Marine Deck Foam System Calculator

Fixed low-expansion foam systems for petroleum/chemical tanker decks and machinery spaces (NFPA 11-2021 §11.2–.6)

◉ NFPA 11-2021 CHAPTER 11 STYLE CHECK · NOT A REGULATORY SUBMISSION TOOL

⚠ Indicative tool only. This source PDF has no text layer at all (a pure scan), so this was read directly from page images. This chapter covers marine vessels (deck and machinery-space protection on ships), relevant to jetty/tanker operations at a terminal rather than the shore-side storage tanks the rest of this suite covers — it's a different application from every other calculator here. Polar-solvent application rates are inherently product-specific (per §11.3.4.2, set by fire testing and the manufacturer's design manual) — this tool applies the standard's stated percentage relationships to a rate you supply, it doesn't know or estimate that rate itself.

Identification

Company

Vessel / Berth ID

Location

Record Type

Research entries stay private to you for practice/testing. Switch to Official once this is a real design your company should see.

Ship & Cargo Geometry

Unit System

Ship Maximum Breadth ft

Longitudinal Extent of Cargo Tank Spaces ft

Deadweight Tonnage MT

Single Largest Tank — Horizontal Sectional Area ft²

Largest Monitor — Protected Area (forward of monitor) ft²

Result

Cargo block deck area (breadth × longitudinal extent)—

Hand hoseline eligibility (§11.4.2, DWT < 4000 MT)—

Fixed Foam — Machinery Spaces (§11.2)

Largest Area Over Which Oil May Spread ft²

System must also be capable of providing a foam depth of at least 6in (150mm) over this area (§11.2.1) — a separate volumetric criterion this tool doesn't convert to a water/concentrate quantity, since that depends on the specific foam's expansion characteristics.

Result

Minimum application rate0.16 gpm/ft² (6.5 mm/min)

Minimum duration5 minutes

Minimum foam solution flow rate—

Deck Foam — Hydrocarbon Cargo (§11.3.4.1)

Governing rate is the greatest of three methods.

Result

(1) Deck spill: 0.16 gpm/ft² over 10% of cargo block deck area—

(2) Largest tank: 0.24 gpm/ft² of largest tank sectional area—

(3) Largest monitor: 0.074 gpm/ft² of monitor area, not less than 330 gpm—

Governing hydrocarbon deck rate—

Deck Foam — Polar Solvents (§11.3.4.2) optional

Cargo includes polar solvents

Highest Required Foam Application Rate for Any Polar Solvent Carried gpm/ft²

Result

(a) Deck spill: rate × 10% of cargo block deck area—

(b) Most demanding tank: 150% × rate × largest tank sectional area—

(d) Largest monitor: 45% × rate × monitor area, not less than 330 gpm—

Governing polar-solvent deck rate—

Discharge Duration & Monitor Sizing (§11.3.5, §11.5)

Hydrocarbon-only cargo, with gas inerting of cargo vapor spaces

Result

Required discharge duration—

Overall governing deck rate (greater of hydrocarbon / polar solvent)—

Minimum single monitor capacity (≥50% of rate, not less than 330 gpm)—

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