Walk into any fabrication shop, steel plant, cement facility or warehouse in India and look up. That steel bridge running across the roof, carrying a hook that can lift several tonnes without a single person straining a muscle, is an EOT crane. It is one of the most widely used pieces of material handling equipment in industry, and for good reason: it moves heavy loads vertically and horizontally across an entire work area without occupying a square inch of floor space.
But here is where most buyers go wrong. They ask for "a 10 tonne crane" and stop there. An EOT crane is not a single product. It is a category with several distinct configurations, each engineered for a different combination of load, span, lift height, duty cycle and working environment. Choose a single girder crane where a double girder was needed and you will be replacing it within five years. Over-specify in the other direction and you have spent lakhs on capacity and civil structure you will never use.
Understanding the different types of EOT crane is what separates a purchase that runs reliably for two decades from one that becomes a maintenance headache. This guide breaks down every major EOT crane type, the specifications that actually matter, how EOT cranes compare to other overhead crane types, and the practical factors that should drive your selection.
What is an EOT Crane?
EOT stands for Electric Overhead Travelling crane. Break the name down and the machine explains itself:
- Electric - all motions are driven by electric motors, not manual chain pulls or hydraulics
- Overhead - the crane operates above the workspace, on runway beams mounted along the building columns
- Travelling - the entire bridge travels along the length of the bay
An electric overhead travelling crane performs three independent motions:
- Hoisting - the hook raises and lowers the load vertically
- Cross Travel (CT) - the trolley or crab moves across the width of the bay, along the bridge girder
- Long Travel (LT) - the whole bridge moves along the length of the bay, on the runway rails
Together, these three motions give the hook access to almost every point inside a rectangular working volume. That three-dimensional coverage is the core value of an overhead crane and the reason it remains irreplaceable in heavy industry.
The main structural components are the bridge girder (single or double), the end carriages that carry the travel wheels, the hoisting mechanism (a wire rope hoist, an electric chain hoist on lighter duties, or an open winch crab), the runway rails and their support structure, the electrical panel and drives, and the current collection system that feeds power to a machine that never stops moving.
Common applications across industries
Electric overhead cranes appear wherever heavy or awkward loads need repeated movement:
- Steel plants and rolling mills - ladle handling, coil handling, slab and billet movement, scrap charging
- Heavy fabrication and engineering - moving fabricated assemblies between welding, machining and paint bays
- Foundries - pouring molten metal, handling moulds and castings in extreme heat
- Automotive and manufacturing - die handling for press shops, machine loading, assembly line support
- Cement, power and process plants - turbine hall maintenance, mill and crusher servicing, equipment erection
- Warehousing and logistics - container and palletised load handling, roll and coil storage
- Paper, textile and plastics - roll handling, mould changing on injection moulding machines
- Shipyards and railway workshops - hull sections, bogie and wheelset handling
The common thread is repetition. A forklift can move a load once. An EOT crane moves loads hundreds of times a shift, on a fixed path, safely, at a fraction of the operating cost.
Types of EOT Cranes
EOT cranes are classified along several different axes, and this is where most comparison articles cause confusion. A single crane can be described as a double girder, top-running, cabin-operated, Class III crane - all four labels are correct and describe different aspects of the same machine.
