Gantry Crane Power Draw: What an RTG or RMG Really Costs to Run, 5 to 100 Ton

Written by Li Ming, Senior Applications Engineer at SIEC Cranes. Oct 9, 2026.

A gantry crane from 5 to 100 tonnes costs somewhere between USD 2,500 and USD 60,000 a year to power. On most yard machines the biggest single item is not the hoist. It is the gantry travel drive dragging a 40 to 400 tonne portal frame up and down the rail. This 2026 guide breaks the gantry crane power draw down by motion, compares diesel RTG with cable reel and busbar electrification, and shows which upgrades actually pay back.

Where Does the Power Go on a Gantry Crane?

On an overhead crane the hoist takes most of the energy. Our own breakdown of a double girder machine put the hoist share at 65 to 80%. A gantry crane behaves differently, and the difference is not subtle.

The Energies 2024 paper “Analysis of Energy Consumption of Container Cranes” (Energies 2024, 17(5), 985) measured a berth crane at roughly 62% hoist, 31% gantry and 7% trolley. Run the same paper's model on a land-side container yard and the split flips hard: about 85% gantry, 9% hoist, 4% trolley and 2% for handling. That paper also clocked one class of machine at 69.8 kWh per hour at a marine terminal and 17.23 kWh per hour at an inland yard. Same equipment, four times the draw.

So the first question to ask about any gantry crane is not "how big is the hoist". It is "how far does the load travel along the ground". A crane that picks up and sets down in the same bay still lives on its hoist. A crane that runs a 200 m yard lives on its long travel motors.

Gantry type	Hoist	Trolley	Gantry travel	What drives the number
Berth / quay gantry	55 - 65%	5 - 10%	25 - 35%	Short travel along the quay, tall lifts
Rail mounted yard gantry (RMG)	35 - 50%	10 - 15%	35 - 55%	Long yard travel on low friction rails
Rubber tyred gantry (RTG)	20 - 35%	5 - 12%	50 - 70%	High rolling resistance on tyres
Outdoor double girder gantry	55 - 75%	8 - 15%	10 - 25%	Wide span, load moves in the trolley not the rail

Shares are SIEC planning figures built on the motion split published in Energies 2024, 17(5), 985 and on our own commissioning records. They are a planning aid, not a published statistic.

Why Does Long Travel Cost So Much on a Tyred Crane?

Friction. That is the whole story, and it is easy to put numbers on.

A steel wheel on a steel rail rolls with a resistance coefficient of roughly 0.002 to 0.005. A rubber tyre on a paved yard rolls at 0.010 to 0.020, and on soft or poorly compacted ground it climbs to 0.03. That is a four to ten times difference in the force the motor has to pull against. Nothing else about the crane changes.

Now put it on a real machine. A 32 tonne RTG with the spreader and a loaded container weighs around 200 tonnes in service, and it travels at about 100 m/min, which is 1.67 m/s.

Tyre resistance F = 0.015 × 200,000 × 9.81 = 29.4 kN, giving 29.4 × 1.67 = 49 kW
Steel wheel resistance F = 0.003 × 200,000 × 9.81 = 5.9 kN, giving 5.9 × 1.67 = 9.8 kW

Five times the steady power, for the same load and the same speed. And steady power is not the worst case. Accelerating that 200 tonnes to full speed in 6 seconds needs another 55 kN, or roughly 93 kW on top. That peak, not the rolling figure, is what sizes the drive and the genset.

Wheel and surface	Resistance	Force at 200 t	Steady power at 100 m/min
Steel wheel on steel rail	0.002 - 0.005	3.9 - 9.8 kN	6.5 - 16.4 kW
Rubber tyre on concrete	0.010 - 0.020	19.6 - 39.2 kN	32.7 - 65.4 kW
Rubber tyre on compacted gravel	0.025 - 0.035	49.1 - 68.7 kN	81.9 - 114.5 kW

This is the single reason an RTG needs a 300 to 450 kW diesel genset while an RMG of the same duty runs happily off a modest cable reel. The tyre, not the container, is paying for the power plant.

What Motors Does a 5 to 100 Tonne Gantry Crane Have?

Here is the motor inventory we quote against. Numbers are SIEC planning figures at 400 V / 50 Hz with VFD drives and A5 to A7 duty.

