i

I

blodein Railway Track 7 7 HIGH-SPEED TRACKS r - 4 -

q7 HIGH-SPEED TRACKS

L A7.1 .I Vehicle reactions

Despite vehicle runnlng stability, wheellrail forces and car body accelerations at high speeds should $" k

be confined to acceptable llmits As far as the track is concerned, these vehicle reactions can be influ- enced by the track geometry. In addition to the quasi-static components, which occur in curves, the response components comprlse a dynamic part. The dynamlc components can be further split up into low frequency steady-state contributions and high frequency impact loads occurring locally at welds

C and generated by wheel flats. F

a On account of the quasi-static and low frequency loads, the track may not drsplace permanently In the lateral drrection, i.e. the Prud'homme criter~on should be met. To guarantee safety agalnst derailment, the YIQ ratio should be less than a speciflc value, normally 1.2. For the sum of the quasi-static and low frequency Q-force, i.e. the 97.5% value, DB apply a standard of 170 kN. According to [252], BR calculations use 340 kN for the sum of the quasi-static, low frequency, and high frequency Q-force. In the case of the TGV, a maxlmum Q-force of 137 kN was attained for the quasl-stat~c Q-force supple- mented by twice the standard devlatlon of the low frequency dynamic component [231] T h ~ s 67% value of the Q-force is practically the same as the value applied to the German ICE

As far as passenger comfort is concerned, the quasi-static and low frequency dynamic car body accelerations are dominant. In extreme cases a non-compensated lateral accelerat~on of 1 5 m/s2 IS

allowed For both the TGV and the ICE the absolute maxlmum for the total peak value of the car body acceleration is set at 2.5 mlsz. Under normal conditions the standard devlation of the car body accel- erations will be limited to 0.2 m/s2.

In the case of the various high-speed projects, extensive series of measurements have been per- formed to check that the llmits discussed earlier are not exceeded. A summary of the DB measure- ments on wheelirail forces, published in [147], was drscussed in Chapter 4. The 97.5% value of the Q-force attributable to locomotives appears to Increase up to 150 kN at 250 kmlh. Frelght wagons with 22 5 t axle loads exert the same Q-force on strarght track at 120 kmlh According to [231], during measurements on TGV trains a 67% value of the Q-force of 134 kN was found.

PAlf In [27] measurements on the German ICE are described. Figure 17.1 shows the CY2, forces as a hi function of speed, measured in a curve wlth R = 3400 m and in a curve wrth R3495 m and a cant deficiency of 140 mm. In all cases the Prud'homme criterion was met. No acceleration at car body level was found that exceeded 2.5 m/s2.

p iu

In order to test the viability of the system periodic acceleration measurements should be carried out The safety llmits according to the SNCF are set as follows:

Transverse bogie acceleration

Transverse body acceleration

Vertical body acceleration

Table 17 1 Safety 11m1ts for hrgh-speed operation kd

The above values are absolute safety criteria Under normal conditions the values of Table 17.2 should not be exceeded. With the opening of new lines these values are used d u n g the so-called homologation runs in whlch the speed is step wise increased until the maxlmum llne speed plus 10 % is achieved. These measurements are periodically repeated. If the values of Table 17 1 are exceeded the SNCF should report this to the M1nlsti-y of Transport. 1

- .-. . .- P

Fj

6 m/s2

2.5 mls2

3 m/s2

v .r 350 kmih

17 HIGH-SPEED TRACKS Modern Railway Track

Table 17 2 Maximiim accelerations to be adhered to ~n high-speed operation ,.

Transverse bogle acceleration

Transverse body acceleration

Vertlcal body acceleration

Table 17 3 Maximum values for the equ~valent conicity in high-speed operation

The SNCF's policy IS to start with a very low conlc-

I i", ity of 0 025, achieved by conical wheels with an "2m Lateral forces at tractive u n ~ t

inclination of 1/40 Durlng service the conicity i wheelset, curve R = 3400 rn

increases t111 approximately o 10, with exceptional 70 Prud'homme limit

4 m/s2

1.5 m/s2

1 75 m/s2

For a stable runnlng performance of high-speed trains the equivalent conicity is a prime factor. According to the European Traln Standards for lnteroperabllity (TSI) the following values should be adhered to:

if cant deficiency < 120 mm

~f cant deficiency > 120 mm

Speed range

230 < V < 250 kmlh

250 < V < 280 kmlh

280 km/h < V

values of 0.13, the maxlmum value the SNCF allows. The DB is starting with a much higher equivalent conicity, in the order of 0.1, associated with the philosophy of worn wheel profiles. DB's

p"1 maxrmum value IS 0.15 for high-speed operat~on. k 0

17.1.2 Track geometry 200 210 220 230 240 250 260 270 280

1 Y,, Lateral forces at tract~ve unlt

w As far as the track is concerned, tight tolerances A wheelset, straight track should be imposed to restrict the dynamic vehicle

