Behind the Scenes

This is a behind the scenes subpage for Diesel.
This subpage contains all behind the scenes material relating to said article.

Background information

The Railway Series

Diesel is a fictional standard gauge diesel locomotive created by the Rev. W. Awdry.

He first appeared in the Railway Series book, Duck and the Diesel Engine, which was published in 1958. His last appearance was in Thomas and the Evil Diesel, published in 1987.

Front of Diesel:

Rear of Diesel:

Diesel is based on the BR Class 08.

The Television Series

Diesel reprises his roles from the book Duck and the Diesel Engine in the second series. He has also appeared in original stories written by various writters.

After only appearing as a background character in the fourth series episode Rusty to the Rescue and being absent for the fifth series, Diesel returned in the following series.

Up until the sixth series, stories focusing on Diesel usually involved him causing trouble and being sent away for it. However, since the seventh series, Diesel has not had any form of acknowledgement that he belonged to the Other Railway and has remained on the North Western Railway ever since. His usually plays the role as the antagonist or the bully in each episode he appears in, essentially building him up as the main antagonist of the series.

Behind the Scenes

Gauge 1 model

Diesel’s model was custom built with a perspex body shell and used a Märklin locomotive as a donor for the chassis and various parts. It was painted using glossy car body paint.

Diesel’s wheels were sourced from a gauge 1 locomotive made by Märklin, the BR 80. The bufferbeam and stepladders was sourced from the DHG 500. The coupling chain was made by Tenmille.

There are sixteen different facial expressions sculpted for Diesel, although only fifteen were used on-screen. The faces were first sculpted in clay and from that resin casts were made using a silicone mould. One of Diesel's screen used and production made faces are now owned by Twitter users ThomasTankMerch and TomsProps.

The eye mechanism had two servos, one for up and down movement and one for left and right movement. The up/down servo was attached to the body. The left/right servo had a rod attached to the arm, which connected to a bracket. The eye balls were coupled to the bracket and locked in by the face-plate, so whenever the servos were powered, the eye balls would move however the crew member desired.

The twelfth series marked the beginning of the show's transition into CGI and the characters' faces were animated through CGI with the aid of motion capture animation. The physical models' moulded faces were replaced by white targets with triangles to fix a computer-animated face in post-production. Diesel’s resin faces were only used in background shots.

Diesel has had modifications throughout the model era. These include:

  • Series 6:
    • His paint was given a matte finish.
    • His side rods changed from silver to black.
    • His brake pipe began facing upwards.
    • His wheels became unpainted.
  • Series 9:
    • He gained a lamp under his face on the left.

Diesel's model is now on display at the Explore the Rails exhibition. It was previously on display at the British Museum during the 70th Anniversary.

CGI model

In 2009, the series introduced Computer-Generated Imagery (CGI) as a replacement for the show's long-standing live-action models. Diesel was recreated from scratch in CGI by Nitrogen Studios. His model was "hand-sculpted" in Maya, a 3D animation and modelling software.

Photographs of Diesel’s Gauge 1 model were used for referencing. According to Greg Tiernan, every detail of the original television series models for each character is carefully reproduced in the CGI model. The models are subjected to many rounds of review before they are submitted to HiT Entertainment for final input and approval.

Diesel has had modifications throughout the CGI series. These include:

  • Series 13:
    • His lamp disappeared.
  • Misty Island Rescue:
    • His horn sound changed to that of a generic "American" Nathan K3LA diesel.
  • Day of the Diesels:
    • His horn sound changed back to its original sound.
  • Series 19:
    • He gained a headlamp above his face.
    • His coupling chain became red.
    • He gained a permanent tail lamp.
  • Series 20:
    • His coupling chain changed back to black.

CGI Testing Model

A CGI Diesel model appeared in the CGI test of the episode Thomas and the Stinky Cheese. The testing model's face was re-used for one of The Mainland Diesels.

Voice Actors


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