"Devious" Diesel, as his name implies, is a sinister diesel shunter and the first diesel engine to arrive on Sodor who originates from the Other Railway. In the television series, Diesel becomes a permanent resident of Sodor.
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. Diesel then blamed Duck for not helping him. Diesel swore a vendetta plan 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 Linewhilst 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 him and Diesel, although he returned to the Other Railway, is always welcome on Sodor.
Thomas & Friends
Diesel first arrived on Sodor in the same way as he did in the Railway Series and was sent away for telling lies about Duck, but returned when Duck and Percy needed help at Knapford Harbour. 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 sneaked 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 Sodor Cement Works. Diesel became jealous of Fergus' reputation as the "pride of the Cement Works". He also became cross because of Fergus' deep regard for the rules and always telling him "Do it right". He then 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 since the eighth series.
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 in one day than any other diesels and proved to Thomas that he did not 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. But failed when he was scolded by Sir Topham Hatt
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 series, 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 braked 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 had to learn the proper way of handling trucks by Hiro.
In the eighteenth series, Diesel, along with Sidney, Den and Dart, hid from Paxton at the Dieselworks, which resulted in 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 Knapfordduring 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 series, he 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 tracks 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.
He later 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.
In the twentieth series, Diesel was shown to care for some ducklings that he thought were cute. Later, Annie and Clarabel played a trick on Daisy while Thomas was on quarry duty, and after Diesel was sent to pull them instead, much to their dismay though Diesel was polite to them despite bumping them.
In The Great Race, Diesel wanted to go to the Great Railway Show, but the Fat Controller was hesitant. To prove himself, Diesel had crates put over Den, Dart and Paxton so that they would resemble trucks and put them in a long train. When the Fat Controller was in the final stages of choosing who would go to the show, Diesel planned to demonstrate how strong he was by pulling the train, while in reality, Den, Dart and Paxton were doing most of the work. However, his unusual train was blocking any way into Knapford Yard. Thomas was coupled to the train both so that he could get into the station and so that he could prove himself worthy to go to the show. The diesels heard Thomas's whistle and thought it was Diesel's horn, so they began pushing, much to Diesel's horror. Thomas then collided with Norman at a set of points and lost his left buffer as a result. Diesel later got stuck inside one of the crates, and was accidentally loaded onto a shipby Cranky.
In the twenty-first series, he damaged Daisy's springs and caused mischief between her and Harvey by telling them both that the other was boasting about being unique, which led him into the sea after his plan failed.
Diesel is, in essence, the average pantomime villain. He is oily, malicious, devious, scheming and full of ideas to get revenge. He views himself and any other diesel as highly above the steam engines, and believes that all diesels are "revolutionary" - he has also claimed diesels should be "rough and tough", as an excuse for bullying the other engines. His antics give diesels on Sodor a bad reputation, which causes most steam engines, particularly Duck and Thomas, to mistrust him. His rough demeanor also affects his fellow diesels, who are often victims of his tricks alongside steam engines.
However, despite his antics, Diesel still wants to prove himself to be a really useful engine. He is also very proud to be the first diesel on Sodor and seems to have a soft spot for cute ducklings.
Diesel is based on the BR Class 08. Over seventy members of this class survive today in preservation, while around 100 remain in service on the national rail network. They are in fact the most successful shunting engines in the world, with 996 of them built. Splatter, Dodge, 'Arry, Bert, Paxton, Sidney, Ulli and the Mainland Diesels are also members of the class.
Diesel is painted in British Railways' black livery, which was the standard livery for shunting engines from 1948 until the mid-1960s. His side rods were silver until the sixth series, where they have changed to black.
