Apparently the engineers for the Midland 25 Class 4-2-2 made a huge mistake. They designed an engine capable of going 142 km/h just to use a slow tender limiting it to 135 km/h. They made the same mistake with the Midland 1738 Class 4-4-0 as well.
I am not sure if a faster tender is introduced later to accompany these engine but otherwise they will never obtain maximum speed due to the tender limiting them. I am reporting this in case it is a bug (the engines are meant to have a >135 km/h tenders). If a faster tender is introduced later there really has to be some kind of comment somewhere to inform the user of this.