The tunnel in the central part of the tram route to Mistrzejowice requires the heaviest workload in the project. It will be constructed with the use of the top-down method on diaphragm walls. Here is an overview of individual steps.
Usually, before a tunnel is constructed within developed areas, buried utilities conflicting with the planned structure are relocated. In such a way, the site is prepared for further works, and residents of the neighboring areas are provided with continuous supply of all utilities. In the area of Polsadu roundabout, the network of underground utilities is dense, therefore, it was a huge challenge to design new routes for the water main, gas main and sewer piping.
Construction of a tunnel on the route to Mistrzejowice requires also that the underground stream Sudoł Dominikański running currently mostly under the median strip between the roadways of Młyńska Street is relocated. – According to the design, the stream will be moved under the western roadway of Młyńska Street and led in a southerly direction up to Młyńskie roundabout – explains Ewelina Woch, structure coordinator in Gülermak.
What are diaphragm walls and how are they constructed?
Once the site is prepared for construction works, trenching of diaphragm walls (d-walls) is commenced, that is of RC structural walls constructed in a narrow trench. They form the tunnel lining, transfer soil and groundwater pressure. They also minimize the impact of the excavation on the neighboring buildings and protect the tunnel against underground water inflow. Thanks to their structure, they can transfer significant loads and provide tunnel stability in such a way.
How are they created? First, a narrow and deep excavation is made with the use of a grab (in the case of KST IV, the excavation depth will reach from 11 to 24 m). Then, a reinforcement cage is placed in the excavation and filled with concrete with the use of the tremie method. It consists in concreting the wall upwards from the excavation bottom. When such walls are ready, construction of the top slab, that is, the bearing upper slab of the tunnel can start.
Top slab, excavation and bottom slab
The top slab is made on the ground, on a layer of lean concrete, with the use of waterproofing membranes. Once the upper slab is ready, the excavation can be commenced.
There are two methods of extracting soil from the tunnel: the top-down method and the boring method. – In order to extract spoil in the top-down excavation, a construction opening should be kept in the top slab, whereas in the boring method, soil is excavated from the tunnel portal. Both the methods will be used during the construction of KST IV – says Ewelina Woch.
Then, bottom slab of the tunnel has to be installed which is to be made on a layer of lean concrete – as in the case of the top slab. Its important element are membranes protecting the tunnel against groundwater permeability.
Finishing and fitments
After completion of structural works, the tram trackbed and various systems will be constructed, among others: water supply, catenary, telecoms and storm sewer systems. Also finishing works will be carried out in the tunnel for which fitments will be provided for the purpose of circulation, safety and traffic control. At this stage, also works on the ground surface are performed – necessary infrastructure is restored, vegetation is introduced in the area by means of adequate plant species.
Construction of the tram route to Mistrzejowice is a practical response to the objectives specified in the Climate change adaptation plan for the City of Kraków until 2030. This will lead to reduction of traffic pollution and increased resistance of the transport sector to adverse effects of extreme weather events.
One of the most important objectives of Kraków is to reduce air pollution emissions. Particulate matter, sulfur oxide, nitric oxide – dispersion of these substances which are hazardous to health can be stopped. The actions taken however have to be diversified. One of the tools is to encourage as many residents as possible to use collective transport and to show that there is a more eco-friendly alternative, e.g. riding a bike or using public transport. However, in order to convince the motorists of Kraków to change their habits, a friendly infrastructure is indispensable.
Construction of a fast tram connection between the densely populated area of Mistrzejowice and the city center will be a special response to the residents’ need to be provided with well-organized collective transport in this part of the city. A dedicated tunnel, traffic control system, modern rolling stock powered by “green” energy – all that is to encourage residents to leave their cars parked and take the public transport.
Blue-green infrastructure for northern Kraków
The project will also lead to reduction and mitigation of effects of high temperatures and heavy rainfalls which have an increasing impact on the cities at our latitudes, since the tram route project is to be accompanied by the so-called blue-green infrastructure along the tracks: green trackbed increasing the natural water retention, “green” passenger waiting shelters, wildflower meadow, shared foot and cycleways as well as solutions for the elderly and people with disabilities. Also, compensation plantings are planned (1:1); they will include species resistant to difficult urban conditions, among others: drought, salinity or freezing.