Capacity	Hoist	Trolley	Gantry travel	Installed total	Typical span
5 t	7.5 kW	1.5 kW	2 × 1.5 kW	13 kW	12 - 18 m
10 t	13 kW	2.2 kW	2 × 2.2 kW	20 kW	15 - 22 m
20 t	22 kW	3.7 kW	2 × 3.7 kW	33 kW	18 - 26 m
32 t (RTG, 1 over 5)	45 kW	15 kW	4 × 22 kW	150 kW	23 - 26 m
40 t (RMG)	55 kW	22 kW	4 × 15 kW	142 kW	30 - 40 m
65 t (RMG)	90 kW	30 kW	4 × 22 kW	208 kW	40 - 50 m
100 t heavy gantry	132 kW	45 kW	4 × 30 kW	297 kW	30 - 40 m

Two things worth noticing. First, the gantry travel motors on the two yard machines together draw as much as the hoist. Second, none of these figures sizes your genset. Peak demand during a simultaneous hoist and travel, plus wind, is what does that. Every one of these gantry crane configurations is quoted with its own motor schedule.

How Do You Work Out the Hourly Cost?

Four steps. Install power times a demand factor, divided by drive efficiency, times the tariff. That is it.

The demand factor is the honest part and the one most quotes get wrong. It is the average load over running time as a fraction of installed power:

Duty class	Demand factor	Drive efficiency	Fuel path efficiency
A5 medium	0.35	0.85 (VFD)	0.33 diesel genset
A6 heavy	0.45	0.85 (VFD)	0.30 diesel mechanical
A7 very heavy	0.55	0.78 slip ring	—
A8 continuous	0.65	0.85 (VFD)	—

Worked example, 32 t RTG on A6, 150 kW installed, grid power at USD 0.12 a kWh:

150 × 0.45 ÷ 0.85 = 79.4 kW of electrical input. Times USD 0.12, that is USD 9.53 per running hour. Now run the same crane on its own diesel genset at 33% conversion: 79.4 ÷ 0.33 = 240.6 kW of fuel energy, which at 9.97 kWh per litre of diesel is 24.1 litres an hour. At USD 0.85 a litre that is USD 20.50 per running hour.

Same crane, same work, twice the money. That gap is the entire reason electrification keeps coming up in terminal meetings.

What Does a Diesel RTG Actually Burn?

Published figures for a 40 t class RTG with a 350 to 450 kW genset cluster around 1.4 to 2.2 litres per container move, or roughly 20 to 35 litres per running hour. An RTG working a 3,000 hour year at 20 moves an hour lands near 60,000 moves, which is 84,000 to 132,000 litres of diesel a year. At USD 0.85 a litre that is USD 71,000 to USD 112,000 per crane per year.

Put that next to the crane price. A 40 t class RTG sells for roughly USD 900,000 to 1,600,000. Fuel is 5 to 12% of the purchase price, every year, for the whole service life. It is the largest operating cost on the machine and it is the one most terminals under-budget.

Item	Diesel RTG	Electrified RTG (cable reel or busbar)	Hybrid RTG (battery or supercapacitor)
Onboard power	350 - 450 kW genset	None, 380 - 480 V supply	150 - 200 kW genset plus storage
Energy per move	1.4 - 2.2 L diesel	4.5 - 7.0 kWh	0.7 - 1.2 L plus regen
Cost per move	USD 1.19 - 1.87	USD 0.54 - 0.84	USD 0.60 - 1.02
Annual energy cost, 60,000 moves	USD 71,000 - 112,000	USD 32,000 - 50,000	USD 36,000 - 61,000
Yard emissions and noise	NOx, PM, diesel noise	None at the crane	Much reduced

Diesel at USD 0.85 a litre and grid power at USD 0.12 a kWh is a two to one ratio in favour of electricity. Where industrial power is cheaper, or diesel dearer, the gap widens further. In markets where diesel is subsidised, it can close. Check your own two numbers before you accept anyone's payback claim.

Is Electrifying an RTG Worth the Money?

Usually yes, but the honest answer is that it depends on how many hours you run. Electrification is a capital purchase that buys a cheaper litre, so the more litres you would have burned, the faster it pays.

