Determining performance allowances

[Tom]

[snip] ... at any one signal/platform, there is only one berth offset expected to report the arrival/departure of multiple types of rolling stock, be it diesel, electric, steam or pump-trolley, each with different acceleration/braking characteristics. ... [/snip]

While that may be the case in the core SMART data set, there are various programmes in place amongst various organisations that have multiple offsets including varying on parameters such as rolling stock and length.