Shake but not broken

PUBLISHED : Sunday, 04 December, 2011, 12:00am
UPDATED : Sunday, 04 December, 2011, 12:00am


It began far out at sea, in a little-watched segment of a fault off Sendai, Japan. It reached land first as sound, the bass drum roll of heaven, amped up so that hundreds of miles away the sound blotted everything else out, pushed against ribs, even before the earth beneath began to shake. Later measurements showed the earthquake moved the entire island of Honshu eight feet closer to the United States and released energy equivalent to the explosion of nearly 500 megatons of TNT, roughly the same as letting off a tenth of the world's nuclear weapons at once.

The sound was not perceptible as far away as Tokyo, 300 kilometres to the south, but the vibrations were: buildings shook, some lost tiles and sheathing, there was damage at Tokyo Disneyland, in Chiba prefecture, and every earthquake detector in the Kanto area, which encompasses seven prefectures, registered the seismic waves.

It was 2.46pm on Friday, March 11, two hours before most office workers would normally head home. On the transport system were shoppers, children returning from school, tourists and others who did not have to be at a desk. With the confirmed detection of a major earthquake (the exact magnitude was, at first, underestimated), trains were halted mid-journey.

The United Nations Secretariat for International Strategy for Disaster Reduction called the near-total collapse of infrastructure (electricity, telecommunications, transport and water systems) caused by the quake 'synchronous failure'. The idea of such a failure in a highly modern, hard-wired society may seem counter-intuitive. We are used to being told that modern technological society is more adaptable and better able to cope with the unexpected. The internet, after all, was partly designed to serve as a series of redundant nodes in the event of a nuclear attack.

Of all places, Tokyo, with its huge LED displays and intersections that, even at night, are bright as a summer noon, has so often served as a showroom of technology: here is how the future will look and how it will work. But the earthquake kicked over the city as easily as Godzilla wreaked havoc on its cardboard incarnations in old movies. Those modern pieces of infrastructure, all wired together like nerve endings, failed: they failed individually, they failed in groups, and they left a large metropolitan area without much of its transport lifeline.

Tokyo itself was not left entirely without electricity, but the places outside the capital that did lose their power supply did not simply lose lighting. Homes and offices with internet phones (an increasingly popular option) lost communications as servers went dead. Laptops with batteries, and certain wireless connections, fared better initially, but in many places the power was off for far longer than the life of the average mobile phone or laptop battery.

The mobile phone network (Japan has a 96.8 per cent mobile penetration) collapsed partly because of the inability of the system to cope with the number of calls and partly because of the loss of power, which left many mobile base stations with nothing but a standby battery. Reports verify that social media platforms such as Skype and Twitter, and some phone system e-mails, running on discrete systems, kept working, and were used for emergency communication, but the near collapse of the public communications grid added to the immedi- ate problems faced within the Tokyo metropolitan area.

Tokyo lives or dies on commuters travelling in and around the city by train. Those trains circle the city and stop at hundreds of underground stations, as well as travelling along a large number of overhead lines. They are fed by numerous lines from the Greater Kanto area (much of which lost power), all the way up to Tohoku (where the tsunami hit). Of course, there are cars and buses, but they carry only a small fraction of the number of commuters that the trains do. When the trains stopped, there were no immediate replacements, or even remotely foreseeable replacements. Stranded passengers were at risk, and there was no possibility of restarting the systems without first clearing them. That procedure could only be done by manual inspections of the trackbed, which had to be carried out amid huge aftershocks.

Less than an hour after the initial quake there were three aftershocks of magnitude seven or greater (7.0 at 3.06pm, 7.4 at 3.15pm and 7.2 at 3.26pm). Any one of those would have counted as a major quake in itself, and all struck after evacuation attempts had begun, posing additional hazards, some obvious, some not.

Earthquake damage can be immediate or cumulative. In Tokyo, where even the initial damage to tracks, tunnels and overhead railways was not immediately known, each large aftershock raised the possibility that minor damage could become major, and major damage could become catastrophic.

'We had 176 trains in the system at 2.46pm,' says Toshiake Kogure, manager of the technology section at the safety affairs department of Tokyo Metro. Tokyo Metro is one of two rapid-transit systems that make up the city's subway. 'At the first shock, an emergency stop order was transmitted via the railway radio system. This enabled all train engineers to apply emergency braking systems. The second, stronger shock resulted in an automatic power shut-off throughout the system.

