Delays caused by leaves on the line have long been the bane of rail commuters in autumn.

Yet experts have admitted they are no nearer to finding a solution than they were 40 years ago, according to the latest jargon-riddled report from an obscure industry body devoted to working out which rail company is to blame for delays.

Written by the Delay Attribution Board (DAB), the ‘Autumn Trust Delay Attribution Process Best Practice – 2015’ report is a study in badly written English.

Delays caused by leaves on the line have long been the bane of rail commuters in autumn yet experts have admitted they are no nearer to finding a solution than they were 40 years ago. Above, the track at Matlock, Derbyshire

Admitting that rail managers ‘frequently suffer from a lack of detailed information and resource during the autumn period’, it says leaf-fall is a ‘challenge to the entire industry’ and that ‘the exact circumstances of delay due to the wheel/rail interface are complex [and] not fully understood’.

Delays occur when locomotive wheels slip on the mush left by wet leaves that have dropped from trackside trees. The most up-to-date figures, for 2013, reveal that leaves on the line resulted in more than 8,000 hours of delays.

Dr Paul Allen, assistant director of the University of Huddersfield’s Institute of Railway Research, told The Mail on Sunday: ‘When leaf mulch combines with dew or light rain, the friction level between wheel and rail can drop to a 20th of the level when dry.’

The first piece of research into the problem was commissioned by British Rail in 1973 and the industry has been grappling with the dilemma ever since. Network Rail, which is responsible for stations and track, and the train operators have even established a so-called ‘Neutral Zone’ to cover leaf-fall delays, which means that the blame and any financial penalties are split equally between the two sides.

In a sentence unlikely to win an award for plain English, the Delay Attribution Guide states: ‘Where a train has been delayed by multiple leaf-fall incidents, attribution of reactionary delay is to that incident causing the majority delay.’ The DAB, which costs about £100,000 a year to run, adjudicates in disputes between Network Rail and the train operating companies over who is responsible for hold-ups.

Network Rail – which has 165 employees working full-time on ‘delay attribution’ matters at an estimated total annual salary of £5 million – says it is tackling the autumnal menace with 55 ‘leaf-busting’ trains that travel 22,000 miles of track shooting out high-pressure jets of water.

Network Rail – which has 165 employees working full-time on ‘delay attribution’ matters at an estimated total annual salary of £5 million – says it is tackling the autumnal menace with 55 ‘leaf-busting’ trains that travel 22,000 miles of track shooting out high-pressure jets of water. Above, two workers survey tracks

But independent experts claim this technique has changed little since Victorian times, when workers with buckets and cloths scrubbed foliage off the line.

Other remedies include a Scandinavian-built locomotive, equipped with 16 wire brushes, known as the ‘Swedish Scrubber’.

Transport campaigner Christian Wolmar told the MoS: ‘This is one of the madnesses of rail privatisation. There are hundreds of people employed on allocating blame for delays, but that does nothing to improve services and ultimately it’s the taxpayer and passenger who is paying.

‘Other countries seem to manage better in tackling leaf-fall. It either means cutting back trees or simply having enough people working overnight on clearing the track. It’s extraordinary that we are still joking about leaf-fall delays nearly 20 years after British Rail was abolished.’

A Network Rail spokesman said: ‘We are much better at dealing with the leaf-fall issue than 50 years ago but we will never be able to eradicate it completely.’