The project includes a partial modernization of the drainage system in the area where the tram route is to be located, which will also have an impact on water retention in case of rainstorms.
Tram to Mistrzejowice powered by clean energy
Modern, quiet and energy efficient rolling stock which will run on the designed route does not need fossil fuels to transport the passengers. It is electricity powered – in Kraków, it is “green” energy from renewable sources which are climate neutral. On the basis of a 2-year contract with a big energy company, Kraków is provided with supplies of clean power, used i.a. for trams.
As part of the project of the tram route to Mistrzejowice, also the use of small photovoltaic systems, producing power for the operation of the route is being considered. They could be installed e.g. on some of the waiting shelters, providing self-sufficient power supply for lighting.
Local governments in Poland and throughout Europe are seeking opportunities for quick and effective development. Just like Kraków, they are choosing the PPP formula to offer residents the highest quality services without overburdening budgets.
Polish cities are developing intensively which triggers major investment needs. The big question is where to get money for the construction of roads, schools, water supply and at the same time not to neglect the maintenance of the existing infrastructure. Each infrastructure project is a burden on the budget (own contribution, loan) and affects the overall investment plans. To respond to these dilemmas, regulations were put in place to facilitate the public-private partnership (PPP) model which generates virtually no costs for the local government at the construction stage. It does not require a time-consuming search for financing and does not affect the local government’s debt ratio. A private partner performing the task receives the first payment only after the residents start using the new infrastructure.
PPP: spending money more effectively
According to the Ministry of Funds and Regional Policy, 165 PPP contracts have been made in Poland since 2009, mainly covering projects in the field of energy efficiency, sports and tourism and transport infrastructure. Not an impressive number yet the interest in PPP is growing year by year. 68 projects are currently being prepared which will potentially be implemented in this formula. Most of them are for the transport infrastructure. They are estimated at a total of PLN 8.3bn.
“There are not many projects of this type on the market right now, but this should change in the coming years. We can clearly see public awareness and practice is being developed in this matter, which makes potential private partners – who are ready and willing to participate in tender procedures – very happy” – says Michał Wójcik, COO with Gülermak, in a recent interview for inwestycje.pl website.
Awareness is growing and advantages seem attractive. What are these? “Number one, from the perspective of public finance: it is cheaper – says Marcin Hanczakowski, Director of Kraków Municipal Road Authority (ZDMK) in an interview for transport-publiczny.pl whose institution is developing the tramway route to Mistrzejowice in partnership with Gülermak. “The amount [approx. PLN 1.3 billion – ed.] includes not only the construction of approximately 4.5 km of the route, but also its maintenance for the next 20 years. Afterwards, the partner will hand us over the route already renovated” – he adds.
“The second advantage is completion time. A private partner is not restricted by various procedures binding on the public sector – it implements the investment faster, with fewer risks, and has wider access to appropriate human resources and new technologies”.
Several European countries can boast of a really wide and effective use of PPP. According to the latest Review of the European PPP Market in 2020, 34 PPP transactions reached financial close. The biggest number of such projects was launched in France (e.g. the RCEA route, consisting of a series of roads connecting the east and west of the country) while the projects performed in Germany were of the highest value (e.g. extension of the A3 motorway). In general, transport sector tasks are predominant and are considered to be the most promising for the PPP model.
The tramway to Mistrzejowice is not the only investment of this type in Europe. The first tramway route is currently being developed in Liege and is scheduled for completion in 2023. For several years, routes built as part of PPP in Zaragoza and Dijon have been successfully operating. Success stories are there and once the investment is completed, it is worth passing on the experience.
Kraków as the role model
The tramway to Mistrzejowice is already today labeled the largest transport project in Poland made in the PPP formula. Kraków is supported by the government in its preparations and partnership while the private partner is approaching international funding institutions. Kraków’s experience will serve as the basis for developing guidelines for other cities planning to leverage on the PPP while implementing their projects aimed at serving the residents.