Option	Capital premium per crane	Annual saving, 3,000 h year	Simple payback
Genset auto start / stop and eco mode	USD 3,000 - 8,000	USD 12,000 - 30,000	3 - 8 months
Regeneration on hoist and trolley	USD 14,000 - 40,000	USD 8,000 - 18,000	1 - 4 years
Hybrid retrofit, battery on existing genset	USD 150,000 - 350,000	USD 30,000 - 55,000	3 - 9 years
Full electrification, cable reel plus trench	USD 250,000 - 550,000	USD 40,000 - 65,000	5 - 11 years
Full electrification, conductor bar	USD 300,000 - 600,000	USD 40,000 - 65,000	6 - 12 years

Capital premiums and savings above are SIEC planning figures for a 40 t class yard crane, not vendor quotations. Run them against your own fuel and power prices, because a payback that looks strong at USD 0.85 diesel looks weak at USD 0.50.

The row most people skip is the first one. An RTG genset idles for 30 to 50% of its shift, burning fuel with nothing moving. Auto start and stop costs a few thousand dollars and usually beats every hardware upgrade on this page. If you do one thing after reading this, do that.

Rubber Tyres or Steel Wheels, Does It Change the Energy Bill?

It changes almost everything about the energy bill, which is why RTG against RMG is an energy decision as much as a civil works decision. The RMG wins on every energy line. The RTG wins because it does not need rails.

Item	RMG, steel wheel on rail	RTG, rubber tyre
Long travel resistance	0.002 - 0.005	0.010 - 0.020
Travel power, 200 t at 100 m/min	6.5 - 16.4 kW	32.7 - 65.4 kW
Energy per 40 t container move	2.5 - 4.0 kWh	4.5 - 7.0 kWh
Power source	Cable reel or conductor bar, from the grid	Diesel genset, or hybrid with storage
Regeneration destination	Back into the terminal network	Only into a battery or supercapacitor
Civil works	Rails, foundation, drainage	Paved runway and compaction

The counterweight is that RMG civil works are expensive and permanent, while an RTG can be moved to another yard. Terminals that expect their layout to change buy RTGs and pay the fuel bill. Terminals that know their layout buy RMGs, lay rail once and take the cheaper energy for twenty years. Both are rational. Mixing the two by accident is not.

What Does Wind Add to Gantry Travel Power?

On an outdoor crane, more than most people expect. Wind force is 0.5 times air density times wind speed squared times a drag coefficient times the exposed area.

Take a 32 t gantry with 120 m² of exposed area and a drag coefficient of 1.3, travelling at 100 m/min:

Wind speed	Wind force	Extra travel power	Compared with tyre resistance
10 m/s	9.6 kN	16.0 kW	About half
15 m/s	21.5 kN	35.9 kW	About the same
20 m/s	38.2 kN	63.8 kW	Nearly double
25 m/s, non working	59.7 kN	Anchored, clamps take it	Not a motor duty

Now the consequence people miss. A travel drive sized on the calm-day rolling resistance is undersized for the windy day, and it will trip out on overload exactly when the yard is busiest. That is why a 45 kW travel motor shows up where 22 kW would do the arithmetic on a still day. It is not padding. It is the wind case.

A tailwind is the other edge of the same blade. Pushed along by the wind, the drive regenerates instead of consuming, and on an RMG that energy goes back into the terminal network. You cannot bank on it, but it is real, and it is another reason a grid connected gantry beats a diesel one.

Does Duty Class Matter More Than Tonnage?

Yes, and by a wide margin. Here is the same 32 t electrified yard crane at four duty classes with a 5.6 kWh per move figure, over a 3,000 hour year.

Duty class	Moves per hour	Moves per year	Annual kWh	Annual cost	Ten year cost
A5 medium	10	30,000	168,000	USD 20,160	USD 231,000
A6 heavy	20	60,000	336,000	USD 40,320	USD 462,000
A7 very heavy	30	90,000	504,000	USD 60,480	USD 693,000
A8 continuous	40	120,000	672,000	USD 80,640	USD 924,000

Ten year figures apply a 3% annual power price escalation, a factor of 11.46.

Four times the energy on the same crane, purely from how hard you work it. Anyone comparing two gantry crane quotes has to compare the duty classes first. A cheap A5 machine asked to do A7 work will not last, and will not save you anything.

What Do the Motor Efficiency Rules Require in 2026?

