Maligaon, March 24 (MExN): The Darjeeling Himalayan Railway (DHR) has successfully conceived, developed and tested two air-conditioned narrow gauge coaches for running in the UNESCO World Heritage railway soon. These air-conditioned coaches will make travelling in the hill railway more comfortable for travellers from the plains of New Jalpaiguri to the hill station of Darjeeling in all seasons. The commercial service of the AC coaches is expected to start from April 1. Pranav Jyoti Sharma, Chief Public Relations Officer in a press release said that the two air-conditioned coaches were developed by refurbishing two first-class coaches at a cost of about Rs. 43 lakhs. The air-conditioning unit are roof-mounted and a small silent power-pack provides power to the units. Each of the coach has a sitting capacity of 15 people and the interior of the coaches are done by using teak panels, large toughen laminated safety-glass windows for passengers to enjoy the scenic beauty and a music system-cum-announcement system for entertainment. Similarly furnished non-AC coach for use in the Joy Ride services between Darjeeling and Ghum are also being developed. One 150 Ah battery has also been provided as back-up for lights and for starting the power pack.