Today I tried to ignite coal on a grill device, without using kindling (we ran out of it). I gathered a lot of small twigs and a bit of medium ones. I managed to set all this on fire, but the coals didn't ignite, and it was extinguished soon after the twigs were out.
I've observed my grandmother putting coals into the fire in the oven, but after twigs, she put blocks of wood into the fire, so the temperature was quite high. It's not applicable on a grill device.
Are there any special techniques of putting coal into the fire with the campfire of limited size, such as those on a grill device? Is it possible to achieve the temperature with such a small fire?