EU Regulation 2019/1781 sets the floor. From 1 July 2021, three phase motors from 0.75 to 1,000 kW had to reach IE3, and smaller ones from 0.12 to 0.75 kW reached IE2. From 1 July 2023, non-brake, non-Ex motors from 75 to 200 kW had to reach IE4.

Read the exemption carefully, because it matters on a gantry crane. Annex I point 2(c) excludes motors with an integrated brake that cannot be removed or separately powered for testing. Nearly every gantry travel and trolley motor is a brake motor, so the IE4 tier does not catch them. The IE3 baseline still does.

Rating, 4 pole	IE3 efficiency	IE4 efficiency	Gap
5.5 kW	89.6%	91.4%	1.8 points
11 kW	91.4%	93.3%	1.9 points
22 kW	93.0%	94.5%	1.5 points
55 kW	94.6%	95.4%	0.8 points
90 kW	95.2%	95.8%	0.6 points

On a jib crane this table is a rounding error. On a gantry crane it is not, because there are four or more travel motors and they run for thousands of hours. Take a 22 kW travel motor at 45% load over 3,000 hours. One efficiency point is 0.79 kW, or 2,380 kWh a year. Two points across four motors is roughly 19,000 kWh a year, about USD 2,300 at USD 0.12. That is worth asking your supplier about.

NEMA 480 V or IEC 400 V, What Changes?

North American terminals run 480 V at 60 Hz. Europe and most of Asia run 400 V at 50 Hz. Both work. They do not mix.

Item	NEMA practice	IEC practice
Voltage tolerance	Plus or minus 10%	Zone A plus or minus 5%, zone B plus or minus 10%
Frequency tolerance	Plus or minus 5%	Zone A plus 2%, zone B plus 3% minus 5%
Overload allowance	Service factor 1.15	No service factor, use duty types S1 to S10
Gantry duty type	Continuous rating with service factor	S4 or S5, intermittent with electric braking or starting
Speed at 4 pole	About 1,750 rpm at 60 Hz	About 1,450 rpm at 50 Hz

That last row is the practical trap. Move a 60 Hz gantry to a 50 Hz grid and the motors turn about 20% slower unless you change the gearbox or re-rate the drive. Every speed in the datasheet shifts with it. Cable reels and conductor bars are voltage specific too, so a crane relocated across markets usually needs its supply system rebuilt rather than adapted.

What Is the Power Factor Cost on a Gantry Crane?

Most terminals are billed on kVA as well as kWh, and a poor power factor makes the kVA number climb.

Power factor	kVA drawn for 135.9 kW	Extra kVA against 0.95	Extra demand charge, USD 12 per kVA month
0.95	143	0	USD 0
0.90	151	8	USD 1,152 a year
0.85	160	17	USD 2,448 a year
0.80	170	27	USD 3,888 a year
0.70	194	51	USD 7,344 a year

Published utility case studies put power factor correction at a mid four figure capital cost with payback under a year when penalties are already being charged. An active front end on the large drives does the same job harder: power factor near 0.99 and total harmonic distortion below 5%, plus 15 to 20% off the drive energy on drives above about 50 kW. Slip ring motors converted to VFD get all of this at once.

How Much Does Regeneration Recover?

Lowering is the only motion that hands energy back, and a gantry crane does a lot of lowering.

A 40 t container lowered 15 m releases 40,000 × 9.81 × 15 = 5.886 MJ, which is 1.63 kWh. At 70% recovery that is 1.14 kWh per lowering move. Over 60,000 moves that is 68,400 kWh a year.

Now the part that surprises people. On a grid connected crane that 68,400 kWh is worth about USD 8,200 at USD 0.12. On a diesel RTG, where every electrical kWh costs roughly USD 0.258 to make from fuel at USD 0.85 a litre through a 33% efficient genset, the same 68,400 kWh is worth about USD 17,600.

Regeneration is worth more than twice as much on a diesel machine as on an electric one. That is counter-intuitive until you remember that on the diesel crane you are not buying cheap grid power, you are refusing to burn diesel.

Practical limit: a diesel RTG with no battery has nowhere to put the recovered energy, so it burns it in a brake resistor. That is exactly why the hybrid retrofit exists. On an RMG with a regenerative drive, the energy simply flows back through the conductor bar into the terminal network.

