"Devious" Diesel is one of the main antagonists and sometimes an anti-hero in Thomas the Tank Engine & Friends. He is oily, malicious, devious, scheming and full of ideas to get revenge. But from Season 10 and onwards, Diesel shows that he actually does have a good side in him, but one would still have to look quite deep to find it. He appears in many seasons of the television show and in the movies, Calling All Engines, Misty Island Rescue, Day of the Diesels, Blue Mountain Mystery, King of the Railway, as a minor antagonist and The Great Race.
As a hero, he wants to try to prove himself Really Useful, but instead he usually acts more like a school yard bully and still hates steam engines. It can be possible that Diesel is a permanent resident of Sir Topham Hatt's railway since Season 8.
Bio in the Railway Series
When Diesel came on trial to the North Western Railway, Duck was asked to show him around. Duck was unimpressed by Diesel's claims of being "revolutionary" and left him to his own devices. As a result, Diesel was made into a laughing stock by the trucks for trying to pull some rusty old trucks and failing spectacularly, and Diesel blamed Duck for not helping him. Diesel swore a vendetta, and spread rumours that Duck had given the big engines rude nicknames. Duck was sent to Wellsworth pending an inquiry into the matter, but Diesel got too big for his buffers and tried telling lies about Henry. He was found out and sent home in disgrace.
Several years later, Diesel was brought back to help on Thomas' Branch Line whilst Percy was being repaired. Diesel tried to win Thomas and Toby over, without success, and after he destroyed several trucks he was to be sent away. However, on his day of departure, Clarabel slipped on oily rails left by Daisy and came off at some points near Dryaw. Diesel, realising that Thomas was blocking his only way home, went to the rescue. Clarabel put in a good word for Diesel, and Diesel, although he returned to the Other Railway, is always welcome on Sodor.
Bio in the Television Series
Diesel first arrived on Sodor in the same way he did in the Railway Series and was sent away, but returned when Duck and Percy needed help at Arlesburgh. Diesel proved to be as bad as ever and was sent away for good after shunting some trucks of china clay into the sea, but he somehow mysteriously snuck back to give Mavis advice, taunt Gordon about the triumph of Diesel power on the mainland, and shunt trucks in the Shunting Yards. It is possible that these events happened during Diesel's stay or that Diesel returned at some point with goods from the Mainland.
When Henry was derailed by some trucks, Diesel was brought back as a last resort to do his goods work, but his attempt to prove his worth resulted in him falling in a barge, and he was sent back to the mainland yet again.
Later on, Diesel returned yet again, this time to assist Fergus at the Cement Works. Diesel became jealous of Fergus' reputation as the "pride of the Cement Works" and concocted a scheme to make Fergus run away. Diesel was partially successful - he managed to make Fergus abandon his post for a time - but was ultimately foiled. Amazingly, Diesel was not sent back this time round and remained on the North Western Railway.
Despite remaining tricky and devious, Diesel learned how useful steam engines can be when Thomas brought fresh diesel fuel for him and the other diesel engines and James pushed him back to the Repair Yard when he broke down. However, he tried to convince Gordon that he was old and clapped out, Ben that there was a monster inside a tunnel, and Thomas about the "Curse of the Cliffs" and scared him at Halloween.
But Diesel proved to have a good side inside him when he told Emily about his record he made for shunting lots of trucks, and proved to Thomas that he didn't ruin the photograph for the billboard on purpose.
Although Diesel made fun of James when he was painted pink, he tried his best to prove himself to be as useful as the steam engines when he took all of the Jobi wood to the Sodor Search and Rescue Centre - only to put himself in danger requiring Thomas to rescue him. However, Diesel tried again to prove how special he is when he took Thomas and Rosie's loads to market and stole James' pigs so that the children could see them. But it was only when Diesel brought the load of slate for the school that he proved himself Really Useful.
Diesel was also one of the Diesels that took over the Sodor Steamworks. He later teased Flynn for just standing around and doing nothing.
In Blue Mountain Mystery, Paxton told Diesel about Luke and Diesel tried to get Luke sent away from Sodor.
Diesel was annoyed when Percy thought he was the Monster of Brendam and later teased Thomas for being a stinky engine and teased Gordon when he was fitted with a yellow and black Diesel bufferbeam. When he and Percy collected a calliope, he thought Percy would not be able to make it play, but was surprised when he did.
