The Chee Tor Tunnel portal seen from the Number Two Tunnel which has been resurfaced. Photo: Simon Leatherdale CC-BY-SA-2.0

An innovative national park route which passes through four former railway tunnels will open later this month.

Transport minister Norman Baker will officially open the extended Monsal Trail to the public, allowing walkers, cyclists and horse riders to use the tunnels for the first time since they were closed to railway traffic in 1968.

The £2.25m scheme has seen the former Midland Railway bores cleared out, repaired, resurfaced and lit to enable the public to use them.

The tunnel openings will extend the Monsal Trail in the Peak District by 2km (1½ miles); the route runs from Bakewell to the edge of Buxton. Work to reopen the tunnels started in December 2009. They will be officially opened on Wednesday 25 May.

The four tunnels being reopened – Headstone, Cressbrook, Litton and Chee Tor – vary in length from 400m to nearly 500m. They have been resurfaced using environmentally friendly materials and have had long-life light fittings installed.

The remainder of the trackbed between the tunnels has been resurfaced with a recycled material called Toptrec derived from the demolition of buildings and old road surfaces which is treated and filtered for reuse on paths and cycleways.

Two existing open tunnels, Chee Tor Number Two and Rusher Cutting, have also had repairs and resurfacing works carried out.

The tunnels have been lit by 123 fluorescent long-life fittings capable of 80,000 hours usage powered by water-resistant cable. All have a three hour emergency battery capacity to remain lit in case of power failure and ensure safe withdrawal from the tunnels by users.

They are programmed via photocell sensors to shut off at night to save power; new signs warn users not to enter at night. The sensor then detects light levels in the morning and they switch back on.

Jim Dixon, chief executive of the Peak District National Park Authority, said: “This has been a huge engineering project and is generating a lot of interest and excitement among local residents and visitors.

“Through this project we are opening up the important limestone landscape of the Wye Valley with all its industrial and environmental heritage so that more people can come, experience and learn about it.

“By investing in the new route we increase opportunities to go cycling, walking and horse riding instead of using the car. Some local residents will use the new route for commuting or a social ride, while for tourists it offers a safe, traffic-free environment to enjoy what is so special about a national park.”

Two privately run cycle hire businesses have been set up along the Monsal Trail to take advantage of the extra cyclists expected to be attracted by the opening of the tunnels.

Interpretation panels and audio listening posts providing information about the trail, the tunnels and the route’s former history as the Midland Railway have been installed at various points along the route. Improvements have also been made to access points and direction signs put up.

The work to open the tunnels is the first phase of a longer term plan which would see a circular cycling route created to link Buxton, Matlock and Bakewell. Planning permission and further funding would be needed before this can happen.

Funding for the tunnel work has come from the Department for Transport as part of the national park authority’s Peak District Pedal Project.