New study considers Queensbury tunnel risks

The 1.4-mile long Victorian structure, linking Bradford and Keighley to Halifax, is currently the focus of a campaign to reopen it as part of an ambitious cycle network, but Highways England’s Historical Railways Estate (HRE), which looks after the tunnel for the Department for Transport (DfT), intends to abandon it as part of a £3.2 million project starting in September.

Over recent weeks, conflicting views have been expressed as to whether the tunnel - which has suffered two partial collapses - could cause damage to houses built on the surface, more than 350 feet (107 metres) above. In June, Highways England suggested that “action now needs to be taken…in order to protect the community”, however it was unable to provide evidence to support this claim when challenged by Queensbury’s three local Councillors.

The report, produced by the Queensbury Tunnel Society, considers a number of statements made by HRE in email exchanges with DfT officials, in which it sets out the need to make progress with the abandonment scheme. In one, HRE says: “There is a risk, which grows daily, that one of the two known areas of collapse could unravel the tunnel lining back to one of the shafts causing a risk to properties above those shafts.” It has since described this as “the worst scenario”.

However the new report makes clear that the condition of the tunnel is “generally stable”, the partial collapses have not structurally changed in the four years since the most recent one occurred, there are no recorded defects close to the shafts and no signs of deformation or distress to their support structures. HRE inspection reports identify the shafts as being in Fair condition.

It concludes that HRE “appears to have chosen to abandon Queensbury Tunnel without first seeking to formally establish whether there is any realistic likelihood of that [worst] scenario occurring and, if so, within what timescale.”

Graeme Bickerdike, Engineering Co-ordinator for the Queensbury Tunnel Society, says: “The tone and content of some of HRE’s emails suggest an urgency and threat level that are simply not sustainable. The risks do not ‘grow daily’ in any meaningful sense and the idea of an ‘unravelling’ is difficult to sustain as each collapse is a discrete event caused by unique local conditions. But most importantly, the shafts are in Fair condition; the tunnel lining beneath them isn’t squatting and there are no cracks or compression failures as would be the case if the arch was subject to excessive loads.

“In our opinion, Queensbury Tunnel currently presents little short-term risk to the community, as has been the case for several decades.”

Norah McWilliam, leader of the Queensbury Tunnel Society, says: “We’re pleased that our engineering team has been able to put some of HRE’s claims into context, looking at the defects in the tunnel and how they might develop. Their conclusion that abandonment cannot be justified by any reasonable approach to risk management is something we’ve suspected for a while; it’s more a function of fear and ignorance.

“HRE shouldn’t be making decisions or exaggerated statements without evidence to back them up. There is the potential to cause undue concern to people living above the tunnel and we share the view of local Councillors who regard these statements as irresponsible.”

The Society has sent a copy of the report to Chris Grayling, Secretary of State for Transport, asking that he seek “some evidence from HRE to demonstrate a realistic short-term need to put a potentially useful structure permanently beyond use... If it is unable to provide that evidence, we would respectfully ask again that you pause the abandonment process.”

Meanwhile on Thursday (19th June), members of the Society joined representatives from Sustrans and Calderdale Council at a meeting with Bradford Council officials to discuss how a positive future for Queensbury Tunnel might be secured.