Line D of Prague Metro is the first time a new metro line is being constructed in 43 years in Prague Metro. Last time was in 1978. The City of Prague has perfect information on the construction which I selectively and probably imperfectly translated below.

On April 21, near the existing station Pankrác C, in the locality PAD2, today hl. Prague, Dopravní podnik hl. The City of Prague (DPP) and the contractors ceremoniously started one of the most important transport constructions of the decade not only in Prague, but also the whole Czech Republic - the construction of metro D, specifically the first section I.D1a Pankrác - Olbrachtova.

This is the most complex part of the entire route, which includes two stations, one of which is a transfer, and a total of almost three kilometers of various tunnels. The construction will take place in six localities for the next 90 months, the first excavations have already begun by the contractors these days.

The Pankrác D - Olbrachtova section will be built by the international "Metro I.D Association" by Subterra, HOCHTIEF CZ, STRABAG, HOCHTIEF Infrastructure and Ed. Züblin. DPP expects the completion of not only the first section, but also the entire metro D, and its commissioning at the end of 2029.

The new line will be fully automated. The existing line  will be modernized too, said Adam Scheinherr, Deputy Mayor of Prague. of the City of Prague for Transport and Chairman of the Supervisory Board of DPP.

At the same time, "we are negotiating a loan with the European Investment Bank, and we continue to call on the state to provide financial assistance to Prague with this supra-regional transport construction, "said Pavel Vyhnánek, Deputy Mayor of the City of Prague. of Prague for finance and budget.

As part of the construction under construction, STRABAG will be primarily in charge of the construction of the Olbrachtova station. It is an atypical two-aisle station in difficult geological conditions. The entire I.D1a section is excavated, with the exception of the vestibules, and will be performed by the so-called new Austrian tunneling method (NRTM), ie conventional excavation using mechanical rock breaking with continuous face and excavation, "added Ondřej Novák, Chairman of the Board of STRABAG.

Four stages of construction of line D of the Prague metro

The construction of the fourth line of the Prague metro, line D, is divided according to the complexity into four successive stages. Work begins on the most demanding section, the construction of which will take the longest, up to seven and a half years. On the contrary, the simplest section will be the last, where the construction work will take only about four years. In the first stage, referred to as I.D1a, DPP and the association of contractors will build the section Pankrác D - Olbrachtova. It will be followed by a second section, called I.D1b, Olbrachtova (outside) - Nové Dvory. DPP will announce a public contract for the contractor of this section in the coming weeks, and plans to start construction in autumn 2023. Three stations will be built in this phase: Nádraží Krč, Nemocnice Krč, Nové Dvory and three interstation tunnels, starting behind Olbrachtova. The third in a row should start the construction of the section from Pankrác towards the center of Prague, ie I.D3 Náměstí Bratří Synků - Náměstí Míru, assuming the beginning of the spring of 2024. As the last DPP plans to start the construction of the I.D2 section Libuš in autumn 2025 - Depot Písnice, where three stations, inter-station line tunnels and also the depot for trains of line D will be established. Completion and commissioning of all sections of the DPP is expected in the autumn of 2029.

The first section of I.D1a Pankrác – Olbrachtov: three kilometers of tunnels

The construction of the first section of route D will take place in a total of six localities designated as PAD1b, PAD2, PAD4, VO-OL, OL1 and OL2 (PAD = Pankrác D, VO-OL = ventilation building Olbrachtova, OL = Olbrachtova), which are located around the street Na Strži from the access ramp on 5. května Street in the direction of the center to the intersection of Na Strži and Antala Staška streets. DPP has been conducting a geological survey at four of these sites (PAD1b, PAD4, VO-OL and OL1) since June 2019. The contractors will follow up with the construction of the first section of route D. The main sites from which tunnels and stations will be excavated will be PAD1b, VO-OL and OL1. The excavations in this section of route D will be carried out by the contractors of the New Austrian Tunnelling Method (NATM). This method was first used in the construction of the Prague metro in the 1990s in the excavation of the left single-track line tunnel between Kolbenova and Hloubětín stations as part of the extension of line B (section IV.B).

As part of the first stage of construction, the contractors will build two stations - Pankrác D and Olbrachtova, inter-station line tunnels, tunnel for turning tracks, parking tunnel, technological tunnels for air conditioning, connection between lines C and D, and last but not least several escalator tunnels for exits to vestibules. . From the operational point of view (stationing), the first section of route D will measure 1.3 kilometers, however, in this stage it will be necessary to set out a total of almost three kilometers of tunnels, which represents about 300 thousand m3 of rubble.

Pankrác D - the largest station "Déčka" and three championships

Pankrác D will be a single-ship transfer station with side platforms. It will be the largest station on the entire line D and will have three firsts within the Prague metro: it will be the first transfer station excavated by the NATM, the first single-aisle transfer station and the first transfer station with side platforms. The station will be excavated from two directions, from the PAD1b and VO-OL localities, the lobbies will be excavated from the construction pit at the PAD2 locality, where the construction of the D metro station was ceremoniously started today. In addition to the line, the station will also be followed by a 168-meter-long tunnel of turning tracks and a technological tunnel for air conditioning and its engine room in the direction of Náměstí Bratří Synků. In addition, the contractors will set out here and build a transfer tunnel on route C, which will lead to the southern front of the existing station Pankrác C and two exits, which will lead to the vestibules Arkády and Gemini.