'We had to restore our own signal system power, but after that was restored we [allowed] the trains that were between stations to [proceed] to the next station at a speed of 5km/h or less. This slow speed allows the train to be stopped instantly if something is seen to be wrong or the line is broken or otherwise damaged.'

Tokyo Metro's dedicated communications systems were not damaged, Kogure says, and the transit company did not call for assistance from the police, fire or other emergency services. He also says that 'moving the trains at 5km/h was not a response that had been preplanned'.

'We train personnel on how to evacuate from trains and stations, and how to assist passengers, and we test that the automatic earth- quake signal/alarm systems in the crew cabins of the trains are in good working order.'

Once the train systems were shut down, the crowds being evacuated from offices, residences, hotels and so on in Tokyo, most of whom had no way of communicating with family or friends, had to be steered away from the stations, which posed both a crowd control problem and a logistical problem. Millions would have been planning to take trains home.

In a survey conducted by Japanese research company Survey Research Centre one month later, 30 per cent of the more than 2,000 respondents reported that they had walked home - a journey that took some up to 12 hours.

That was the experience of Ushioda Steven, visiting from the US. His train was at a station on the Shinagawa line when the carriage he was in was lifted a couple of feet in the air before dropping and rising again.

'No one screamed, but there was a lot of chatter,' Steven says. 'Some people got off immediately, eventually everyone did, and we were told to wait, the train would continue in a while. But it didn't, so I went up the street. I could not reach my girlfriend or my father, so I just walked for hours, [and] finally managed to make a call back to the US.'

Another survey found that about 20 per cent of respondents did not get home that night. It is unclear what percentage of respondents who were travelling into areas where there was no train service or power were fortunate enough to get a hotel room.

The nature of the 'long walk home', which involved millions of people, is typical of the day's events. While there were emergency crews on the streets of Tokyo, and personnel to open public places as rest stops, there was, as yet, no general mobilisation of the armed forces (and when there was, they were needed for the urgent tasks at Fukushima, searching for tsunami victims and clearing highways).

Many restaurants stayed open and served soup and other food until supplies ran out. In fact, many restaurants and ramen shops still had power, and those that had radio or television were much more aware of the scope of the disaster than many of the stragglers.

Key highways were rendered impassable. Some would not be reopened until after the Ground Self-Defence Force had cleared them.

The trains that had been stopped between stations posed specific problems. Nonetheless, the passengers and crew, spread across the entire metro area, had to be evacuated. This was done with little government assistance. A department head in the emergency services section of the Tokyo metropolitan government says the city government co-operated at ground level, in such matters as helping wards (districts) set up emergency shelters, open public facilities for use and move crowds away from transit stations that had been closed. However, the official confirms that no emergency, fire, police or paramedics were dispatched directly to the transit stations or facilities, nor were any requested.

The Japanese Ministry of Land, Infrastructure, Transport and Tourism (MLIT) lists 957 trains that were within a 30-kilometre radius of Tokyo when the disaster struck. MLIT estimates the trains were carrying 190,000-plus passengers. Of those trains, 613 were stationary (either at a stop on their route or at their end terminal) while the remaining 344 were between stations. The passengers of 134 trains had to be evacuated along the rails, on foot.

The 27 Shinkansens, or 'bullet trains', that were travelling routes in the badly hit Tohoku region were stopped and evacuated without injury or loss, though there was substantial damage to rail lines and trackbeds. A bullet train travelling at top speed (about 322km/h) needs up to 6.5 kilometres to come to a stop.

WHEN THE QUAKE HIT, the Diet (parliament) was in session. In the main hall there is a large crystal chandelier, which began to swing as the walls shook. The building was evacuated and a national emergency command centre set up within four minutes. By 3.37pm, there was an emergency meeting of the top advisers to the prime minister. Ten minutes earlier, the first of three waves had struck Fukushima, and an even larger tsunami had hit Sendai and points south.

The synchronic failure, had, in fact, begun before anyone had had time to react. In Tokyo, however, most people did not know what was happening further north - although it was hard to miss what was happening around them.

Isabell von Rein is an exchange student from Leipzig, Germany. Her brother had come to visit her a few days earlier. They were in the Hard Rock Cafe at Ueno station.

'We did not hear anything before,' she says. 'There was a kind of jolt, hard. I joked with my brother that there was an earthquake, but the shaking continued and several people inside the cafe ran out, and other people started screaming. Then the cafe staff told everyone to get out of the cafe. Most people were standing in the main hall or just outside the plaza. There was no panic, but there was confusion.'

