I'm with Ralph. The rail line I'm used to is WAY too tough to simply split like that, in fact it would merely only bend with sufficient force. My guess is they're splitting cast iron rails used for a light weight tramway or workshop railway.
In our old mill they used to heat railroad axles and roll them directly into rebar which has a very loose tolerance for alloy. Those pieces look a nice shape for a one or two step process at limited cost.