Chief engineer Robert White had five ten-wheelers built for mail traffic on the meter-gauge routes, including in the direction of Sri Lanka. These used the BESA standard design and came from Hawthorn, Leslie & Co. at Newcastle. Thus they had 16.5 inch diameter outside cylinders, 57 inch diameter coupled wheels and Belpaire firebox with a long narrow grate.
However, only one engine was built according to the design using saturated steam, the others being the first narrow-gauge superheated locomotives in India. With the results of the five locomotives, White was able to substantiate his assumption that superheated steam should have a clear advantage despite the greater complexity. Thus, the only saturated engine was soon retrofitted with a superheater.