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Cake day: May 11th, 2026

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  • iocase@lemmy.zipto196@lemmy.blahaj.zoneTrains rule btw
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    9 hours ago

    In order of most frictiony to least frictiony

    Stiction (stationary object you forced to move)

    Rolling

    Sliding

    Which is why ABS exists. When you lock your wheels up your coefficient of friction tanks and your stopping distance can double or more depending on conditions. ABS unlocks your wheels sometimes so you can at least steer, unlike a skid. If you know how to pump brakes properly a skilled driver can beat ABS handily.

    There’s also the fact that couplers have these hard rubber disks that act as springs and shock absorbers (railroading is kind of caveman-like in its solution to things) so when you try to pull a train it might look like you’re moving but you’re just taking the slack out. If you don’t you can bust a coupler from shock loading, so you can’t cheat physics that way (how I move heavy furniture around by myself personally so you would think it applies to trains)

    As a result you take the slack out of a train and make the cylinder part of the boiler until:

    A) she moves!

    B) your wheels slip!

    Once it’s moving it’s easy going.

    As for why an electric engine can’t keep hauling overloaded it’s because it’s above 100% rating. It can only do that for a short while or things start melting and letting out magic smoke.

    A steam locomotive can haul anything it can get moving since it’s lower friction once rolling, and requires less drawbar force.



  • iocase@lemmy.zipto196@lemmy.blahaj.zoneTrains rule btw
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    13 hours ago

    It’s a railroader saying. Steam makes 100% torque at a dead stop so if it can start moving it can haul it.

    So it means if our little train gets going nothing can stop it.

    For comparison a diesel-electric locomotive makes 300% torque at a dead stop so it can move things it cannot haul for long distances. The motors would catch on fire or you would burn out your electronics.

    Another railroader saying that sounds like a tautology is

    “Steam can’t start a load it can haul. Electric can start a load it can’t”