As much as 74% of the area used for the construction of the tram route to Mistrzejowice is to be biologically active. An important element will be the so-called green trackbed where sedum mats will be installed. It is an eco-friendly and cost-effective alternative to a traditional lawn.
Green trackbed technology is becoming increasingly popular in Polish cities. It is not only aesthetic but also eco-friendly and cost effective. This solution enables filtration of pollution, e.g. dust stirred up by vehicle traffic, and, to a certain extent, reduces the noise by absorbing acoustic energy. Therefore, when designing KST IV, the private partner undertook to introduce greenery within the trackbed area, wherever technically feasible, instead of using concrete or crashed stone ballast. And this all will be done in an exceptional way.
Colorful drought-resistant carpets
Instead of traditionally sown grass, the trackbed will be decorated with sedum mats made of drought-resistant plants. In spring and in summer, sedums bloom beautifully creating a colorful carpet, whereas in autumn, their colors change to brown and red. So, they please they eye, regardless of the season. What is more, installation of sedum mats is quick and extremely easy. And what about the effect? It is immediately visible – without waiting for the greenery to sprout.
It is worth mentioning that maintenance of sedum mats is easy and cheap – they do not have to be mown or regularly watered since they are drought-resistant. As a comparison: in order to mow grass sown within the area of the designed trackbed between the intersection of Meissnera / Lema Streets and the Mistrzejowice terminus, 37,182 liters of fuel would be needed per year*. This amount refers to the mowers only (excluding the fuel needed to transport the equipment, personnel or the grass cut). In order to water such grass-covered tram tracks just once, 123,970 liters of water would be needed, totaling 5,578,650 liters of water per year!** These are real benefits for the environment (resource saving) and for the budget.
The company Tramwaje Warszawskie calculated that maintenance of 1 linear meter of a single track of a green trackbed made of sedum mats is cheaper by ca. 85 zlotys/year than maintenance of 1 linear meter of traditional lawn.
Less dust, greater diversity
As regards more mundane environmental benefits – urban areas planted with sedums are an example of green infrastructure creating the so-called green corridors which increase biodiversity and reduce the temperature of the surrounding environment. They also retain rainwater at the place of their accumulation and filtrate air by preventing dust emission. Furthermore, they reduce the level of noise generated by trams. Such a solution, the benefits of which are obvious, can be applied also on roofs of passenger waiting shelters.
* assuming that the surface area of the green trackbed amounts to 12,397 m2, the period it has to be mown lasts 6 months a year and 1.5 l of fuel is needed to mow 1 m2 of the lawn
** assuming that grass has to be watered 3 times a week during 15 weeks per year
photo: UM Poznan
By phone, e-mail or Messenger? Here’s how you can reach us to get reliable information about the construction of Tramway route to Mistrzejowice.
Since mid-June 2021 when the design hotline was launched and a dedicated inbox set up for the Tramway to Mistrzejowice, several dozens of individuals and organizations have used these communication channels. This is the easiest and fastest way to obtain information about the future construction or to make a comment or file a request. Each contact made is recorded together with the response time. We want our replies to be helpful and comprehensive and made in the shortest possible time.
Hotline +48 722 22 00 88 is available throughout the entire design and construction phase from Monday to Friday between 8 am and 4 pm. Please send your e-mails to email@example.com. However, these are not the only contact channels with the tramway construction site office.
Tramway to Mistrzejowice in the social media
Many residents are reaching us in the social media – they post comments or use Messenger at the Facebook page of the Tramway to Mistrzejowice. Since the project is still in the design phase, responses reflect the current state of works and the solutions addressed in the questions may still be subject to adjustments. Thank you for your opinions, we follow and participate in the discussions on our Facebook page. Don’t forget to follow our LinkedIn profile and the project website to find regular updates. We will launch Instagram channel once the construction starts.
In the future residents will be able to visit us personally – there are plans to open a permanent information point in the area of the construction site.
Disability ramps, elevators, tactile paving – these are just selected examples of solutions that make it easier for disabled passengers to use public transport. The design of the tram route to Mistrzejowice features many more of them. It is focusing especially on the needs of persons with reduced mobility, using wheelchairs as well as the blind and partially sighted.
