``Slums are the biggest problem on the suburban railways,'' said a senior Central Railway (CR) official. Nearly the entire 21-km stretch from Chhatrapati Shivaji Terminus (CST) to Mankhurd on the harbour line and some stretches on the 53-km line to Kalyan on the Central line are flanked by slums. There are 25,150 slums on CR, 12,700 of them fall into the critical 10-metre safety zone on either side of the tracks.

On Wednesday, a division bench of the High Court comprising of Chief Justice Y K Sabharwal and Justice Ajit Shah directed railway authorities to begin removing encroachments.

Giving the direction after hearing a petition filed by Citizens for a Just Society (CJS), the HC also indicated that the demolition should be phase-wise namelyon the three lines, central, western and harbour.The harbour line which is choc-a-block with slums caused even a visiting World Bank team last year to throw up their hands and suggest that rehabilitation was impossible.

But each time the railways embark on a demolition drive, they are issued a notice by the state government which undertakes to rehabilitate hutments before January 1, 1995. In the meantime, the railways have been able to demolish only `soft encroachments', or those which sprang up after this date. The HC order states that the government policy is not applicable in this case. The petition will now come up for hearing on Monday, February 8, where a final decision is expected. The proliferation of slums has led to falling train speeds over the years. ``The journey from Khandeshwar to CST takes one and a half hours. If slums are removed this trip can be done in an hour. What's more, with the time saved we can also increase harbour line services from 427 to 500 and also withdraw two rakes for useon the main line,'' he said.

But amongst the major improvement would be towards increased passenger safety especially the growing incidents of stone throwing reported every year, say railway officials.

Meanwhile, Minister of State for Railways Ram Naik's scheme of providing amenities to slum dwellers also remains firmly paper bound. Suggested by the minister last year, the proposal envisaged rehabilitating encroachments from the safety zone under the state government's scheme and providing civic amenities to those beyond this boundary.

But the state government and the Brihanmumbai Municipal Corporation (BMC) can provide civic amenities to slumdwellers only if they get a No Objection Certificate from the railways who are the owners of the land.

``The ball is now in the state government's court,'' a railway spokesperson said.