23 November 2022

The spectacular construction is completed – the shipping channel through the Vistula Spit is ready!

The construction of one of the most complex hydrotechnical investments in Poland has been completed – the channel connecting the Gulf of Gdańsk with the Vistula Lagoon is ready. Thanks to a good design and perfect organisation of all deliveries and works, the construction of the Vistula Spit crosscut was completed in just 35 months.

-The Vistula Spit crosscut is a strategic investment for Poland. Thanks to it, for the first time in the post-war history of Poland, it will be possible to enter the Vistula Lagoon bypassing Russian territorial waters. The legitimacy of the government’s decision to start this investment is particularly visible in today’s geopolitical situation – said Minister of Infrastructure, Andrzej Adamczyk.

-We are opening the Vistula Spit crosscut. We have been waiting for this moment for many years. On September 17, 2022, the Shipping Channel will be launched. On this day, ships will have free access to all ports of the Vistula Lagoon and, most importantly, to the seaport in Elbląg. In this way, the first, most important stage of this investment will end – added Deputy Minister of Infrastructure, Marek Gróbarczyk.

From the very beginning, the construction of the shipping channel that connected the Vistula Lagoon with the Gulf of Gdańsk was a spectacular investment. This is evidenced by both the wide and extremely diverse range of tasks to be performed, as well as the amount of material used. The project assumed the simultaneous construction of a protective harbour from the side of the Gulf of Gdańsk and a shipping channel with a lock and construction of closures along with berths from the side of the Gulf of Gdańsk and the Vistula Lagoon, as well as the construction of a new road system with swing steel bridges with a vertical axis of rotation, and even the construction of the so-called artificial island in the Vistula Lagoon.

-We can say that everything is wrapped up. It took us less than three years to build a passage through the Vistula Spit together with an artificial island in the Vistula Lagoon. We have done a lot of pre-investment work that took several years. We implemented the assumed schedule as planned. It was possible thanks to the commitment, going beyond the scope of normal work, of the team implementing the project, consisting of substantive employees of various specialties of the Maritime Office in Gdynia. I would like to thank all of them for this enormous amount of work! – said the director of the Maritime Office in Gdynia, Wiesław Piotrzkowski.

Today, apart from the cleaning works, which will take several more weeks, the shipping channel through the Vistula Spit is ready. The ships that will cross it from the Gulf of Gdańsk will enter the newly built protective harbour. This one consists of the over 1000-metre-long eastern breakwater and the over 500-metre-long western breakwater. Its total area is 260 thousand m2.

We are glad that we have completed the work in accordance with the assumed schedule. The construction of the shipping channel and the artificial island is one of the most unusual hydrotechnical projects in Poland and we are extremely pleased that we have participated in its implementation – said Małgorzata Winiarek-Gajewska, President of the NDI Group. – The project aroused great interest, which is why, together with the Investor, we tried to regularly inform the public about the progress of works, as well as share experiences from the implementation with the environment of engineers and students of technical universities. Thanks to this, not only our staff, but also many interested people could learn about the solutions applied in practice. On this occasion, I would like to congratulate and thank the whole team who put a lot of strength and heart into the implementation of this project – adds the President of the NDI Group.

For the first time in the world

The amount of materials used to build it is impressive – it is 400,000 tons of stone rip-raps made on breakwaters and almost 10 thousand pieces of the so-called x-blocks, i.e. precisely arranged prefabricated concrete elements to attenuate dangerous waves during difficult weather conditions.
Let us recall that the breakwaters were made in a technology unique in the world – prefabricated elements of “x-block plus”. Previously, they were used only on the Afsluitdijk dam – the Shield Dam, which is the main dam and dyke in the Netherlands. There, however, they were mounted on the water. On the other hand, on the Spit, they were laid under water for the first time in the world. Divers and heavy equipment was also used.

