Friday , 22 January 2021

Monorail Mumbai’s new travel option

Mumbai Monorail, to be operational by March 2011 as a four-car carrier, will have the carrying capacity of approximately 600 passengers, thereby easing the troubles of millions of harried Mumbai commuters. With a speed of 30kmph and a headway of nine minutes, India’s first monorail will carry approximately 15,000 passengers per hour per direction, i.e. 10-12 times more than a city bus. There is, however, a cap on its speed – 80kmph. To be converted into a six car train later thereby increasing the carrying capacity to 900 commuters, it will be based on three elements of nature – Mother Earth, Nature and Sky. That explains its colour palette – maroon, green and sky blue.

Divided into two phases, it will cover a distance of 20km from Jacob Circle to Wadala. While the work of first phase of a distance of eight km between Wadala and Chembur is in progress right now, the second phase between Sant Gadge Maharaj Chowk (Jacob Circle) to Wadala is expected to be operational by 2011 end. There will be 18 elevated stations from Chembur to Sant Gadge Maharaj Chowk. “We are working very actively on this stretch and the civil work is likely to be completed by December this year. After that it will take two-three months for testing. By March we should be able to operationalise the first phase of monorail and the second phase would take another six-seven months thereafter,” says Ashwini Bhide, Joint Metropolitan Commissioner, Mumbai Metropolitan Region Development Authority which is responsible for the implementation of the project.

Operating from 5am to 12pm, the monorail will take merely 20minutes to cover the distance of 20km which takes more than an hour at present. The highlight of the project is that it will occupy less space, reduce travel time, can take sharp gradients and turns, has a small footprint, is very light and can go through congested areas where other means of transport cannot move.

In a Monorail System, a train runs on a narrow Guideway Beam, the wheels of which are gripped laterally on either side of the beam. A Light Weight System, it requires 1.00m wide space (column size 0.8×1.5m) to run and rests on a single 6.5m high pillar without disturbing the existing traffic. As it produces less noise than the other trains and is eco-friendly, it can safely be run inside congested residential areas.

Monorail technology

The Monorail is put together by a consortium of Malaysia-based leading Global Technology Enterprise SCOMI Group Bhd (for design and integration) and the Indian infrastructure giant Larsen & Toubro (for infrastructure, power supply and ticketing). SCOMI’s design SUTRA (Scomi Urban Transit Rail Application), a new generation product, has been adopted for the monorail.

Using a design crush load factor of seven persons per sqm, each ‘SUTRA’ rake can carry 140 passengers. Well lit air-conditioned rake interiors have stainless steel seats and grab rails for easy maintenance and protection, and large tinted window panels to provide maximum natural light inside the car. There are controlled doors for the safety of the passengers and special provisions have been made for wheelchair users as well.

Each single rake, approximately 11.1metres long, is built in aluminium by Alcan composite structure which makes the rake lighter, increases its carrying capacity and reduces strain on mechanical parts resulting in reduced maintenance cost. Every rake is fitted with an intercom system allowing communication by passengers with the driver and the Operation Control Center in emergencies while a PA system enables communication by the driver with the passengers.

Of the two broad classes of monorail straddle-beam (popularised by the German company ALWEG) and suspended monorails, Mumbai Monorail has opted for the straddle-beam system in which the train straddles along a two to three feet wide beam and a number of rubber-tired carriages contact the beam on the top and both sides of the traction to stabilise the vehicle. This makes derailments virtually impossible. In the suspended form of monorail developed by the French company SAFEGE, the train cars are suspended beneath the wheel carriage which rides inside the single beam.

For the switching facility, the beam structure itself is moved to direct the train to another line. This movable portion of switch is made of steel unlike the other beam structure which is made of concrete. A switch is hydraulically operated and is placed on a switch deck which is an elevated concrete structure. The switching for a two point switch can take place in as less as 15 seconds.

The construction of monorail structure is quite challenging and complex.Investigating underground utilities like water pipeline and sewage lines for piling work in a congested Mumbai is difficult and cumbersomeas proper coordination is required. Any error in judgement can lead to damage to a pipeline or cable causing disruption of services. – S N Roy

In case of a train failure or any other emergency, there is a provision for emergency evacuation. If the train fails mid-way, a rescue train can either be brought from behind and pull/push the failed train to the nearest station or depot or it can be quickly placed parallel to the failed train and the commuters can be evacuated with the help of a temporary bridge as the distance between the two beams is just one metre.

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