Pop Goes the Diesel

"Trucks are waiting in the Yard; Tackling them with ease'll, "Show the world what I can do," Gaily boasts the Diesel. In and out he creeps about, Like a big black weasel. When he pulls the wrong trucks out – Pop goes the Diesel!"

- Troublesome Trucks

Pop Goes the Diesel is the twelfth episode of the second season. It aired in the US on the Shining Time Station episodes, Promises, Promises in 1989 and Yabba, Yabba, Yabba in 1991.

Plot
Duck the Great Western engine works very hard on the Island of Sodor and everything goes smoothly when he is around. He can keep the coaches quiet, the trucks behaving, and the passengers happy. He is also very proud of his Great Western heritage and talks endlessly about it, which irritates the larger engines who quickly grow tired of hearing about "the Great Western way".

One day, a visitor arrives in the shed. The Fat Controller introduces the new engine as Diesel, stating that he is going to be given a trial and charges Duck with showing him around and teaching him what to do. Diesel introduces himself before heaping compliments on Gordon, James, and Henry, which quickly win them around to the newcomer. Duck, however, takes a dislike to Diesel's oily nature and shows him to the yard.

There it becomes apparent that Duck's dislike of Diesel is mutual as Duck orders Diesel to refer to the Fat Controller as "Sir Topham Hatt", before Diesel smugly tells Duck that he does not have to be taught what to do. As a diesel, he already knows everything and that diesels will always improve a yard, calling diesels revolutionary. Duck is not very happy about this and orders Diesel to arrange the trucks while he leaves to take Gordon's coaches to the station.

Diesel, eager for the chance to show off, quickly gets to work. However, he attempts to move the wrong trucks; some really old ones which have stiff joints and brakes. When Diesel cannot move them, he tries getting very forceful with them. Duck arrives, and realises what is happening, but decides to let events play out. Diesel gets so frustrated with the trucks that he accidentally overturns some when their brakes snap. Diesel still cannot move the remaining trucks and is forced to give up.

Duck finally comes forward carrying some other trucks and Diesel asks Duck why he did not tell him about the others. Duck simply reminds Diesel that he was supposed to instantly improve the yard. Duck leaves happily, while Diesel fumes.

Diesel is later forced to help clean up the mess, a duty that he hates especially as the trucks have started teasing and singing at him. When the clean-up is over, Diesel, now unhappy with the trucks and with Duck, storms off back to the shed.

Characters

 * Henry
 * Gordon
 * James
 * Duck
 * Diesel
 * Sir Topham Hatt
 * Percy (cameo)

Locations

 * Tidmouth Sheds
 * Knapford Yards
 * Sodor Shipping Company
 * Brendam Warehouse

Trivia

 * This episode is based on the story of the same name from The Railway Series book, Duck and the Diesel Engine.
 * The title is a pun on the nursery rhyme, "Pop Goes the Weasel".
 * In the Korean and Hungarian versions, the song sung by the troublesome trucks is still in English, though the Korean version of the song has subtitles.

