Emma and Pip make up a BR HST InterCity 125 train set.
Pip and Emma who were brought to stand in for Gordon when he took a special to Charlsie. Although that they suffered problems when they tried to help, the other engines took an instant liking to their kindness they received from them.
In 1995, Pip and Emma were borrowed to take a royal personage and some guests to Tidmouth for the Railway Series' Golden Jubilee.
In 2011, the Fat Controller purchased them to run a faster service to London following Privatisation. They brought Prince Charles to unveil a bust of the Thin Clergyman at Tidmouth in celebration of the Clergyman's one-hundredth birthday.
Pip and Emma are based on the British Rail Class 43 HST. This engine holds the world record for fastest rail speed for a Diesel: 238 km/h or 148 mph.
- Pip and Emma happen to be the names of two siblings in the Agatha Christie novel "A Murder is Announced".
- Thomas and his Friends was the first time Pip spoke. Until then, only Emma had speaking roles.