Inter - station tunnel and connection between routes D and C

From the Pankrác D station, a line tunnel will lead towards the Olbrachtova station. The length of this section is 675 meters. The first part, less than 400 meters, will be run as a double-track line tunnel, from the mouth of the junction between lines D and C then as two single-track tunnels to the Olbrachtova station. Behind the Pankrác D station in the direction of Krč, the contractors will build a parking tunnel, which will be used to park reinforced trains or sets with a defect. The parking tunnel will be followed by a technological tunnel for air conditioning and its engine room, ending with a shaft with a ventilation object on the surface.

Until route D will have its own Písnice depot, DPP will send automatic trains for lines D and C from the existing Kačerov depot. The connection between lines D and C, which the contractors will build at this stage, will primarily be used for this purpose. The connection measures almost half a kilometer (468 meters), at this distance it exceeds the altitude gradient of 15 meters between lines D and C. On line C, the connection will open into a branch, which was built on the south side of station Pankrác C in the 1970s and it was envisaged to connect the future route D.

The excavation of inter-station tunnels will take place from the VO-OL site at a depth of approximately 35 meters below the surface. In the direction of Pankrác, the contractors will follow up on the work created during the geological survey and will excavate the tunnel in full profile to the foot of the Pankrác D station. The contractors will excavate tunnels with a total length of 1,908 meters. It was in the VO-OL locality that the first excavations of route D began these days. Olbrachtova - the first Prague metro station with platforms in the arch.

The final part of the first section I.D1a of metro D is the station Olbrachtova. It consists of two station tunnels in an arch with internal platforms, between which there will be three jumpers. From the northern and southern jumpers, the exits on the surface will lead to two vestibules at the same time. The southern vestibule will be located on the corner of Na Strži and Antala Staška streets, the northern one on the corner of Na Strži and Jeremenkova streets. The station will also include a technological tunnel for air conditioning and other equipment necessary for the operation of the station. Olbrachtova will also have several firsts - it will be the first two-ship station in the Prague metro and will be the first with a platform in the curve of the line.

Construction phase of the first section I.D1a Pankrác - Olbrachtova

In the first phase of the construction of the Pankrác - Olbrachtova section this year and next, relocations of engineering networks will take place at individual locations, which will then be followed by the excavation of access shafts necessary for the excavation of the metro stations themselves. From the VO-OL site, the tunnels of the inter-station sections will be excavated in both directions, and from the PAD1b site, the approximately 142-meter-long access tunnel required for the construction of the Pankrác D station itself will be excavated.

In the second phase in the years 2024 and 2025, the excavations of the stations, ie Pankrác D (from localities PAD1b and VO-OL) and Olbrachtova (from localities VO-OL and OL2) and excavation of construction pits needed for the construction of future vestibules (localities PAD2, OL1 and OL2). At the same time, the excavation of the tunnels of the inter-station section, including the connection between routes D and C, will be completed. In addition, the excavation of escalator tunnels will begin.

In the third phase of construction, concreting of the final lining of tunnels and metro stations, construction of excavated vestibules of stations and completion of all internal structures necessary for the installation of technologies necessary for metro operation will take place.

In the final phase, in the years 2028 and 2029, the contractors will install all technologies, carry out surface treatments in the vicinity of future stations, including landscaping, ie planting shrubs and trees. At individual localities, DPP will have a total of 141 new mature trees with a trunk circumference of at least 12–18 cm and a cultivated crown, as well as 7,028 deciduous low shrubs and 3,675 perennials, ornamental grasses and bulbs. At the end of 2029, the DPP expects to put line D of the Prague metro into operation. Basic information about the first section of I.D1a Pankrác - Olbrachtova:

Station Pankrác D

Length: 305 meters, width 23 meters, height 19-22 meters
Estimated extracted volume of rubaniny: approx. 135 thousand m3
Height of overburden above the station ceiling: 20.7 meters
Track depth: 33 meters below the ground

Olbrachtova station

 Length: 221 meters, width 32 meters, height 10 meters
 Estimated extracted volume of rubaniny: approx. 85 thousand m3
 Height of overburden above the station ceiling: 20-25 meters
 Track depth: 30 meters below the ground

The total estimated costs for the construction of the I.D1a section, including monitoring and certification, amount to CZK 14.54 billion.

Route D

Total operating length: 10.6 kilometers
Route: Náměstí Míru - Depot Písnice
Number of stations: 10 - Náměstí Míru, Náměstí Bratří Synků, Pankrác D, Olbrachtova, Krč Railway Station, Krč Hospital, Nové Dvory, Libuš, Písnice and Písnice Depot.
Total estimated future costs for the construction of the entire route D: 97.79 billion crowns
How time went with meter D

Selective translation of https://www.dpp.cz/spolecnost/pro-media/tiskove-zpravy/detail/278_1639-den-d-pro-metro-d-stavba-ctvrte-trasy-prazske-podzemky-zahajena

Map is OpenStreetMap contributors, ODbL, via Wikimedia Commons