Brocklebank Line ships normally had their names beginning with the letter "M" with an Indian connection, the Company's main trade being UK to India.
As for the name of the vessel MAIDAN," Wikipedia advises that Maidan is the largest urban park in Kolkata (Calcutta) in the Indian state of West Bengal.
It is a vast stretch of field, and home to numerous play grounds, including the famous cricketing venue Eden Gardens.