Code of practice for design and construction of fire service drill-tower

IS 5888: Introduction - Key Specifications & Tables

Types of Drill Towers (Clause 3.1)

• Type A: Masonry, large fire stations, no hose drying, no smoke chambers.
• Type B: Masonry, small/medium stations, hose drying, can be smoke chambers.
• Type C: Steel, small/medium stations, hose drying, can be smoke chambers.
• Type D: Steel, small/medium stations, hose drying & drill, no smoke chambers, max hose length for drying: 25 m.

Floor Dimensions (Clause 6.4.2)

• Overall internal floor: 4.5 m × 4.5 m
• Clear drill area: 4.5 m × 2.25 m
• Remaining area for hose drying (partition wall thickness deducted)

Drainage (Clause 6.6.5)

• Drains from each floor to external drainage system.

Recommended Timber Species for Window Sills & Hose Toggles

*Treatability Grades:
A = easily treatable, B = treatable, C = partially treatable, D = refractory, E = very refractory

Summary Diagram of Tower Types

graph TD
A[Type A: Masonry, Large] -->|No hose drying| NoSmokeChamber
B[Type B: Masonry, Small/Medium] -->|Hose drying| SmokeChamber
C[Type C: Steel, Small/Medium] -->|Hose drying| SmokeChamber
D[Type D: Steel, Small/Medium] -->|Hose drying & drill| NoSmokeChamber

For detailed structural design, use relevant IS codes for steel, bolts, reinforcement, and aggregates as referenced in IS 5888.

IS 5888 Scope Summary & Key Specifications

• Scope (Clause 3.1): Covers functional design of four types of drill-towers for fire stations:

  • Type A: Masonry, large stations, no hose drying or smoke chamber.
  • Type B: Masonry, small/medium stations, hose drying, smoke chamber use.
  • Type C: Steel, small/medium stations, hose drying, smoke chamber use.
  • Type D: Steel, small/medium stations, hose drying with central suspension, no smoke chamber; floor area adaptable by removable boards.

• Floor Dimensions (Clause 6.4.2):

  • Overall internal floor: 4.5 m × 4.5 m
  • Drill area: 4.5 m × 2.25 m
  • Remaining area (less partition thickness) for hose drying

• General Functional Requirements: Clauses 6.2.1 to 6.2.11 apply to all tower types.

Key Notes on Materials & Bolts (Referenced Standards)

• Structural steel: Ordinary quality
• Bolts/nuts: Black hexagon & square bolts/nuts (6–39 mm diameter)
• Reinforcement: Mild steel, medium tensile steel bars, hard-drawn steel wire
• Aggregates & sand: For concrete/masonry mortars

Diagram: Functional Layout of Type D Tower Floor

graph TB
    A[4.5m x 4.5m Floor]
    A --> B[Drill Area 4.5m x 2.25m]
    A --> C[Hose Drying Area]
    C --> D[Central Hose Suspension]
    B --> E[Removable Boards for Floor Area Adjustment]

For detailed design, refer to IS 5888 clauses 6.2 & 6.4 and related material standards.

IS 5888: Key Material Specifications and References

• Mild Steel Flats and Sections (Clause 2.5):
  Use mild steel conforming to IS: 1977-1962 (Steel St. 32-0) for ladders and steel tower structure.

• Reinforcement Steel (Clause 2.7):
  Steel reinforcement must comply with one of these standards:

  • IS: 432 (Part I & II) - 1966 (Mild steel and medium tensile steel bars)
  • IS: 1139-1966 (Cold twisted bars)
  • IS: 1566-1966 (Hard-drawn steel wire)
  • IS: 1786-1966 (High strength deformed bars)

• Cement (Clause 2.4):
  Cement shall conform to:

  • IS: 269-1967 (Ordinary Portland Cement)
  • IS: 455-1967 (Portland slag cement)

• Material Strength Considerations (Clause 2.1):
  Strength must be calculated based on the drill tower design and use.

