BJ knob looks like choke pull?

[ZeroOctane4me]

Does anyone know what the pull knob that has a choke looking symbol on it was originally supposed to do given that this is a diesel engine?

 

[bcsteel]

Hand throttle

 

[Fandrover]

As above..... Highly dangerous but I have used it as a cruise control

I believe original concept and use was for pto winches and accessories but that maybe an old timer myth

 

[jim land]

It is very helpful on winter after a cold start , at -20 c idle need to be higher or its very bad until it warm up