Here are the classification systems that matter:
1. By girder configuration
- Single girder EOT crane - one bridge girder, hoist runs underneath
- Double girder EOT crane - two bridge girders, crab runs on top
2. By degree of electrification
- Manual / Hand Operated Travelling (HOT) crane - all three motions operated by hand chains, suitable for very light, infrequent use
- Semi-EOT crane - hoisting is electric, cross travel and long travel are manual (or one motion manual)
- Full EOT crane - all three motions electrically driven, the standard industrial configuration
3. By runway arrangement
- Top-running EOT crane - end carriage wheels run on rails fixed on top of the runway girders. The most common arrangement, supports the highest capacities
- Under-running / underslung EOT crane - wheels run on the bottom flange of the runway beam, which can be hung directly from the roof structure. Saves headroom and avoids building a separate runway girder, but capacity is typically limited to around 10 tonnes
4. By structure type
- Gantry crane (Goliath crane) - the bridge sits on two legs that run on rails at ground level, used in open yards where no building structure exists
- Semi-gantry crane - one end runs on an elevated runway inside the building, the other on a leg at floor level
- Wall-travelling crane - a bracket-mounted crane that travels along one wall, often used as a secondary crane under a main bay crane
- Monorail hoist - a single beam with a hoist that only traverses, no bridge travel
5. By application and lifting attachment
- Hook type crane - standard configuration with a single or ram's horn hook
- Grab bucket crane - fitted with a mechanical or motorised grab for bulk material such as coal, scrap or aggregates
- Magnet crane - an electromagnet lifts ferrous scrap, plates and billets
- Ladle crane - heavy duty, Class IV crane for molten metal in steel plants, built with redundant braking and heat shielding
- Flameproof (FLP) crane - explosion-protected electrics for chemical, paint and petrochemical plants
- Clean room crane - low-particulate design for pharma and electronics facilities
Quick comparison of the main EOT crane types
| Parameter | Single Girder | Double Girder | Underslung | Gantry |
|---|---|---|---|---|
| Typical capacity | 0.5 – 20 T | 5 – 500 T | 0.5 – 10 T | 2 – 100 T |
| Typical span | 5 – 25 m | 10 – 40 m | 3 – 15 m | 10 – 35 m |
| Hook height utilisation | Moderate | Excellent | Very good | Good |
| Duty class | Class I – II | Class II – IV | Class I – II | Class I – III |
| Dead weight | Low | High | Low | High |
| Civil/structural cost | Low | High | Lowest | Rail foundation needed |
| Speed capability | Moderate | High | Moderate | Moderate |
| Relative cost | ₹ | ₹₹₹ | ₹₹ | ₹₹₹ |
Single Girder EOT Crane
A single girder EOT crane uses one bridge girder spanning between two end carriages. The hoist - usually a standard electric wire rope hoist or an electric chain hoist - is mounted on the lower flange of that girder and travels along it in an underslung arrangement.
Specifications
| Specification | Typical Range |
|---|---|
| Capacity | 0.5 T to 20 T (up to 25 T in special designs) |
| Span | 5 m to 25 m |
| Lift / hook height | 6 m to 20 m |
| Hoisting speed | 3 – 8 m/min, with 0.5 – 1 m/min micro speed |
| Cross travel speed | 10 – 20 m/min |
| Long travel speed | 15 – 30 m/min |
| Duty class | IS 3177 Class I – II (FEM M3 – M5) |
| Girder section | Rolled I-beam or fabricated box / plate girder |
| Control | Pendant push button or radio remote |
| Power supply | 415 V, 3 phase, 50 Hz with 110 V control |
Advantages
Lower total cost of ownership. The single girder crane weighs considerably less than an equivalent double girder machine. That reduced dead weight means lighter runway girders, lighter columns and lighter foundations. The savings on the civil and structural side often exceed the savings on the crane itself.
Faster delivery and simpler installation. A single girder crane with a standard hoist is a largely catalogue-driven product. Manufacturing lead times are shorter and erection at site is quicker.
Easier maintenance. Standard wire rope hoists are modular. A hoist can be lowered, serviced or replaced without dismantling the bridge structure. Spares are widely available and inexpensive.
Good headroom in low buildings. Because the girder sits above the hoist rather than beside it, the crane can often fit into buildings with limited clearance between the runway and the roof truss. For very light, localised lifting in the same kind of low-clearance bay, a jib crane is often the cheaper option.
Limitations
Hook approach on the sides is restricted by the end carriage, which reduces usable span at the extremes. Maximum hook height is lower than a double girder crane of the same building height, because the hoist hangs below the girder. There is no walkway on the girder, so maintenance access requires a man-lift or scaffolding. Duty class is limited - a single girder crane is not the right choice for continuous, multi-shift heavy operation.
Typical applications
Light and medium fabrication shops, machine shops, assembly lines, warehouses, workshop maintenance bays, water treatment plants, packaging units, plastic and injection moulding facilities, and any application with intermittent lifting below 20 tonnes.
