RailwayTechnologyAvalanche

The Joetsu Shinkansen, which was disrupted by the NiigataChuetsu Earthquake, restarted services on December 28,2004, and was put back into normal operation for the firsttime in 66 days. Despite the fact that the earthquake causedderailment of a train on the line, there was not a singlecasualty. Some say that was "lucky." I do not think that thiswas merely good luck. Forty years have passed since thefirst Shinkansen was put into operation. Since then,Japanese railway engineers have made continued efforts toimprove the earthquake-resistance of the Shinkansensystem, while learning lessons from, say, the great Hanshin-Awaji Earthquake in 1995. I feel, therefore, that in theNiigata Chuetsu earthquake, fortune favored these efforts.However, there are still many things to do to make theShinkansen system much more resistant to earthquakes.RTRI has been striving to clarify the mechanisms of trainderailment during an earthquake. At present, a significantamount of resources is being poured into the research onthis particular subject. As increasing quantities of researchresults are accumulated, we anticipate that new technologydevelopments will be implemented for improving theearthquake-resistance of the Shinkansen system, includingvehicle/track structures which reduce the possibility ofderailment, inventions to minimize the damage topassengers in case of derailment, wayside structures havingbetter resistance to earthquakes, and more sophisticatedearly warning systems.Starting in April 2005, RTRI will launch research activitiesbased on its new master plan—Research 2005. For thecoming five years, RTRI will implement R&D in accordancewith this master plan. (For a detailed description of themaster plan, see the relevant article in this volume.)Since 1990, RTRI has implemented technology

development for Maglevon the Yamanashi testline. This stage of projectwas finalized in March2005. The MaglevPractical TechnologyEvaluation Committee ofthe Ministry of Land,Infrastructure and Transport has judged that "The keytechnologies for practical application of Maglev have nowbeen established." In Research 2005, therefore, RTRI is tofocus on applying its accumulated Maglev technologies toconventional railways, instead of extensive Maglevtechnology development.Research 2005 has been formulated based on predictedchanges in the Japanese railways and social structure duringthe next 5 to 10 years. The major changes predicted include:(1) a continually declining birthrate and increasingly agedsociety in Japan, (2) growing national awareness of theglobal environment and (3) rapid progress in IT.With the recognition of the above trends, RTRI intends tocreate new technologies for the future of railways byimplementing R&D activities more energetically than everbefore. These include new railway management technologiesfor saving labor, railway services that are convenient andcomfortable even to the elderly, fuel cell vehicles, technologyfor saving energy, and maintenance technology applyingremote monitoring and satellite communication.

Mr. Mitsutoshi INAMI

1

45

■ Foreword Mitsutoshi INAMI ................................................................ 45

■ Outline of the New Master Plan (RESEARCH 2005) Kiyomitsu MURATA ............................................................................... 46

■ Development of Magnetic Rubber Damper with a Constraining Layer (MRDC) Masanori HANSAKA ............................ 47

■ Adhesive Waterproof Sheeting for Preventing Water Leakage into Underground Structures Naoyuki YAGUCHI and Masaru TATEYAMA ... 48

■ A Study of Method for Assessing The Overall Environmental Impact of Railways Naoki AIHARA ............................ 49

■ Manufacturing and Applications of High TemperatureSuperconducting Bulk Hiroyuki FUJIMOTO ........................................ 50

GENERAL INFORMATION

ARTICLES

March 1, 2005 No. 8

Railway Technical Research Institute2-8-38 Hikari-cho, Kokubunji-shiTokyo 185-8540, JAPAN

Copyright © 2004 Railway Technical Research Institute. All rights reserved.Reproduction in whole or part without permission isprohibited. Printed in Japan.

Newsletter on theLatest TechnologiesDeveloped by RTRI

Foreword

Mitsutoshi INAMIBy Mitsutoshi INAMI, General Manager, Planning Division

From EditorToru MIYAUCHI: Assistant Manager, International Affairs, Information and International Affairs DivisionA web page has been created for the Railway Technology Avalanche (Newsletter). Please click the "Newsletter" icon on the Railway Technical Research Institute website

（http://www.rtri.or.jp/index.html）. You can also take out a subscription to the Newsletter and download back numbers in pdf format.