Which Upgrades Actually Pay Back?

Ranked by return, not by how interesting the engineering is.

Order	Action	Capital	Annual effect	Payback
1	Stop the genset idling, add auto start and stop	USD 3,000 - 8,000	USD 12,000 - 30,000 saved	Under a year
2	Tyre pressure discipline and steering mode rules	None	5 to 12% off travel energy	Immediate
3	Regenerative drive on hoist and trolley	USD 14,000 - 40,000	USD 8,000 - 18,000 saved	1 - 4 years
4	Power factor correction or active front end	USD 12,000 - 30,000	USD 3,000 - 7,000 saved	2 - 5 years
5	Hybrid battery retrofit	USD 150,000 - 350,000	USD 30,000 - 55,000 saved	3 - 9 years
6	Full electrification	USD 250,000 - 600,000	USD 40,000 - 65,000 saved	5 - 12 years
7	IE4 motors on non-brake drives only	Motor price step	About USD 2,300 on four 22 kW motors	Rarely on efficiency alone

Note what sits at number one and number two. The two best returns on a gantry crane cost almost nothing and are not products. They are a control change and a maintenance habit. The expensive hardware is at five and six, and it earns its place only when the crane genuinely runs thousands of hours a year. If your gantry crane works 800 hours a year, skip everything below row three and go home.

What Should You Meter to Prove the Saving?

If you cannot measure it, you cannot claim it, and you cannot tell whether the upgrade worked.

A bidirectional meter to IEC 62053-22 class 0.5S on the crane supply, so regeneration shows up as a negative number rather than vanishing
Fuel flow metering or a disciplined tank dip log on any diesel machine
Cycle counts from the PLC, so energy can be normalised to kWh per move
A four week baseline at normal workload before any change, and the same four weeks afterwards

Normalise everything to kWh per move. That is the one figure that stays comparable when volumes change, and it is the only number a terminal manager can use to compare two cranes or two years. For our own machines we log the same set and hand it over at commissioning, and every rail mounted and rubber tyred gantry crane we build is quoted with the metering you ask for.

Frequently Asked Questions

How much electricity does a gantry crane use in a year?

An electrified 32 t yard gantry on heavy duty uses roughly 336,000 kWh a year, about USD 40,000 at USD 0.12 a kWh. A small 5 t outdoor gantry on medium duty uses closer to 20,600 kWh, about USD 2,500. The spread between those two machines comes more from duty class and travel length than from lifting capacity.

Why does a rubber tyred gantry crane use more energy than a rail mounted one?

Rolling resistance. A rubber tyre on concrete rolls at 0.010 to 0.020, while a steel wheel on steel rail rolls at 0.002 to 0.005. For the same 200 t service weight at 100 m/min that is 33 to 65 kW on tyres against 6.5 to 16 kW on rails. The RTG also carries its own diesel genset, which adds a conversion loss of two thirds before the energy even reaches a motor.

Is electrifying an RTG worth the money?

Usually, if the crane runs more than about 2,000 hours a year. Full electrification costs USD 250,000 to 600,000 per crane and saves USD 40,000 to 65,000 a year in energy, which pays back in five to twelve years. Before that, spend USD 3,000 to 8,000 on genset auto start and stop, which typically saves USD 12,000 to 30,000 a year by itself.

Does the hoist or the long travel motor use more power?

On a yard gantry crane, long travel. The Energies 2024, 17(5), 985 study puts a land side container yard machine at about 85% gantry, 9% hoist and 4% trolley. On a berth crane or an indoor gantry crane the hoist usually leads instead. The deciding factor is how far the load travels along the ground.

What is a good energy figure per container move?

For an electrified rail mounted gantry, 2.5 to 4.0 kWh per 40 t container move. For a rubber tyred gantry, 4.5 to 7.0 kWh. If your numbers are far below that, check the meter is capturing regeneration. If they are far above, look at tyre pressure, steering mode and how much of the shift the machine spends idling.

How much does a gantry crane cost to run per hour?

A 32 t electrified yard crane on heavy duty costs about USD 9.50 per running hour in electricity at USD 0.12 a kWh. The same crane on its own diesel genset costs about USD 20.50 per running hour at USD 0.85 a litre. That roughly two to one gap is the whole case for electrification in one line.