Functional Requirements for Crash Fire Tender for Air Fields

IS 951: Scope - Key Specifications & Tables Summary

1. Scope Overview

IS 951 covers design, performance, and documentation requirements for airport crash fire tenders (ACFT), including:

• Operator, Parts, and Repair Manuals with technical details, maintenance, and repair instructions.
• Markings on Vehicle Body such as:
  • Airport fire service
  • Year of manufacture
  • Engine & chassis numbers
  • Pump and tank capacities
  • Fire service emblem, safety instructions, etc.

2. Performance & Dimensions (Clause 6.4)

3. Pump Capacity & Drive

• Pump Capacity: Minimum 4000 l/min at 8.5 kg/cm² pressure
• Drive: Preferably all-wheel drive, right-hand steering

4. Schedule of Equipment (Annex B)

Key firefighting tools with IS references include:

• Suction Strainer (IS 907)
• Basket Strainer (IS 3582)
• Suction Wrenches (IS 4643)
• Hose Bandages & Clamps (IS 5612)
• Branch Pipes & Nozzles (IS

IS 951: Key Material Specifications & Requirements

Material Quality (Clause 5.1 & 5.2):

• Use new, defect-free materials ensuring strength, lightness, and durability.
• Metals must have high strength-to-weight ratio to reduce dead weight and increase payload.
• Avoid dissimilar metals contact to prevent electrolytic corrosion; use plating, spraying, or insulation if unavoidable.

Corrosion Resistance (Clause 5.5):

• All waterway parts and foam-contact metals must be stainless steel.
• All metal pipelines: stainless steel.
• Exposed metal parts: corrosion-resistant or suitably treated.
• Ferrous fasteners: galvanized or chrome plated.

Relevant IS Standards for Materials & Components

Summary Table: Material Requirements

flowchart LR
    A[Material Selection] --> B{New & Defect-Free?}
    B -- Yes --> C[High Strength-to-Weight Metals]
    C --> D[Check for Dissimilar Metals]
    D -- Yes --> E[Apply Plating/Spraying/Insulation]
    D -- No --> F[Proceed]
    F --> G[Use Stainless Steel for Waterways & Foam Contact]
    G --> H[Use Galvanized/Chrome Plated Fasteners]
    H --> I[Final Assembly]

This ensures durability, corrosion resistance, and operational reliability of fire fighting equipment per IS 951.

IS 951 - General Requirements Summary

1. Manuals to be Provided (Clause 8.5)

• Operators Manual: Technical description, layout drawings, operation instructions, maintenance, lubrication schedule, fault finding, storage, warnings.
• Parts Manual: Exploded views, parts identification, source details.
• Repair Manual: Illustrated repair/overhaul instructions, fitment tolerances, special tools.
• General Arrangement Drawings: Layout of equipment, piping, fluid controls, electrical and structural design.

2. Markings on Vehicle Body

• Airport fire service
• Year of manufacture
• Engine and chassis number
• Fire service emblem
• Job or SI number
• Pump, water tank, foam tank capacities
• Pump SI number
• Chassis supplier name and origin
• Left hand drive warning
• Precautionary instructions

3. Key Dimensions & Performance (Clause 6.4)

4. Equipment List (Annex B)

Includes hoses, strainers, wrenches, clamps, nozzles, axes, ropes, cutters, emergency lights, etc. Each item references relevant IS standards (e.g., IS 907 for suction strainers, IS 903 for nozzles).

IS 951: Water and Foam Systems - Key Specifications & Formulas

Material Specifications (Clause 5.5)

• Waterways & foam-contact parts: Stainless steel only.
• Metal pipelines: Stainless steel mandatory.
• Atmospheric exposure: Use corrosion-resistant materials or apply protective treatment.
• Ferrous fasteners: Must be galvanized or chrome plated to prevent rust.

Foam Quality Requirements (Clauses 4.4 & 7.25)

• Foam from turrets and hand-lines must comply with IS 4989 (Part 1).
• Minimum expansion ratio: 8 (foam volume/water volume).