I reactlons. If the transfer functions between geome-

1 try and reactlons are known. the vehicle reactions can be calculated using the recorded geometry. The VRA system discussed in sect~on 16.11 cov- ers thls aspect. [kmlh]

In principle, standards can only be defined for Y 2 forces at tract,ve

vehlcle reactions and not for track geometry as wheelset, curve R = 495 m , h, = 140 rnrn

Maximum at starting operation

0.25

0.20

0.10

3 each track geometry component contributes to a 70

speclfic reaction. It is In particular this comblnatron of geometrical contr~butions which may be decl- 50

sive, although each geometrical devlation as such 40

should not necessarily lead to vehicle reaction 30

standards being exceeded. 20

10

In the absence of a VRA system, track standards 0

Maximum value in service

0.30

0.25

0.15

Pruddhornrne I I ~ I L ---------- I

_V [kmlh] F

have been developed based on practical expen- 70 80 90 100 110

e w e . For instance, for 200 kmlh lines BR applies a Fig~ i re 17 I bleasured /atela/ track force exerted by the maximum value for alignment of 1.8 mm ~ B ~ S and German ICE

for level a value which is 1.5 tlmes greater, i.e 2.7 mm. Thls is based on a vertical car body acceleration of o = 0.2 m/s2.

I 41 id .

F-

L

Modern Railway Track 77 HIGH-SPEED T8ACKS r I-

0 4 0 3

r 0 2 P= 0 1 i. 0 03 r

k

0 01 P

kk

0 001 Figure 17 2 Target psd-fi~nction for level and allgn- ment for tracks operated at 300 km/h pll

3

According to [186], SNCF applies a mean absolute value of 0.6 -0.8 mm, wh~le local peaks In cant and level should be kept to 10 - 12 mm. These Mauzln car values apply to an extended measuring base of 33 m obtalned by means of recolouring

In fact such an approach is too global as these standard dev~atlons refer to a waveband of 0 - 25 m. This waveband covers the Q and Y forces qulte well, but car body acceleratlons originate from much longer waves. For natural frequencies of the order of 0.7 to 0.9 Hz the dom~nating wavelengths at 300 kmlh are 119 - 93 m. For thls reason the total measuring range should be extended to a wavelength of about 120 m This waveband is too long to determine one standard devlation and, therefore, should be split up, for Instance, as follows:

- 3 - 25 m. short-wave geometry associated wrth Q and Y forces, automatic, tamplng actions, and exceedences due to local ~rregular~ties;

- 25 - 70 m: assocrated with car body acceleratlons at medium speeds;

- 70 - 120 m: associated with car body acceleratlons at high speed. PI

In vlew of the lack of preclse knowledge of the transfer functions of the rolling stock and the lack of h experience in calculating vehicle response on-line as descr~bed ~n section 6.7, power spectral density funct~ons of the track geometry have been examined and from these a waveband cornposition with corresponding standards for variance of standard deviat~on has been derived.

In Flgure 16.102 psd funct~ons for different types of track are given. These functions have been estl- mated over a track length of about 100 km each. Regardless of the track type, the shapes are very similar There IS also a dlstinct correlation between short-wave and long-wave irregularrtles. The psd functions for NS UIC 54 concrete track are extremely good and may be considered as the best possi- ble rn practice Flgure 16.101 shows another set of psd functions. Except for the BR .ones, they were recorded on conventional speed lines The 6R spectra refer to tracks for V = 200 kmlh. The target spectra for 300 kmlh lines, presented in Figure 17.2, have been derived from thls ~nformation.

Standard devlations which are to be used as target value and as limit value according to Table 17.4 have been derlved from these spectra.

