Innovation By Indian Railways (CDTS & The Bio-Digestor Toilet System)

Indian Railways with its vast tracks network has been The World's biggest Mobile Toilet

60% (626 million) in India do not have toilet

This makes India the number one country in the world where open defecation is practised
Indonesia with 63 million is a far second!
Less than 10% of Gram Panchayats in India are ODF

ØPollution of fecal matter with drinking water leads to contamination of food, fruits & vegetables, animals (direct contact, flies & rodents)

ØWater borne diseases

ØViral gastroenteritis

ØTyphoid 

ØCholera epidemics

ØDiarrhoea (annually kills 5 Lakhs children)

ØViral hepatitis (100 cases per 100,000 people)

ØOrganic pollution

ØAesthetic nuisance

Controlled Discharge Toilet System (CDTS)

LHB coaches are fitted with controlled discharge toilet units to avoid soiling of train in station and inhabited areas.

The toilet system is designed to operate with a pressurized water bowl wash that covers 100% of the toilet bowl area. The waste is removed from the toilet bowl and transferred to a retention tank with a minimal amount of water. Water consumption is only 2.5 liters per flush cycle for the Indian style toilet bowl and 

       1.5 liters for the European style toilet bowl.

The abstract phenomenon of this system is to operate the valve of the toilet in accord to the speed of the train. The train while entering a station subsequently reduces its speed to halt. The valve of the is operated by electric controls and pneumatic cylinder which is closed below 30kmph (estimate). At higher speed above 30kmph the valve would open discharging the waste.

Operating Principle of CDTS

Ø  This system works on electrical & pneumatic pressure arrangement. The retention tank stores effluent has two openings. These two openings activates by double acting pneumatic cylinders fed by Feed pipe of air brake system with the help of electromagnetic solenoid valves.

Ø  The system starts working on a single push of flush switch. As the flush switch is pressed, water flows into the toilet bowl & the upper slide valve opens which is connected between the toilet bowl & retention tank. All the toilet waste is transferred into the retention tank. At the end of each flush cycle the supply of water is stopped & the upper slide valve is closed. Thus, the toilet is sealed from the retention tank, preventing odor entering from the toilet room.

Ø  The waste accumulated in the retention tank remains in the retention tank until two parameters are satisfied.

Ø  A predetermined no. of flush counts, &

Ø  The train is reached a predetermined speed.

Ø  As soon as these above two parameters are met, the lower slide valve of retention tank opens & the toilet waste accumulated in the tank is discharged out of the tank to the rail side, away from the station & city.

Ø  The lower slide valve of the retention tank remains open for only small period of time to empty the retention tank. The lower slide valve then remains closed until the above discharge parameter conditions is again satisfied.

Salient Features

Ø Programmable.

Ø Requirement of less Air and Water.

Ø P.L.C Controlled.

Ø Easy to clean.

Ø Hygienic.

NOTE: Eventually the CDTS were phased out as The new innovative Bio-digestor Toilet Sytem took over with more promising clean tracks .

BIO-DIGESTOR TOILET SYSTEM

The bio toilets being utilized as a part of IR are first of its kind in Railway Systems on the planet. 


The anaerobic microorganisms has been painstakingly gathered and examined by DRDO from Antarctica and the productivity of this sytem has been tested by DRDO in extreme atmospheres and conditions like those at Siachen Glacier. The anaerobic microscopic organisms in the bio-architect survive extreme cold and warmth as well as survives when subjected to regularly accessible disinfectants.





Important Dimensions & Volume of Biodigester Tank:
1. Length - 1150 mm 2-Width - 720 mm, 3. Height – 540 mm
4. Total Volume of Tank – 400 lt. 5. Effective Volume of Tank – 300 it.
6. Empty Tank weight – 110 Kg. 7. Full Tank Weight – 410 Kg.

8. Height from Rail level -225 mm

Advantage of IR-DRDO Bio-Digester :

1. No bad smell in toilets from the tanks
2. No infestation of Cockroaches & flies
3. Fecal matter in the tank not visible
4. No clogging of digester
5. Effluent is free from off odour and solid waste
6. No maintenance required
7. Reduction in organic matter by 90%
8. No requirement of adding bacteria/ enzyme

9. No need of removal of solid waste

Here is the Detailed Video For the same By IR-DRDO