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
Diesel trains, apart from diesel-electrics which have essentially the same transmission as AC or DC electric trains, have gearboxes. In most cases the gearboxes are fluid-filled torque converters with automatic gearchange from one or more torque ratios to direct drive ratio (equals top gear) and are known as diesel-hydraulic.
Some older trains were diesel-mechanical with manual gearchange. These were nearly all multiple-units as opposed to locomotives, and had a clutch-less planetary gearbox controlled through electro-pneumatic valves. There might be some of these left around the world, but the UK withdrew them about 15 years ago.
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