Originally Posted by HotDog
As far as I know, the lower cargo fire extinguishing system is similar to the Classic set up.
Yes,
HotDog, the -400 is very similar to the Classic, but slightly enhanced and automated. The details are:
Four cargo compartment fire extinguisher bottles, designated A, B, C, and D are installed for fire control in the forward and aft lower cargo compartments. The four bottles provide a total of 195 minutes of extinguishing.
Pushing a Cargo Fire Arm Switch arms all four bottles for discharge into the selected compartment. Pushing the Cargo Fire Discharge Switch discharges bottles A and B into the armed compartment. The EICAS advisory message >CGO BTL DISCH is displayed and the Cargo Fire Discharge Light illuminates when bottles A and B are discharged. Bottles C and D automatically discharge after a brief delay and maintain a metered flow. The EICAS advisory messages >BTL LOW CGO C and >BTL LOW CGO D are displayed when the respective bottles discharge. If not previously discharged in flight, bottles C and D discharge on landing.
PS sorry,
ETOPS, just seen you beat me to it !!