2

46 Railway Technology Avalanche No. 8, March 1, 2005

Our new master plan, "RESEARCH 2005", designed tocover the five years starting with fiscal year 2005, has fivebasic activity policies: (1) The creation of railwaytechnologies for the 21st century, (2) The display ofintegrated power as a railway engineering group, (3) Quickresponse to needs, (4) The communication of railwaytechnologies to the next generation and accumulation ofbasic technologies, and (5) The dissemination of railwaytechnologies and communication of railway-relatedinformation. On the basic of these policies, we intend tocarry out various activities, including research anddevelopment (R&D).

1. R&DIn order to concentrate our power and effectivelyimplement R&D activities in line with the basic activitypolicies mentioned above, we have set "R&D objectives"(Reliability, Convenience, Low cost and Environmentalcompatibility), which define the directions of our R&D, and"prioritized R&D objectives" (R&D for the future ofrailways, Development of practical technologies and Basicresearch for railways), which clearly shows the R&D itemsto be focused on (see Fig. 1).

(1) R&D for the future of railwaysWe shall positively tackle themes that will enable us toachieve technological breakthroughs for the future ofrailways, and give our minds to putting the R&D resultsinto practical application in 5 to 10 years. Table 1 lists theR&D themes to tackle for railways in the future. As anexample, the "Development of high-speed, large-capacityinformation and telecommunication technologies forrailways" shown in the table, features commonspecifications of the telecommunication infrastructure thatwill be established in order to offer an advanced networkservice to passengers on trains running at high speeds. Inthe "Development of fuel cell vehicles", which is positionedas one of the most important themes relating to theenvironment and energy issues, we shall conduct runningtests with railway vehicles on which fuel cells are mounted.

In line with the theme"Application of linearmotor car technologiesto the conventionalrailway system", weshall carry out R&Dinto applying advancedtechnologies that havebeen developed forMAGLEV, such as thesuperconductivity and linear motor, to the conventionalrailway system. Specifically, we shall tackle, for instance,the development of superconducting magnetic bearings anda rail brake system which employs linear induction motors.

(2) Development of practical technologiesIn response to specific requirements from JR Companies, weshall promote R&D that will help them to solve problems inthe field. In addition, we shall set our voluntary themes tofocus on the technological fields where the developmentshall be given top priority. Furthermore, we shall continuewith contract-based research and development.

(3) Basic research for railwaysWe shall carry out "analytical research" into the elucidationof railway-specific phenomena such as dynamics andtribology, and simulations of non-steady state aerodynamicphenomena. In addition, we shall try "exploratory andintroductory research" aiming at applying new technologies,materials and research techniques to railways, such as thepossibility of applying nano-materials to railways, etc.

2. International ActivitiesBy attending various international conferences, includingmeetings of the World Congress on Railway Research(WCRR), we shall strive to promote the exchange ofinformation on railway technology. In addition, we shallengage in joint research with research organizations inEurope and Asia, and help establish international standardsfor railways.

Outline of the New Master Plan(RESEARCH 2005)Kiyomitsu MURATADeputy General Manager, Planning Division

Figure 1. R&D activities of RTRI.

Highly-reliable railways

More convenient railways

Low-cost railways

Environment-compatiblerailways

Bas

ic r

esea

rch

for

railw

ays

R&

D fo

r th

e fu

ture

of r

ailw

ays

Dev

elop

men

tof

pra

ctic

al te

chno

logi

es

R&D 0bjective Theme[Improvement of train running safety] • Configuration of signaling systems with RAMS index and its application• Development of method to evaluate characteristics of vehicle dynamics with a

hybrid simulator[Securing of stable transportation] • Evaluation of earthquake-resistance of existing railway facilities and implementation of

seismic measures • Application of sensing technology and information technology to railway facilities

management

[Improvement of convenience] • Development of high-speed, large-capacity information and telecommunication

technologies for railways • Improvement of efficiency of transportation planning based on dynamic demand forecast [Improvement of comfort] • Development of human simulation technologies to improve safety and comfort

[Reduction of maintenance cost] • Creation of models to simulate rail damage and ballast track deterioration and

evaluation of techniques to reduce maintenance costs • Development of a new maintenance-free and low-noise track

