The right power supply for a transfer trolley is decided by the route, not the load: a fixed indoor run takes a cable reel or busbar, a route that crosses gangways or serves several stations takes a battery, and an outdoor or very long run takes a diesel generator.
The four options
Cable reel. A spring or motorised reel on the trolley pays out a trailing cable as the car moves. It is the simplest and cheapest supply and the standard fit on a motorised transfer trolley running a fixed route inside a bay. Its limits are cable length, typically under 100 m, and the need for a trench or guard so nothing runs over the cable.
Busbar. A conductor rail along the route with a collector on the trolley. Unlimited run length and no cable to damage, at the cost of installing and maintaining the rail along the whole route. It cannot cross a doorway or a road without a break, and it is only worth the installation on a route that will not change for years.
Battery. An onboard lithium iron phosphate or lead-acid pack on a battery operated transfer trolley. No trackside installation at all, so the car can cross gangways, serve several stations and be re-routed later. Endurance is six to eight hours on a sized pack, and the plant needs a charging point and either charging gaps or a spare pack.
Diesel generator. An onboard set on a DG powered transfer trolley. No cable, no rail and no charging window; endurance is a fuel tank. It is the answer for stockyards, inter-shed routes across open ground, unreliable grid supply and the highest continuous power draws.
Decision table
| Route | Best fit | Why |
|---|---|---|
| Fixed, indoor, under 100 m | Cable reel | Cheapest, simplest, nothing to install trackside |
| Fixed, indoor, long | Busbar | No cable length limit, no trailing cable to damage |
| Crosses gangways or serves several stations | Battery | No trackside installation, re-routable |
| Outdoor, very long, or unreliable grid | Diesel generator | Runs on fuel, unaffected by weather or outages |
Two things that override the table
The heaviest loads push towards rail and towards cable or DG power. A 150 ton coil car draws more than a sensible battery pack can supply for a full shift, so on the heaviest builds the choice is between a busbar and a generator. And a route that will change within a few years argues against a busbar regardless of length, since the conductor rail is the one part that cannot move with the trolley. The layout side of the decision is covered in fixed-rail vs mobile coil transfer systems. If the route is not obvious, describe it to us and we will recommend a supply before you commit to trackside work.
Frequently asked questions
Can the power supply be changed later?
Cable reel to busbar is a straightforward retrofit on the same trolley. Converting to battery or DG needs deck space for the pack or set and a new panel, so it is better decided at the design stage.
Which option has the lowest running cost?
Busbar and cable reel, since they draw mains power with no fuel or battery replacement. Battery is next; a diesel set costs the most to run but is often the only option that works at all on its routes.
Does the choice affect the trolley's capacity or speed?
Not the capacity. Speed is 0 to 25 m/min on all four, with the heaviest DG and battery builds geared slower to keep the onboard power source to a sensible size.
Export Availability
For an overseas plant we make the power selection from a route sketch and a description of the site's grid reliability, then build the panel to the destination's voltage and frequency. Battery and DG units are the usual export choice, since neither needs trackside electrical installation at the buyer's end; a busbar car is only quoted where the buyer's own contractor is installing the conductor rail.
Manufactured at Pragya's Pithampur (Indore) works and exported to steel mills worldwide — 22+ countries across 5 continents to date. Every export order ships with mill test certificates, ocean-freight packing, and full customs documentation, quoted FOB or CIF.
Interested in our industrial equipment?
Our export team, based in Indore, India, will recommend the right solution and quote FOB or CIF pricing for your shipment.
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