Toilet waste from trains is building up on parts of the rail network, affecting track inspections and raising fears about health risks to staff.
By Tom Geoghegan
BBC News Online
Inspections have had to be altered in Nottingham, where one track worker says maintenance is suffering - a claim denied by management.
All new trains are able to store their waste in retention tanks, but the old "slam-door" rolling stock and some high-speed diesel trains still dump it on the tracks.
The mess litters the railway nationwide and samples are being tested for disease by rail safety experts.
The waste leaves a white residue
Although new stock is being introduced all the time, the problem is increasing in areas where trains are spending more time in stations.
Track maintenance staff at Nottingham station have abandoned their vain attempt to remove more and more of the stubborn discharge from the rails.
One track worker told BBC News Online the problem meant some maintenance work was not being carried out and platforms may have to close within weeks, if a major fault was detected.
He said the problem demoralised staff, who feared for their health.
But Serco, which works in the East Midlands for Network Rail, denied work was being neglected.
Contract director David Godley said a specialist firm was removing the waste when repairs were required.
Network Rail, which has been told to save £2bn by the Rail Regulator, could not say how much the specialists were costing them.
Track inspections have also been altered so staff do not have to tread on parts of the track heavily coated with waste.
But the Health and Safety Executive said the new practices were not compromising safety.
Nottingham station's owner, Central Trains, has promised a major clean of the track.
Rail safety experts are also studying the possible risk of workers contracting disease and the effect on staff morale.
A Rail Safety & Standards Board spokeswoman told BBC News Online the study's findings were three months away, but samples of discharge were being tested for disease bugs such as hepatitis A and gastroenteritis.
The HSE says workers are sufficiently protected by their standard issue clothing and risks to passengers at platforms is negligible.
A spokesman for the RMT union told BBC News Online: "Health and safety is the number one priority in the railway industry.
Trains that dump...
Midland Mainline, St Pancras to South Yorkshire
Connex, Kent Coast to London stations
First Great Western, Paddington to South Wales and South West
South Central, South Coast to London stations
GNER, London Kings Cross to Edinburgh
"But usually, you think of large lumps of metal moving at great speeds - this is a biological source of danger which is too often not treated with the urgency it deserves."
When the trains are moving, the excrement is dispersed, but toilets flushed at stations - despite the warning notice to passengers - leave a mess on the tracks that eventually becomes a residue of white tissue.
Passengers have also complained about the sight of toilet waste on the tracks as they wait at platforms.
....and trains that don't
Jo Peake, 26, at East Croydon station, told BBC News Online: "I had never noticed it before, but it's pretty disgusting.
"It's really unhygienic - like an open sewer."
John Cartledge, deputy director of the London Transport Users Committee, said it was unattractive for passengers, but getting a seat was a far greater priority.
He said: "It does nothing to enhance the amenity of the station environment and does nothing to improve the perception of the way the railways are managed."
Soroptimists International, which champions women at work, investigated passenger safety last year by inspecting 68 stations.
June Bridgeman, who headed the report, said they found human excrement with litter on tracks at platforms, and the situation had deteriorated over the past five years.
Passengers ignore the warnings
She said: "It's not trivial. It's well known from research that graffiti and litter are key factors in making people feel neglected and unsafe."
A spokeswoman for Network Rail told BBC News Online: "We're working with contractors and train operating companies to keep the tracks clean and deal with the effluent waste and litter whenever it appears.
"But the emphasis should be on train companies which do not yet have retention tanks."
She said they were using new equipment such as trays and sheets to stop the waste falling on the track, and had asked train firms to lock toilets at stations.
The slam door trains, common in the South East, must be phased out by the end of 2004.
But the high-speed diesel trains are not subject to any legislation and most companies have no date for their replacement.