Double Girder EOT Crane
A double girder EOT crane uses two parallel bridge girders. Rails are mounted on top of both girders, and a crab - a self-contained trolley carrying the hoisting drum, gearbox, motor and brakes - runs on those rails. This is the workhorse configuration of heavy industry.
Specifications
| Specification | Typical Range |
|---|---|
| Capacity | 5 T to 500 T (higher for special process cranes) |
| Span | 10 m to 40 m |
| Lift / hook height | 8 m to 40 m and above |
| Hoisting speed | 2 – 10 m/min main, 6 – 15 m/min auxiliary |
| Cross travel speed | 15 – 30 m/min |
| Long travel speed | 20 – 60 m/min |
| Duty class | IS 3177 Class II – IV (FEM M5 – M8) |
| Girder section | Fabricated box girder with internal diaphragms |
| Hoist arrangement | Open winch crab, main + auxiliary hoist available |
| Control | Cabin (open or air-conditioned), radio remote, or both |
| Drives | VFD on all motions, or slip-ring motors with rotor resistance |
Advantages
Maximum hook height. Because the crab sits on top of the girders rather than below them, the hook can be raised much closer to the roof. In a building of fixed height, a double girder crane will deliver noticeably more usable lift than a single girder crane - often one to two metres more, which can decide whether a tall vessel fits under the hook.
Higher capacity and longer spans. Two girders sharing the load allow capacities into the hundreds of tonnes and spans beyond 35 metres without unacceptable deflection.
Built for continuous duty. Open winch crabs with crane-duty motors, thruster brakes and heavy-section wheels are designed for Class III and Class IV service - foundries, steel plants and round-the-clock operations.
Attachment flexibility. Magnets, grabs, C-hooks, coil tongs, ladle hooks and rotating hooks are all straightforward to mount on a crab. An auxiliary hoist can be added for lighter, faster picks without engaging the main hoist.
Safe maintenance access. A walkway runs along the girder, giving technicians safe access to the crab, drives, festoon and end carriages. On a Class IV crane this alone justifies the configuration.
Better load control. VFD drives with anti-sway logic, micro-speed and precise inching make the double girder crane the right choice for machine loading, die setting and any task where the load must be positioned to the millimetre.
Limitations
Higher capital cost, higher dead weight, and a correspondingly stronger and more expensive runway and building structure. Longer manufacturing lead time. More components to maintain.
Typical applications
Steel plants and rolling mills, foundries and forging shops, heavy engineering and boiler fabrication, power plant turbine halls, cement plants, shipyards, railway workshops, paper mills, and any facility where lifting is continuous, loads exceed 20 tonnes, or maximum hook height is critical.
Electric Overhead Travelling Crane: The Full Picture
The term electric overhead travelling crane covers the entire family described above - single girder, double girder, top-running and underslung. It is worth understanding what "electric" actually implies in engineering terms, because this is where quality differences between manufacturers show up.
The electrical system
Motors. Crane duty motors are not standard industrial motors. They are rated for S4 duty with 40% or 60% cyclic duration factor, high starting torque, and frequent start-stop cycles. Using an ordinary motor on a crane is a common cost-cutting shortcut that leads to early burnout.
Drives and control. Three approaches are common:
- Direct on line (DOL) - simplest and cheapest, suitable only for light duty with low speeds
- Slip-ring motors with rotor resistance - traditional, robust, allows stepped speed control, still preferred on some heavy process cranes
- Variable frequency drives (VFD) - now the standard for anything above light duty. Smooth acceleration, precise stopping, reduced load swing, less mechanical shock on the structure and lower energy consumption
Braking. Each motion has its own brake. Hoisting typically uses electro-hydraulic thruster brakes or DC electromagnetic brakes, often with a secondary brake on high-capacity or molten-metal cranes.
Current collection. Power reaches the moving crane through a Downshop Line (DSL) busbar system, a festoon cable arrangement on a C-track, or a cable reeling drum. DSL is compact and clean, festoon is more tolerant of dust and impact.