The Railway Series-
- Duck and the Diesel Engine - Pop Goes the Diesel, Dirty Work and A Close Shave (mentioned)
- The Little Old Engine - Rock 'n' Roll (not named; mentioned)
- Thomas and the Evil Diesel
Thomas & Friends
- Series 2 - Percy Takes the Plunge (cameo), Pop Goes the Diesel, Dirty Work, A Close Shave (mentioned) and Thomas and the Missing Christmas Tree (cameo)
- Series 3 - Gordon and the Famous Visitor (cameo), Thomas, Percy and the Dragon (cameo), Diesel Does it Again, Mavis, Edward, Trevor and the Really Useful Party (deleted scene), Tender Engines and Escape (cameo)
- Series 4 - Rock 'n' Roll (not named; mentioned) and Rusty to the Rescue (cameo)
- Series 6 - Salty's Secret, The World's Strongest Engine and Buffer Bother
- Series 7 - Bill, Ben, and Fergus and Fergus Breaks the Rules
- Series 8 - Thomas to the Rescue, Squeak, Rattle and Roll and James Goes Too Far (cameo)
- Series 9 - Respect for Gordon, Bold and Brave and Flour Power
- Series 10 - Thomas and the Shooting Star (mentioned) and Emily and the Special Coaches
- Series 11 - Don't be Silly, Billy and Thomas and the Stinky Cheese
- Series 12 - Thomas and the Billboard and Don't Go Back
- Series 13 - Tickled Pink, Percy's Parcel (cameo), A Blooming Mess (cameo) and Thomas and the Runaway Kite (cameo)
- Series 14 - Thomas' Tall Friend (cameo), James in the Dark (cameo), Toby and the Whistling Woods (cameo), Diesel's Special Delivery, Victor Says Yes (cameo), Thomas in Charge (cameo), Thomas' Crazy Day (cameo), O the Indignity and Jitters and Japes (cameo)
- Series 15 - Surprise, Surprise (cameo), Stuck on You (cameo), Kevin the Steamie (cameo), Tree Trouble and Fiery Flynn
- Series 16 - Percy and the Monster of Brendam, Thomas and the Rubbish Train, Bust My Buffers!, Percy and the Calliope and Emily's Winter Party Special (cameo)
- Series 17 - Henry's Hero (cameo), The Missing Christmas Decorations, Away From the Sea (cameo), Gone Fishing (cameo) and No More Mr. Nice Engine
- Series 18 - Disappearing Diesels, Thomas the Quarry Engine, Last Train for Christmas and Samson at Your Service
- Series 19 - Henry Spots Trouble, Very Important Sheep (cameo), Reds vs. Blues (cameo), Philip to the Rescue(cameo), Diesel's Ghostly Christmas, Goodbye Fat Controller and Wild Water Rescue
- Series 20 - Sidney Sings (stock footage cameo), Diesel and the Ducklings, Saving Time, Pouty James (cameo)and The Railcar and the Coaches
- Series 21 - Springtime for Diesel, A Most Singular Engine, Dowager Hatt's Busy Day (cameo), P.A. Problems(cameo), The Big Freeze and Daisy's Perfect Christmas
- Series 22 - Forever and Ever (cameo), Confusion Without Delay, An Engine of Many Colours, Seeing is Believing (cameo), Apology Impossible (stock footage), Kangaroo Christmas (stock footage cameo), Rosie is Red, The Case of the Puzzling Parts (mentioned), Banjo and the Bushfire (stock footage) and Counting on Nia (stock footage cameo)
- Series 23 - Heart of Gold, Diesel Glows Away, Diesel Do Right and All Tracks Lead to Rome (stock footage)
- Series 24 - Nia Pulls the Express
- Other - Thomas & Friends in 4-D: Bubbling Boilers (cameo)
- 1992 - Thomas and the U.K. Trip (cameo)
- 2005 - Calling All Engines!
- 2008 - The Great Discovery (cameo)
- 2009 - Hero of the Rails (cameo)
- 2010 - Misty Island Rescue
- 2011 - Day of the Diesels
- 2012 - Blue Mountain Mystery
- 2013 - King of the Railway
- 2015 - Sodor's Legend of the Lost Treasure (cameo)
- 2016 - The Great Race
- 2017 - Journey Beyond Sodor (cameo)
- 2018 - Big World! Big Adventures!
- 2019- Thomas and Friends: Revenge of the Scrap-Yard Diesels
He was also likely to appear in the WWII film.
- Series 3 - Thomas' Anthem
- Series 4 - Thomas' Anthem Grand Finale
- Series 5 - Night Train and Come for the Ride
- Series 6 - Down by the Docks and Winter Wonderland
- Series 7 - There Once Was an Engine Who Ran Away, Troublesome Trucks, and The Whistle Song
- Series 8 - Determination
- Calling All Engines! - Trying and Together
- Series 10 - Doing it Right, Favourite Place, There's Always Something New, Responsibility, and Jingle Bells
- Hero of the Rails - Go, Go Thomas
- Series 13 - Roll Along, Thomas, You're the Leader, and Sounds
- Series 14 - All You Need and Sir Topham Hatt
- Day of the Diesels - Day of the Diesels
- Series 15 - Hear the Engines Coming
- Series 17 - Hey, Hey Thomas!