[Noise-less railways] • Development of a tool to predict rolling noise and structure-borne noise and measures

for noise reduction [New energies] • Development of fuel cell vehicles • Application of linear motor car (MAGLEV) technologies to the conventional railway system

Table 1. Themes of R&D for the future of railways

Highly-reliablerailways

Moreconvenientrailways

Low-costrailways

Environment-compatiblerailways

3

Railway Technology Avalanche No. 8, March 1, 2005 47

Recently, with the increase in demand for faster railwaycars (from railway users) and for a quieter livingenvironment (from communities along railway lines), thereis a growing need to control railway noise and vibration. Ofthe various railway facilities, steel bridges are one of themajor sources of noise and vibration. Accordingly,controlling their noise and vibration has become animportant problem. The steel railway bridges arecharacteristic in that the noise (structure-borne noise) due tothe vibration of girder members is extremely loud. Becauseof this, providing the girder members with a damper hasbeen studied as a measure to reduce the noise and vibrationof steel railway bridges. Most conventional dampers are ofthe type that is bonded to the girder. Since the work withdampers of this type requires a number of processes,including the surface preparation of the vibrating body(base layer), a high-performance damper which offers betterworkability is called for. Under these conditions, we havedeveloped a magnetic rubber damper with a constraininglayer, MRDC, as shown in Figs. 1 and 2.This new damper consists of a constraining layer(galvanized steel sheet) laminated with a magnetic rubberlayer. The magnetic rubber layer is made of butyl rubberwith added ferrite powder (particle size: 5 to 10 µm) formagnetization. The constraining layer is used to improvethe damper performance (e.g., the shear deformation can beamplified by constraining the magnetic rubber damper). Asshown in Fig. 3, MRDC utilizes the magnetic attraction of the magnetic rubber layer to facilitate installing

it to the steelvibrating body. The performance of conventionaldampers dependsupon the internalloss due to theshear deformation of the rubber layer. With MRDC, theinternal loss of the magnetic rubber layer is smaller thanthat of the rubber layer of a conventional damper, but, thefrictional loss due to the slide displacement between themagnetic rubber layer and the base layer (vibrating body)comes into action, in addition to internal loss of magneticrubber layer. Therefore, as shown in Fig. 4, thanks to theeffect of frictional loss, which is little influenced bytemperature, MRDC retains its high performance over awide temperature range, whereas the conventional dampershows high performance only within a certain limitedtemperature range, because of the temperature dependenceof the rubber layer.As shown in Fig. 3, the levels of noise at a steel bridge on aconventional JR line were measured before and afterapplication to the web plate of the main girder of MRDC.As shown in Fig. 5, at a measuring point about 12.5 m fromthe center of the near-side track, a noise level decline ofabout 3 dB was observed over a wide frequency range.Thus, it was confirmed that MRDC was effective inreducing the noise produced by steel railway bridges.

Development of Magnetic Rubber Damper with aConstraining Layer (MRDC)Masamori HANSAKASenior Researcher, Vibration-Isolating Materials, Materials Technology Division

Figure 1. Structure and vibration damping mechanism of magnetic rubber damperwith a constraining layer (MRDC).

MRDC

Main girder of steel brige

Figure 3. A picture of installation ofMRDC.

Constraining layer

Magnetic rubber layer

Base layer (plate of steel brige)

Vibration

Magneticallyattractive force

Internal loss

Frictional loss

-400.02

0.05

0.1

0.2

-20 0 20Temperature (°C)

Loss

fact

or η

40 60 80

Conventional damperMRDC

Figure 4. Loss factor of MRDC andconventional damper.

η is loss factor at 500Hz measured by theresonance method with two beam-type sampleswhose size was 225mm long × 25mm wide ×5.5mm thickness on both sides of a steel beamwhose size was 500mm long × 25mm wide ×10mm thickness

Figure 2. A picture of MRDC.

Constraining layer (zinc-plated steel)

Magnetic rubber layer

63 125 250 500 1k 2k 4k 8k A.P.

100

90

80

70

60

50

Frequency (Hz)

Noi

se le

vel (

dB(A

))

Before installationAfter installation

Figure 5. Measuring result of noise levelaround steel railway bridge before and afterinstallation of MRDC (at a point distant fromthe center of near side track).

