Thomas the Tank Engine Wikia
Thomas the Tank Engine Wikia
This article is about the diesels. You may be looking for the steam engine, the Story Library book, the cleaner or the porter.

'Arry and Bert (also known as Iron 'Arry and Iron Bert) are twin diesel engines who work at the smelters and scrapyards of the Sodor Ironworks. They have also been seen frequently working at Ffarquhar Quarry.


Thomas & Friends

In their first appearance, 'Arry and Bert crept alongside a lonely Stepney, who had traveled to the smelters by mistake. They shunted Stepney into the larger smelting shed underneath a giant grabber and left him there to be scrapped. Thankfully, Stepney was saved by the Fat Controller at the last second.

As well as being villainous, 'Arry and Bert are also known for playing tricks on steam engines such include making them "middle engines". Once, they shunted trucks in front of and behind Percy. This later led him to being pushed onto the coal tipper by mistake. When James took over Percy's duties following the incident, 'Arry and Bert played the same trick on him. Some time later, they gave Fergus - who was tricked into going to the smelters by Diesel - such a fright that he broke the rules and ran away. On another occasion, they bullied Neville by making him think he was not close enough to his trucks. This caused him to bump into them and ended up with 'Arry and Bert insulting and laughing at him for his mistake, calling him "clumsy wheels".

On some occasions, 'Arry and Bert's teasing ways backfire; they once played a ghostly prank on Thomas and Emily during Halloween, though they ran away when they thought Emily was a ghost. Another time, 'Arry and Bert teased Percy when he whistled hello. Bert responded by loudly blowing his horn to one-up Percy, rattling him. Percy paid them back by creeping up behind them and blowing his whistle as loudly as possible. Later, they and Diesel began teasing Thomas for being smelly, but later got covered in stinky cheese. By the time they had a washdown, Diesel, 'Arry and Bert were assigned the task of shunting Thomas' delivery of stinky cheese while Thomas got a washdown, much to Thomas' delight.

'Arry and Bert were also part of the group of diesels that took over the Sodor Steamworks. Soon after that, the pair teased Henry because of the coal he had to use by calling him "Mr. Special Steam". They also laughed at Gordon after he ran into Diesel's flatbed and damaged his buffer beam.

Diesel claimed that his friends, 'Arry and Bert, like him because he is rough and tough, to which they responded in kind as they passed by, despite chasing a butterfly when they said so. Thomas later attempted to blackmail Diesel into being nice with the threat of telling everyone of his secret affection for a group of ducklings. When Diesel broke this promise, Thomas took 'Arry and Bert to the ducklings while Diesel followed behind them. Although Thomas had intended to embarrass Diesel like this, the two found out that 'Arry and Bert also took a liking to the ducklings and are just as big softies as Diesel when it comes to them.

After Diesel had bumped Daisy (which broke her springs), Mavis told 'Arry and Bert that Den and Dart were having trouble repairing Daisy and thought she would be possibly scrapped, horrifying them. They told Diesel, who thought that they were blaming him.


'Arry and Bert are unquestionably devious and scheming. They feel superior to steam engines and working at the scrapyards, they enjoy the chance to break up engines or at least make their lives more difficult. Due to their grim task, they have earned a reputation on Sodor as "The Grim Messengers of Doom". According to their merchandise bios, they wish to scrap Oliver and Stepney who have both escaped the cutter's torch once before. They have also attempted to scrap Fergus.

'Arry and Bert also have a tendency to act scheming, slimy, greasy and oozy, playing tricks and coming up with schemes to make the steam engines' lives miserable and more difficult.

However, despite their prejudices, the diesels have co-operated with steam engines on occasions. The steam engines have also often come to the rescue when they are in trouble.

They also have a soft spot for ducklings and chase butterflies, and they appear to be more level-headed and have a caring side when it comes to hearing about a fellow diesel potentially having to be scrapped.

Technical Details


'Arry and Bert are based on British Rail (BR) Class 08 diesel-electric shunters. In the real world, BR Class 08s were in fact the most successful shunting engines in the world with 996 of them built. Over seventy of them are preserved by heritage railways, such as the Dean Forest Railway and museums, such as the National Railway Museum. Around one-hundred BR Class 08s also remain in service on the national rail network. 08850, a BR Class 08 preserved by the North Yorkshire Moors Railway, appears in a Mr. Perkins' Railway segment.

Diesel, Splatter, Dodge, Paxton, Sidney, Ulli, the Mainland Diesels and Fernando are also based on BR Class 08s along with the international Brazilian, Indian and Chinese diesels. Two BR Class 08s also appear in The Railway Series. Unlike these engines, 'Arry and Bert along with Splatter and Dodge have been modified without ladders going up on the sides of their fronts.


'Arry and Bert are painted green-grey with yellow cabs and yellow hazard stripes on their fronts. They have their company's name (Sodor Ironworks) painted on their sides in white.


Thomas & Friends


Music Videos

Learning Segments

Magazine Stories

Audio Files



First used Last used Sound Effect
Percy's New Whistle Percy's New Whistle
First used Last used Sound Effect
Calling All Engines! Series 11

In Hide and Peep, 'Arry is incorrectly portrayed with Dennis' horn.

First used Last used Sound Effect
Hide and Peep Hide and Peep
First used Last used Sound Effect
Series 14 Active



First used Last used Sound Effect
Percy's New Whistle Percy's New Whistle
First used Last used Sound Effect
Calling All Engines! Fun Cubes

First used Last used Sound Effect
Series 14 Active

On the Diesel's Locomotion Mayhem ride at Drayton Manor Theme Park, Bert is incorrectly portrayed with Diesel's horn.

