Mumbai will gets its first-ever local train service with Automatic Sliding Doors (ASDs) on Sunday, when a rake with one set of closed doors, which had a trial run on Friday afternoon for the media, is pressed into regular service.

How was the trial run?The Friday trial run, which started from Mahalaxmi around 3pm, was a 'satisfactory' one, with most criteria — airflow, timing of the doors remaining open — being met, said Western Railway officials.

What's the plan Sunday onwards?Since it is early days for the concept, for the first few days, WR staff will be stationed in the coach having ASDs, so that crowd behaviour, live feedback etc, can be taken and changes, if any, can be made to the project.

What's WR saying?Speaking to dna, WR chief spokesperson Sharat Chandrayan said, "The carbon dioxide level was tested and it was within stipulated norms. The door remains open for around 25 seconds at every station and we believe it is good enough for people to alight and board, even in crowded conditions."

What's ahead?While the railways has decided that all local trains for the city, except the 70 Bombardier rakes to be built at ICF Chennai, will have ASDs, the plan for Mumbai also involves installing these doors to the existing 200-odd rakes belonging to both WR and CR. At a cost of Rs4 crore for retro-fitting each rake, the total cost would be around Rs900 crore, said officials.

The automatic door-closing system, developed by Faively, has been primarily provided in WR's ladies first class coach no. 2274 A of EMU rake no. 2273-2274.

Salient featuresThe system will be controlled from the guard's cab. Any indication of the door remaining open will be available to the guard.The guard will be able to control left/right side of doors, depending on which side the platform is, with the help of two separate set of push buttons provided for this purpose in individual DTCs.The system will ensure starting of train only after all the doors are closed. Similarly, doors can only be opened after the train has come to a stop.There is an Emergency Egress Device (EED) inside the coach in a sealed enclosure which can be operated to open the door from inside in case of any emergency. One EED has also been provided outside the coach in the underframe for opening door from outside in case of any emergency.In case the doors are open while the train is in motion, emergency brake will be applied to stop the train.In case of the door system failing, it can be isolated from the guard's cab after manually locking the door open for rest of journey till it is attended to in the shed.

How much new trains with ASDs would cost (as per 2014 prices)Without vestibules, without AC: Rs39 crore, completion time around 18 monthsWith vestibules, without AC: Rs41 crore, completion time around 22 monthsWith vestibules, with AC: Rs43 crore, completion time over 26 months

Why the city needs trains with ASDsEvery year, around 700 people die after falling off local trains, according to railway police statistics. Figures with the railways show that a local train has the capacity to seat 1,167 people. During the normal hours of the day, the general consensus is that for every person sitting, there are about two people standing, making it a total of 2,334 standees. During dense peak, the number of standees could go up to 3,500 or even 4,500 on certain routes, giving rise to a very Mumbai-specific term called the Super Dense Crush Load. Commuter numbers continue to rise at a rate of around 3% on WR, which carries 35 lakh people, and CR, which carries 41 lakh, and a whopping 9% on Harbour line.