Each such concrete element (from 2.5 to 12 tons) has its history and number. A specification sheet has been created for each one in order to know how it was created and how it was stored in case of any problems during operation. Earlier, a project was also prepared, in which each x-block found its place, defined by coordinates. Thanks to it, x-blocks were stacked like blocks.

The lock – the heart of the investment

In addition to the construction of the protective harbour, a big challenge was also the construction of a shipping channel into which ships will enter both from the Gulf of Gdańsk and the Vistula Lagoon. The total length of the channel is approximately 1,300 running metres, the width at its widest point is 120 metres and the depth – 5 metres. In order to do it, it was necessary to excavate, among others, 800 thousand m3 of material – says Mariusz Janczewski, site manager from the NDI / Besix consortium -the general contractor. – As part of the construction of this element, the heart of this investment should also be made – a lock with four gates for its closing. Each of them is composed of six segments, and each segment of 730 elements. One gate weighs about 160 tons, and the heaviest of its elements – about 33 tons – adds Mariusz Janczewski.

The lock is probably the largest facility of this type in Poland – its length is less than 270 metres, and the width is 25 metres. The depth reaches 6.5 m below the water level, and the height of the walls with caps is over 9 metres.

However, an unusual element in the structure of the lock is not only its size, but also the way its gates move. The rope method was used here – thanks to rope winches, the steel gates move on rails specially made in the bottom. Paired gates, the so-called redundancy, allows you to maintain security even in the event of failure of one of the lock gates.

But the movement of ships would not have been possible had it not been for the Harbour Master Office, built at the channel, in which a superior control system was installed, including large-size touch monitors and emergency panels, which in the event of a fault will allow you to control the gates of the lock or close / open a given bridge.

Unique bridges in Poland

One of the largest hydrotechnical investments also involved the construction of a road system with two swing bridges. It is one of the longest facilities of this type in Poland. Thanks to them, the traffic of ships will not interfere with car traffic along the shipping channel. The total length of one of the two bridges on the Vistula Spit is over 60 m, and the weight of the steel structure of the system with counterweight is approx. 550 – 560 tons. Each of these bridges consists of 44 elements that were manufactured in a steel structure prefabrication plant, delivered to the construction site and put together as blocks. The heaviest of the individual elements weighed over 48 tons. Despite such a specific structure and weight, the bridges have been assembled down to the millimetres and balanced to the kilograms.

Importantly, the first one – the south bridge – had to be put into use in June last year.

-All this makes this investment extremely complicated in terms of logistics. For example, nearly a million tons of hydrotechnical stone was delivered to the construction site, which was built into the structure of the breakwaters and into the envelopes of an artificial island – says Jacek Szymański, project director from the NDI / Besix consortium. – Taking into account this volume of materials and the pace at which the contract was carried out, i.e., 35 months, the project was really difficult. It required us to carry out many works at the same time and perfect organization in terms of logistics. At the peak, about 400 people were employed on the construction site, but an additional several hundred people worked for this investment outside the construction site. In total, nearly 3,000 employees were involved in the works – adds Jacek Szymański.

Unique Aestian Island

An additional element of this investment is an artificial island, where the excavated material from the dredging works and dredging of the channel will be deposited. Interestingly, nature has already loved it – it is a habitat for birds and vegetation.

Aestian Island with dimensions of 1906 by 1166 metres, a circumference of 4.9 kilometres and an area of 180 hectares is one of the largest islands of this type in Poland. Only the area of steel sheet piling used to shape it and maintain the filling with sand from the dredging of the bottom of the fairway is almost 112.5 thousand m2 – for comparison, it would cover almost 16 full-size football fields.

In turn, one million tons of sand will be used for backfilling the dyke, which would fill approx. 37 thousand trucks. In addition, about 140 thousand tons of hydrotechnical stone was used, which would fill 3.5 thousand railway carriages.

The island has already “survived” two winters with the ice rush, which has proved that the selected structure and designed cross-sections have fulfilled their task and that it can be safely used for the next years.

The construction of the first stage of this investment has already been completed. Only cleaning work remains to be done.

 

 

 

 

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