Mobile
Semi-stable
Traditional stable
Pi Foam System
Normal fire-vehicle system with water tank and foam monitor
Semi-stable firefighting system with water/foam source
Automatic pump and foam generator-type extinguishment system
Tank-type pneumatic detector activated Pi Foam System
Time until extinguishment starts
30 - 120 min
15-30 min
3-5 min
0.5 - 1 min
Damage before extinguishment starts
heat stress and deformation on the upper side of the tank wall
heat stress and deformation on the upper side of the tank wall
low scale
not expected
Normal foam-solution intensity (L/min/m2)
5 - 10
5 - 8
5 - 12
15 - 50+
Typical extinguishment time
2 - 48 hours
1 - 24 hours
30 min
2-3 min
Overall damage
severe damage to the tank, usually needs to be demolished
large-scale damage, high repair cost or demolition required
low-scale damage
low-scale or no damageĀ 
Extinguisment cost
very high
high
low
low
OUTSIDE FACTORS
Special staff requirements
very high
high
not required
not required
Roads, traffic
yes
yes
no
no
Fuel
yes
yes
yes
no
Electricity
no
yes
yes
no
OPERATIONAL RELIABILITY
Operational Reliability level
high
low
moderate
very high
Variables that affect operational reliability; potential pitfalls
Condition of fire vehicles and their equipment, traffic, fire brigade skill and training levels, access to water, availability of fire engines, availability of foam concentrate
Condition of fire vehicles and their equipment, traffic, fire brigade skill and training levels, condition of water pumps, access to water, availability of fire engines, availability of foam concentrate, maintenance failure
Electricity supply, condition of pumps and foam mixers, foam concentrate supply, maintenance failure
Mechanical damage, maintenance failure
EXTINGUISHMENT RELIABILITY
Extinguishment Reliability level
low
moderate
moderate
very high
Variables that affect extinguishment reliability; potential pitfalls
foam, fuel or water supplies run out, updraft, wind or long extinguishment distance
foam, fuel or water supplies run out
expired or poor-quality foam concentrate, capacity limitations
expired or poor-quality foam concentrate
FINANCIAL COMPARISON
CAPEX
moderate
moderate
high
low/moderate
OPEX
extremely high
extremely high
high
low
Maintenance requirement
high
moderate
high
low