On one project I once worked on, we had a large electric motor (approx 300
HP) that had to turn a huge 12' diameter wood-chipper, there was so much
inertia that It would take about a minute to start up.
The motor had a wire-wound rotor (ie  It was a 3-phase induction motor that
instead of having huge copper bars embedded in the rotor to carry the
induced currents, this motor had wire winding that were connected to the
outside world via brushes.
There was no outside power connected to this rotor, it was only connected to
a huge resister box that had a large rotary switch on it that allowed the
operator to vary the amount of resistance in the wire-wound rotor circuit.
At immediate start-up, maximum resistance was applied to the armature
windings, then as the rotor speed increased, resistance was gradually
removed from the circuit, until at full speed the rotor windings were
connected to a dead short.
The motor then ran as a regular induction motor.

So maybe an industrial electrical shop would have these resister boxes
available. It looked sort of like a bed-spring in a box and was obviously
able to burn-off a huge amount of electrical power.

Robin


Rail salvage?  Locomotives have large fan cooled electric grids to
implement dynamic braking.


Matt-