Sizing a crane is a short list of questions. Get the answers right and the crane fits the building, the work and the budget. Get them wrong and you pay later in repairs, or you cannot lift what you need.
1. Capacity (SWL)
Add up the heaviest load, the lifting beam or sling, and the hook block. Then think about growth: will heavier dies, coils or machinery come in the next five to ten years? Choose a main hoist for the heaviest lift and, if useful, an auxiliary hoist for lighter, faster lifts. We manufacture up to 300 T.
2. Span
The span is the distance between the rail centres. It sets girder length and, with capacity, girder size. Measure the building, not the crane; our DG cranes go up to 40 m span. Leave room for end carriages and cabin.
3. Duty class
Duty describes how often the crane lifts and at what share of its capacity. IS 3177 groups cranes into duty classes (we build up to M8). A crane lifting near its rating many times each hour needs a higher class than one that lifts occasionally. Underrating duty is the most common sizing error.
4. Headroom and hook approach
Headroom is the distance from the rail top to the highest obstruction, usually a roof truss. The crane, its trolley and hoist must fit in it, with the hook still reaching the height you need. Hook approach is how close the hook can get to the wall at each end and side. A short hook approach wastes floor space. Our design aims for minimum headroom and maximum hook approach.
5. Lift height (hook path)
From the floor to the highest hook position you need. Our cranes lift up to 50 m.
6. Speeds and control
Hoisting, cross travel and long travel speeds suit the work: precise placing needs slow speeds, while long runs need higher ones. Variable-speed drives (VFD) give smooth motion at both ends. Choose pendant, radio remote or a cabin by how the operator sees the load. Speeds go up to 90 m/min.
7. Indoor, outdoor or hazardous area
Outdoor cranes need weather protection and often a gantry structure. Hazardous areas need flame-proof equipment. Tell us the environment, including heat, dust, corrosion and the temperature range.
8. Power supply and conductor system
State the voltage and frequency available. We supply shrouded DSL bus bars or cable festooning, and a trailing system where needed.
9. Building and runway
Check the runway girders, columns and foundations, or have us check them. A new crane adds wheel loads to an old structure.
10. Standards and testing
Every crane is load tested at 100% and 125% of SWL, with Form 10 in Gujarat or the equivalent form in other states.
What to send us
Capacity of the main and auxiliary hoist, span, hook path, runway length, indoor or outdoor, lifts per hour and typical load, speeds and control, power supply and site location.
Frequently asked questions
- Should I buy a larger crane than I need?
- Some margin is sensible, but a much larger crane costs more to build and runs slower. Size to the real heaviest load plus planned growth.
- Is single or double girder right for me?
- See "Single girder or double girder".
- Can you check my building?
- Yes, as part of a site survey.