Florence – Rome high-speed line

Florence – Rome high-speed line
Viaduct near Arezzo
Route number (RFI) :	92 (Florence – PC Bassano) 114 (PC Bassano – Rome)
Course book series (IT) :	47
Route length:	261.1 km
Gauge :	1435 mm ( standard gauge )
Power system :	3 kV direct current  =
Maximum slope :	8.5  ‰
Top speed:	250 km / h
Train control :	BACC with SCMT
Legend Direttissima and SFS from Bologna from / to Pisa 4,840 Firenze Rifredi 0.000 Firenze Santa Maria Novella 2.830 Firenze Statuto 2,380 Deviatoio Estremo FI Statuto to Faenza 311,900 Deviatoio Estremo FI Campo Marte (by Faenza) 257.096 Firenze Campo Marte 254,083 Firenze Rovezzano 253,382 PM Rovezzano to Rome 240.468 PCS Donato Arno A 1 Florence – Rome Arno 234.788 1 ° Bivio Valdarno Nord to Rome A 1 227.713 PC Renacci 214.755 1 ° Bivio Valdarno Sud of Rome 212.627 PC Ascione Arno Florence – Rome 199.595 1 ° Bivio Arezzo Nord to Rome 189,071 1 ° Bivio Arezzo South of Rome A 1 183,576 PC Rigutino 156.327 PC Montallese 154.251 1 ° Bivio Chiusi North by Empoli 9.731 Montallese from Florence 0.000 Chiusi-Chianciano Terme to Rome 134.391 1 ° Bivio Chiusi Sud A 1 Florence – Rome Florence – Rome Paglia 121.108 PC Allerona 114.920 1 ° Bivio Orvieto Nord to Rome 104.425 1 ° Bivio Orvieto Sud of Rome Tiber 93.387 PC Civitella d'Agliano 76,306 PC Bassano 74.219 1 ° Bivio Orte Nord to Rome 64.684 1 ° Bivio Orte South of Rome Florence – Rome railway line 60.864 PC Gallese Tiber Tiber Florence – Rome Tiber Tiber Tiber 43,936 PM S. Oreste 31.955 PC Capena from Florence 16.227 Settebagni 4.505 Roma Tiburtina 3.419 Deviatoio Int. DD / AV from and to Naples and Pescara from Pisa , Formia and Cassino 0.000 Roma Termini

The Florence-Rome high-speed railway ( ital . Direttissima Florence-Rome ) connects Florence , the capital of the Italian region of Tuscany , with Rome , capital of Italy . The construction work to build the approximately 240 Kilometers of route began in 1970. The first part of the route was opened in 1978, but the entire route was not put into operation until 1991. The 10,954 m long tunnel near San Donato was completed in spring 1984. The 5,375 m long Paglia Viaduct is the longest railway bridge in Italy and one of the longest arched bridges in Europe. It is part of the European railway axis Berlin-Palermo and therefore of great importance for international traffic.

history

The existing routes between Rome and Florence had a curve share of 68 Percent up and were up 45 Percent of the total length only with 90 to 105 km / h passable. With up to 220 trains per day, various sections of the route had reached their limits in the mid-1970s. The planned expansion of the existing infrastructure by a third and fourth track was abandoned in favor of a faster new line.

The 254 km long connection runs on 236 km length on new infrastructure. Opposite the 314 km of the existing route was shortened by 60 km. In connection with an increase in the permissible speed to 220 km / h was a reduction in travel time in long-distance traffic of up to 88 km / h in the mid-1970s Minutes expected.

The construction work began in 1970 and extended to a length of around 140 in mid-1974 km.

In February In 1977 a train opened on 138 km long route from Roma Termini to Città della Pieve officially operates. Then the sections followed

• Città della Pieve - Arezzo in September 1985 (51 km),
• Valdarno - Florence in May 1986 (20 km) and
• Arezzo - Valdarno in May 1992 (44 km)

Lines and technology

The route has an arc radius of at least 3000 m on. The permissible longitudinal inclination was set to 7.5 Per mille in the tunnel, 8 Per mille outdoors or 8.5 Per mille limited as an exceptional value outdoors. The design speed was 250 km / h with a maximum cant of 125 mm and a cant deficiency of 130 mm, resulting in an unbalanced maximum lateral acceleration of 0.85 m / s². The track spacing was set to 4.00 m set.