P! Waveband

3 - 2 5 m

25 - 70 m

70- 120 m

Tabie 171. Target and 11rn1t standard devlations for h~gh-speed tracks operated at 300 krn/h

Level

Otarget [mmI 1 0

2 0

2.7

Al~gnment

"ilmit [mmI 1.5

3 0

4.0

otarget ImmI 0.7

1 3

3 4

011rn,t fmmI 1 0

2 0

5.0

17 HIGH-SPEED TRACKS rl/lodern Railway Track

17.1.3 Rail geometry and weld geometry

For reasons of dynamic Impact, dev~ations In the short waves should be kept to a minlmum. The NS tolerances, specified in Chapter 16, are well suited to high-speed tracks. According to [I861 the per- missible dev~ations In rail and weld geometry for the TGV track amount to 0.3 mm on a basis of 1.6 m.

The forces in the 0 - 150 Hz frequency band, which are associated with unsprung mass, are very det- rimental to the track. Axle box acceleratlons represent these forces very well. On ground tracks axle box acceleratlons of the order of 10 m/s2 have been found on the TGV, and on non-ground tracks these values reach a maximum of 25 m/s2. In order to sufficiently limit the transfer of these dynarnlc forces to sleeper and ballast, SNCF employ 9 mm thick high-resilience pads.

17.1.4 Track qual i ty standards for 300 krnlh

This section specifies the standards which should be applied in order to maintaln the requ~red quality level on high-speed tracks The standards are basically formulated in terms of vehlcle reactions, 1.e. wheellra~l forces and car body accelerations If the transfer functions between track geometry and vehicle react~ons are known, the vehlcle reactions can be calculated directly mak~ng use of the meas- ured track geometry This requlres an ultra-fast on-line computing system as described in Chapter 16

Aga~n, if the transfer functions of the rolling stock are known it is, in principle, posslble to make some estimates of the admissible geometry to prevent vehicle reactions exceeding therr lrmit values In this

1 process one should realise that several geometrical components will contribute to a specific reaction and there is, therefore, no unique relationship between maxlmum vehicle response values and admissible track geometry

The steady-state vehicle reactions have a random character and are expressed in terms of standard deviations Isolated or local ~rregularities possess a deterministic character and are expressed In terms of peak values.

Rail geometry I

I The recommended standards for rail geometry are specified in Table 17.5.

If welds are produced or inspected manually, ti IS recommended that a 1.2 m straight edge provided with two LVDTs be appl~ed 0 2 m apart as described In Chapter 10. The recommended admissible deviations are:

- versine: k 0 2 mm,

- step: 0.1 mm.

If these standards are exceeded the welds should be straightened and ground, for Instance using Plasser and Theurer STRAITlGWM220 machines.

kd Table 17 5 Ra11 geometry standards f o ~ 300 kln/h

Slgnal

Vert~cal axle box acceieratlon

If displacement is measured

Peak accelerations due to welds

Vertical rail irregularities due to the rolling process 7

Standard Waveband

0.03 - 0 3 rn

03-10m

10-30m

Peak Pno,,

72 m/s2

onor, 200 rn section 90 %-value MAINS

12 m/s2

0 05 rnm

014mm

The recommended standards for vehicle reactions are specified in Table 17.6 The IS0 filter charac- terlstlcs are presented in Figure 6.26 and Fgure 6.27. Non-compensated lateral acceleration is defer- mined according to (16.31). The derivative of the lateral acceleration is used in expressions (16.33) and (1 6.34). The Prud'homme ratio follows from (1 6.40).

I I

Modern Railway Tiack 17 HIGH-SPEED TRACKS I I

Requirements for check ing track geome t ry

ivloclern Ra~lway 7iack 17 HIGH-SPEEC TRACKS I

i

As the construction progresses, the installed girders serve 1 -

the access route for the special carrier. This method, of cou I,

1.. is particularly advantageous for long bridge structures ( Figure 17.4).

,/" r 17.2.3 Track Character is t ics

The general track characteristics are as follows: Ballast: Crushed stone 31 5150 mm

Thickness min. 35 cm Sleeper: Prestressed concrete mono- block r

L = 2.6 m C, Weight = 3 kN

Sleeper spacing: 60 cm Fastening: Elastic Pandrol e-clip, 25 kNlrail

Elastic Pandrol Fastclip (future), 20 kNlrail Rail pad: Studded rubber pad, 10 mm thickness, stiffness 65-95 kNlmm Rail: UIC 60, grade 880 NImm2 Track gauge: 1435 mm

Speeds: 300 kmlh (no freight) Axle loads: 170 kN Curve radii: Min = 7,000 m Cant: Normal = 130 mm

Max = 180 mm Cant deficiency: Normal = 65 mm

Max = 85 mm Grades: Normal maximum = 25 per rnille

Exceptional maximum = 30 per rnille Vertical curve radius: 25 - 40,000 m Transition curve lenqth: 630 m - Track distance: 5.0 m F