Safety systems
A properly specified electric overhead crane includes:
- Overload protection via load cell or load limiter
- Upper and lower hoist limit switches, with a rotary limit switch as backup
- Long travel and cross travel limit switches
- End buffers (polyurethane, spring or hydraulic) on bridge and trolley
- Anti-collision system where two cranes share a runway
- Rail clamps or storm anchors on outdoor and gantry cranes
- Audible warning hooter and rotating beacon
- Emergency stop on pendant, remote and cabin
- Phase failure and phase reversal protection
Operator interface
Pendant control - the operator walks with the load, holding a push-button station suspended from the crane. Economical, but the operator's position is dictated by the crane.
Radio remote control - the operator stands wherever visibility is best. Safer and increasingly the default on cranes up to medium capacity.
Cabin control - a dedicated operator sits in a cabin travelling with the crane. Essential on high-capacity, high-duty cranes and in hot or hazardous environments where the floor is no place to stand. Air-conditioned cabins are standard on steel plant cranes.
Overhead Crane Types Beyond EOT
An EOT crane is one member of a wider family of overhead crane types. Knowing the alternatives helps confirm you are specifying the right machine.
Gantry crane (Goliath). The bridge is supported on legs running on ground-level rails. Used in open storage yards, precast concrete plants, container depots and shipbuilding, where there is no building to carry a runway. Capacities from a few tonnes to several hundred.
Semi-gantry crane. One end of the bridge runs on an elevated runway, the other on a floor-mounted leg. Useful when a building wall can support a runway on one side only, or to serve an area alongside a main bay.
Jib crane. A boom rotating around a pillar or wall bracket, covering a circular or semi-circular area. Capacities typically 0.25 T to 5 T. Ideal as a workstation crane serving a single machine - complementary to an EOT crane rather than a replacement.
Monorail hoist. A fixed beam with a travelling hoist, offering movement along one line only. The simplest and cheapest option where the load path is fixed.
Stacker crane and automated storage crane. Column-mounted overhead cranes used in high-density storage and automated warehouses.
How EOT cranes compare
| Feature | EOT Crane | Gantry Crane | Jib Crane | Monorail |
|---|---|---|---|---|
| Coverage | Full rectangular area | Full rectangular yard | Circular sector | Single line |
| Floor space used | None | Ground rails | Pillar base | None |
| Location | Indoor, inside building | Outdoor / yard | Indoor, workstation | Indoor |
| Capacity range | 0.5 – 500 T | 2 – 500 T | 0.25 – 5 T | 0.5 – 10 T |
| Requires building structure | Yes | No | Minimal | Yes |
| Installed cost | Medium to high | High | Low | Lowest |
The decisive question is coverage. If you need full-area access inside a building, an EOT crane is the answer. If the work happens outdoors with no roof structure, look at a gantry. If one machine needs to be served repeatedly within a small radius, a jib crane costs a fraction of the price.
Specifications of EOT Cranes
When you send an enquiry to a crane manufacturer, these are the parameters they will ask for. Getting them right at the enquiry stage prevents expensive surprises later.
Core specifications
Capacity / Safe Working Load (SWL). The maximum load the crane will lift, in tonnes. Critically, this must include the weight of the lifting tackle - slings, spreader beams, magnets, grabs and C-hooks all count against capacity, not on top of it.
Span. The distance centre-to-centre between the two runway rails. Not the building width - the rail centres. An error here is not correctable after fabrication.
Lift / Height of lift. The vertical distance from the lowest hook position to the highest. Measured from floor level (or pit level if there is a pit) to the top hook position.
Duty class. The single most important and most frequently ignored specification. Indian practice follows IS 3177:
| Class | Description | FEM equivalent | Typical use |
|---|---|---|---|
| Class I | Light duty | M3 – M4 | Maintenance workshops, powerhouses, occasional use |
| Class II | Medium duty | M5 | General machine shops, assembly, warehouses |
| Class III | Heavy duty | M6 | Foundries, heavy machine shops, multi-shift use |
| Class IV | Very heavy / severe | M7 – M8 | Steel mills, ladle cranes, continuous operation |
Duty class is determined by how often the crane operates and how close to rated capacity it typically works - the load spectrum. A crane running twenty lifts a day at 30% load is a different machine from one running two hundred lifts a shift at 90% load, even if both are rated 20 tonnes.