4

48 Railway Technology Avalanche No. 8, March 1, 2005

IntroductionIn subway construction works, underground concretestructures in stations, or sections under a thin overburdenlayer, are built by the cut-and-cover tunneling method. Withthose underground structures, damage to various facilitiesinside the structures caused by the leakage of water, or theextra costs required to prevent water leakage, can become aproblem. As a measure to prevent the leakage of water intoan underground concrete structure, the pre-waterproofingmethod is used, in which waterproof sheeting or some othersuitable covering is applied to the earth-retaining wallsbefore construction of the structure (Fig. 1). However, evenwith this method, it is difficult to prevent the leakage ofwater completely. One of the conceivable causes of waterleakage is local damage to the waterproof sheeting. Namely,with conventional waterproof sheeting, it is considered thatif the sheeting is damaged, the groundwater that seepsthrough the damaged part flows freely between the sheetingand the structural concrete, and therefore the water leaksthrough cracks in the concrete regardless of where thesheeting is damaged (Fig. 2(A)). In view of this, we havedeveloped a new type of waterproof sheeting which preventsthe leakage of water more effectively. This new sheeting,called adhesive waterproof sheeting, forms tight chemicalbonds to the structural concrete, and thereby prevents thewater from flowing between the sheeting and the concrete,even if the sheeting is partially damaged (Fig. 2(B)).

Construction of adhesive waterproof sheetingAs shown in Fig. 3, the newly developed adhesivewaterproof sheeting is composed of three layers—adhesive layer, protective layer and waterproof layer. Theadhesive layer is made of a special ethylene-vinyl acetate

copolymer with ahigh affinity forstructural concrete.The protective layer, which prevents the sheeting from beingdamaged by rugged surfaces of the soil-mortar undergroundwall, is made of polyester cloth. The waterproof layer ismade of an ethylene-vinyl acetate copolymer that has provenperformance in the NATM method, etc.

Verification of performance of adhesive waterproof sheetingTo verify the performance of the adhesive waterproofsheeting, we carried out watertightness tests, strength tests,etc. As a result, it was confirmed that the sheeting hadsufficient waterproofing performance and bond strengtheven under high water pressure of 500kPa. In order toconfirm the adhesion between the sheeting and concrete,and the applicability of the sheeting, we also carried out afull-scale work execution test in the field. As a result, it wasconfirmed that the sheeting that was bonded tightly to theentire concrete surface showed no damage or deformationunder fluid pressures during concrete placement, and fittedthe irregular surface of the soil-cement wall satisfactorily,displaying good applicability (Fig. 4). In addition, themeasured bond strength demonstrated that the sheetingwould develop sufficient strength even in practicalapplication. From all these results, it was confirmed thatwhen the adhesive waterproof sheeting was used in actualworks, the free flow of groundwater between the sheetingand concrete could be effectively prevented. Since itsapplicability in actual works has been sufficiently proved,the adhesive waterproof sheeting is being increasingly usedin subway construction work, by the cut-and-covertunneling method (Fig. 5).

Adhesive Waterproof Sheeting for PreventingWater Leakage into Underground StructuresNaoyuki YAGUCHI Assistant Senior Researcher, Vibration-Isolating Materials,

Materials Technology DivisionMasaru TATEYAMA Senior Researcher, Laboratory Head, Foundation &

Geotechnical Engineering, Structures Technology Division

Figure 1. Conceptual diagram of cut-and-cover tunneling method

Ground

Water

Fault

Crack

Waterleak

Waterproofsheeting

Concretestructure

[Nonadhesive waterproof sheeting](A)

Ground

Water

Fault

Crack

Waterproofsheeting

Concretestructure

[Adhesive waterproof sheeting](B)

Figure 2. Mechanism of water leakage

Ground Ground

Waterproof sheeting

Concrete structure

Soil mortar wall

Adhesive layer

Waterproof layer Damage protection layer

Figure 3. Structure of adhesive waterproof sheetingFigure 4. Adhesive waterproofsheeting bonded to concrete

Reverse side of sheeting

Naoyuki YAGUCHI Masaru TATEYAMA

Figure 5. Adhesive waterproofsheeting being applied in tunnel

5

Railway Technology Avalanche No. 8, March 1, 2005 49

A Study of Method for Assessing The OverallEnvironmental Impact of RailwaysNaoki AIHARASenior Researcher, Materials Technology Division

Figure 1. Overall environmental assessment based onLIME.

