/c

script.on_event(defines.events.on_train_created, function()
	for i, loco in pairs({global.loco1, global.loco2}) do
		if loco.valid then
			game.print(i .. " valid")
			if loco.train == nil then
				game.print(i .. " no train")
				
				game.print("This will crash the game.")
				loco.connect_rolling_stock(defines.rail_direction.front)
				loco.connect_rolling_stock(defines.rail_direction.back)
			else
				game.print(i .. " has train - ignoring")
			end
		else
			game.print(i .. " not valid - ignoring")
		end
	end
end)



local locos = game.surfaces[1].find_entities_filtered{name="locomotive"}
global.loco1 = locos[1]
global.loco2 = locos[2]

global.loco1.destroy()