!hi

17.2.4 Track Laying ?

For the 57 km long test section concrete sleepers in ballast were selected. The prestressed mono- block sleepers were fitted with Pandrol e-clip fasteners. The rail profile was UIC60. On all bridge decks ballast mats with a thickness of 25 mm were ~nstalled on top of the protective waterproofing layer over the bridge to reduce the track stiffness. All the track components have been tested, e~ther in Korea or abroad, to ensure that they meet the requirements of the high-speed track performance specifications. p bd

17.2.5 Track Installation

On the test sectlon track ~nstallation started in February 1999 at a rate of 400 meters a day. The Osong Depot located 120 km south of Seoul was the operat~onal center of the test section and served n as the s ~ t e office for the civil construction and the work base for the track and catenary installation. It lj includes 25,700 m of tracks, a maintenance workshop, storage areas and s~ te offices. The welding facility that welds 25m long rails into 300m long rails is also located at the Osong site (See Figure 17.5) p d

7 1 HIGH-SPEED TPACKS niodern Railwav Track J

I

F~gure 17 5 Grinding facility at the Osoncr W

Track rnstallatron started by iayrng a temporai. track rn order to provide access to the work +-- -

When a suffrcrent length of temporary tra variable, the specral trarn transnnrhnn ti-

Y \ Lldlrls. ck was

-,- - -.. *r le 300- meter long welded rarls unloaded the rails on both tracks (see Frqure 17.61. The train u13c fitt5-j - - - -.. 3 ""U.2 , I L L ,

specral rarl support devrces to transnnrt Itn i - -r-. . LO thrrty rails, and negotiates curves wrth a mrnrmum radius of 150 m In the Osong depot.

In six successrve steps, ballastrng and tamping operations ensured that the track IS lifted to its final level, provrdlng a mrnimum ballast thickness of 350 m m Dynamic stabrlrzing is carr~ed out three times

I

Id during the lrftrng process.

Modern Raiiway Track 77 HIGH-SPEED T2ACKS ix' I

17.3 Dimensions of railway t u n n e l s

In the design of tunnels the dimension of the cross section is an important factor for the total costs of the tunnel. In tunnels the resistance IS greater than in the open air. At the entrance and the exit there are sudden air pressure variations. wh~ch are uncomfortable for passengers because they can cause problems like ear pain and headache These air pressure variations have an effect in the whole tunnel because they cause air-pressure waves in longitudinal direction. Especially the ~ntroduction of high- speed tralns, wlth speeds greater than 300 kmihour and wlth sometimes many long tunnels made a new approach of this Item necessary. In the next part a short explanation IS given of the problem associated w~th runnlng at high-speed trains through tunnels. At flrsi there is a cornpartson between the srtuation rn the open air and in a tunnel.

P' L

17.3.2 Air resistance in the open field situation

In the open air the train resistance is normally considered under the assumption that the air is incom- pressible. The air resistance normally consists of two components as shown in Figure 17.8:

- Difference in air pressure at the front and the rear of the train due to air pressure variations along slde the train;

11n a ~ D C I ~ l t nf thn cl t r f - ~ n r n c ; ~ t - - ~ ~ -6 4 ~ - +--:- R!

Turbulent flow Surface res~stance

----- - - - - _ _ D~versed flow

I FI I

Ring tra~n tunnel

----- 1 - ---

u I u a I u I Flbi

-t------- __f

I

7 I

I ___f

'rri

I"la t

- - - - &?I - --- b, In a tunnel

Y

Figure 17 8 Two a ~ r pressure situat~ons

Ps

Rlcidern Ra~lrvay Pack 17 HIGH-SPEED TRACKS

Figure 17.1 1 shows the characterrstrcs of the arr pressure rn tunnel (external pressure) and tram (internal pressure) In case of a sealed tram and a stand- ard train. In a sealed train the Internal pressure differences are much lower than in the standard train. The differen- tial values are in the order of some kPa, being a few percent of the atmos- pherlc pressure.

Line (1) gives the posrtion of the com- pression wave (front) caused when the tram entered the tunnel. Thls compres- sion wave propagates wrth the sound speed (340 m/s) to the end of the tun- nel and IS then reflected as a depres- sion wave (red llne (3)).

