- “Sir Handel likes Gertrude and Millicent best. He always tries to take them alone. They have bogies, and he says they're the only real coaches we have. They remind him of when he used to pull our express. Both have seats for passengers, but Millicent has a Guard as well. He sells tickets and travels in a tiny cupboard place.”
- ―Peter Sam
Gertrude and Millicent are two coaches rescued from the Mid Sodor Railway which the Skarloey Railway restored while Skarloey was being mended. They run on bogies, which led Sir Handel to consider them the only "proper" coaches on the railway. Millicent has a small covered compartment for a guard where they can sell tickets, although Peter Sam does not like that as he believes that guards need vans.
Gertrude and Millicent are based on the Talyllyn Railway's ninth and tenth carriages, respectively.
Gertrude and Millicent are painted blue with cream window surrounds.
- The Little Old Engine - Home at Last (do not speak)
- Gallant Old Engine - Special Funnel (cameo)
- Great Little Engines - Patience is a Virtue (one makes a cameo) and Pop-Special (cameo)
- New Little Engine - Speedkiller (cameo)
- 1987 - The Island of Sodor: Its People, History and Railways (mentioned)
- 1996 - Thomas the Tank Engine: The Complete Collection (does not speak)
- 2005 - Sodor: Reading Between the Lines (mentioned)
- 2007 - Thomas the Tank Engine: The New Collection (cameo)