DC Structures Studio is working with Buller District Council (BDC) to design a new pedestrian bridge for Westport, New Zealand. The proposed steel truss pedestrian bridge will cross the rail corridor west of the main Westport town centre and connect the community to the waterfront over the existing railway. The pedestrian bridge is part of a larger landscaping initiative referred to as the “Westport Waterfront Riverbank project”. The project has received Provincial Growth Funding to help revitalize this region of Westport and bring added connectivity to the West Coast.
The pedestrian bridge runs parallel (and in line with) Brougham Street and perpendicular to Adderley Street (one block behind and parallel with Palmerston Street).
Not only will the bridge connect the local community to the waterfront but it will also complete the connection of the recently funded $18M “Pounamou Pathway hubs” that seeks to invigorate tourism in the region by showcasing Maori culture specific to the region. The bridge will be a key connection between the Pounamu Pathway to the west of the town and the soon to be revitalized Westport Museum (Coaltown Museum). The museum will be one of four key hubs on the Pounamou Pathway.
Westport Waterfront’s The Riverbank project is the revitalisation of the current industrial area between the Buller River and the town centre. It forms part of the Westport master plan and features the “Toki Poutangata” bridge over the existing railway line. The bridge allows people to easily transition from the main street to a new riverbank space in a safe way. This is the first significant step in Westport turning to face the river, Westport’s greatest natural asset.
Architectural intent for the “Toki Poutangata” pedestrian bridge
The name chosen for the bridge “Toki Poutangata” (or Toki for short), describes a ceremonial adze of chiefly authority, and consists of a pounamu blade lashed to an elaborately carved handle. This styling has been carried through into the truss design of the bridge structure, with its distinctive tapered shape and green colour, drawing focus to the Buller River. The concept has support from local iwi Ngāti Waewae. It represents strength, mana, bravery and triumph, all traits and characteristics synonymous with the Buller district.Not only will the pedestrian bridge provide safe access over the rail, but it will also integrate a look-out platform so that visitors can stop to take a breath and marvel at the west coast landscape and Buller River.
Structural concept for pedestrian bridge design
The steel truss pedestrian bridge is a 29m spanning warren truss carrying a 2. 5m wide pedestrian and cyclist friendly walkway. Top and bottom chords of the truss are fabricated from square hollow section (SHS) and the diagonals in the vertical plane are created from circular hollow sections (CHS). Cross beams and plan bracing are fabricated from rectangular hollow sections (RHS). The top chord of the pedestrian bridge changes in vertical elevation from east to west to create a tapering overall elevation. The main driver for the vertical alignment and span, was crossing the Kiwirail rail corridor with a minimum clearance of 4.7m.
Steel PFC joists attach to the truss cross beams which carry a lightweight fiber reinforced polymer (FRP) decking. The FRP decking of the pedestrian bridge features a non-slip surfacing and is installed with a central crown to enable run-off of stormwater over the sides. This product was recently used on the Wairoa Cycleway Trusses (designed by DC Structures Studio).
Early stakeholder engagement
Buller District Council hosted a public open day on 21st October 2020 to present the “Waterfront Redevelopment” project. The project was only at the Preliminary Design stage and it was great to see such a proactive approach from council to engaging the community.
I remember Mike Duff from BDC sending our original ideas/sketches straight to local iwi Ngāti Waewae for comment and input. Literally these were ideas sketched on the back of Napkin (well… free hand doodles on some google images of pounamu). Far too often we take a concept all the way to fancy renders before seeking feedback. By starting at the “ground floor” iwi were able to understand the “idea” and input/collaborate from Day #1. This was a very refreshing approach from council that shows a clear commitment to working collaboratively with (and not for) stakeholders. Bravo!
See below the original sketches. First sketch was produced 23 June 2020 and was sent straight to Ngāti Waewae for feedback. The second image was produced 1 July once the idea for a toki truss was considered. Again this was then sent straight to Ngāti Waewae for comment.
Check out the cool video of the community presentations.
Key pedestrian bridge design specs
| Location = Westport, New Zealand | |
| Main Truss Span Length = 29.6m (over railway) | |
| Main span usable width = 2.5m | |
| Truss depth = VARIES: 1.6m to 5.6m | |
| Design Basis = NZ Transport Agency Bridge Manual v3.3 | |
| Clear height over railway = 4.7m min | |
| Design Live Load = 5KPa (circa 500kg/m2) | |
| Seismic design to NZS1170.5 with Importance Category 2 | |
| Footbridge design software = SAP2000 v22 & IdeaStatica v20 | |
| Structural form for main span = Steel truss | |
| Structural form for ramps = Engineered timber (glulaminated) beams | |
| Corrosion category for steelwork design = C5M (Coastal marine) |
Delivery Partners
Being delivered for Buller District Council with funding from the Provincial Growth Fund (PGF).
Local Landscape Architecture Collective – Landscape Design of pedestrian bridge approaches, adjoining streetscapes, and an awesome sounding board for ideas relating to the pedestrian bridge!
CGW Consulting Engineers – Project Management and general “wrangling” of everyone involved in delivering this unique pedestrian bridge.
Abley – Transportation inputs and cool ideas for changing the car focused status quo into a “people first” shared space.
Riley Consultants – Our trusted partner for all geotechnical design inputs relating to the bridge. One of many bridges we have delivered together.
Truecost Ltd. – Les Lewer is a guru when it comes to high quality estimates for pricing and producing schedules for tendering purposes.
Pedestrian bridge design details
More info
For more info refer to Buller District Councils Website: https://bullerdc.govt.nz/westport-riverfront-project/
