Overhead Crane Calculator

Preliminary design chain for a double-girder overhead (EOT) crane — from rated load through wheel & impact loads, girder bending moment and deflection, to hoist-rope, motor and running-gear sizing.

ModuleOverhead CraneMethodImpact Load ChainVersion1.0.0

Crane Parameters

Load & Duty

Rated Load / SWL

Impact Factor (φ)

Number of Wheels

Dead Weight Components (kg)

Bridge (W_b)

Trolley (W_t)

Hoist (W_h)

End Carriage (both)

Miscellaneous

Bridge Girder & Deflection

Span (S)

Modulus of Elasticity (E)

N/mm²

Girder Moment of Inertia (I)

mm⁴

Deflection Limit (S / ratio)

S /

Hoist Rope

Safety Factor (SF)

Rope Constant (K)

Motor & Running Gear

Motor Torque (T)

N·m

Motor Speed (N)

rpm

Efficiency (η)

Wheel Constant (K)

Results

Ready to compute?

Enter your crane parameters and press Calculate Crane Design

Reference Codes & Standards

IS 3177Governing Code

Code of Practice for Electric Overhead Travelling Cranes & Gantry Cranes (other than steel works)

Scope:Duty classification, hook approach and design load conventions.

IS 807Governing Code

Design, Erection & Testing of Cranes & Hoists

Scope:Structural design factors and permissible girder deflection limits.

CMAA 70-2025Governing Code

Specifications for Top Running Bridge & Gantry Multiple Girder Cranes

Scope:Impact/load factors, wheel loads and structural design of the bridge.

FEM 1.001Governing Code

Rules for the Design of Hoisting Appliances

Scope:Crane group classification and dynamic (impact) coefficients.

Literature & Further Reading

[1]Rudenko, N. Materials Handling Equipment — overhead crane girder design.
[2]Gorla & Khan, Mechanical Design of Machine Elements — wire rope & drive sizing.
[3]IS 3177 / IS 807 — governing Indian codes for the classification & deflection limits.
[4]Shapiro, H. Cranes and Derricks — practical crane engineering.

Engineering Tips

CMAA 70 / IS 3177 Design Steps:

Total Design Load: SWL × φ + Dead Weight.
Girder Bending Moment: M_max = P × S / 4 (center-span point load).
Deflection Check: δ_max ≤ S/800 (or S/600 for lighter duty).
Hoist Rope: Safety factor ≥ 5; MBL = Total Lift Load × SF.
Hoist Motor Power: P = (Total Lift Load × V_lift) / (6.12 × η).

CMAA Crane Classes:

Class	Service	Deflection
A–B	Standby / Light	S/600
C–D	Moderate / Heavy	S/800
E–F	Severe / Continuous	S/1000

Preliminary sizing only — confirm all results against IS 3177 / IS 807 / CMAA 70 / FEM.

Safety Factors

Structure (Bridge)1.5 – 2.0
Wire Rope5 – 7
Hook3 – 5

General guideline — always follow the governing standard.