The hostel she and her brother were staying in was in Akihabara, so they walked back. 'All of the convenience stores were being emptied, there were only toys and drinks with alcohol left.'

The hostel had not lost power or its phone service. When they managed to phone Germany, their parents told them to fly home as quickly as possible.

Narita airport had been closed and evacuated on the Friday night (several US-flagged airliners were permitted to land at a nearby US military base under a special agreement with the Japanese government.)

'The next day, getting to Narita we had to take three separate side lines, as a direct service was not available,' von Rein says. 'The airport was filled with people, very chaotic, and we wound up sleeping there that night. On Sunday, we were finally able to get seats on a flight to Vietnam, from where we were able to get a flight back to Frankfurt.'

Hajime Saito, 41, a systems engineer with an applied robotics company in Tsukuba was in Chiba, 30 kilometres west of Tokyo, for a meeting.

'There was no advance sound but the building shook, hard. It was not just the jolt from the usual earthquake or tremor, it was a rolling motion that went on and on. People began to scream and we threw open the doors of the hall to let people out as quickly as possible. Outside, I could see there was no power for at least three to four kilometres. I was also concerned about liquefaction from such a prolonged quake, with aftershocks coming so frequently.'

Liquefaction is a physical process in which saturated soils exposed to extreme stress or repeated vibrations in certain frequencies, such as earthquakes, begin to behave like liquids. The results are devastating for any structure that doesn't have sunken support piers stretching down into bedrock. In an area such as Chiba, where so much development was done on reclaimed rice fields and man-made lands without support piers, the threat was imminent. Liquefaction was observed at Urayasu and Abiko, in Chiba, and Kuki, in Saitama prefecture. A part of Tokyo Disneyworld had to be shut down because of liquefaction in one of the car parks, according to a government official.

'I decided the best way was to walk to Tokyo, where I hoped there would be power, and I would be better able to judge what to do next,' Saito says. 'Walking the 30 kilometres took about five hours so I was in Tokyo before 10pm. By then the hotels were filled, but there were Tokyo Metro government personnel on hand and they opened the Tokyo International Forum for people who needed to rest.'

Saito has family in Yokohama, which had not lost power. He was able to reach there the next day and then to return to Tsukuba on an express train run very slowly.

ACCORDING TO MLIT, trains operating in the Tokyo region are equipped with automatic shutdown mechanisms, and, when these are not operating, the standard procedure is for a train engineer to stop the vehicle and report on its situation and location. All of these reports are conveyed to an emergency centre, which acts as a clearing house for information, a dispatcher of specialists and a control centre. This was the way it had been practised and prepared for, based on previous quakes and predicted scenarios.

Once the trains have been halted, there are several factors that determine what will happen next: the objective conditions (in this case, the earthquake and aftershocks), the train engineer's assessment of track conditions, the information reaching the emergency centre, the immediate needs of the passengers and the availability of emergency or rescue crews, if they are needed.

The railway companies' post-quake course of action combined procedures they had practised and systems that were familiar with very necessary improvisations. That combination, along with at what levels and how integration between the planned and the improvised took place, are now major areas of attention for MLIT, which oversees the railways.

Joe Zearfoss, a senior consultant with Aon Global Risk Consulting, said about the evacuation: 'That kind of experience, particularly when it is a success, represents the sum total of [the transit company employees'] experience. Despite the overwhelming nature of the disaster, their command and control were intact and they were individually and collectively organised. It is clearly a success story, but that kind of success does not happen accidentally. There had to have been a structure in place that was flexible enough to allow it to happen. And that never happens by accident. That happens when drills and exercises are continuously followed up by good critiques.'

Zearfoss points to the decision to move the trains at 5km/h. 'That is a clear indication of a risk assessment made under pressure, even on the fly, but one that takes into account that the prime goal is to get the people in the trains to the safest possible point in the safest possible manner.' Walking through a tunnel that is also carrying active power lines is not the safest activity, Zearfoss adds, particularly during a time of strong aftershocks.

'There were certainly elements of luck: the number of trains that were already in stations and only had to let passengers out; the time of day; and the fact that they retained the ability to communicate between particular crews, stations and sub-command or command centres,' he says. 'It was not a crisis that self-resolved, but it was a crisis where the elements to resolve it were, fortunately, in place and/or well deployed.

'And there are certainly lessons in that.'

This article has been adapted by the author for Post Magazine from his original, which appeared in US transportation magazine InTransition.