How could the crank operated Gatling gun have stayed the pinnacle of semi-automated firepower for several decades longer than iotl.
Indeed. Those ideas have come up before on the one or two occassions this has been discussed. Really, the uses of a motorized Gatling gun are so obvious I'm frankly surprised it wasn't pursued IOTL. I mean, sure there are drawbacks, but I find it hard tp believe it wouldn't have been useful in some niche.As Captain Jack mentioned, Gatling did motorize his gun. Rather than keeping the normal machine gun from being developed, perhaps the motorized Gatling gun gets improved as well. Useless in the trenches due to the need for a power supply, it could still have some significant uses. As a fortification gun, it would be without peer. It would be a fearsome AA gun, especially in the larger calibers. Carry a pair aloft in an airship, and the sheer amount of lead could keep enemy fighters from becoming as much of a problem.
Mount it on ships, or on the first tanks and armored cars, and it'd be murder on infantry.