Jack is a friendly and enthusiastic front loader, who works for the Sodor Construction Company. He is Alfie's best friend
Thomas & Friends
When Jack first arrived on Sodor, he worked with the Pack to clear room for railway lines. Jack did well with Alfie - that is, until he tried to take some stone up a ledge but failed to pay attention to where he was going and accidentally drove onto an edge of a hill and tipped over. After Miss Jenny scolded him as soon as he was put back on four wheels, Jack learned his lesson and redeemed himself by holding up a collapsing bridge until Thomas had passed over, at the cost of damaging his arms. Jack has since become part of the Pack.
When Jack was being careless again at the warehouse, he accidentally knocked over some slate, but he did not want to be sent back to the yards and left the mess not knowing that Ned had been blamed for it. Ned was about to be sent back to the yards when Jack admitted that he was the one who broke the slate, so Miss Jenny sent him back instead. Later, when Max and Monty carelessly crashed into the lightning tree, Alfie, Oliver and Kelly hold the tree up while he ran to Thomas for the props. Luckily, he made it in time, and the tree was saved.
He, along with the rest of the Pack, helped with the restoration of Great Watertonand worked with Alfie to build a bandstand there. Jack also helped with the restoration of Ulfstead Castle and later saved Stephen and Thomas after the tracks they were on started to collapse.
He also helped with the construction of the Harwick Branch Line, along with Alfie, Oliver, Max and Monty and later attended the branch line's opening ceremony.
Later he, Alfie, Oliver, Max and Monty were working on Thomas' Branch Line and he, Oliver and Alfie helped clear the branch line around the Rail Under Road Bridge and Signalbox after Max and Monty dumped their loads on the line.
After James' accident at Tidmouth Sheds when his brakes malfunctioned, Jack assisted with the shed's reconstruction.
Jack is brave and will not take any hassle, as seen whenever he stands up to Max and Monty when they bully him and Alfie. He is also kind and caring, he also likes to jump in and get the job done even with other jobs that the other vehicles are assigned to do. But despite the fact that he was trying to be helpful and mean well, he has learned from Miss Jenny's words, to not jump into another job that is not his own.
Between the sixth and twelfth series, Jack was based on a Nuffield tractor with an added front loader.
Since the special, King of the Railway, Jack was designed as a International 454 tractor. Because of this, his face shape has changed dramatically from round to rectangular.
Jack was painted red with the top half of his cab and his wheels painted cream. He had the number 11 painted in cream on his sides. From King of the Railway onwards, the top half of his cab and his number are painted white, his back wheels are painted grey and his front wheels are painted red.
Thomas & Friends
- Series 6 - Jack Jumps in and A Friend in Need
- Jack and the Sodor Construction Company - A Visit from Thomas, Jack Owns Up, On Site with Thomas, Percy's Scary Tale, Kelly's Windy Day, A Happy Day for Percy, A Tale for Thomas, Thomas and the Moles, The Tortoise and the Hare, Alfie Has Kittens and Mud Glorious Mud
- Series 12 - Percy and the Bandstand
- Series 19 - The Other Side of the Mountain (cameo)
- Series 20 - Mucking About
- Series 21 - A Shed for Edward (cameo)
- Series 22 - School of Duck (cameo)
- Series 23 - Mines of Mystery, Out of Site, First Day on Sodor! and Deep Trouble
- Series 24 - Cleo's First Snow (life lesson; cameo)
Jack had a role in the cancelled episodes, Jack's Snow Rescue, Bossy Byron, The Importance of Being Patrick, Jack and the Quack, Pop Goes the Diesel, Alfie Has a Secret, Isobella Gets Steamed and Grass is Greener.
- 2008 - The Great Discovery
- 2013 - King of the Railway
- 2015 - Sodor's Legend of the Lost Treasure
- Jack and the Sodor Construction Company - The Work Song and One Friendly Family
- The Great Discovery - There's a Job for Everyone, Where, oh Where is Thomas? and Thomas, You're the Leader
- King of the Railway - Working Together Again, Searching Everywhere and It's Gonna be a Great Day
- Thomas' YouTube World Tour - Never, Never, Never Give Up
- Sodor's Legend of the Lost Treasure - We Make a Team Together
- Series 23 - Lorenzo's Song and The Sodor Construction Crew
- 2019 - Meet Gina of Italy (cameo), Meet the Sodor Construction Company! and Meet Ester of Italy! (does not speak)
- Guess Who? Puzzles
- 2005 - Snowy Surprise!
