Mumbai: Get ready for sweat-free, smell-free local train rides. In a salute to the massive crowds inside Mumbai’s local trains and the city’s humid weather, the first AC local train for Mumbai will have the most powerful cooling mechanism ever for any Indian train.
At 15 tons each, these monster machines – called Roof-Mounted Packaging Units (RMPU) in rail lingo – will be much more effective than the 10 ton RMPUs, the highest on Indian Railway currently installed in the newly built double-decker rakes and some trains of Kolkata Metro. Most of the trains on Indian railways, including the Rajdhani, have RMPUs of 7 tons, said officials.
According to officials working on the plans for the AC train, each coach will have two such units making it a total of 24 RMPUs for the 12-coach train. Top officials of the Integral Coach Factory in Chennai – where the AC trains is being built – have been trying to finalise the firms that have the capability to build these kind of air-conditioners.
Considering that most home ACs have the capacity of 1 ton, each of the coaches will provide cooling equivalent to 30 such home ACs.
Sources said one firm has already been shortlisted, while another is expected to be finalised by May 15 after a fresh round of technical demonstration.
“Mumbai is a peculiar case because of the kind of crowds that use local trains during peak hours. The density per square meter can go up to 16 people. We expect the AC rake to take in heavy crowds and so the cooling has to be stronger than anything tried before on Indian Railways. Hopefully it will set the benchmark for the future as far as train air-conditioning is concerned,” said a senior railway official.
Officials said special provisions are being made to ensure that the AC works at full blast. They said the electrical systems and the Train Control and Management System are being supplied for the train by Netherlands-based firm Strukton. The rolling stock is designed to take the extra load of these 15-ton AC units.
The rake is expected to arrive by August. After trials, it should be commissioned by the later part of this year, said officials.
Tonnage in air-conditioning
In air-conditioning, a ton is the cooling capacity or heat-removal capacity of an AC unit. One ton means means the cooling effect equivalent to convert 1 ton of water into ice at the same temp. It is measured in terms of British
Thermal Units (Btu) and a 1-ton AC is rated at 12,000 Btu per hour. A Btu is the amount of heat required to increase the temperature of a pint of water (16 ounces) by one degree Fahrenheit. Higher the tonnage of an AC, the greater its cooling capacity.