Typical Material Strength Values (for reference)

flowchart TD
    A[Materials] --> B[Mild Steel - IS 1977]
    A --> C[Reinforcement - IS 432, 1139, 1566, 1786]
    A --> D[Cement - IS 269, IS 455]
    B --> E[Used for ladders & tower structure]
    C --> F[Used for concrete reinforcement]
    D --> G[Used for concrete mix]

Summary: Use locally available materials meeting IS standards for strength and durability. Mild steel per IS 1977, reinforcement per IS 432/1139/1566/1786, and

IS 5888: Types of Drill-Towers – Key Specifications & Design References

The code classifies drill-towers into four types (A, B, C, D), each with specific design provisions:

General Design Considerations (Clause 6.2)

• Structural stability under wind and operational loads
• Material specifications and member sizing
• Foundation requirements

Typical Design Formulae (General)

• Wind Load, W = 0.6 × V² × A × Cd
  Where:

  • V = design wind speed (m/s)
  • A = projected area (m²)
  • Cd = drag coefficient (from IS 875 Part 3)

• Buckling check for compression members:
  [ f_{allow} = \frac{f_y}{\text{Factor of Safety}} \quad \text{and} \quad \lambda = \frac{L_{eff}}{r} ] Use Euler's formula or IS 800 for slenderness limits.

Summary Table of Drill-Tower Types

IS 5888: Site Selection and Location - Key Specifications & Tables

1. Foundation Requirements (Clause 5.2)

• Foundation must be on a hard bed.
• Must be heavy enough to prevent toppling under wind loads.
• Superstructure preferably bolted to steel posts embedded in heavy concrete.
• Cross pieces at bottom ends for stability.

2. Drainage (Clause 6.6.5)

• Drains required on each floor of drill section.
• Drains must connect to external drains (Clause 6.2.9).

3. Internal Platform Sizes (Clause 6.2.2)

4. Recommended Timber Species for Window Sill & Hose Toggles

Treatability Grades:

• A: Easily treatable
• B: Treatable but incomplete penetration
• C: Partial treatability
• D: Refractory; incision needed
• E: Very refractory; negligible penetration

Summary Diagram: Site Selection & Structural Stability

graph TD
A[Site Selection] --> B[Hard Bed Foundation]
B --> C[Heavy Foundation to Resist Toppling]
C --> D[Steel Posts Embedded in Concrete]
D --> E[Superstructure Bolted to Posts]
A --> F[Drainage System]
F --> G[Drains on Each Floor]
G --> H[Connection to External Drain

IS 5888: Foundation Design Key Points

Foundation Requirements (Clauses 5.1 & 5.2):

• Foundations must rest on a hard soil bed.
• Must be heavy enough to prevent toppling under wind loads.
• Steel tower superstructures should be bolted to steel posts embedded in heavy concrete with cross pieces at the base.
• Foundation design varies with soil strata and must comply with IS 1904-1966 (Code of Practice for Structural Safety of Buildings: Foundations).

Relevant IS Codes for Materials:

• Aggregates for concrete: IS 383-1963
• Steel reinforcement: IS 1786 (hot-rolled deformed bars)
• Bolts & nuts: IS 1363 (black hexagon bolts), IS 1364 (black square bolts)

Foundation Design Summary:

Typical Foundation Stability Check:

[ \text{Overturning Moment} \leq \text{Resisting Moment} ]

• Resisting moment from foundation weight ( W ) and lever arm ( d ):

[ M_r = W \times d ]

• Overturning moment from wind load ( F_w ) and height ( h ):

[ M_o = F_w \times h ]

Ensure: ( M_r \geq M_o )

Illustration: Foundation Stability Concept

graph LR
A[Wind Load (F_w)] -->|Moment M_o| B((Tower Top))
B -->|Height h| C[Foundation Base]
C -->|Resisting Moment M_r| D[Foundation Weight W]

Note: For detailed design, refer to IS 1904 for soil parameters and IS 456 for concrete design.

IS 5888: Design Considerations for Fire Service Drill Towers

General (Clause 6.2)

• Structural stability for wind and live loads.
• Use of durable materials resistant to weather.
• Provision for safe access and egress.
• Removable gratings and wooden shutters for openings.
• Steel uprights fixed in ground for tying ropes.

