The Indian Railways has a bit of a mess on its tracks.
It has rather belatedly discovered that letting stuff simply fall out of thousands of train toilets every day is causing serious corrosion of railway tracks.
In addition to being a potential safety concern, the problem has become so endemic that, in some instances, the Railways has had to replace stretches of track every two years, while in the normal course, it would have done so once in three decades or so.
The toilet tab: a tracks replacement cost of a whopping Rs400 crore every year.
Now the Railways wants to build better train toilets, ones that will keep the waste from doing damage to the tracks even as it searches for corrosion-resistant rails.
Researchers at the Indian Institute of Technology in Kanpur, who are working with the Railways to solve this sticky problem, place the current woes on wind, which disperses the waste on to tracks, as well as the acidic nature of human waste.
“When the matter comes in contact with the track, metal iron becomes brittle and starts to corrode,” says Vinod Tare, a member of the Technology Mission on Rail Safety at the Institute. “You can observe this phenomenon on leaking metallic pipes, for instance.”
Another of Prof. Tare’s colleagues on the project is R. Balasubramaniam whose claim to fame is his research into corrosion of the famous Ashoka Pillar in New Delhi.
Prof. Balasubramaniam notes that the problem with train toilets is that discharge sticks to critical corners, such as the place where the tracks are attached to the concrete sleepers, raising what he says are potentially serious safety issues.
The scientist, who is also leading a team of researchers to develop corrosion-resistant rails for the Technology Mission, says the bio-waste problem has been even more acute in several states, such as Andhra Pradesh, Tamil Nadu, Gujarat, Kerala, Maharashtra and West Bengal, especially on the miles of tracks on their coastline. That is because the corrosion is compounded by exposure to salt-laden sea breeze.
The Railways, through its Rail Design Standards Organisation, has conducted field trials for a new toilet on a new, high-speed Shatabdi train. “These toilets hold the waste when the train is travelling at speeds lesser that 30 kilometres per hour so (at least) the stations are not dirtied,” says an official in the safety wing of the Railways, “The specially designed toilet also ensures that the discharge—due to it’s design—is thrown by the side of the tracks and not on it.”
Shifting the problem to the side of the tracks might help the Railways thought it does hark back to days, in the early history of the Indian Railways, when trains actually had no toilets and passengers had to use open fields during “toilet halts.”
Indeed, “hygiene movements such as Sulabh need to tie up with the Railways” to deal with track-side issues, says this Railways official asserting that in any case, passenger safety was not being compromised by this problem because the railways monitors its track conditions very closely.
Still, track damage is one big reason why many countries have more sophisticated toilets in their trains.
Passenger train toilet systems used in most Western countries are of two types: compost and chemical toilets. Chemical toilet systems use disinfectants—usually formaldehyde—as part of the flushing system and then store the waste in a storage tank that is then emptied into the sewage systems at stations. That approach requires a meticulous disposal system at stations and storage tanks that are large enough for long-haul trips between stations that might not have such sewage facilities.
Compost toilet tank systems work on a different technology where liquid wastes are treated with chlorine, while solid wastes are converted into liquid, and, via a microbial treatment, carbon dioxide.
Both carbon dioxide and chlorinated liquid waste are non toxic, which are released on the track without causing any noticeable damage to the tracks.
The Railways is also looking to steel companies, which provide tracks, to deal with the problem .
It has tied up with the Steel Authority of India Ltd, along with Prof Balasubramaniam’s team to develop corrosion-resistant rails that will be manufactured in the steel giant’s Bhilai plant.