Foam Production Design (Clause 4.4)

• Systems must ensure satisfactory foam quality with:
  • Expansion ratio ≥ 8.
  • Consistent foam discharge from monitors and hand-lines.

Typical Foam Expansion Ratio Formula:

[ \text{Expansion Ratio} = \frac{\text{Volume of Foam}}{\text{Volume of Solution}} ]

Material Protection Summary:

flowchart LR
    A[Water Source] --> B[Foam Compound Mixing]
    B --> C[Stainless Steel Pipelines]
    C --> D[Foam Monitor/Hand-line]
    D --> E[Foam Discharge]
    E --> F{Foam Quality Check}
    F -->|Expansion Ratio ≥ 8| G[Acceptable Foam]
    F -->|Expansion Ratio < 8| H[Adjust System]

For detailed foam quality tests, refer IS 4989 (Part 1).

IS 951 - Fuel System Key Points & Specifications

Clause 7.3 Fuel System:

• Fuel system must comply with engine manufacturer's specifications.
• Include fuel pump, fuel filtration, flexible fuel lines.
• Lines must be protected from damage, exhaust heat, and ground fires.
• A drain at the bottom of the fuel tank is mandatory.

Clause 8.5 Minimum Fuel Supply:

• Minimum flow: 4,000 l/min at 8.5 kg/cm² pressure.

Fuel System Components:

• Fuel pump
• Fuel filtration system
• Flexible fuel lines (non-percolating, IS 636 compliant)
• Drain valve at fuel tank base

Markings on Vehicle Body:

• Fuel system related markings include engine number, chassis number, and fuel tank capacity.

Recommended Fuel System Layout (Simplified):

flowchart LR
  FuelTank -->|Fuel Line| FuelPump -->|Filtered Fuel| Engine
  FuelTank -->|Drain Valve| Drain
  FuelLine -.->|Protection: heat & damage| Shield

Important IS References for Fuel System Accessories:

• IS 636: Non-percolating flexible fire fighting delivery hose
• IS 907: Suction strainers for firefighting
• IS 4643: Suction wrenches

Summary:

• Design fuel system per engine maker's guidelines.
• Ensure minimum 4,000 l/min at 8.5 kg/cm².
• Include filtration, flexible lines, and protection.
• Provide drain at fuel tank bottom for maintenance.

Suspension and Axles - IS 951 Key Points

Suspension Design Requirements (Clause 7.7):

• Allow vehicle to travel at specified speeds on improved/unimproved surfaces.
• Provide diagonal opposite wheel motion over 350 mm obstacles without lifting other wheels.
• Allow minimum 50 mm axle travel before suspension bottoms on ground.
• Prevent damage from wheel movement.
• Ensure crew comfort on all surfaces.

Axle & Weight Specifications:

• Axles must carry maximum imposed load safely (Clause 7.6.5).
• Axle tread variation ≤ 20% of tyre sectional width.
• Weight distribution:
  • Tyre load difference ≤ 5% of average tyre load per axle.
  • Axle load difference ≤ 10% of heaviest axle load (Clause 6.2).

Dimension & Performance Table (Clause 6.4):

Summary Formula for Axle Tread Variation Limit:

[ \Delta Tread \leq 0.20 \times \text{Tyre Sectional Width} ]

Weight Distribution Limits:

• Tyre load difference per axle:

[ \Delta W_{tyre} \leq 0.05 \times \text{Average tyre load} ]

• Axle load

IS 951 - Cabin and Crew Accommodation Key Points

Cabin Layout and Seating (Clause 7.13.1)

• Seating for 5 persons:
  • 2 adjustable seats (including driver)
  • 1 long fixed seat for 3 crew members
• Forward-mounted cabin with instrument panel and equipment arranged without hindrance.

Cabin Construction & Safety (Clause 7.13.3)

• Weatherproof, thermally & acoustically insulated with fire-resistant materials.
• Structure: unitized rigid body/frame or separate unit flexibly mounted.
• Cabin roof covered with aluminium chequered sheet with gutters to prevent water/foam entrapment.
• Designed for safety during vehicle rollover and heat exposure.

