The questionnaire sent to the MoT described the MSLR’s fleet as three 0-6-0 side tanks, constructed to run at speed in either direction. The weight of each locomotive in working order was shown in the following table:
It appears from a comparison of the total weights that the table lists locomotive numbers 1 & 3 first, then number 2, although the latter was shown as nearly half a ton heavier than the maker’s official figure.
The authorised axle load refers to the maximum permissible for any vehicle running on the MSLR’s lightweight track. It is interesting that the lightest engine should have the greatest wheel loading: perhaps its slightly different design and shorter wheelbase had a significant effect on the weight distribution across the three axles.
Boiler pressure for all three locos had been reduced from an initial 150 pounds per square inch to 140 psi, presumably reflecting their increasing age.