Trains accelerate incredibly slowly and often have a single gear that is optimised for high speed. Similar to trying to pull away in your car in too high of a gear this makes trains really slow and takes along time for them to hit their high speed.
Most cars will often have 4 (for very old cars) – 6 gears to keep acceleration smooth and fast whilst still being efficient at high speed but trains don’t.
I get that electric motors have all of the torque available at low RPMs whilst ICE only have full power at a high rpm but wouldn’t gears still allow trains to get to higher speeds quicker?
In: Engineering
Some trains do actually have gears. Diesel multiple units (DMUs) are often used in the UK and other countries for short passenger runs. They consist of 1-3 train cars, with diesel engines underneath. The engines are coupled to the wheels either via a mechanical gearbox (usually with automatically changing gears), a hydraulic transmission (potentially also with a gearbox), or electrically via a generator and motor.
The mechanical gearboxes are kinda rare nowadays, but there are still some trains (class 143/144 Pacers) in the UK that use them – albeit that they’re on schedule to be replaced pretty soon.
Also, smaller lighter trains can have better acceleration – underground trains in particular are pretty snappy. They’re never going to be going all that fast, so I guess the motors can be optimised for high acceleration.
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