Visibility & Access (Clause 7.13.2)

• Windshield: shatterproof safety glass; other windows: approved safety glass.
• Wide gutters to prevent foam/water dripping on windows.
• Doors operable at 90° for easy ingress/egress.
• Space for crew (except driver) to wear protective clothing and breathing apparatus en route.

Summary Table of Cabin Requirements

Additional Notes:

• Manuals (Clause 8.5) must include operator, parts, repair manuals, and general arrangement drawings.
• Markings on vehicle body include fire service emblem, year, engine/chassis number, pump capacity, etc.

flowchart TD
    A[Cabin mounted forward] --> B[Seating for 5]
    B --> C{Seats}
    C --> D[2 adjustable seats]
    C --> E[1 fixed long seat for 3]
    A --> F[Weatherproof & insulated]
    F --> G[Fire-resistant materials]
    F --> H[Aluminium chequered roof with gutters]
    A --> I[

Key Formulas & Specifications for Pump and Foam Proportioning (IS 951)

Foam Induction Ratios:

• Induction ratios must be 3%, 6%, and 8% ± 0.5% variation.
• Once fixed, the ratio must remain consistent over the entire inductor setting range.

Pump Capacity & Pressure:

• Minimum pump output:
  • 4,000 l/min at 8.5 kg/cm² pressure with suction lift 1.5 m
  • 3,000 l/min at max 12.5 kg/cm² pressure for monitor operation (same suction mode)
• Pump driven by vehicle PTO, mid-ship mounted.

Foam Concentrate:

• Use AFFF or protein-based foam concentrate.
• Foam concentrate tanks must be separate and sized as per system requirements.

Automatic Proportioning System:

• Must support automatic induction with selectable ratios (3%, 6%, 8%).
• Should not require frequent calibration.
• Proportionator around the pump with clearly marked ratios.

Summary Table

flowchart LR
    Pump["Pump (4000 l/min @8.5 kg/cm²)"]
    FoamTank["Foam Concentrate Tank (Separate)"]
    Proportionator["Automatic Proportionator\n(3%, 6%, 8%)"]
    Monitor["Combination Monitor & Hand-lines"]

    FoamTank --> Proportionator
    Pump --> Proportionator --> Monitor

This setup ensures consistent foam induction across varying flow rates with reliable pump performance as per IS 951.

IS 951: Electrical and Lighting Equipment Key Points

1. Electrical Gadgets (Clause 7.28.1)

• Siren: 95 dB at 100 m, 90° side coverage, mounted on cabin roof, protected from foam, rain, dust.
• Flashing ray light/light bar: Roof mounted.
• Headlights: Selective beam pattern.
• Dual tail & stop lights.
• Signal lights: Four corners, visual + audible.
• Spotlights: Both ends of windshield, hand adjustable, 152 mm diameter.
• Reflectors & markers: Indicate vehicle dimensions.
• Reverse light: With audible warning.
• Panel, cabin, engine compartment, tools compartment lights.
• Inspection lamps: Two, with connection provisions.
• Fog lamps: Two, low mounted front.

2. Vehicle Electrical System (Clause 7.5)

• Designed for reliability under operational conditions.
• Includes power supply, wiring, and controls for above gadgets.

3. Equipment & Tools (Annex B)

• Includes insulated pliers (IS 3650), emergency lights, nozzles (IS 903), hose clamps (IS 5612), etc.
• Manuals required: Operator, Parts, Repair, and General Arrangement Drawings (Clause 8.5).

Summary Table: Lighting & Electrical Equipment

graph TD
    A[Electrical System] --> B[Siren 95 dB]
    A --> C[

IS 951 Key Specifications for Hoses & Nozzles

• Hose:

  • 30 m long rubber hose as per IS 636 (Non-percolating flexible fire fighting delivery hose).
  • Hose bandages and clamps as per IS 5612 (Parts 1 & 2) for securing and repairing hoses.

