New Delhi, The Indian Railways which has prepared 5,231 coaches as isolation ward coaches for the novel coronavirus (Covid-19) patients on Friday said that the decision to convert non AC coaches was taken as AC coaches would not be suitable in view of the potential transmission risk as compared to non AC coaches which have cross ventilation through open windows.

In a statement the national transporter said, "It was stipulated that the facility should be well ventilated with adequate scope for natural lighting. The issue of AC versus non AC coaches was discussed with Niti Ayog and Ministry of Health and Family welfare before converting these coaches for Covid patients. It was agreed that AC coaches would not be suitable in view of the potential transmission risk of Covid-19 virus through AC ducting, and generally a higher ambient temperature was expected to assist in fighting the virus and cross circulation of air through open windows will benefit patients," it said.

The ministry added that it was advised that these isolation ward coaches would be used only when the state facilities would get overwhelmed and it was expected that these coaches could be required for use by mid July, by which time the virus was expected to peak. "It is reiterated that it was decided by the Empowered Group to convert non AC coaches into isolation ward coaches because of the unsuitability of AC coaches due to the potential transmission risk, and the fact that a well ventilated area with slightly higher temperature was expected to aid in recovery," it said.

The national transporter said that the non AC coaches would be a little warm in mid June if the windows are kept closed, and the ambient temperature may also be around 43 degree Celsius. "But, once mosquito nets are installed and the windows kept open, the cross circulation of air is expected to improve the temperature. It may be noted that even this kind of temperature is expected to be temporary phenomenon as the arrival of monsoon and rains would bring relief," it said.

The ministry said that it has taken steps to lower the temperature inside these coaches. "In order to beat the heat build-up inside the coaches due to summer temperatures, a multi-pronged strategy is being adopted, which will provide comfort to the patients and staff," it said, adding that railways has tried cover sheets (White Canat) or suitable material being placed over the isolation coaches stationed at platforms. The railways is also applying bubble wrap films on the coaches, which are expected to reduce temperatures inside the coaches by 1 degree celsius.

The railways is also providing heat reflective paint on the roof. "During trials, it was found that temperature inside the coaches can be reduced up to 2.2 degrees Celsius. Trials are also being planned for another coating developed in association with IIT, Mumbai."

The railways said there is also a proposal to provide a bamboo chik etc. which will lower the temperature further. A trial has also been carried out by placing portable coolers inside the coaches, which reduced the temperature by 3 degree Celcius.

The railways is also trying water mist systems. "In the current season of dry air, it is expected that the resulting temperature reduction would enhance the comfort of expected patients," it added.

The railways has placed over 970 isolation ward coaches in five states for the Covid-19 patients.