Figure 3. External cost by transportation facility between Tokyo andShin-Osaka.

Figure 2. Breakdown of emissions of environmental pollutants by type in the construction, manufacturing and operation of TokaidoShinkansen.

RC structures1.6%

Steelstructures

1.8%Earth

structures0.4%

Tunnels0.9% Tracks

6.0%

Electric powergeneration

0.3%Signals0.1%

Stations0.7%

Electric power usedby vehicles

88.0%

(a) CO2 emissions

RC structures20.4%

Steelstructures

12.9%

Earthstructures

3.2%

Tunnels9.7%

Tracks0.8%

Electric powergeneration

0.2%

Signals0.1%

Stations0.5%

Electric power usedby vehicles

52.2%

(b) NOx emissions

RC structures3.3%

Steelstructures

7.9%

Earthstructures

2.0%Tunnels

1.6%

Tracks 0.5%

Electric powergeneration

0.1%

Signals0.1%

Stations0.4%

Electric power usedby vehicles

84.2%

(c) SOx emissions

In modern society, there is a cry for measures to curb globalwarming and other far-reaching environmental impacts, aswell as local environmental impacts (environmentalpollution, etc.) that have long presented various differentproblems. Under this condition, industry has been strivingto understand and to reduce emissions of environmentalpollutants. Recently, efforts have also been made to assessthe effects of those pollutants on the environment andeconomy.In view of this, we have carried out a quantitative analysisof the global environmental impact of transportationfacilities by means of life cycle assessment (LCA). Theassessment method we use is the Japanese version of thelife cycle impact assessment method, based on endpointmodeling (LIME) that has been advanced in the LCAproject?an R&D project sponsored by the Ministry ofEconomy, Trade and Industry. This assessment methodconsists of calculating the amounts of variousenvironmental pollutants emitted from all transportationfacilities (inventory analysis) and the effects of theindividual pollutants on the environment (impact analysis),converting those effects in terms of monetary value, andassessing them as external costs (Fig. 1).In order to reach external costs, we first calculated theamounts of environmental pollutants (CO2, NOx, SOx)emitted from various types of transportation facilities. Forthe Tokaido Shinkansen, giving consideration to its lifestages, we studied the quantities of materials and energiesused in the development of ground facilities and the

manufacturing,operation andmaintenance of vehicles, and calculatedthe masses ofthe individualpollutants (Fig.2). Concerning automobiles and aircraft, we calculated themasses of individual pollutants emitted from theirinfrastructure against the yen amounts of transactionsshown in the latest inter-industry relations table. Thequantities of energy used were obtained from the lateststatistics.On the basis of the calculated amounts of pollutantemissions, for each of various types of passengertransportation facilities, we calculated the external cost perperson between Tokyo and Shin-Osaka (distance: 551 km).As a result, it was found that the external cost of theShinkansen was about ¥31/person/551 km. On the otherhand, the external cost for the national average of railwaysin Japan in the same 551 km section was estimated to beabout ¥73/person (Fig. 3).Converting environmental impacts in terms of external costby means of LIME as above has the advantage ofpermitting any industry to easily express various kinds ofenvironmental impacts numerically. In the future, we intendto improve the accuracy of the assessment method andapply it in various other sections.

External cost (\/person/551 km)

Railway(national average)

Shinkansen

Private car

Bus

Aircraft

0 100 200 300 400 500

Inventory analysis Calculating emissions of environmental pollutants from product and service.

Impact analysis Analyzing effects of environmental pollutants on human health, social assets and temporary production.

Calculation of general index

Expressing various environmental impacts on the same basis (value of money).

