Thomas the Tank Engine Wikia

Sonny is a well tank engine who used to work at a coal mine and was brought to Sodor by two criminals named Baz and Bernie, but later joined the North Western Railway.


Thomas & Friends

Before arriving on the Island of Sodor, Sonny worked at a coal mine, pulling heavy trucks of coal up steep hills. He was one of the first engines to be built with piston valves, allowing him to control the amount of steam he used.[1]

At some point after being withdrawn, he was acquired by Baz and Bernie and first came to Sodor with the two on board. They arrived at Vicarstown to get directions to The Technology Fair and then continued on to Ulfstead Castle.

Following an accident with a strong magnet during the Technology Fair, Sonny was sent to collect some fresh milk from the Sodor Dairy. During his trip to the Dairy, Sonny met Thomas, who taught him the ways of Sir Topham Hatt's railway. Upon his arrival back to the castle, he was praised by Sir Robert Norramby for being a really useful engine.

The evening after, when Baz and Bernie began plotting to steal the plans to Ruth's Hover-Car, Sonny stood up to the pair, encouraged by the idea of becoming a really useful engine. As a result of his defiance, Baz and Bernie opted to use Kenji as their getaway vehicle instead and tied Sonny's regulator open to create a distraction. After being caught by Thomas, Sonny revealed Baz and Bernie's plans. Once the pair had been caught, Sir Topham Hatt - encouraged by Thomas - decided to give Sonny a second chance and brought him into the North Western Railway's fleet.

Though Sir Topham Hatt gave him a second chance, Sonny was still not accepted by the other engines and many remained suspicious. This led to Sonny eventually forming a "friendship" with Diesel, who manipulated Sonny and used him to do his jobs for him. Sonny soon found out Diesel's plans following a confrontation with Percy at Ffarquhar

When Diesel later derailed over a dangerous drop, Sonny pulled him back from the ledge, accidentally derailing his trucks in the process. Sir Topham Hatt initially planned to send him away after the accident, until Diesel admitted that the accident was really his fault and that Sonny saved him. Following this act of heroism, Sonny was officially accepted onto the Fat Controller's Railway.

Sonny later came the wrong way down Toby's Branch Line after the collapse of The Rickety Old Bridge and had to be rescued by Ruth's Walking Bridge.


Sonny is a complicated engine. While a bit of an outsider, he often follows along to whatever orders he has been given from his superiors, unfortunately landing him at the hands of Baz and Bernie's scheming minds. During his time at the ownership of the two thieves, Sonny displayed tendencies to be gruff, sinister and rude, repelling other engines. However, after Thomas helped him on a dairy run and he got praised by Sir Robert Norramby, the well-tank engine turned over a new leaf, standing up to the thieves and working hard to be really useful, as well as willing to tell the truth if needed. Although he is sometimes distrusted for his past sins, Sonny has proven to be trustworthy and reliable, making him a true asset to the North Western Railway.

Technical Details


Sonny is based on the Haydock Foundry well-tank locomotives, built between 1868 and 1887 and designed by Josiah Evans. The only surviving Locomotive is "Bellorophon" With over 90 years of service and lasting up to 150 years old as of the present day, the locomotive was an icon to railway fans, and ran on the Foxfield Railway until being withdrawn for repairs in 2018. The locomotive is currently preserved by the Vintage Carriages Trust.


Sonny is painted dark navy blue with gold lining and white boiler bands. His dome, safety valve stand, wheels and running board are painted black. His bufferbeam is also painted black, albeit with red sections around the coupling hook and either side of his buffers. His number is painted on his cab sides in white.


Official Description

From Official Media:[1]

Sonny: Sonny is a tank engine who, unfortunately, fell in with the wrong crowd. Two rogue engines forced Sonny to be their partner in crime. Sonny feared them and tried to act tough when necessary, but deep down he longed to leave his life of crime behind him. Sonny's a loveable rogue who wanted to prove that he can be a true hero and a Really Useful Engine. The Fat Controller gives Sonny a second chance on the Sodor Railway. The other engines are wary because of his troublemaking past, but soon wins them over with his heroic actions.

Audio Files


First used Last used Sound Effect
Series 24 Active


  • Sonny speaks with a Cockney accent and uses Cockney slang such as "Gov'nor" when addressing authority.
  • Sonny's bunker lining has two additional lines on his right side which are not present on his left side.
  • Sonny's backhead is incorrectly modelled, as it is much smaller in diameter than his firebox.
  • Sonny is the first engine since Nia to have his arrival to Sodor seen in full. He is also the first mainland engine with this distinction.
  • Sonny is the second vehicle character to have been owned by antagonistic human characters before reforming. The first was Skiff to have formerly owned by Sailor John and the first steam engine to do so.
  • Sonny is the last new engine to join the North Western Railway and the last named new steam engine character introduced in the CGI series and thus, the show overall.




* RWS only | ** T&F only | --- Dropped