- Series 18 - It's Christmas Time and The Best Friends Express
- Thomas' YouTube World Tour - A World Around You, Navigation, Never, Never, Never Give Up, and Thomas' Anthem (mentioned)
- The Adventure Begins - Troublesome Trucks
- Series 19 - There's Snow Place Like Home and Engine Roll Call
- Sodor's Legend of the Lost Treasure - Never Overlook a Little Engine and We Make a Team Together
- Series 20 - It's Halloween and Accidents Will Happen
- The Great Race - Will You Won't You and I'm Full of Surprises
- Journey Beyond Sodor - I Want to Go Home (cameo)
- Series 21 - Set Friendship in Motion and Trying
- Big World! Big Adventures! - Where in the World is Thomas? and We're Friends
- Series 22 - Engine Roll Call
- Series 8 - Steamies and Diesels Sounds (stock footage cameo)
- Calling All Engines! - Banana Tricks (does not speak) and Which Diesel Engine with Which Steam Engine? (does not speak)
- Series 9 - Sir Topham Hatt's Helping Hand and Getting to the Washdown (does not speak)
- Series 10 - Diesels and Steamers (cameo)
- 1989 - Diesel's Christmas, The Party, Diesel's Race, Showing Off and One Good Turn
- 1990 - One Bump Too Many, Daisy and Diesel and Too Hot
- 1992 - Diesel Pulls Hard
- 1993 - Roof Repairs! and Too Fast!
- 1994 - A Special Treat!
- 1995 - Watch Out, Gordon! (does not speak) and Tricking Trucks!
- 1996 - Percy Saves the Day, Thomas Takes a Ride! (does not speak), Singing in the Rain! and Really Useful Oliver!
- 1997 - Showing Off, Percy's Puzzling Trip!, Diesel and the Trucks, The Posh Coaches, April Fools and Diesel Becomes a Coach
- 1998 - Runaway Percy!
- 1999 - Duck and Diesel
- 2000 - Back to Front!, Henry's Freight Cars and The End of the Rainbow! (mentioned)
- 2001 - A Special Story About Diesel, Diesel Day! (does not speak), Down at the Docks, A Burst Balloon! (does not speak) and Diesel's Ditch
- 2002 - The Fat Controller's Diesels! (does not speak), The Blue Engine Club (cameo), Diesels and Steam Engines, Clean Up Chaos and Diesel's Drums
- 2003 - Shady Business! and New Year Promise!
- 2004 - More Mischief!, Place to Play, Broken Biscuits, Engine Trouble, Toby's Troubles!, Ben's Blunder, Night Lights (cameo), Spotty Thomas , Fergus Runs Away, Dazzling Diesel! and Glider Rider (cameo)
- 2005 - Spooky Shape, Perfect Percy, Snow Drop, Ben's Blunder, Pop Goes the Diesel and Squeak, Rattle and Roll
- 2006 - Monster Mistake, Shower Power, Well, well! and Disgusted Diesels
- 2007 - Flour Power, Look and Hook, Rusty's Rescue!, Everyone's Friend and Emily's Present
- 2008 - Fast and First!, New Year Promise! and Come Back, Please!
- 2010 - Diesel's Special Delivery, Disgusted Diesels, Creepy Causeway (cameo) and Proud Puffers (cameo)
- 2011 - Flaming Flynn, Monster Mistake, Musical Trucks, The Treasure Hunt, (cameo), Scaredy Cat, Tickled Pink (mentioned), O, the Indignity (does not speak), Show Time, Slowcoach Diesel and O, the Indignity! (does not speak)
- 2012 - Clever James, Bubbling Boiler, A Whoosh of Water! (cameo) and Thomas and the Rubbish Train
- 2013 - Caught on Camera and Coal and Treacle
- 2014 - No More Mr. Nice Engine
- 2015 - Thomas Saves the Day and Diesel's Drums
- 2016 - Tickled Pink!
