The HS2 project has been granted the permission to construct two new viaducts by Birmingham City Council, which will see the new high-speed railway roll into Curzon Street Station in the city centre.
Curzon Viaduct No.3 and Lawley Middleway Viaduct are part of the Curzon Street Station Approach area, which sees a collection of four connected viaducts situated between Duddeston Junction and Curzon Street Station situated in central Birmingham. The other Viaducts within consist of Curzon Street No.1 Viaduct (furthest from the station) and Curzon Street No.2, which is currently undergoing a planning application.
David Speight, Client Project Director at HS2 Ltd said:
“We are very pleased that Birmingham City Council’s planning committee approved the plans for these viaducts. This decision represents a significant approval for HS2 in Birmingham city centre and means we are on track to bring high speed rail to the West Midlands, increasing capacity and connectivity across the UK. In addition, our design refinements on the viaducts will bring a range of extra benefits, including reducing the construction time and materials, reducing the amount of carbon we need on the project.”
The designs for these viaducts are being conceptualised by a Design Joint Venture of Mott MacDonald and Systra, with architects Weston Williamson + partners. These collective parties are working under HS2’s construction partner Balfour Beatty VINCI joint venture. Through the collaborative efforts of the parties involved, a shorter construction programme has been achieved, with less overall concrete required for the viaduct build. These design refinements also created positive environmental and community benefits.
Nick Robertshaw, Project Manager from the Design Joint Venture Mott MacDonald and Systra said:
“BBV and the DJV design team have brought their global expertise to tackle the significant engineering challenges involved in fulfilling HS2’s design vision for this iconic structure, which will provide a catalyst for social and economic development.
“This landmark milestone for the programme has only been made possible through the ‘one team approach’ facilitated by HS2 with Birmingham City Council, whose critical input and collaboration has enabled this achievement.”
Nick McGough, Director at Weston Williamson and Partners said:
“The key design challenge of Curzon 3 was to address varied sites with differing technical requirements whilst providing both a level of consistency as well as ensuring the viaduct contributes positively to its surroundings. Toward the HS2 Curzon Street Station the viaduct is over 60m wide and so the design maximises daylight under the structure through the introduction of light slots with a unique lightweight parapet design. Over the Digbeth Canal the opportunity is taken to reference Birmingham’s canalside heritage whilst the large span required over Lawley Middleway is achieved through the use of heroic weathering steel girders which arch over the carriageway.”
The Curzon Viaduct No.3 is approximately 300 metres long, with the above ground level height reaching between 6-5 metres and a width of 65 metres at the widest point which requires support from 30 piers. The deck of the viaduct widens as it approaches the Curzon Street Station, opening to four separate decks at the western end.
The four separate decks are designed to widen to maximise the daylight in an ergonomic design that will allow maximisation of the daylight in the public spaces’ underneath. V piers have been developed to support the viaducts because they assume less room at ground level and will also have a side recess for future potential services to be visually integrated. As well as separating the viaduct into four separate decks, the V piers will also help to maximise the opportunities to create a usable and flexible public space under the viaduct.
As Curzon Street No.3 Viaduct crosses the Digbeth Canal, the concrete V piers are substituted with four inverted steel piers which reference the heritage of canal-side cranes in Birmingham. This also means the Digbeth Canal area will remain a visually attractive area to the public, combining the twenty first century HS2 infrastructure and the nineteenth century Digbeth Canal area, ensuring a positive legacy for this part of the city.