Freight wagons usually have a maximum CC ( Carrying capacity). Earlier, the max axle load for the freight wagons was around 20.3 tons. At that time, CC + 2 was the maximum capacity to which freight wagons could be loaded i.e., each freight wagon can be loaded to 2 tons more than the carrying capacity. Over time, IR has increased the limits to which wagons can be loaded, by allowing higher axle loads on the route. By allowing the increase to 22.8 tons of axle load, it was possible to have CC + 8 + 2T or CC + 6 + 2T loading for freight wagons ( 10 or 8 tons more loading than the carrying capacity). CC+6+2T is usually seen with Coal wagons. So this board indicates that the speed limit is 60 kmph, for trains with this axle load.