The right cars are not enough to make public transport friendly for the disabled, the elderly or parents with children in prams. Getting on and off a tram or bus safely is equally important. It is vital that the newly designed stops be safe and comfortable for passengers with special needs.
The tram route to Mistrzejowice was designed both in accordance with technical requirements for roads and engineering structures as well as with the guidelines of the Consulting Team for the accessibility of urban infrastructure for the disabled. “We put special emphasis on eliminating potential barriers on the stop platforms for people with mobility limitations, people in wheelchairs, partially sighted and the blind” – says Anna Marczewska-Wojtas, KST IV Architecture Coordinator with Gülermak. The solutions also include amenities for parents with small children.
Tram stops on the route to Mistrzejowice are available for the disabled
Platform edges and areas just before steps to the underground stops (by the stairs) will feature warning stripes with a changed texture and contrasting colors. “Convenient elevators will be providing access for persons with reduced mobility, including wheelchair users, to all levels of underground stops at Polsadu and Młyńskie roundabouts” – says Marcin Hanczakowski, Director of Kraków Municipal Road Authority (ZDMK). Parents with children in prams will also be happy to use them.
Underground floors will have tactile paving for the blind and partially sighted to guide them to all areas and devices that can be used by these persons, e.g. elevators, stairs, platforms. “Marked changes in traffic directions together with media lanes form an uninterrupted communication route to facilitate movement and orientation in the facility” – says Anna Marczewska-Wojtas. The floor and walls of the underground areas will be made of various materials, contrasting in color, and the finishing materials will not be glaring. The surface of floors or stairs will be anti-slippery.
As the underground station at Polsadu roundabout will have public toilets, there will be a separate toilet equipped with sanitary facilities adapted to the needs of the disabled. There will also be a room for parents with children with a changing table and a feeding place.
Safe pedestrians along the tram route to Mistrzejowice
Warning stripes will also be made before and at pedestrian crossings, on the border between the pavement and the street lane. Pedestrian routes have been designed so that people on wheelchairs have room for movement, including maneuvering space for changing direction. They will also be free from any obstacles while and the so-called street architecture items, like litter bins, information boards, etc., will be placed outside the main communication space. Pavements and external ramps will be made of durable materials intended for intensively used areas.
– Use of private capital from the free market enabled commencement of a project which is vital for the residents. First payment will be made to the partner only once the route is opened – stresses Marcin Hanczakowski, Director of Kraków Municipal Road Authority (ZDMK).
Why has the city decided to choose the PPP model for this project?
Investment budgets of local government administration are limited due to the necessity of financing an increasing number of new tasks. The ability of local government to incur liabilities, hence to provide direct (own) financing, is getting smaller. Thus, the city of Kraków decided to use government support for projects in the public-private partnership (PPP) model. It presented the task which was noticed and selected. Use of private capital from the free market will enable construction of this connection within only a few next years, which connection is so important for the residents. One of the main challenges is to provide a connection between this part of the city and the city center as soon as possible. The first tranche payment will be made to the partner once the rout is opened.
The new tram route is to run along Meissnera, Młyńska, Lublańska, Dobrego Pasterza, Bohomolca and Jancarza Streets. What led to the selection of this route?
As a matter of fact, the Mistrzejowice district located in the northern part of Kraków has a tram connection with the city center, however it is an indirect route running through the neighboring district – Nowa Huta. In order to get to the so-called first bypass of Kraków, the tram from the Mistrzejowice terminus has to cover the distance of 11 km. Several options of the new tram route connecting this part of the city with its center have been discussed in Kraków for a long time as the next stage of extension of the Kraków Fast Tram (KST). In public consultations, 63% of the residents opted for the chosen route. In 2015, the city finally decided to choose a route of approx. 4.5 km, running almost the entire length along existing streets and crossing three major roundabouts crucial for the communication system of Kraków. The line would connect with the existing tram road to Nowa Huta at the intersection of Meissnera and Jana Pawła II streets.