I 3 I I I I Line (2) shows the positron of the

depression wave (front) caused when the rear of the train entered the tunnel. Thrs depression wave also propagates with the sound speed (340 m/s) to the end of the tunnel and is then reflected as a compression wave (red line (2)).

c These waves move between the tunnel Line 1 compression wave (blue 11ne) caused by the front of the ends wh~le a train is passing through tra~n when enter~ng the tunnel the tunnel. The polnts A to E show the

pos~ t~on and time where the tram front Line 2. depression wave caused when the rear of the tran IS negotiates the compression and entering the tunnel depression waves.

Line 3 position of the front of the tra~n In the tunnel Durrng the tram passage in a tunnel the

Line 4 positron of the rear of the tra~n ~n the tunnel (red l~ne) alternating alr pressure waves may resonate, which may cause great changes IR alr pressure Measure-

F~gure 17 1 I Wave forms in t~ inne l ments have shown values of 7.5 kPa. The tunnel length and cross sect~on, the train dimensions and speed deter-

mine the external air pressures on the t ram The air tightness of the trarn determrnes how the external air-pressures are transformed Into Internal air-pressure variat~ons causrng passenger discomfort.

Modern Railway Track 17 HIGH-SPEED TRA C,ys

Real tlme [s] Real t~rne [s]

Figure 17 13 Influence of afr pressure wfthout shafts and F~gure 17 14 Influence of air pressure with shafts and perfo-

perforations rations

17.3.7 Calculation o f air-pressure variations i n trains

External alr-pressures cause Internal air-pressures because a train is not air t~ght. The speed of reduclng the difference In air-pressure in- and outside is depending on the form of the leak in the exte- rior of the trarn and on the magnitude of the alr-pressure-d~fference itself.

The project organlsation High Speed Line South in The Netherlands developed for the new railway llne from Amsterdam to the Belgium border a model in wh~ch the train is a permeable and compressi- ble box Depending on the shape of the leak the stream will be viscose or not.

Not-viscose stream

A not-vlscose stream is proportional to the square root of the difference of the in- and external pres- sure.

3 = - c , s g n ( p , - p , ) J F j dt

(1 7.3) C

p, = Internal air-pressure pe = external air-pressure

C, = constant factor, to be determined with a static test for the specific leak Sgn: If p, - p, > 0 the value is 1 and if p, - p, < 0 the value is -1.

Viscose sfream I"! ibi

If the flow IS viscose the pressure variation is dlrectly proport~onal to the difference in air pressure:

I- - d'/ - - - ~ , s g n i p , - p , ) d l

(1 7.4)

C2 is dependent on the leaks, the sound propagation speed and the volume of the train.

, -93

17 HIGH-SPEED TF?ACKS lWodern Ratlway ~~~~k

I

I For safety reasons (for example if a window is broken) a maximum external pressure varlatlon of =

L l 10 kPa is attained.

I I -I For tralns a model exists (not shown) with a Wohler curve which shows a relation between the

number of air pressures on the train and the allowed intensity of these air pressures. i i l

, 17.3.9 R e s u l t s of ca l cu la t ions fo r t u n n e l s in t he H S L in The Netherlands

Table shows computed results for the required square meters of the Cross section of two tunnels in the HSL South wlth a different length and a different combination of shafts and periorations,

131161

pnl TS (1 ) Two single track tunnels wlthout shafts and perforations

ki TS (2) Two single track tunnels with only shafts TS (3) Two single track tunnels with shafts and perforations

P1 I

lul GH = "Groene Hart"-tunnel (to be bored) OM = tunnel under the river "Oude Maas"

ma TGV = High Speed Train (design speed = 300 kmlh)

Lli SMT = Standard Modern Train (also used on existing network, design speed = 220 kmlh)

PI 17.4 Maglev Applicatjons 1 tul

17.4.1 In t roduct ion pm\

I

kuli There is a growing interest in the possible use of magnetic trains for very high-speed traffic, Test

tracks exists in Germany and Japan and application in operational lines is cons~dered. With magnetic A ~ Y

trans the supporting action is achieved by electromagnet~c levitation while the propulsion is also per-

formed magnetically by means of a linear motor. In test tracks Very high speeds were reached up to brl

500 kmlh.