- 2006 - Jack and Thomas' Sticker Express
- 2007 - Alfie and Thomas' Giant Coloring Book
- 2009 - Watch Me Draw Thomas & Friends
- 2010 - Hero of the Rails (cameo), Movie Theater, On Track with Phonics and Steam Engine Celebration
- 2011 - Alfie the Excavator, Jack the Front Loader, The Big Book of Engines and Thomas Saves Christmas
- 2012 - Copy the Stickers Colouring Book, Cranky's Surprise, Full Steam Ahead! and Thomas' Super-Jumbo Coloring Book
- 2013 - King of the Railway, King of the Railway (UK book), King of the Railway: The Movie Storybook, The Lost Crown of Sodor, The Secret of the Mine (does not speak) and Thomas' Color Book
- 2014 - Bust My Buffers!, The Big Book of Engines and Thomas the Really Useful Engine
- 2015 - A Really Useful Engine, Pirate Treasure, Sodor's Legend of the Lost Treasure (does not speak), Sodor's Legend of the Lost Treasure: Sticker Activity Book, Sodor's Legend of the Lost Treasure: The Movie Storybook (cameo) and Thomas' New Friend
- 2016 - 6-Movie Coloring Collection, Bill and Ben
- 2003 - Jack Helps Out
- 2012 - Jack's Tracks!
- 2014 - Jack's Tracks
- 2007 - DVD Bingo
- 2008 - Begins Educational Learning
- 2017 - Read and Play!
Jack also appeared in the first story of Thomas and Friends - The All Aboard Live Tour.
- Steven Kynman (UK)
- David Menkin (US)
- Tim Kreuer (Germany; King of the Railway only)
- Daniel Schütter (Germany; Sodor's Legend of the Lost Treasure onwards)
- Naomi Shindō (Japan; sixth series only)
- Hideki Nakanishi (Japan; The Great Discovery - twelfth series)
- Keiko Nemoto (Japan; King of the Railway onwards)
- Artur Pontek (Poland)
- TBA (France and French speaking Canada; King of the Railway only)
- Yannick Blivet (France and French speaking Canada; Sodor's Legend of the Lost Treasure onwards)
- Gilan Shachaf (Israel; Sodor's Legend of the Lost Treasure and King of the Railway only)
- TBA (Israel; twentieth series onwards)
- Paul Disbergen (The Netherlands)
- Scott Maurstad (Norway; King of the Railway only)
- TBA (Norway; Sodor's Legend of the Lost Treasure onwards)
- Nacho Rodríguez (Latin America)
- Mariano García (Spain)
- Joonathan Kettunen (Finland)
- In some promotional sketches of the Pack, Jack is seen with a backhoe arm and bucket. According to an SiF interview with Chris Lloyd, the arm was built, but was too problematic as it was hard to store all of the radio gear inside the model. An interview with Phil Fehrle gives a very different reason: "...if a story required Jack to be digging (using his back-hoe) and interacting with another character working at the same time, his face would be facing away from the action. For story purposes, it was important to feature the faces as much as possible; thus, the backhoe was removed".
- Jack has had a few modifications in the television series:
- King of the Railway:
- He gained hydraulics.
- His exhaust pipe became taller and gained holes on the sides, as well as a handle.
- He decreased in size.
- His face changed from round to square.
- His rear wheelwells were moved back.
- The tread patterns on his tyres changed slightly.
- The colour of his alloys also changed from cream to grey.
- His roof became completely orange.
- His number increased in size.
- His bucket increased in size.
- The colour of his cab changed from cream to white.
- King of the Railway:
- Nathan Clarke did an audio sample for Jack on his DAA Management Page.
- A semi-complete face mask of Jack was preserved by the Top Props preservation group.
- Jack's Trackmaster Push Along toy lacks his number, his larger wheel is also sized down.
- Jack had a total of fifteen face masks, six of which were not used on-screen.
- "Spot on, Jack! You'd make a mother proud!"
- "And a tank engine grateful!"
- Miss Jenny and Thomas praising Jack, A Friend in Need, sixth series
- ERTL (discontinued)
- Wooden Railway (discontinued)
- Take Along (discontinued)
- Take-n-Play (discontinued)
- TrackMaster (motorised and un-motorised; discontinued)
- My Thomas Story Library (discontinued)
- Thomas Engine Collection Series (discontinued)
- Mini Die Cast Collection (discontinued)
- Thomas Town (discontinued)
- Capsule Plarail
- Pocket Fantasy (discontinued)
- Nakayoshi (discontinued)
- Adventures (sold only in Jack and the Pack 4-Pack; discontinued)
- TrackMaster Push Along (sold only in Hard at Work 4-Pack and Really Useful Friends 10-Pack)