The turnouts for branch points were for 160 km / h (3000 m radius); points for 100 km / h (1200 m radius). At a distance of about 16 km, double track changes between the main tracks are planned.

More than 30 Percent of the route (around 75 km) run in 28 tunnels. 13 Percent of the route (30.6 km) run on 325 bridges.

Train control system

As the first new line for high-speed traffic in Europe, it also required new train control systems . As in other countries, the previous systems were no longer up to the task. The self-block with coded track circuits BACC used in Italy and the driver's cab signaling RS4 Codici (monitoring of a section of 1,350 m, maximum speed 180 km / h, four transmittable signal aspects) was developed through a compatible further development to the RS9 Codici (monitoring of four block sections with a total length of 5,400 m , Maximum speed 250 km / h, nine transmittable signal aspects) expanded. Ultimately, the many incompatible national safety systems for high-speed traffic led to standardization within the framework of the EU from the beginning of the 1990s.

The RS9 Codici on the Direttissima has been supplemented in recent years by the SCMT punctual train control system. Track vacancy detection, route block and continuous driver's cab signaling are still based on BACC . In addition to the RS 9 Codici, the Eurobalises of the SCMT enable precise location determination and detailed data telegrams with precise information on the maximum speed, route profile, slow driving positions and other information - the combined on-board computers enable more precise monitoring of the braking curves and the maximum speed. The uniform European ETCS system is also to be installed by the end of 2019 . RS9 Codici, SCMT and ETCS are then operated in parallel. The ETCS parallel operation initially serves to increase interoperability and capacity, but in the long term BACC and RS9 Codici are to be eliminated, which would also enable the interlocking technology to be switched to more maintenance-friendly solutions that are compatible with the 25 kV system without track circuits.

electrification

The rail power supply takes place with 3 kV DC voltage from substations at a distance of about 16 km each, which from 132 kV overhead lines are fed. The supply of direct voltage turned out to be a problem when high-speed traffic with ETR500 trains was introduced, as arcing arcs between the overhead contact line and pantograph are not extinguished at zero crossing, as with alternating voltage . In addition, the low voltage for power transmission requires high currents and thus large cross-sections of the overhead line wires, which has an unfavorable effect on their vibration behavior and the dynamics of the pantograph. The plan pursued in the 1970s to reduce the overhead line voltage of 3 kV throughout Italy to 6 Increasing kV has been abandoned. Instead, after lengthy development work, the components of the 3rd kV systems can be optimized so that stable operation at 250 km / h is possible. For later high-speed lines in Italy, due to these difficulties, the decision was made to have the power supply at 25 kV / 50 Hz AC voltage.

The conversion of the Direttissima to 25 According to the current state of the art, kV would involve considerable effort and major operational disadvantages and is therefore only available as a long-term option. The track circuits of the block and train control system RS 9 codici work with a base frequency of 50 Hz and would be disturbed by the overhead line. The conversion to 25 kV alternating current would only be possible with a complete conversion of all interlockings and block sections and the exclusive use of ETCS. Since currently only the vehicles of the high-speed traffic for the 25 kV power supply and ETCS are equipped, the Direttissima would lose its currently important function for mixed regional, intercity and freight traffic.

See also

• High-speed routes in Italy

literature

• W. Hardmeier, A. Schneider: Direttissima Italy. The high-speed lines Bologna – Florence a. Florence – Rome. Zurich 1989, 127 S., ISBN 3-280-01817-X

Web links

Commons : Rome – Florence high-speed line  - collection of images, videos and audio files

Individual evidence

1. ↑ Notification of the Direttissima tunnel completed . In: Railway technical review . ISSN  0013-2845 , 33, no. 5, 1979, pp. 479.
2. ↑ ^{a b} Luigi Misiti: Four tracks from the Tiber to the Arno: the new Tirettissima Roma-Firenze . In: Railway technical review . ISSN  0013-2845 , No. 1/2, 24 (1975), pp. 2-10.
3. ↑ PIANO DI SVILUPPO ERTMS / ETCS e GSM-R. (PDF; 2.7 MB) In: Website. Rete Ferroviaria Italiana , March 30, 2017, pp. 39-40 , accessed on February 18, 2018 (Italian). 
4. ↑ Direttissima Firenze-Roma, Adeguamento tecnologico della linea AV / AC. In: website. Italferr , accessed February 18, 2018 (Italian).