Type-wise Specifics:

Key Specifications:

• Removable Grating: For floor openings, ensuring safety and easy access.
• Horizontal Rail: 750 mm high steel rail fixed on uprights for hose hoist ropes.
• Window Planks: 50 mm thick, 375 mm wide hardwood planks.
• Materials: Use of hardwood or light alloy sheets for slats and shutters.

Structural Design Focus:

• Load calculations for live, wind, and operational loads.
• Stability against overturning and sliding.
• Safe anchorage of ladders and rails.

flowchart LR
    A[General Design Considerations] --> B[Type A Drill Tower]
    A --> C[Type C Drill Tower]
    A --> D[Type D Drill Tower]
    B --> E[Wooden Slats & Hinged Doors]
    C --> F[Removable Wooden Shutters]
    D --> G[Enhanced Structural Details]

For detailed load formulas and material specs, refer to IS 875 (Loads) and IS 800 (Steel Structures).

IS 5888: General Functional Requirements for Drill-Towers

Key Points from Clause 6.2 (General Functional Requirements):

• Applies to all types of drill-towers (Type A, B, C, D).
• Ensures towers meet functional needs for fire service training and hose drying.
• Design must consider:
  • Structural integrity.
  • Hose drying arrangements.
  • Smoke-chamber provisions (where applicable).
  • Floor area usability.
  • Height adequacy for hose length (max 25 m for Type D).

Types of Drill Towers (Clause 3.1):

Functional Design Requirements Summary (6.2.1 to 6.2.11):

• Adequate floor space for drills.
• Provision for hose drying racks or suspensions.
• Structural safety per relevant steel and masonry standards.
• Accessibility and safety for firefighters.
• Use of removable boards for flexible floor use (Type D).
• Compliance with material specifications (steel, bolts, concrete reinforcement).

Typical Functional Dimensions (from figures referenced):

• Tower height: Sufficient to accommodate hose length plus clearance.
• Floor area: Large enough for simultaneous drills.
• Hose drying sections: Central or side arrangements depending on type.

Summary Diagram:

flowchart LR
    A[Drill Tower Types]
    A -->|Type A| B[Masonry, Large Stations]
    A -->|Type B| C[Masonry, Small/Medium Stations]
    A -->|Type C| D[Steel, Small/Medium Stations]
    A -->|Type D| E[Steel, Small/Medium Stations]

    B --> F[No Hose Drying]
    B --> G[No Smoke Chamber]

    C --> H[Hose Drying Available]
    C --> I[Smoke Chamber

IS 5888 - Type 'A' Drill-Tower Design Key Points (Clause 6.3)

• General Design: Follow Clause 6.2 general provisions plus 6.3.1 to 6.3.5 specific to Type 'A'.

• Representative Design: Refer Fig. 1 for typical geometry and member layout.

• Structural Elements: Usually consists of vertical legs, bracing, and platforms designed to resist drilling loads and wind forces.

• Load Considerations: Include self-weight, drilling equipment loads, wind pressure (as per IS 875), and dynamic effects.

• Key Design Checks:

  • Axial load capacity of legs.
  • Buckling checks for compression members.
  • Shear and bending in bracing.
  • Connection design per IS 800.

• Typical Formulas:

  • Axial Load Capacity: [ P_u = A \times f_y / \gamma_m ] where ( A ) = cross-sectional area, ( f_y ) = yield strength, ( \gamma_m ) = partial safety factor.

  • Buckling Load (Euler's formula): [ P_{cr} = \frac{\pi^2 E I}{(K L)^2} ] where ( E ) = modulus of elasticity, ( I ) = moment of inertia, ( K ) = effective length factor, ( L ) = unsupported length.

• Typical Bracing Layout:

graph TD
    A[Leg 1] --- B[Bracing]
    B --- C[Leg 2]
    C --- D[Bracing]
    D --- A

For detailed dimensions and member sizes, refer to Fig. 1 and tables under Clause 6.3.1-6.3.5 in IS 5888.

