According to The Island of Sodor: Its People, History and Railways, there were three 0-4-0T engines - one of which was Neil - with open cabs and square tanks that operated on the Sodor and Mainland Railway from 1856 until the line went bankrupt. They were typical contractors' engines of the period and due to the S&MR's casual attitude to record keeping, details of their acquisition and lives have sadly been lost. It is unknown if they were named.
The last locomotive had to be scrapped in 1901 which brought services to a close.
1 and 3 are based on Neilson 0-4-0 box tanks, a simple and robust class of engines built in Glasgow, Scotland and sold all over the world. Specifically they were based on 'The Box' built for the West Somerset Mineral Railway in 1856.
One was painted dark green with "S & M 1" and the other was also painted dark green with "S & M 3" written on both their side tanks in yellow.
- 1987 - The Island of Sodor: Its People, History and Railways (mentioned)
- 2005 - Sodor: Reading Between the Lines (mentioned)