In the seventeenth season, Diesel was one of the diesels that brought the Christmas decorations to Tidmouth Sheds. Later, he was biffing trucks around even when Edward told him to stop. Diesel spilled the milk in the trucks, and when the Fat Controller opened the truck doors, the milk splashed all over his trousers. When Hiro told Diesel, he told Hiro to toughen up with the trucks. But when Hiro would not listen, he coupled himself up on the back of his train and helped the trucks play tricks on Hiro. To make the trucks stop, Hiro brakes suddenly before the platform, causing three barrels of cream to splash all over Hiro, Edward, and the Fat Controller. Diesel tried to get away, but was blocked off by Thomas. As punishment, Diesel has to learn the proper way of handling trucks by Hiro.
In the eighteenth season, Diesel, along with Sidney, Den, and Dart, hid from Paxton at the Dieselworks, which resulted on Paxton going on a wild goose chase to find all of the diesels and ended with Diesel running out of fuel, so Paxton helped him to the next station to get some more. Later, he argued with Thomas over who should be the back engine for a train of trucks heading from Ffarquhar Quarry to Brendam Docks, and when he tried to delay Mavis returning to the quarry, Thomas took the train by himself, which resulted in him having an accident. Diesel even tried to blame Mavis for it, but the Fat Controller was wise to his tricks and he let Thomas work with her instead. He later joined the engines at Knapford during the Christmas Holidays, and agreed with Sir Topham Hatt that the last train might have to be cancelled. He also teased Samson about how the tank engine got lost when he first came to Sodor.
In the nineteenth season, he tricked Percy into going to an old quarry so that he could do Percy's job of picking up the mayor to take him to a ceremony. Diesel later found Percy stuck in a flood with his fire out. He tried to rescue the tank engine but only made the situation worse when the water damaged his generator, so he got stuck too. After the two were rescued by the Search and Rescue team, Diesel was sent to have his engine repaired. He later covered Paxton in a cloud of black smoke from his engine, leaving Paxton's face covered in black spots.
At Christmas time, Diesel was being very unhelpful with the extra work, so Thomas and the other engines made a plan. On the night before Christmas morning, Thomas, Emily, Salty and Paxton pretended to be ghosts to scare Diesel, scaring him to the point where he flew off the line and derailed. After he was recovered the next day, he learned the true meaning of Christmas. On Christmas morning, Diesel was feeling very merry, and he brought the Fat Controller to the Earl's Christmas lunch at Ulfstead Castle.
Diesel is, in essence, the average pantomime villain. He is oily, malicious, devious, scheming, and full of ideas to get revenge. However, despite his antics giving diesels on Sodor a bad reputation, he still wants to prove himself to be a really useful engine. He is also very proud to be the first Diesel on Sodor.
- In Calling All Engines, he helped clean the wreckage of the Sodor Airport.
- In Don’t Go Back, he helped Thomas clean the mess that they did.
- In Day of the Diesels, he helped restore the Dieselworks.
- In The Big Freeze, he came with the coal trucks to get the Steam Team back in action and then he causes the big freeze to end.
- In Diesel and the Ducklings, he warned Thomas to not crash into the ducklings.
Diesel is a BR Class 08 0-6-0. Over seventy members of this class survive today in preservation. They were in fact the most successful shunting engines in the world, with 996 of them built. The Diesel Shunter, Splatter, Dodge, 'Arry, Bert, Paxton and Sidney are also members of the class.
Diesel is painted in the black livery used by British Railways for shunting engines in the 1950s. His side rods were silver until the sixth season and have been black in every season after.
- Diesel was the first diesel to be introduced in both the Railway Series and Television Series.
- According to the magazines and the DVD Bingo game, he and Bulgy are good friends.
- Between the thirteenth and sixteenth seasons, Diesel was the only character from the model series to still be voiced by the narrator in the CGI series, though this was only in the US narration.
- Diesel has had a few modifications in the television series:
- His side rods changed from silver to black.
- His brakepipe began facing upwards.
Misty Island Rescue
- His horn sound changed to that of a generic diesel.
Day of the Diesels
- His horn sound changed back to how it originally sounded.
- He gained a light above his face.
- His coupling chain became red.
- He gained a permanent tail lamp.
- In some merchandise lines he is referred to as "Devious Diesel". It wasn't until Fergus Breaks the Rules that they referred to him by this name.
- Diesel has travelled at well over his top speed of 20 miles per hour on numerous occasions.
- Diesel's face in the magazine stories is often smaller than in the television series.
- Nathan Clarke did an audio sample for Diesel on his DAA Management Page.