Summary: Design Type 'A' drill towers by combining IS 5888 Clause 6.2 general rules with specific checks in 6.3, focusing on axial, buckling, and bracing strength, using standard structural formulas and representative layouts.

IS 5888 - Type 'B' Drill-Tower Design (Clause 6.4)

Type 'B' Drill-Tower is a lattice structure designed for drilling operations, with specific provisions in Clauses 6.4.1 to 6.4.5 supplementing general design rules in 6.2.

Key Specifications & Design Considerations:

• Geometry: Refer Fig. 2 (IS 5888) for typical dimensions and bracing layout.
• Loadings: Design for axial loads, wind loads, and drilling equipment loads per Clause 6.2.
• Material: Use steel with specified yield strength and corrosion protection.
• Bracing: Cross-bracing to resist lateral loads as per 6.4.3.
• Connections: Bolted or welded joints designed for load transfer (6.4.4).
• Foundation: Adequate to resist overturning moments and vertical loads (6.4.5).

Typical Formulae:

• Axial Load Capacity:
  ( P = A \times f_y )
  Where:

  • ( A ) = cross-sectional area
  • ( f_y ) = yield strength of steel

• Wind Load:
  ( W = C_w \times A_p \times V^2 )
  Where:

  • ( C_w ) = wind pressure coefficient
  • ( A_p ) = projected area
  • ( V ) = design wind velocity

Summary Table (Example):

graph TD
A[Base Plate/Foundation] --> B[Vertical Legs]
B --> C[Horizontal Bracing]
B --> D[Diagonal Bracing]
C --> D
D --> E[Top Platform/Drilling Equipment]

For detailed dimensions and member sizing, refer directly to Fig. 2 and Clauses 6.4.1 to 6.4.5 in IS 5888.

IS 5888 — Type 'C' Drill-Tower Design (Clause 6.5)

Type 'C' drill-tower is a lattice structure designed for drilling operations, with specific provisions beyond general design (Clause 6.2). Key points:

Key Specifications:

• Geometry & Configuration: Refer Fig. 3 for typical bracing and member layout.
• Load Considerations: Includes self-weight, drilling loads, wind, and dynamic effects.
• Material: Use structural steel as per IS standards.

Important Design Provisions (6.5.1 to 6.5.3):

• Member Sizing: Based on axial and bending stresses using:

  [ \sigma = \frac{P}{A} + \frac{M}{Z} \leq f_y ]

  Where:

  • (P) = axial load,
  • (A) = cross-sectional area,
  • (M) = bending moment,
  • (Z) = section modulus,
  • (f_y) = yield strength of steel.

• Bracing: Adequate bracing to prevent buckling, designed per IS 800.

• Connections: Bolted or welded as per IS 800, ensuring load transfer and stability.

Typical Member Design Table (Example):

graph TD
A[Base] --> B[Leg Members]
B --> C[Bracing Members]
C --> D[Top Platform]

For detailed dimensions and load factors, always refer to IS 5888 Fig. 3 and clauses 6.5.1–6.5.3.

IS 5888 - Type 'D' Drill-Tower Design (Clause 6.6)

Type 'D' drill-towers are designed per general provisions in Clause 6.2 plus specific rules in 6.6.1 to 6.6.5. Key aspects include:

Key Design Considerations:

• Structural Configuration: As per Fig. 4 (not shown here), typically a lattice tower with bracing.
• Loadings: Wind, drilling equipment, and dynamic forces must be considered.
• Member Design: Use IS 800 for steel design; ensure adequate section modulus and slenderness limits.
• Bracing and Stability: Must comply with lateral stability requirements.
• Foundation: Designed for combined axial and lateral loads.

Important Formulas:

• Axial Load Capacity (P):
  [ P = A \times f_y / \gamma_m ] where (A) = cross-sectional area, (f_y) = yield strength, (\gamma_m) = partial safety factor.

• Buckling Check:
  [ \sigma_{allow} = \frac{\pi^2 E}{(K L/r)^2} ] where (E) = modulus of elasticity, (K) = effective length factor, (L) = member length, (r) = radius of gyration.