• Nozzles:

  • Squeeze grip nozzle for hose delivery (Clause 7.30.5).
  • Dual purpose jet diffuser nozzles with hand control and trigger as per IS 2871.
  • Light alloy branch pipe nozzles in sizes 12 mm and 19 mm as per IS 903.
  • Nozzle spanners as per IS 903 for fitting/removal.

• Pressure Release:

  • Filling/opening with suitable tight-fitting cap for overpressure release (Clause 7.30.5).

• Auxiliary Hand-lines:

  • Dry powder hand-lines with nozzles discharging 1.5 to 3 kg/s, 8 m range, made of non-ferrous or stainless steel (Clause 7.24.5).

Relevant IS Standards Summary Table

Hose & Nozzle Pressure Release Concept

flowchart LR
    A[Filling Opening] --> B[Pressure Release Valve]
    B --> C[Tight-fitting Cap]
    C --> D[Rubber Hose (IS 636)]
    D --> E[Squeeze Grip Nozzle]

Summary: Use 30 m IS 636 hose with squeeze grip nozzle, ensure pressure release via tight cap, and use nozzles per IS 903/287

IS 951: Access and Maintenance Key Points

Manuals to be Provided (Clause 8.5)

• Operator's Manual: Equipment layout, operation, commissioning, lubrication schedule, fault finding, storage, warnings.
• Parts Manual: Exploded views, sub-assemblies, part numbers, suppliers.
• Repair Manual: Repair/overhaul instructions, fitment tolerances, special tools.
• General Arrangement Drawings: Layout of equipment, piping, electric, structural design.

Markings on Vehicle Body

• Airport fire service, manufacture year, engine/chassis no., fire service emblem, job no., pump/tank capacities, chassis supplier, left-hand drive warning, precautionary instructions.

Access Doors (Clause 7.15.2)

• Provide access doors for:
  • Foam proportioning system
  • Battery storage
  • Fluid reservoirs
  • Engine oil level indicator

Piping and Controls (Clause 7.20.6)

• Piping must be accessible for maintenance.
• Drain cocks with vibration-proof controls.
• Valve/cock operation direction clearly marked.

Equipment List (Annex B)

• Includes suction strainers, hose clamps, nozzles, branch pipes, tools (axe, crowbar, hacksaw), emergency lights, insulated pliers, hydraulic cutters, etc.

Summary Table: Access & Maintenance Essentials

flowchart TD
    A[Vehicle Body] --> B[Access Doors]
    B --> C[Foam System]
    B --> D[Battery Storage]
    B --> E[Fluid Reservoirs]
    B --> F[Engine Oil Indicator]
    A --> G[Piping & Controls]
    G --> H[Drain Cocks]
    G --> I[Valve Markings]
    A --> J[Manuals]
    J --> K[Operator Manual]
    J --> L[Parts Manual]
    J --> M[Repair Manual]
    J --> N[General Arrangement Drawings]
``

IS 951 — Instrumentation and Controls: Key Points

Instruments & Warning Lights (Clause 7.14.4)

Minimum required instruments/warning lights include:

• Speedometer/Odometer
• Engine tachometer
• Fuel level indicator
• Air pressure indicator
• Engine temperature & oil pressure indicators
• Voltmeter
• Trafficator light
• Transmission oil temperature
• Pump pressure gauge (glycerin filled)
• Water & foam tank level indicators
• Low air pressure warning
• Headlight beam & hazard warning lights
• PTO engagement light
• Oil temperature gauge light

Illumination (Clause 7.14.2)

• All instruments and controls shall be illuminated, preferably with backlighting for visibility.

Manuals & Documentation (Clause 8.5)

• Operator manual with technical details, operation, maintenance, lubrication schedule, and fault finding.
• Parts manual with exploded views and part numbers.
• Repair manual with overhaul instructions and fitment tolerances.
• General arrangement drawings for equipment layout and controls.

