During the 1980s a number of class 37s were modified and refurbished to provide a planned life extension and better fit for the work the locomotives were required to perform. The 37/7 sub-class were fitted with the more robust AC alternator in place of the original DC generator to provide traction current and around 10 tons of additional ballast was added to provide a greater tractive effort, improving reliability and train-hauling capability for heavy freight service.
Functions and sounds available
F0
|
Locomotive Directional Lights On/Off
|
F1
|
Sound On/Off
|
F2
|
Single Horn Note
|
F3
|
Two-Tone Horn
|
F4
|
Fan
|
F5
|
Notch Up (Increase engine rpm)
|
F6
|
Notch Down (Decrease engine rpm)
|
F7
|
Shunting Speed / Inertia On/Off
|
F8
|
Cab Lighting On/Off
|
F9
|
Buffer Collision Sound
|
F10
|
Coupling Sound
|
Supported CVs and default values/settings
CV
|
Definition
|
Min-Max
|
Default
|
1
|
Locomotive Address
|
1-127
|
3
|
2
|
Start Voltage
|
1-75
|
3
|
3
|
Acceleration
|
0-64
|
8
|
4
|
Deceleration
|
0-64
|
6
|
5
|
Max Voltage
|
0-64
|
64
|
6
|
Medium Speed
|
0-64
|
22
|
7
|
Version
|
0-63
|
0
|
8
|
Manufacturer ID
|
ESU
|
151
|
17
|
Extended Address
|
128-9999
|
disabled
|
18
|
Selected by CV29
|
Â
|
Â
|
29
|
Decoder Configuration
|
Â
|
6
|
Refer to data sheet
|
Â
|
Â
|
49
|
Back EMF Selector
|
Bit 0
|
1/Enable
|
Â
|
Â
|
Bit 1
|
1/30kHz
|
Â
|
Â
|
Bit 4
|
1/Enable
|
53
|
Feedback Reference
|
0-63
|
56
|
54
|
Feedback Parameter K
|
0-63
|
32
|
55
|
Feedback Parameter I
|
0-63
|
24
|
63
|
Sound Volume
|
0-64
|
64
|