Bill and Ben

Bill and Ben are tank engine twins belonging to the Sodor China Clay Company. They are young and cheeky and love playing jokes on the bigger engines, but are kept in order by Edward and BoCo. They work in the china clay works and at Brendam Docks, where they are kept busy shunting trucks.

In the television series, they briefly worked at Anopha Quarry, thus the task of keeping them in order fell upon Mavis.

Personality
Bill and Ben are Sodor's mischievous saddle tank engine twins, who have great fun in teasing the other engines of the railway. Each has four wheels, a tiny chimney and dome, and a small squat cab. They often work in the China Clay pits and quarries. Their loads of clay can be used for many things such as paper, paint, and pottery. They take trucks for engines on the main line and ships in the harbour and are regularly seen around Brendam Docks. They enjoy attention and love taking visitors and being photographed. They tend to work together, like most twins, but even this youthful pair can have their arguments among themselves and can squabble with one another. They are highly prone to playing tricks and being cheeky. They have even teased Gordon on more than one occasion. Duck has called them "the bees" before, for being terrors when they start buzzing around. Edward and BoCo are the only engines who can really keep them in order enough to put a stop to their games and make them scamper along and behave. There is no real harm to them, but even Edward admits that they are maddening at times.

Despite their cheeky and mischievous antics, if a dangerous event occurs, such as a rockslide, they are shown to be quick-witted and capable to act to rescue anyone in trouble. This was shown when they saved a group of workman and Thomas from many different rockslides.

Basis
Bill and Ben are based on the Bagnall 0-4-0STs "Alfred" and "Judy" of Par, Cornwall, who are both preserved and in working order at the Bodmin and Wenford Railway.

Alfred and Judy are painted in a green coat of paint, with yellow lining, although the former was once repainted in a yellow coat of paint, very similar to Bill and Ben's yellow coats of paint.

According to the foreword of Thomas and the Twins, Alfred and Judy are both Bill and Ben's twins.

Trivia

 * In the Railway Series, from Wrong Road onward, Bill and Ben have their names painted on their saddle tanks instead of having nameplates to avoid the trick they played on BoCo from happening again.
 * A behind the scenes picture of Bill's model reveals that he and Ben were to have numbers on their smokeboxes above their faces, as they did in the Railway Series.
 * Bill and Ben's television series models are currently on display at the Hara Model Railway Museum in Japan.
 * In the television series, Bill and Ben are twice the size of their basis'; Alfred and Judy. This was so their eye mechanisms and motors could be accommodated. When they returned in CGI, they were rendered in the same larger size.
 * The twins' whistle sounds are really Thomas' at higher pitches. Often, throughout the CGI Series, they swap whistle sounds.
 * Bill and Ben were known as Guillaume and Benjóin in the French version of the Classic Series.
 * Nathan Clarke did an audio sample of Bill and Ben on his DAA Management Page.
 * In an interview with SiF, Andrew Brenner stated that Bill and Ben were two of his favourite characters, along with James and Toby.
 * They might have been named after Bill & Ben the Flowerpot Men, who were first created in 1952, the same year Toby the Tram Engine was first published.
 * Bill and Ben went through several aesthetic changes in the television series:
 * Season 3:
 * Their nameplates were painted on instead of being actual plates.
 * Buffer Bother:
 * Ben gained gold buffers.
 * Season 7:
 * Ben regained black buffers.
 * Season 11:
 * Ben gained a new cheeky facemask.
 * Season 17:
 * Their faces became smaller, and were raised slightly higher up.
 * Permanent lamps and taillamps.
 * An additional sandbox was added on the footplate to mount the lamp.
 * An extra wood panel was added to the rear window to accommodate the taillamp.
 * Taller cabs.
 * Brass nameplates.
 * Red lining behind the "SCC" lettering on their boilers.
 * Red wheels.
 * External brake shoes.
 * Black domes and crossheads.
 * Brake pipes.
 * Yellow wheel lubricators on both sides, that connected to their valve gears.
 * Yellow siderod guards.
 * They speak with a Brummie accent
 * Season 19:
 * Their crossheads became grey again.
 * The text on their nameplates became gold.
 * Season 21:
 * Their crossheads became black again.