June 13: Lack of EMU rakes and the space to operate them, indefinite delays in the laying of new rail corridors and an alarming cost escalation in the development of the city's suburban system have frozen all chances of Western and Central Railways' adding any new trains to their services at least for a decade.However, senior officials say, some alterations in schedules may be possible considering the demands from passengers, which have remained unheard for many years.Both CR and WR are still operating EMU rakes which have outlived their stipulated age, sources said. They added the addition of new rakes being a lengthy process, there is very little scope for adding new services to the already saturated schedule. The WR operates over 956 services while the CR operates 1,044 services daily on the suburban section. With a head-way time between two trains oscillating between four and five minutes, both have not been able to achieve 100 per cent punctuality in the last one year. Other factors like technical snags and derailments are not accounted for while calculating average punctuality.A senior CR official said the CR has been dogged by several problems, the most serious of which are the slums colonies along the tracks. Sources in the passenger transport department said they have already stretched their train schedules to the limit. ``Due to want of space and the obstacles faced while evicting encroachers from railway land, we have been left with no option but to freeze the time-tables,'' said an official.Similar is the reaction of WR officials facing identical problems. They claim the phasing out of old rakes is not possible right now as the supplies from the Integral Coach Factory (ICF), Perambur, near Chennai, are uncertain.To make the matters worse, the Kurla-Thane corridor and the Santacruz-Borivli and Borivli-Virar quadrupling projects have run into rough weather due to political interference.