First used Last used Sound Effect
Drayton Manor Theme Park Drayton Manor Theme Park


In Thomas & Friends: MINIS, Bert incorrectly has a whistle, despite him being a diesel and having a horn. His whistle in the app is Emily's Series 7 whistle, Peter Sam's Series 9-12 whistle, and Freddie's whistle at two steps lower pitched.

First used Last used Sound Effect
Thomas & Friends: MINIS Thomas & Friends: MINIS


  • 'Arry and Bert are actually not quite identical: Bert has more stubble.
  • Bert is the first character in the franchise to share his name with another character, the second being Oliver sharing his name with Oliver.
  • The 1998 official website and Question Time with Sir Topham Hatt refers to 'Arry and Bert as "The Yellow Diesels".
  • In merchandising and the official website, the twins are named "Iron 'Arry" and "Iron Bert".
  • 'Arry and Bert were possibly named after the nicknames of two brothers, from the 1970s BBC animated children's show Adventures of Sir Prancelot. These characters full names were Harold and Albert respectively. [1]
  • 'Arry is called "Harry" in the Latin American Spanish (from the fourteenth to the sixteenth series), Dutch (in the eighth series episode, Percy's New Whistle only) European Spanish (in the eighth series episode, Percy's New Whistle as well), German (in Percy's New Whistle, the fourteenth and fifteenth series), Japanese and Norwegian dubs respectively.
  • 'Arry and Bert's television series models do not have handrails, although some of their merchandise lines do.
  • 'Arry and Bert's fifth series models were repainted and constructed into Splatter and Dodge for Thomas and the Magic Railroad.
  • 'Arry and Bert's models used to be on display in Canada at Nitrogen Studios and wore their sly and cross faces.
  • 'Arry's name was not revealed until merchandising of him was released.
  • On 'Arry's trading card and Bachmann model, he has more stubble than Bert, the opposite of how they actually are.
  • There were a few occasions where 'Arry and Bert went faster than their basis' top speed.
  • 'Arry and Bert's horn sounds from Calling All Engines! to the eleventh series are Diesel's, but at three steps lower-pitched ('Arry) and five steps lower-pitched (Bert), respectively.
  • 'Arry and Bert's horn sounds from the eighth series episode, Percy's New Whistle were later reused for Salty from Toby's Afternoon Off to the twelfth series and Thomas' musical day for Percy in the kids app Speakaboos.
    • It is also a stock sound effect that can be heard and found in other various pieces of media such as the television shows Swat Kats: The Radical Squadron and Gravity Falls. It was also heard in the 3-2-1 Penguins! song, "Spaceship Drivin' Man."
  • Bert's current horn sound from the fourteenth series onwards was previously used as a sound effect for a ship's horn in the fifth series episodes, Horrid Lorry and Something in the Air.
  • 'Arry is the only character whose Minis toy does not have a classic variant, despite having a DC comics variant.
  • 'Arry and Bert's liveries might have been inspired by the NS Class 600's livery of black and yellow in some merchandise, even though the NS Class 600 resembles a BR Class 11 more than 'Arry and Bert's basis, a BR Class 08.
  • In the fifth series episode, Stepney Gets Lost, 'Arry and Bert have the same engine sounds as Rusty, Mavis, BoCo and Derek (both only in the fifth series episode, "Double Teething Troubles"). Diesel would later reuse it in one scene in Calling All Engines!.
  • 'Arry and Bert are accompanied by a triplet in the 2006 video game, Right on Time.
  • During the model series era, both 'Arry and Bert had a total of seventeen facial expressions, three of which (depressed, disgusted and tired) were not used on-screen.
  • In a Ravensburger puzzle, 'Arry and Bert are depicted in a BR Black livery.


Stepney was all alone, but not for long. Two diesels approached.
"Got ya this time, Stepney. You'll make very fine scrap indeed. Buffer 'im, Bert!"
The diesels took him to the large smelting shed
"Bye-bye, Stepney!"
said the diesel.
―'Arry and Bert's introduction, "Stepney Gets Lost", fifth series
The next day, James arrived at the smelters. He was determined not to be tricked by 'Arry and Bert.
"'allo, James!"
oozed 'Arry. "Come to learn a thing or two from those who know?"
"Just get my trucks ready and stay out of my way!"
huffed James importantly.
"Yes, sir".
Bert chimed greasily.
―James meets 'Arry and Bert, "Middle Engine", sixth series
Fergus and his driver arrived at the smelters.
"I want to go back to the Cement Works! None of the other engines like coming here, its so scary!"
"You're right!"
said his driver.
Just then, the scrap diesels emerged.
"'Ello! Are you happy to be here?"
cried Fergus.
―Fergus meets 'Arry and Bert, "Fergus Breaks the Rules", seventh series


  • Ertl (discontinued)
  • Wooden Railway (normal, oil-covered; discontinued; cheese-covered Bert; discontinued)
  • Take Along (normal and metallic; discontinued)
  • Take-n-Play (discontinued)
  • TrackMaster (discontinued)
  • Bachmann (discontinued)
  • Hornby (discontinued)
  • Lionel (discontinued, later reintroduced with LionChief remote)
  • My First Thomas ('Arry only with Bert's face discontinued)
  • My Thomas Story Library (discontinued)
  • Trading Cards (discontinued)
  • De Agostini (discontinued)
  • Minis
    • Classic Minis (Bert only)
    • Neon Minis (Bert only)
    • DC Super Friends Minis ('Arry as Shazam (2015 & 2016) and Bert as Shazam (2017))
    • Electrified Minis (Bert only)
    • Space Minis (Bert only)
    • Aquatic Minis (Bert as a jellyfish; with 'Arry's face mask)
    • Icky Minis (Bert only; as a cockroach)
  • Adventures (Bert only; discontinued)


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