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50 Railway Technology Avalanche No. 8, March 1, 2005

Superconducting technology is considered to be apromising technology for saving energy, while allowing forlarge currents and high magnetic fields, creating newfunctions and potentially helping to solve energy problemsin the future. So far, advanced R&D has been carried out onsuperconducting materials and their application indeveloping new electrical equipment. A high temperature superconducting substance (*1) whosecritical temperature is higher than 30 K was discovered inthe latter half of 1986. In several years that followed,superconducting substances (*2) with a critical temperatureof 90 K to 100 K or higher were discovered one afteranother. There is a high level of expectation regarding thefuture application of these substances as new materialswhich would permit bringing about a superconducting stateby using easy-to-handle liquid nitrogen (77 K) in place ofliquid helium (4.2 K).There are two different forms of superconducting materials.There is "wire", which has been used mainly in low-temperature, metal-based superconducting materials (*3) and"bulk", which was found to have excellent superconductingcharacteristics in the process of research and development onhigh-temperature superconducting materials.In order to develop larger-sized superconducting bulkshaving better superconducting properties we have studiedmaterial manufacturing techniques, evaluated basic materialproperties and discussed the possibility of applying thosebulks to practical applications (Table 1).The candidate materials we used were silver (Ag)-added,Y-based superconductors (*4) and Ag-added, rare earth(RE) -based (*5) superconductors (*6). Manufactured using a melt process, these superconductorshave excellent superconducting properties at 77 K and are

considered capable of generatinghigh magnetic fields of tesla (T)order.In the manufacturing of a superconducting bulk, themicrostructure of the material varies markedly according tothe raw material composition and heat treatment conditions.The reason why Ag is added to the composition is that thiselement is expected to improve both the microstructure andthe mechanical and electromagnetic characteristics of thematerial, and that it permits the use of a lower heattreatment temperature. Concerning the heat treatment conditions, we discussed themelting and solidification method in which, after themaximum temperature is reached, the temperature at whichcrystals grow and the degree of undercooling for heattreatment are kept constant (Fig. 1). Compared with thetemperature gradient method in which the solidificationtemperature is lowered with the lapse of time, the methodwe adopted is considered to facilitate temperature controland promote the growth of crystals.In the seeding process, which has to do with the starting pointof crystal growth, we used an Nd-based thin-film seed in placeof a single crystal or bulk crystal, which has been commonlyused in the past. This thin film has a number of advantages—good crystallinity, stable composition, easy machining, lesscontamination of the material surface, etc. Since theeffectiveness of the thin-film seed and the stable growth ofcrystals were confirmed, we made a Y-based bulk 40 mm indiameter and about 15 mm in thickness (Fig. 2 and Table 2).

*1: lanthanum (La)-based *4: YBa2Cu3OX

*2: yttrium (Y)-or bismuth (Bi)-based *5: samarium (Sm) etc.*3: NbTi (niobium titanium) etc. *6: RE1+XBa2-XCu3OX

Manufacturing and Applications of High TemperatureSuperconducting BulkHiroyuki FUJIMOTOSenior Researcher, Laboratory Head, Applied Superconductivity, Materials Technology Division

900°C

Seedingat room

temperature

Maximumtemperature

Holding temperature

Holding time

1060°C

1020°C1000°C

50h~100h

Tmax

Th

th

1h1h1h1h

Figure 1. Heat treatment pattern discussed in the manufacturing ofhigh-temperature Y-based superconducting bulk.

Applications Basic functions

Superconducting permanent Magnetic field by trapping fluxmagnet

Flywheels Storing electricity by magnetic levitation (bearing)

Motors Generating by trapping flux

Fault current limiter Controlling transmission by current flow & normal resistivity

Actuators Transferring from electricity to power by trapping flux

Magnetic Separation Segregating by trapping flux

Magnetic shielding Expelling magnetic field by diamagnetism or flux penetration

Current leads Transmitting by current flow for equipment

Table 1. Possible superconducting bulk applications in railways.

Figure 2. Photograph of the surface of our Ag-added Y-based high-temperature superconducting bulk (maximum heat treatmenttemperature: 1,060 °C, undercooling temperature: 10 °C).

Manufacturing conditions Effects

Y-based/rare earth element Superior superconducting properties-based super conducting bulk(melt process)

Initial raw material composition with Higher critical current densityexcess Y211 phase

Ag addition Improved mechanical strength

Nd base/MgO substrate; thin-film Improved homogeneity, stability seed (seeding at room temperature) and safety

Isothermal heat treatment Easier temperature control; (holding temperature at a constant possibility of mass productionundercooling rate)

Heat treatment in open air Simple

Table 2. Effects of high-temperature superconducting bulk manufacturingconditions applied in the present study