A part of the route is to run underground. Will there be a tunnel similar to the one under the Main Railway Station which is well-known to the passengers?
The designed tunnel will in fact be similar in certain respects to the existing structure in the area of the main railway station but also to the tram tunnel which is being constructed as part of the Łagiewnicka Route. Its part will be an enclosed structure below the ground level, whereas the rest of it will be open. In the area of Polsadu roundabout, a passenger transfer point is planned to be constructed with tram traffic on -2 level and pedestrian circulation on -1 level. The underground stops will be accessed from entrances located on each side of the roundabout and equipped with elevators and escalators. Such a solution will enhance safety of passengers, in particular the elderly, people with reduced mobility or parents with children in prams. Also at Młyńskie roundabout, the stop will be located on -1 level. It will be accessed by means of two staircases, on the northern side of the roundabout with traditional stairs and elevators.
In Polish cities there are more and more tram routes with the so-called green trackbed. Will the route to Mistrzejowice also follow this trend?
In recent years, it can be seen that in urban agglomeration, where there is a strong emphasis on environmental issues, green trackbed systems are constructed. This solution enables filtration of pollution, e.g. dust stirred up by vehicle traffic, and, to a certain extent, reduces the noise absorbing acoustic energy. Being aware of those advantages, we obliged the private partner to design and apply green trackbed on the route to Mistrzejowice to the greatest extent possible.
What is the current stage of the project?
The partner filed an application for a road construction consent (ZRID). Works on the detailed design are still in progress – the building permit design is being complemented and elaborated. According to the new schedule, the residents will be able to use the new route in December 2024.
There is more into the tramway to Mistrzejowice than a trackbed. It is an urban set-up developed almost from scratch which must support a number of functions. It will not be complete without new plantings designed as part of the vegetation management project. The plan is to introduce over 1,000 new trees in the area of the investment as well as almost 6,500 sqm of shrubs.
Vegetation under scrutiny
The first predevelopment plan along the future KST IV route was made in 2015 at the stage of preparing the environmental impact report. Already then it was revealed that the condition of a large part of the trees leaves much to be desired: mechanical damage to the bark, frost ribs, mushroom fruiting bodies, droughts, deviations from the vertical. These factors may contribute to further degradation of these plantings. In total, 75% of the trees listed were selected for removal, of which 7% were intended for sanitary cuts.
In the spring of 2021 and at the request of the private partner, another predevelopment plan was made, which – given how important vegetation is for the Kraków residents – was repeated in the summer (as part of the verifying and supplementary predevelopment). On top of that, the contractor personally supervised and reviewed the location and condition of each single tree which could still be saved. “We have been looking at every single tree as an individual case. An environmental protection specialist and construction site manager have been scrutinizing the cases of trees colliding with the planned infrastructure. This way the design was modified so that at the design assumptions stage a row of 23 birches at Meissnera street could be saved or black locust at the Bareja roundabout” – says Paweł Motyka, Deputy Project Manager at Gülermak. It was also possible to reduce the area of shrub clearance by 6.2%.
Nevertheless, the predevelopment confirmed the findings from the environmental impact report: most plantings directly collide with the planned tramway route, newly designed pedestrian and bicycle routes or the planned alterations of heat pipeline, sanitary sewers network, gas pipelines or electricity systems. “The project is implemented in a partnership formula, but environmental protection matters were outside of the scope of any negotiations while preparing the contract. There can be no breach to the decision on environmental conditions agreed upon with the local community. The aim of the project is to improve the comfort of residents” – says Marcin Hanczakowski, Director of Kraków Municipal Road Authority (ZDMK).
In addition, given the process of obtaining funding for the project implementation, the requirements of banks approached by the private partner are also taken into account. Since international financing institutions are to be involved, the project must meet not only Polish legal requirements, but also international standards in the field of environmental protection and vegetation management.
You cannot simply ignore that 60% of trees covered by the predevelopment plan have defects, among others drought, humus or traces of pest feeding. 5% are decaying. Some have never been a good fit for urban environment.
