Short-range waterway transport as part of a highway construction project in Linz, Austria

ASFINAG (a publicly owned Austrian corporation which plans, finances, builds, maintains and collects tolls for the Austrian autobahns) is using Inland Waterway Transport (IWT) to make a positive impact on the environment.

The construction of the A26 highway in Linz covers a distance of 4.7 km, including 4 km of tunnels. Two bridges are being built on this stretch, including a 300-metre-long suspension bridge over the Danube. In total, this construction project consists of three stages. In the first two construction stages of the bridge and tunnel construction, waterborne transport will be used. This was ASFINAG’s requirement in the tendering process to minimise noise pollution for local residents. The larger steel elements and the tunnel excavation were therefore shipped on the Danube.

The tunnel excavation will be shipped to the Danube harbour of the Fuchshuber company in Lower Austria over 30 km. The contractor for the ship transport is the company JDK Ship Service from Bratislava. At the harbour, the material is removed by a manufacturer of concrete and asphalt aggregates and processed in a nearby plant in St. Pantaleon for the use in road substructures. In the area of the construction site, a mobile reloading station with a conveyor belt, which is loaded with lorries from the tunnel, was used for removal.

Some key facts:

Name of service Highway Construction in Linz
Operator JDK Ship Service on behalf of ASFINAG
Market Segment Construction materials
Region Danube
Launch year 2019
Barge Capacity 1000 – 1200 t
Fleet Size 2x Push boats with 1-2 barges
Propulsion Diesel
Crew 3 per push boat
Port equipment Loading of excavated material via a mobile conveyer belt, unloading via excavators
Last Mile Transport Truck operation by manufacturers for excavation material
Service frequency c.a. 2 – 3 times per workday
Transport volume About 800,000 t of excavated material in the project overall until now

Some more insights about the service

The transport volume of the tunnel excavation to date comprises 305,000 tonnes of excavated material in 2020 (218,000 m³, 275 barges) and 501,000 tonnes of excavated material in 2021 (358,000 m³, 451 barges). This is where economies of scale of inland waterway transport come into play, as the proximity to the water means that transport is not only environmentally friendly but also reduces noise annoyance.

The volume advantage of the large masses of the tunnel excavation makes the use of a conventional push barge with sufficient capacity necessary. Originally there was planned a fixed waterside loading point for the construction site. However, this concept was replaced with a mobile solution. This minimised the impact on the shoreline and only individual concrete foundations had to be poured for the conveyer belt construction. As there was always a barge under the conveyer belt that was loaded, the ship’s cargo space also acted as additional storage capacity that did not take up any additional space on the construction site itself.

A lack of storage capacity at the construction site due to the geographical limitations of the Danube and mountain slopes made constant removal necessary. In addition to the tunnel excavation, the operation also included the transport of large bridge steel elements. A total of 9 bridge elements were transported to the construction site using pontoons and were hydraulically lifted into the steel cable construction. The individual elements had a length of up to 42 metres.

Lessons learned and roll-out-potential

The use of waterborne transport of construction materials in the course of tunnelling and bridge construction offers various advantages. In the context of this construction project, space savings and noise avoidance were decisive factors in the decision to use the inland waterway transport.

Of course, in tunnelling, waterborne transport is limited to projects where the construction site is close enough to a waterway. If this is the case, there is also likely to be a lack of space in most cases, as tunnelling is most likely to take place in mountainous landscapes that are cut by rivers when close to water. However, the implementation requires planning in public tenders, as otherwise truck transport would be preferred in most cases. This option should therefore be considered when awarding contracts for major public construction sites near water. In Austria, there are currently no other fields of application of this kind in the near future.

Image source: Excavation material loaded onto the vessel for transportation (Source: ASFINAG)