Markings on Vehicle Body

• Airport fire service ID, manufacture year, engine/chassis numbers, fire service emblem, pump & tank capacities, chassis supplier, left-hand drive warning, and precautionary instructions.

Typical Instrument Panel Layout (conceptual):

graph LR
A[Speedometer] --> B[Engine Tachometer]
B --> C[Fuel Level Indicator]
C --> D[Air Pressure Indicator]
D --> E[Engine Temp & Oil Pressure]
E --> F[Voltmeter]
F --> G[Pump Pressure Gauge]
G --> H[Water & Foam Tank Levels]
H --> I[Warning Lights]

Note: For detailed specs on instruments, controls, and accessories, refer to IS 951 clauses 7.14 and 8.5, and related IS standards listed for fire fighting equipment.

IS 951 - Performance Requirements Summary (Clause 6.4 & related)

Additional Notes:

• Pump Capacity: Minimum 4000 l/min at 8.5 kg/cm².
• Drive: Preferably all wheels, right-hand drive.
• Rims, Tyres, and Inflation Pressures: Must be approved by the manufacturer to meet performance.
• Markings on Vehicle: Fire service emblem, manufacturing year, engine/chassis no., capacity details, etc.

Diagram: Vehicle Performance Parameters Overview

graph TD
  A[Performance Requirements] --> B[Acceleration]
  A --> C[Speed]
  A --> D[Clearances]
  A --> E[Angles & Slopes]
  A --> F[Braking]
  B --> B1[Class 1: 0-80 kmph in 25s]
  B --> B2[Class 2+: 0-80 kmph in 40s]
  C --> C1[Max Speed: 100 kmph]
  D

IS 951: Manufacturer's Certificate and Guarantee – Key Points

• Clause 8.1: Manufacturer must provide a certificate confirming appliance compliance with all specifications.
• Clause 8.2: A 12-month guarantee is mandatory, covering:
  • Material quality
  • Workmanship
  • Smooth functioning of the vehicle
• Guarantee period starts from delivery at consignee’s place.
• Clause 8.3: Manufacturer must replace any parts that fail due to:
  • Defective/sub-standard materials
  • Poor workmanship
• Replacement is free of charge during guarantee period.
• Clause 7.32.3 & Annex B: Appliance must be supplied with:
  • Instruction book
  • Spare parts catalogue
  • Repair manual

Summary Table: Manufacturer's Guarantee Requirements

flowchart TD
    A[Manufacture Appliance] --> B[Provide Certificate (8.1)]
    B --> C[Supply Documentation (7.32.3)]
    C --> D[12-month Guarantee Starts (8.2)]
    D --> E{Parts Fail?}
    E -- Yes --> F[Replace Free of Charge (8.3)]
    E -- No --> G[End of Guarantee Period]

IS 951: Documentation & Spare Parts - Key Points

Documentation (Clause 8.5)

• Operators Manual: Technical description, layout drawings, performance, commissioning instructions, maintenance, lubrication schedule, fault finding, storage, warnings.
• Parts Manual: Exploded views of superstructure & sub-assemblies, part numbers, sources.
• Repair Manual: Illustrated repair/overhaul instructions, fitment tolerances, special tools, dismantling procedures.
• Drawings: Complete general arrangement drawings (equipment layout, piping, fluid controls, electric, structural).

Markings on Vehicle Body

• Airport fire service, year, engine/chassis number, fire service emblem, job/SI No., pump & tank capacities, chassis supplier, left-hand drive warning, precautionary instructions.

Spare Parts (Clause 7.29.2 & 7.32.3)

• Adequate spares for 3 years.
• Manuals and diagrams in English with standardized symbols.
• Manuals mounted to resist vibration, noise, and electromagnetic induction.

Equipment to be Carried (Annex B - Selected Items)

Summary Diagram: Documentation & Spare Parts Flow

flowchart TD
    A[Equipment Supplied] --> B[Documentation]
    B --> B1[Operators Manual]
    B --> B2[Parts Manual]
    B --> B3[