Speeds. Specified separately for hoisting (main and auxiliary), cross travel and long travel. Faster is not automatically better - higher speeds increase load swing and demand better control systems. Micro or creep speed matters more than top speed for precision work.
Class of hoisting mechanism. Wire rope hoists are classified per FEM/IS 15560 (1Bm, 1Am, 2m, 3m). Open winch crabs are custom-designed for the duty.
Power supply. Standard in India is 415 V, 3 phase, 50 Hz with 110 V AC control. Note the supply's actual voltage stability - rural and industrial estate supplies with wide fluctuation need drive protection.
Mechanical specifications worth checking
- Wheel material and hardness (forged EN8/EN9 or cast steel), wheel diameter and rail size
- Wire rope construction (typically 6x36 or 6x37 IWRC) and factor of safety
- Hook type and forging grade per IS 3938 - single hook up to around 25 T, ram's horn above
- Gearbox type: helical gearing in an oil-bath housing, not open spur gears
- Girder deflection limit - usually span/750 to span/1000 under rated load
- Structural design and materials per IS 807 and IS 800
Applicable Indian standards
- IS 3177 - Code of practice for design of overhead travelling cranes and gantry cranes
- IS 807 - Code of practice for design, manufacture, erection and testing of crane structures
- IS 4137 - Code of practice for heavy duty EOT cranes
- IS 15560 - Electric wire rope hoists
- IS 3938 - Electric hooks
- IS 13834 - Classification of cranes
Load testing and certification under the Factories Act is a statutory requirement in India, typically at 125% of rated capacity, repeated annually.
Factors to Consider When Choosing an EOT Crane
Operational requirements
Define the real load profile, not the peak. List the heaviest load, the most common load, and how many lifts per shift. A crane sized only on peak load but used constantly at 80% capacity will be under-classed and will fail early.
Measure the space accurately. Rail centre-to-centre span, available headroom between the runway top and the lowest roof member, required hook height, and the length of runway travel. Check for obstructions: ducting, lighting, sprinkler lines, and any existing crane sharing the runway.
Assess the building. Can the existing structure carry the crane's dead weight plus dynamic load, or does the runway need reinforcement? On a retrofit, a structural assessment before ordering is non-negotiable. This is often what pushes a project from top-running to underslung.
Decide on precision. Is the crane placing loads onto machine beds and fixtures, or dropping them onto an open floor? Precision work justifies VFD on all motions, anti-sway control and micro speed.
Choose the operator interface. Radio remote for flexibility and operator safety, pendant for low-cost light duty, cabin for high-capacity or high-duty operation.
Plan for future capacity. Buildings last thirty years; production requirements change in five. Ask what it would cost today to specify a runway that could later carry a larger crane. The incremental cost is usually small compared with rebuilding a runway.
Environmental considerations
Temperature. Foundry and steel plant cranes need heat shields, insulated cables, heat-resistant grease and sometimes cooled cabins. Cold storage cranes need low-temperature-rated lubricants and seals.
Dust and abrasives. Cement, mining and grinding environments demand sealed enclosures, IP55 or higher panels, and festoon rather than open busbar.
Corrosive and chemical exposure. Chemical, fertiliser and coastal installations need epoxy or polyurethane paint systems, galvanised fasteners, and stainless components where exposure is direct.
Explosive atmospheres. Paint booths, solvent handling and petrochemical plants require flameproof (FLP) motors, panels and switchgear certified to the relevant zone and gas group. This must be specified at enquiry stage - it cannot be retrofitted.
Outdoor installation. Wind loading, rail clamps or storm anchors, weatherproof enclosures and rain hoods over motors and panels.
Cleanliness requirements. Pharmaceutical, food and electronics facilities need low-particulate designs with enclosed gearboxes, stainless surfaces and food-grade lubricants.
Commercial factors
Compare lifecycle cost, not purchase price. Energy consumption, spare parts availability, service network proximity and expected downtime cost more over twenty years than the difference between two quotations. Confirm the manufacturer's testing facilities, third-party inspection acceptance, documentation quality, and post-installation service response time. Ask for reference installations in a similar duty class and visit one if the value justifies it.