Goofs

 * In the scene where Duck is exactly side-on, a small space between the face and the model is visible.
 * Henry's tender is missing in the first shot featuring him.
 * When Duck passes James, Gordon, and Henry, there are only two tracks to the right of the water tower and it is not in line with the Sodor Shipping Company building. When Diesel and Duck arrive later on, there are three tracks to the right of the water tower and it is in line with the building.
 * Diesel follows Duck too quickly for the turntable to have turned to face him.
 * Gordon and Henry's faces are crooked when Duck and Diesel leave.
 * When Duck and Diesel frown at each other Duck is missing his eyebrows. Duck is also missing eyebrows when Diesel first backs into the shed.
 * At the beginning of the scene in which Diesel passes through the Sodor Shipping Co., there is a truck directly behind him on the same track. This would have made it impossible for him to pass without shunting the truck.
 * Duck isn't in the siding when Diesel tries to pull the trucks.
 * Steam can be seen around Diesel when he is trying to move the trucks.
 * When the narrator says "Diesel lost patience", one of the trucks has a clump of hair inside it.
 * When Diesel tries to push the trucks back he backs down onto the breakdown train, not the trucks. In the same scene, one of the buffer stops on the left is leaning over.
 * In one scene, there is not a truck in the siding that Duck is in before he goes to collect the other trucks. One appears in the siding during the trucks' song, then after it finishes there is not.
 * In the scene of Duck seeing Diesel after collecting the trucks, Diesel backs down to the trucks he had been struggling with - straight into them - then he comes forward a little so as to be directly in line with Duck. Last of all, when Duck leaves, he goes backwards suddenly before heading off.
 * After Duck leaves to get Gordon's coaches, there is still steam venting from the track.
 * Diesel clearly does not have a driver when he is on the turntable, but he somehow reverses into his shed.
 * When the narrator says "Diesel had to help the workmen clear the mess", the breakdown train is missing a buffer.
 * In a rare picture, Diesel's siderods are crooked.
 * Henry's whistle sound is lower pitched at one point during the scene at Tidmouth Sheds.
 * When Diesel first tries to move the trucks, the front truck which is a china clay truck derails. When its brake snaps, it turns into a coal truck.
 * The narrator says that Diesel was delighted to show off, but he is still frowning.
 * When Duck is on the turntable in the beginning, the turntable bounces back and forth a little when it stops.

Merchandise

 * Buzz Books - Pop Goes the Diesel
 * Ladybird Books - Pop Goes the Diesel/Dirty Work/A Close Shave

Home Media Releases
{{Scroll box|

UK

 * Percy and Harold and Other Stories
 * Percy Takes the Plunge (UK DVD)
 * The Biggest Ever Christmas Collection
 * The Very Best of Thomas and Friends
 * The Complete Second Series

DVD Boxsets

 * Classic Collection

US

 * Better Late Than Never and Other Stories
 * Thomas Comes to Breakfast (DVD)
 * Thomas' Useful Stories

DVD Boxsets

 * Adventure On the Tracks
 * Totally Thomas Volume 9

JPN

 * Thomas the Tank Engine Volume 9
 * The Complete Works of Thomas the Tank Engine 1 Vol.2
 * The Complete DVD Box 1
 * I Will Not Loose to the Diesel

PHL

 * Percy Takes the Plunge (Philippine DVD)

GER

 * Thomas and His Friends Vol. 4
 * The Runaway and 4 Other Adventures
 * Rail Free for Steam and Diesel!

HRV

 * Duck Takes Over

AUS

 * Percy and Harold and Other Stories
 * The Biggest Ever Christmas Collection
 * The Very Best of Thomas and Friends
 * The Complete Second Series
 * My First Thomas with Diesel

DVD Boxsets

 * 60th Anniversary - Limited Edition Boxset
 * Complete Series 1-10 (Boxset)
 * My First Thomas

NZ

 * Bumper Video Collection Volume 3
 * Thomas Train Set Compilation Video Volume 6

UKR

 * A Train Thomas and Friends

NL

 * Percy and Harold (Dutch DVD)
 * The Greatest Stories: The Adventures of Edward, Toby and the Diesels

NOR/FIN/ISL

 * Thomas the Tank Engine 4 (Norwegian VHS/DVD)

ITA

 * The Locomotive and the Helicopter

DNK

 * The Runaway Train and Other Stories

BRA

 * The Earliest Adventures of Thomas

IND

 * Pop Goes the Diesel and Other Stories

MYS

 * Percy Takes the Plunge and Other Thomas Adventures

ROM

 * Thomas and the Great Runaway (DVD)

DVD Packs

 * Triple Pack 1

SER

 * Thomas the Tank Engine 3

CHN

 * Thomas and Friends Season 1-4 (DVD)

TWN

 * Thomas and Friends Volume 4 (Taiwanese DVD)
 * }}