"*1 There is a basic difference between the German Transrapid system and the Japanese system, In the mi German system the levltat~on is achieved by attracting magnets in the vehicle and in the guideway,

resulting in lifting the vehicle. In the Japanese system the levitatlon forces are generated as a result of ~1 the speed of the train, where the super conducting magnets in the vehicle Interact with the coils in the

hi sidewalls to generate the l~fting forces. This means that first the tram 1s running on wheels and is lev,-

tated after a certain speed has been exceeded. ell

rrsd 17.4.2 The Japanese s y s t e m

ma In the Japanese system the "8" figured levitatlon coils are installed on the sidewalls of the guideway When the on-board superconducting magnets pass at a level of about several centimeters below the center of these coils, an electrlc current is induced wlthin the coils, which then act as electromagnets temporarily As a result, there are forces which push the superconducting magnet upwards and ones which pull them upwards simultaneously, thereby levitating the vehicle. The principle IS illustrated in

9 Figure 17 18 The distance between vehicle and guideway is depending On the speed and lies in the

d order of 10 cm.

I

I&/

Length

M

7200

1369

Square meters of Cross section required Design speed TGVISMT

kmlh

3001220

3001220

Lrj

PI I

brvi

P/ hi

Tunnel

GH

OM

TS ( 3 )

2*50

2*45

TS (1

2*80

2*59

TS (2)

2*60

2*49

I

kloder:7 Ra~icvay Track 17 HIGH-SPEED TPACKS -

Gu~deway

Figure 17 18 Levtratton prtnctpie Ftgure 17 19 Lateral positioning pr~nctpie

hiode111 Railwa)/ Tiack 17 HIGH SPEED TRACKS

Propulsion System Electromagnet~c Lev~tat~on

The synchronous longstator linear motor of the Transrapid maglev sys- tem is used both for propulsion and braking The function of this non-con- tact propulsion and brak~ng system can be derived from the functional pr~nc~ple of a rotating electric motor whose stator rs cut open and stretched along both sides of the guideway. Instead of a rotary magnetic field, the motor generates an electromagnetic traveling field The support magnets rn the vehicle function as the rotor (exci- tation portion) of the electrrc motor The principle is explained in the Figure 17.24 and Figure 17.25 In contrast to conventional ra~lway systems, the prlmary propulsion com- ponent of the Transraprd maglev sys- tem - the stator packs with three- phase motor w~ndrng - are not Installed in the vehicle but in the guideway.

By supplying alternating current to the three-phase motor wrnding, an elec- tromagnetic traveling field is gener- ated which moves the vehicle, pulled along by its support magnets which act as the excrtation component (see Figure 17.24)

Support

Ftgure 17 23 Levitation prtnciple Transrapid

Ftgure 17 24 Linear Motor pnnc~ple Transrapid

.The speed can be continuously regu- lated from standstill to full operat~ng speed by varying the frequency of the alternat~ng current. If the d~rection of the travelrng field is reversed, the motor becomes a generator whrch brakes the vehicle without any contact. The brak~ng energy can be fed back into the public network.

The longstator linear motor in the guideway is divided into individual motor sections which a only supplied with power as the vehicle passe The location and the installed ~ o w e r nf the ql~h-

" . .,.' is required, e.g. gradients, acceleration, and braking sections, the power of the substations is

The longstator linear motor in the guideway divided into individual motor sections which a only supplied with power as the vehicle passe The location and the installed power of the s stations depends on the requirements on th propulsion system. In sections where high thrust is required, e.g. gradients, acceleration, an braking sections, the power of the substation higher than on level sections which are travelle at constant speed. And because the prim component of the propulsion system is insta in the guideway, Transrapid vehicles need not carry the entire motor power for the peak requirements, as is the case with other types of vehicles. The support and guidance system is supplied with energy without contact via the lin- ear generators integrated into the support ma

nets. No overhead wires are required for the -

. - . .- . .-. ...~. .. . . .

Figure 1 7 27 Principle ~~TE&~L&T-Z of sw~tch structures

Tunnels

1 With its flexible route alignment parameters. the Transrapid guideway can be adapted to a great extent to the landscape. Therefore, tunnels are seldom necessary, even in hilly and mountainous ter- ra in Even when they are requlred, the tunnel cross-sections necessary for the Transrapid are smaller than those of railways. This 1s due to the smooth, aerodynam~c shape of the vehicle and small clear- ance envelope. Typical tunnel cross-sections for tunnels longer than 150 m and vehicles with 2 to 8 sect~ons are given in Table 17.11.

Figure 77 28 Measured noise levels for d~fferent systems

Speed 250 kmlh 400 kmlh F Cross section of double track tunnel

Cross section of single track tunnel 120 m2 Table 17 11 Tunnel CrGaa aeLuon values

70 m2

36 m2

450 kmlh iin

180 m2 225 m2

85 m2