Frequently Asked Questions
What does EOT stand for in EOT crane?
EOT stands for Electric Overhead Travelling crane. It is an overhead crane in which all three motions - hoisting, cross travel and long travel - are driven by electric motors, and the bridge travels along elevated runway rails.
What is the difference between a single girder and a double girder EOT crane?
A single girder EOT crane has one bridge girder with the hoist suspended below it, suits capacities up to about 20 tonnes, and costs less. A double girder EOT crane has two girders with the crab running on top, supports capacities from 5 to 500 tonnes and higher duty classes, and provides greater hook height in the same building.
What is the maximum capacity of an EOT crane?
Standard double girder EOT cranes are commonly built up to 500 tonnes. Special process cranes in steel plants and shipyards have been built well beyond that. Single girder cranes are generally limited to 20 to 25 tonnes.
What is duty class in an EOT crane and why does it matter?
Duty class defines how hard the crane works - how many lifts per hour and at what proportion of rated load. Indian standard IS 3177 defines Class I (light) to Class IV (very heavy). A crane specified at the wrong duty class will suffer premature wear regardless of its rated capacity.
What is the difference between an EOT crane and a gantry crane?
An EOT crane runs on elevated runway rails supported by the building structure. A gantry crane's bridge sits on legs that run on rails at ground level, so it needs no building. Gantry cranes are used in open yards; EOT cranes are used inside buildings.
What is span and lift in EOT crane specifications?
Span is the centre-to-centre distance between the two runway rails. Lift, or height of lift, is the vertical travel of the hook from its lowest to its highest position.
Which is better: cabin operation or radio remote control?
Radio remote lets the operator choose the best vantage point and is preferred for capacities up to medium range. Cabin operation is better for high-capacity, high-duty cranes and in hot, dusty or hazardous environments where working at floor level is unsafe.
Can EOT cranes be installed in an existing building?
Yes, provided the structure can carry the load. A structural assessment of columns, foundations and roof members is essential before ordering. Where the building cannot take a top-running crane, an underslung crane suspended from the roof structure is often the solution.
What maintenance does an EOT crane require?
Daily visual checks by the operator; monthly inspection of ropes, hooks, brakes and limit switches; quarterly gearbox oil checks and wheel and rail inspection; and annual load testing and certification as required under the Factories Act.
How long does an EOT crane last?
A correctly specified and maintained EOT crane typically operates for 20 to 30 years. Cranes fail early almost always for one of two reasons: under-specified duty class, or neglected maintenance.
Which standards apply to EOT cranes in India?
IS 3177 for design of overhead travelling cranes, IS 807 for crane structures, IS 4137 for heavy duty EOT cranes, IS 15560 for wire rope hoists and IS 3938 for hooks. International projects may specify FEM, CMAA or DIN standards instead.
What factors affect EOT crane price?
Capacity, span, lift height, duty class, girder configuration, drive type (DOL, slip-ring or VFD), control method, safety features, surface treatment, and any special requirements such as flameproof electrics or magnet and grab attachments.
Conclusion
Selecting an EOT crane is a structural, electrical and operational decision rolled into one - and it is a decision you live with for two decades or more. The crane becomes part of the building, and replacing it means disrupting production.
The pattern is consistent across industries. A single girder EOT crane is the right answer for intermittent lifting up to about 20 tonnes in light and medium duty environments, where cost efficiency and simple maintenance matter most. A double girder EOT crane is the right answer when loads are heavy, operation is continuous, maximum hook height is needed, or the crane must carry a magnet, grab or auxiliary hoist. Underslung cranes solve headroom problems, gantry cranes solve the no-building problem, and jib cranes solve the single-workstation problem at a fraction of the cost.
Between those configurations, the specifications that most often get under-specified are duty class and lifting tackle weight. Both are invisible on day one and expensive by year five. Take the time to document your real load profile and lift frequency before you send an enquiry, have your building structure assessed by a competent engineer, and compare quotations on lifecycle cost rather than purchase price - ideally from a manufacturer who will still be servicing the crane in year fifteen.
Get those fundamentals right, and the crane becomes what it should be: infrastructure you stop thinking about, running quietly overhead for the next twenty years.