IT IS not worth the money to strengthen all ‘substandard infrastructure’ on the rail network, train chiefs have acknowledged.

In an interim report following the Stonehaven tragedy, Network Rail has admitted it is not “economically viable to strengthen all sub-standard infrastructure slopes” on its system.

READ MORE: Stonehaven crash: Train hit washed out rocks and gravel before derailing

Even with improvement works, the rail management firm says there will “still be earthwork failures as a result of challenging weather” and has identified almost 600 sites across the country with similar characteristics to the location of the derailment at Carmont, near Stonehaven.

Crash explained

The crash on August 12 claimed the lives of three people – train driver Brett McCullough, 45, conductor Donald Dinnie, 58, and passenger Christopher Stuchbury, 62.

The 06.38 service from Aberdeen to Glasgow encountered problems on the line, with the train being held for more than two hours after the driver of an earlier train reported a landslip.

HeraldScotland:

When it continued again, it hit another landslip while travelling at around 75mph and it came off the tracks.

Almost 600 sites are "similar" to crash location

An interim report commissioned by UK transport Secretary Grant Schapps states 584 sites have been identified across the rail network which “share some characteristics of the Carmont location, constructed from soil cuttings with track drainage, including any local features that are considered a risk.”

Investigators have stressed that none of the 584 locations found during their inspections needed emergency repair work, however 6 of them (1%) have deteriorated further since the investigations concluded just two weeks ago on August 28.

HeraldScotland:

The report states: “The 584 specialist inspections since the Carmont derailment have not identified any significant issues requiring emergency intervention.

“At around 1% of the sites we have identified defects that have deteriorated and require action sooner than originally planned."

"Not every failure will be prevented"

The report also reveals that landslips of earth failures can happen with “little or no” previous indication of a problem, and states: “high rainfall will continue to present challenges as it triggers a high proportion of rapid cutting slope failures with little or no indication of visible distress prior to failure.”

The network operator has said it’s investment plans “target areas that have the highest risk of failure” and renewal work “will prevent many failures”, but still acknowledges not every failure will be prevented.

Climate change is accelerating the deterioration of parts of the rail network, according to the report.

The “threat of extreme weather” and complex drainage systems in the wider area around the railway can “concentrate risks at or near the railway”, say investigators.

Probe to continue for "several months" 

The report also explains that it could take several months before a full industry investigation into the Stonehaven tragedy is concluded. 

Network Rail chiefs explained: " The learnings from the investigations will be fed into our business planning process in due course.

HeraldScotland:

"In the short-term, we continue the work with our meteorological partners to harness real-time, more granular data and incorporate them further into our operational response processes.

"This will be done in conjunction with operators to bring their specific insights into management during extreme weather and the potential impact on passenger and freight customers."