First forest walkway plan

The 400m long, 15m high structure, planned for Northamptonshire’s medieval Selsey Forest, uses wood technologies new to the UK. But, ten weeks before work starts, the experimental nature of the build threatens to outstrip the mostly government-provided budget of £700,000.

The scheme’s project manager, Geoff Freedman, who works for the commission’s Forestry Civil Engineering (FCE) group, said this would be the first time the new method of wood construction, which involves clamping numerous small pieces of wood together, would be used in the UK.

However, high construction costs threaten to scupper the project’s most pioneering details. Freedman said: “We have got to maintain a constant rate of progress and if the tenders come in too dear, we will have to cut it.”

Tenders will be returned next Thursday following a site meeting on Monday. Among the favourites must be Somerset-based William Haley Engineering, a firm that developed, patented and built standard aerial mast bridges in collaboration with Freedman.

Designing the walkway up to all-ability access and safety standards has already proved complex. Ramps of 150m length leading up to the main height were included at either end to allow for faster evacuation in an emergency. The bridge will be mainly wood, up to 3m above the ground, continuing with wooden rails and deck, on a steel structural support.

And while FCE has designed scores of bridges on Forestry Commission land, the height had brought added problems. ‘Crow’s nests’ at 20m had to be beneath the tree canopy to avoid overlooking neighbouring properties.

If the tenders come in too dear, we will have to cut it

Geoff Freedman, FCE

Construction lawyer, Giles Dixon, who has 30 years industry experience confirmed that this type of build is hard to cost.

“It is difficult to figure out the higher and lower levels of a new project and working just to a design can be particularly challenging. A lot depends on the scope tenderers are given, particularly on materials.”

Freedman is hoping for increased government investment. Local sources confirmed that around £400,000 extra funding might be forthcoming from the Deputy Prime Minister’s office if the project looks promising.

The walkway is expected to be formally opened in October.