We have been talking a lot about hydrants these past couple of days, unfortunately inspired by the Charlotte Maxeke Hospital fire. Whilst we cannot comment on what went wrong for that specific incident because we have not conducted a fire investigation at those premises, we thought it would be useful to circulate some information on fire flow and hydrants. Please note that extracts of tabulated data are sourced from SANS 10090: Community Protection Against Fire.
Hydrant Flow (per unit):
Total Fire Flow required, based on the risk category, is as indicated below. Therefore, in the majority of cases, more than 1 fully functional hydrant or other source of firefighting must be available to ensure:
1. There is sufficient water flow and pressure to control/ extinguish the fire; and
2. The duration of the water supply meets the needs of the fire service as per their risk assessment of the area to be protected.
Fire Flow per Risk Category:
Now you may be wondering “What do the Risk Categories A-E mean?”.
Below are the definitions:
Category A: Central business districts and extensive commercial and industrial areas normally found in cities and large towns (areas where the risk to life and property due to fire occurrence and spread is likely to be high).
Category B: Limited central business districts, smaller commercial or industrial areas normally associated with small towns and decentralized areas of cities and large towns (areas where the risk to life and property due to fire occurrence and spread is likely to be moderate).
Category C: Residential areas of conventional construction.
Category D: Rural areas of limited buildings and remote from urban areas.
Category E: Special risk areas. Individual areas requiring a pre-determined attendance over and above the predominant risk category in an area. Includes large shopping/entertainment centres, informal settlements, harbours, hospitals, prisons, large airport buildings and petrochemical plants.
Therefore, whilst hospitals are a Category E, they will reside within a predominant risk category. Thus, the fire services are responsible for conducting a risk assessment of the area under their jurisdiction and determining the appropriate response time, which may be faster than the predominant categorised area based on the fact that there are vulnerable individuals seeking medical attention who would not be able to escape a building fire in the predetermined time due to their specific ailment, there are individuals undergoing surgery, coupled with the majority of persons at a hospital being unfamiliar with the escape plan. Thus, time is of the essence when dealing with such risks.
Attendance Times for Fires:
The maximum attendance time (column 4) was designed for response to a fire by the fire services. It is critical that these times are complied with to ensure life safety and prevention of the spread of fire from one building to another.