The contractor shall replace them with species that are more resistant to traffic pollution, drought, frost and salinity. As part of the vegetation management project developed over 1,000 new trees (e.g. common oak, hornbeam, small-leaved lime, Japanese creeper) will be planted in the area of the investment as well as almost 6,500 sq.m. of shrubs.
“We design cover vegetation that absorbs dust and other impurities as well as decorative vegetation in the form of clusters and cut hedges that create aesthetic multicolored compositions. Wherever technically possible, sedum mats will be placed on the trackbed as an all-year-round aesthetic solution” – says Agnieszka Gurgacz, environmental protection specialist with Gülermak. They are also easy to maintain: they don’t need to be watered or mowed as often as grass which saves resources and money. Decorative plantings (including roses) are considered along the investment as well as the so-called green stops and flower meadows. Eventually, as much as 74% of the area used for the construction of the tram route is to be biologically active. This is the same as 4,514 perpendicular parking spaces.
How trees will be selected for replanting?
The predevelopment also made it possible to select trees for replanting. A meticulous approach to the matter enabled qualifying several dozen young trees for relocation. According to estimates, the age limit for the adaptation of a replanted tree is 20-25 years. The chances for surviving are dropping to below 30% for older trees.
“It is a truth commonly acknowledged that you should not replant old trees – says Agnieszka Gurgacz. – The survival of an older tree in a new environment is very difficult for many reasons and it can take up to 3 years to prepare it for the actual relocation. During this time its roots must be cut in a special way” – explains the expert.
The area of the investment features a number of species that do not tolerate replanting, e.g. English oak, walnut, spruce. There is a high risk of drying out. In turn, features like good phytosanitary condition or symmetry boost chances for successful replanting.
Building a new tramway infrastructure in an existing urban set-up requires compromise and taking into account the interests of many parties. On top of a fast and reliable public transport, residents expect comfortable bicycle paths, wide pavements, lighting that boosts security and neat land development.
Vegetation is part of it. Apart from its aesthetic value, it performs many functions important for the city: it lowers the real feel temperature in the summer and stimulates biodiversity. That is why a vegetation management design is so important and is preceded by a detailed predevelopment plan. It determines the species of trees and shrubs growing in the project impact zone and allows for measuring the circumference of trunks, estimating the height and diameter of crowns and establishing the condition of each tree. The plan serves as the basis for revealing possible collisions with the planned infrastructure and identifying the avoidable ones. Compensation plantings along the investment are also designed. It is important that they have the best chance of surviving for many years in difficult urban conditions, especially given the increase in the average temperature on Earth.
Appropriate tests are needed to ensure that traffic vibrations do not exceed the comfort limit for persons who live around the future tram route. For that purpose, data collected during measurements performed within the area of the project will be used among others.
Sensors on structural components of the buildings and disks inside a chosen room are elements of the instrumentation measuring traffic vibrations in the area of the future KST IV route. They are induced i.a. by a heavy vehicle driving over a speed bump. – In such a way, we analyze the behavior of the structure under the impact of vibrations and we verify stiffness of slabs in representative buildings – explains prof. Tadeusz Tatara, expert in the field of seismic and paraseismic vibrations, building dynamics as well as diagnostics and monitoring of civil engineering structures. At the request of the private partner, the measurements are performed under the supervision of prof. Tatara by accredited Deformations and Vibrations of Structures Laboratory of the Faculty of Civil Engineering of the Cracow University of Technology.
Analysis of vibrations along the planned tram route
Selected representative buildings vary in their functions (e.g. residential or office buildings), type (e.g. one-family houses and multi-family buildings), construction technology (e.g. conventional and precast) as well as distance from the designed tram route. However, they share the same characteristics with other buildings erected or planned in the area of the project. They represent the different types of the structures.
Measurements carried out on that buildings will be used for calibration of dynamic models, which, in turn, will be used in numerical analyses thanks to which it will be possible to estimate the impact of vibrations on the buildings and people inside them. On that basis, adequate vibration isolation measures (if needed) could be chosen in order to minimize that impact and ensure everyday comfort for all people in the neighborhood of the project.
More information about vibration isolation solutions can be found here.