The most noticeable improvement was the shift from small windows for each seating bay to wide windows as with the E4 . The pantograph now had a single arm with an aerofoil-shaped mounting that did not need shrouding. Its exposed components were only those that had a reason to be exposed to the air. Even the horn of the pantograph (the curved ends of the slider or that top bar thingy that glide on the wire) had wavy holes drilled through them to generate vortices to suppresses the pantograph noise at high speed. [ref.]

A total of 53 were built but withdrawals began in 2013 when they began to be replaced by E7 Series trains.

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The E3 Series

This is the fourth of mini-shinkansen designed with reduced width and clearance and to run on gauges for lower loads. Doorway steps fold out to make up the difference width when stopping at regular shinkansen stations. All were replaced by E6 Series trains by March 2014.

The 700 series

Introduced in 1999, with a maximum operating speed of 285 km/h (175 mph), the 700 series is immediately recognisable by its flat ‘duck-bill’ nose designed to reduce the piston effect when the train enters tunnels. The design owes much to the 300X research program. As with the 500 series trains, yaw dampers are fitted between vehicles, and all cars feature semi-active suspension for smooth ride at high speed. These trains were designed to deliver high performance and better ride comfort and interior ambience than the 300 Series but at 20% less cost than the 500 Series. [W.]

Between October 2008 and June 2009, JR Central’s fleet of sixty 700 series sets underwent modifications to increase the acceleration from the original 1.6 km/h/s to 2.0 km/h/s (0.44 m·s⁻² to 0.56 m·s⁻²) on the Tokaido Shinkansen in order to improve timetable planning flexibility.

These trains were the core trains on the mainline shinkansen routes 2006–2011 but were gradually withdrawn and replaced with N700 Series trains and 800 Series trains.   

An 800 Series Train.

The N700 series

N700 series trains have a maximum speed of 300 km/h (186 mph), and tilting of up to one degree allows the trains to maintain 270 km/h (168 mph) even on 2,500 m (8,200 ft) radius curves that previously had a maximum speed of 255 km/h (158 mph). The enhanced acceleration of the 700 Series (1.6 km/h/s to 2.0 km/h/s ) must have produced significant benefits for timetable flexibility because maximum acceleration rate of the N700 Series is 2.6 km/h/s. This means a 715 tonne train can accelerate from 0–270 km/h (170 mph) in only three minutes, and that it can travel between Tokyo and Osaka in 142 minutes, eight less than before. [W.]

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This image of the N700 pantographs shows the (yellow) horn of the pantograph with its small holes that create the noise-surpressing vortices.

The E5 series

The E5 Series was introduced in 2011 and is still in service. Maximum speed is 320 km/h (200 mph). Pantograph improvements continued.

Until the E5, mini-shinkansen innovations had mainly been for width and clearance but the east-west routes through the Japan Alps have more and longer tunnels so the tunnel boom problem was greater for these trains. The E5 is the latest attempt to solve the problem without incurring the expenses of the 300 Series or the undue attentions of biomimeticists.  

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Doctor Yellow

“Doctor Yellow” is the name given to trains specially customised for track checking and diagnosis. Doctor Yellow trains are dispatched to check track immediately after earthquakes and also when track sections are experiencing severe weather conditions. Unlike regular shinkansen, these trains are sometimes operated at full speed (up to 443 km/h ~ 275 mph). [ref.]  It’s a good day for a train enthusiast when they see one. Here’s six loving shots of the two 923 Series Doctor Yellow trains developed from the 700 Series, plus a 0 Series Doctor Yellow from fifty years ago.

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Takeways: 

• Eiji Nakatsu is remarkable for not only for observing Nature but also for listening to the straightforward observations of said junior engineer who was first to articulate the problem in terms of the relevant physics.
• Boundary phenomena are nasty, especially as it’s not part of our psychology to look out for and take responsibility for the effect our actions have on others. Our culture of subcontracting and outsourcing may make some of them easier to identify but at the same time impossible to do anything about. (“Excuse me, there’s nothing in it for you but would you mind changing your way of doing things to solve a problem we’re having?”) Simply exchanging information between disciplinces is not teamwork.
• Two boundary phenomena stood out. One was how reducing the unsprung weight led to track maintenance economies. The other was how the sum of mechanical and physical factors that resut in improved acceleration is recognised as allowing for increased timetabling flexibility. This is probably a Japanese euphemism for “more trains more frequently” but identifying that the two are linked is awesome.
• With different routes needing different solutions for different conditions, the story of technical improvements across the Shinkansen fleets is not linear in the way the development of Sukhoi fighter planes was [c.f. Architectural Myths #8: Clean Lines]. The main revenue-earning lines were not always the ones that identified problems or the initiators of innovation, as shown by the tunnel boom solutions.
• What’s also impressive is that not one shinkansen innovation has been aesthetic for its own sake. Their various noses and front ends have never tried to be beautiful. How a very fast object goes through the air is very important in terms of energy efficiency and the noise it generates, and much research and development understandably went into optimising the shape of Shinkansen lead carriages and the nose in particular. It is a pity these highly visible “faces” of the shinkansen overshadow the effort that went into reducing the noise made by the pantographs that also travel through air at the same high speed.
• And let’s not forget the research and develpment intelligence embodied in the bogies that make high-speed train travel comfortable as well as make it safe and viable by keeping the train on the tracks in the first place. In fifty years and over 10 billion passengers, there have been no Shinkansen fatalities due to derailments or collisions. That’s some track record.

Acknowledgements:

• to www.allaboutjapantrains.com and japan-talk.com for helping me make some sense out of the series numbering
• to Isao OKAMOTO for his 1999 article on Shinkansen Bogies in Railway Technology Today
• to Hiromasa TANAKA for his 2001 paper, High-speed Rail Technology as Revealed by the Shinkansen
• to trainoftheweek.blogspot.ae for the interesting stuff about pantographs, and also the many references
• to www.greenbiz.com for the most convincing version of the kingfisher story.
• In this post I hope I’ve managed to communicate something of the amount of ongoing and focussed intelligence and research and develpment that has gone into making these trains. Many people out there know much more about them than me. I’ll be grateful to anyone who can help me correct any inaccuracies or who can think of more examples of design intelligence that might not be not immediately visible.

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