Typical Specifications:

Summary Diagram (Conceptual):

graph TD
A[Base Foundation] --> B[Lattice Legs]
B --> C[Horizontal Bracing]
C --> D[Diagonal Bracing]
D --> E[Top Derrick]

Note: Refer IS 5888 Clause 6.6 and Fig. 4 for detailed geometry and member sizing. Use IS 800 for member design and IS 875 for load calculations.

IS 5888: Drainage and Safety Features Key Points

Drainage Specifications

• Slope of Yard Surface (6.2.9):
  Yard surface at drill-tower base must slope gently away towards a grating-covered channel for efficient drainage.

• Floor Drains (6.3.5 & 6.4.4.3):
  Each floor of the tower and drill section shall have drains arranged to flow into the external drain channel at the base.

Safety Features (from Figures & Clause 1.2)

• Removable Gratings:
  Openings on all floors must be covered with removable wooden shutters or gratings to prevent falls but allow emergency access.

• Railings & Hoist Ties:
  750 mm high horizontal rails fixed on steel uprights for tying ropes for hose hoists ensure safety during drills.

• Entry and Egress:
  Entry via MS ladders; hinged wooden doors and wooden slats/light alloy sheets for windows provide controlled access and ventilation.

Summary Table: Drainage and Safety Elements

flowchart TD
    Yard_Surface -->|Slope| Grating_Channel
    Floor_1 -->|Drain| External_Drain
    Floor_2 -->|Drain| External_Drain
    External_Drain --> Drainage_System
    Safety_Features --> Railings
    Safety_Features --> Gratings
    Safety_Features --> Entry_Ladders

This ensures efficient drainage and user safety during fire service drills.

Key Electrical Wiring & Installation Specifications from IS 5888

• Internal Wiring: Must comply with IS 732:1963 (Code of practice for electrical wiring installations up to 650 V).
• Floor Dimensions (Clause 6.4.2):
  • Overall internal floor: 4.5 m × 4.5 m
  • Clear drill area: 4.5 m × 2.25 m
  • Remaining area (minus partition thickness) for hose drying.
• Drainage (Clause 6.6.5): Drains provided on each drill floor to external drains.
• Timber for Electrical Fixtures: Recommended species for window sills and hose toggles with treatability classes (A to E) indicating ease of preservative treatment.

IS 732:1963 - Electrical Wiring Highlights

Typical Wiring Formula for Current Capacity (approximate):

[ I = k \times A ]

• (I) = current in amperes
• (A) = cross-sectional area in mm²
• (k) = constant depending on insulation and installation method (e.g., 6-10 A/mm² for copper)

Summary Diagram: Wiring & Floor Layout

graph TD
    A[Internal Floor 4.5m x 4.5m]
    A --> B[Drill Area 4.5m x 2.25m]
    A --> C[Hose Drying Area (Remaining)]
    B --> D[Electrical Wiring per IS 732]
    C --> E[Drain to External Drain]

Note: For detailed wiring design, consult IS 732:1963 and ensure all wiring is done by qualified personnel following safety norms.

IS 5888: Timber Specifications & Recommended Species for Window Sill Facing and Hose Suspension Toggles

Key Clauses:

• Clause 2.10: Use well-seasoned hardwood for window sill facings and hose suspending toggles.
• Clause 6.2.8: Window sill facing thickness: 50 mm hardwood plank, securely bolted or clamped.

Recommended Timber Species (Appendix A)

*Treatability Grades:

• A: Easily treatable heartwood
• B: Treatable, but incomplete penetration
• C: Partially treatable
• D: Refractory; requires incision for treatment
• E: Very refractory; minimal penetration

Summary:

• Use 50 mm thick hardwood planks for window sill facings.
• Select timber species from the above table based on availability and treatability.
• Ensure timber is well-seasoned and treated according to its treatability class for durability.

flowchart TD
    A[Window Sill Facing] --> B[50 mm Hardwood Plank]
    B --> C{Select Timber Species}
    C --> D[Teak (E)]
    C --> E[Sissoo (E)]
    C --> F[Deodar (C)]
    C --> G[Hollock (A)]
    C --> H[Others (Refer Appendix A)]