A Class 20 cab layout. Class 20s, unlike other diesel or electric mainline locomotives, have only one cab and so the controls are duplicated. For travelling in a forwards direction the controls are situated at the front left of the cab and for travelling in reverse, as here, the controls are at the rear right.
The nearest handle to the seat, at left, is the Locomotive brake valve. The handle forward of this is the Train brake valve. To the right of this is the Two-tone warning horn valve.
Mounted on the cab are two switches, which are - Slow speed control switch gear x2 and to the right of these is the - Fire alarm test button.
The bank of three lights next to the horn valve are, at (top) - Engine stopped warning light (middle) - Wheelslip warning light (bottom) - General fault warning light.
Below the lights, from left to right, are four buttons - Start button, Stop button, Anti-slip brake button and AWS reset button.
The dial which is positioned on its own at top right is the - AWS indicator.
The top three dials, from left to right are - Vacuum gauge, Bogie brake cylinder gauge and Main reservoir pressure gauge.
The dial which sits between the two rows is the - Air brake pipe gauge.
The bottom row of three dials, from left to right, are - Speedometer, Ampmeter and Slow speed speedometer.
The large handle, at bottom left, is the - Power controller (Off/On/¼/½/¾/Full).
The small handle beneath it is the - Master switch (Forward/Engine Only/Reverse/Off)
The locomotive - Link