- 2017 - Thomas Saves the Day, Diesel and the Ducklings and The Kind Diesel
Diesel also appeared in the magazine stories, A Special Story about Steam, Blowing About!, Bulgy's Dream, Clean Getaway!, Diesel Display, Diesel's Drums, Diesel's Nasty Turn, Diesel Causes Delay, Engine Plates, Fishy Diesel!, Glider Rider, Henry and Diesel, Making a Mess!, Mountains and Mess!, Nice Neville, Percy and the Trucks, Rhyming Engines, Ride and Slide, Road Ride, Rocking About, Slick Trick!, Sodor's Strongest Engine, Special Places, Stick with Steam, The Christmas Sacks, The Runaway Percy and The UFO
- 1990 - Old Square Wheels
- 1991 - Rusty Red Scrap Iron
- 1992 - Galloping Sausage
- 2001 - Thomas the Famous Engine
- 2014 - Welcome to the Island of Sodor Logan! (stock footage cameo)
- Kerry Shale (UK; thirteenth series onwards, US; nineteenth series onwards, UK only in Thomas and Friends: Revenge of the Scrap-Yard Diesels)
- Michael Brandon (US; thirteenth series - Blue Mountain Mystery then again in Thomas and Friends: Revenge of the Scrap-Yard Diesels)
- Martin Sherman (US; King of the Railway - eighteenth series)
- Jorge Ornelas (Latin America; thirteenth series onwards)
- Daisuke Gōri (Japan; second - eighth series, excluding the sixth series)
- Hisao Egawa (Japan; sixth series only)
- Ken Sanders (Japan; Calling All Engines! onwards; excluding singing voice)
- Shinichi Ishihara (Japan; singing voice)
- Paweł Galia (Poland; thirteenth series only)
- Janusz Wituch (Poland; Misty Island Rescue onwards)
- Christoffer Staib (Norway; thirteenth series - sixteenth series, excluding Day of the Diesels and Blue Mountain Mystery)
- Helge Winther Larsen (Norway; Day of the Diesels - seventeenth series, excluding the fifteenth and sixteenth series)
- TBA (Norway; eighteenth series onwards)
- Martin May (Germany; thirteenth series onwards)
- Christian Rudolf (Germany; Audio Books only)
- Reinder van der Naalt (The Netherlands)
- Anibal Munhoz (Brazil)
- Jorge Teixeira (Spain; thirteenth series - nineteenth series)
- Adolfo Pastor (Spain; The Great Race onwards)
- Michel Lasorne (France and French speaking Canada; eighth - twelfth series)
- Fabrice Trojani (France and French speaking Canada; thirteenth series onwards)
- Gadi Levy (Israel, fifteenth series only)
- TBA (Isreal; sixteenth series only)
- Dor Srugo (Israel; seventeenth - twentieth series)
- Yoli Seker (Israel; twentieth series onwards)
- Petri Hanttu (Finland; Misty Island Rescue onwards)
- Quổc Tín (Vietnam)
- Alexander Kotov (Russia)
- Bohdan Tůma (Czech Republic; Blue Mountain Mystery onwards)
- Vina Papadopoulou (Greece; second - eleventh series)
- Haris Grigoropoulos (Greece; thirteenth series onwards)
- I'm Full of Surprises (entirely performed)
- Will You Won't You (partially performed)
- Where in the World is Thomas? (partially performed)
- Diesel was the first diesel to be introduced in both the Railway Series and television series.
- He was created when Eric Marriott, the editor of the Railway Series at the time, suggested that Awdry should introduce a diesel to in order to keep the books up to date.
- In some merchandise lines he is referred to as "Devious Diesel". It was not until Fergus Breaks the Rules that he was referred to by this name onscreen.
- As revealed in Emily and the Special Coaches, Diesel is a record holder for most trucks shunted in a single day.
- Between the thirteenth and sixteenth series, Diesel was the only character from the model series to still be voiced by the narrator in the CGI Series. However, this was only in the US narration.
- Diesel has travelled at well over his top speed of 20 miles per hour on numerous occasions in the television series.
- Diesel's face in the magazine stories is often smaller than in the television series.
- According to the magazines and the DVD Bingo game, he and Bulgy are good friends.
- Nathan Clarke did an audio sample for Diesel on his DAA Management Page.
- One of Diesel's television series models is now owned by the Explore the Rails exhibition, previously on display at the British Museum during the 70th Anniversary.
- ERTL (discontinued)
- Wooden Railway (several versions; discontinued)
- Take Along (several versions; discontinued)
- Take-n-Play (normal, talking and pull back; discontinued)
- Motor Road and Rail (discontinued)
- TrackMaster (normal, talking and R/C)
- TrackMaster Push Along
- Motorized Railway
- My First Thomas (discontinued)
- Bachmann (HO, G scale cancelled)
- Hornby (discontinued)
- Lionel (discontinued, later reintroduced with Trainchief remote)
- My Thomas Story Library (discontinued)
- Thomas Engine Collection Series (discontinued)
- Mini Die Cast Collection (discontinued)
- Trading Cards (discontinued)
- De Agostini (discontinued)
- Brio (discontinued)
- Mega Bloks (discontinued)
- Discover Junction
- Nakayoshi (discontinued)
- Capsule Plarail
- Puka-Q (discontinued)
- Boss (pull back; discontinued)
- Collectible Railway
- Push Along
- Pullback Racers
- Classic Minis
- Heroes Minis
- Old School Minis
- DC Super Friends Minis (as Batman, Two-Face, Captain Boomerang and Bruce Wayne)
- Warriors Minis
- Christmas Minis
- Tootsie Minis (Charleston Chew)
- Mighty Morphin' Power Rangers Minis (as Alpha 5)
- Sushi Minis
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- Rail Rollers
- Adventures (discontinued)
- Engine Adventures (discontinued)
- Wood (redesigned in 2019)