This chamber has equipment to allow the miners to survive underground for 48 to 84 hours with no outside input. The chambers can come in different shapes and sizes. However all require the same equipment.
Stored air source & power
Air con and bottled water
Air filter, radio, telephone & port-a-loo
First aid kit
The reason we have smaller portable refuge chambers is because a jumbo can’t work up a drive with another piece of equipment working behind it. Whether it be a bogger loading trucks or the service crew installing something without the refuge chamber in place you are not allowed to work behind the jumbo.