A 2 tonne suspension crane weighs 2,783 kg. The steel that hangs it from the roof usually weighs more. Here is the four-number arithmetic, the point load a warehouse roof was never designed for, the headroom credit that pays some of it back, and the ten lines that make two offers comparable.
Two quotations for the same job. A 2 tonne suspension crane at 16.5 metre span, 60 metres of runway, inside an existing warehouse. One supplier quotes 8,400 dollars and calls the installation straightforward. The other quotes 8,900 and asks for the roof drawings before he will sign anything.
The second supplier has done this before. An underslung crane does not stand on its own runway. It hangs from your roof, and that roof was designed for snow, wind and a maintenance worker with a toolbox. Nobody sized it for 3.2 tonnes swinging on a single point twenty times an hour.
So the carbon question here is not really about the crane. A 2 tonne underhung machine at that span weighs 2,783 kg. The steel needed to hang it safely usually weighs more than the crane does. Work out both numbers and the sales conversation changes completely.
This piece does the arithmetic for 0.5 to 5 tonnes. Crane mass comes from published catalogues. Support steel comes from our own designs. Carbon uses worldsteel intensities. Every figure we calculated ourselves is labelled as a planning figure, and nothing is presented as a published statistic unless it is one.
Less than most buyers guess, and the span matters more than the capacity. Table 1 is a published underhung crane range, 0.5 to 10 tonnes, across 3.5 to 22.5 metre spans.
| Capacity | 3.5 m | 8.5 m | 12.5 m | 16.5 m | 22.5 m | Max wheel load | Motor |
|---|---|---|---|---|---|---|---|
| 0.5 t | 1,060 kg | 1,540 kg | 1,876 kg | 1,960 kg | 2,976 kg | 6.3-10.7 kN | 1.8 kW |
| 1 t | 1,075 kg | 1,555 kg | 1,891 kg | 2,309 kg | 3,383 kg | 9.5-14.5 kN | 2.5 kW |
| 2 t | 1,162 kg | 1,541 kg | 2,184 kg | 2,783 kg | 3,903 kg | 16.3-21.7 kN | 4.2 kW |
| 3 t | 1,292 kg | 1,840 kg | 2,379 kg | 3,019 kg | 4,028 kg | 23.1-27.9 kN | 5.7 kW |
| 5 t | 1,599 kg | 2,271 kg | 2,996 kg | 3,675 kg | 5,493 kg | 37.2-43.7 kN | 9.1 kW |
| 10 t | 2,372 kg | 3,189 kg | 4,170 kg | 5,161 kg | 7,532 kg | 64.1-78.3 kN | 15.2 kW |
Read the last two columns against the first. A 0.5 tonne crane at 22.5 metres weighs 2,976 kg. That is 5.95 kg of steel for every kilogram it can lift. A 10 tonne crane at 16.5 metres weighs 5,161 kg, which is 0.52 kg per kilogram of capacity.
Small cranes are steel-expensive machines. The hoist, the end trucks and the electrical set are roughly fixed, so at half a tonne of capacity you are mostly buying structure. Keep that ratio in mind, because the roof steel follows the same curve.
Steel is about 88 percent of a suspension crane by mass. The rest is the hoist, motors, cable and controls. Using the worldsteel Sustainability Indicators Report 2025 (2024 data), global average crude steel sits at 1.92 t CO2 per tonne, blast furnace at 2.34 and scrap-based electric arc at 0.69. Table 2 applies steel-only factors to the 16.5 metre machines.
| Capacity at 16.5 m | Steel equivalent | BF-BOF 2.34 | Global 1.92 | Scrap-EAF 0.69 |
|---|---|---|---|---|
| 0.5 t | 1,725 kg | 4.0 t CO2e | 3.3 t | 1.2 t |
| 1 t | 2,032 kg | 4.8 t CO2e | 3.9 t | 1.4 t |
| 2 t | 2,449 kg | 5.7 t CO2e | 4.7 t | 1.7 t |
| 3 t | 2,657 kg | 6.2 t CO2e | 5.1 t | 1.8 t |
| 5 t | 3,234 kg | 7.6 t CO2e | 6.2 t | 2.2 t |
Fabrication electricity adds roughly 5 to 8 percent on top. Paint, sea freight and the hoist's own components add a little more. None of it changes the ranking: the mill route decides whether your 2 tonne crane carries 5.7 tonnes of CO2e or 1.7.
That is a factor of 3.4 for a decision most buyers never ask about, because the enquiry form asks for capacity, span and lifting height and stops there.
Because the machine has nowhere else to put its load. A top-running crane sits on rails fixed to runway beams, and those beams sit on columns that were going into the building anyway. An underslung crane hangs its track from the roof members, and the roof members were sized by the snow map.
The load path is the whole story. Crane to end truck, end truck wheel to track beam bottom flange, track beam to hanger rod, hanger rod to roof beam bottom flange, roof beam to column, column to foundation. Every link in that chain is steel you pay for and steel that has carbon attached.
So the honest way to answer a carbon question about an underslung crane is to quote the system. Crane plus track plus hangers plus bracing plus whatever strengthening the roof needs. Four numbers, not one.
More than buyers expect. The number that matters is not the rated capacity. It is the suspension point design load, which includes the crane's own weight, the wheel load, and a dynamic factor for the fact that loads are picked up and set down.
| Rated capacity | Max wheel load | Design load per suspension point | What the roof feels in tonnes |
|---|---|---|---|
| 1 t | ~950 kg | ~2.0 t | 2.0 |
| 2 t | ~1,450 kg | ~3.2 t | 3.2 |
| 3.2 t | ~2,100 kg | ~4.6 t | 4.6 |
| 5 t | ~3,200 kg | ~7.0 t | 7.0 |
Those are our planning figures, assuming the worst realistic position: two end truck wheels either side of one hanger, with a 1.3 dynamic factor. Your supplier should hand over the actual wheel load drawing. If they cannot, that is a finding in itself.
Now compare that point load with what the roof beam was designed for. Take a 6 metre roof beam spacing, a 6 metre tributary width, and the EN 1991-1-1 category H imposed load of 0.4 kN per square metre for a roof that is not accessible except for maintenance. That is 2.4 kN per metre on the beam.
| Case on a 6 m beam | Load | Bending moment | Multiple of design imposed load |
|---|---|---|---|
| Imposed load 0.4 kN/m2 | 2.4 kN/m | 10.8 kNm | 1.0 |
| Snow 0.8 kN/m2 | 4.8 kN/m | 21.6 kNm | 2.0 |
| 2 t crane hanger, 31.4 kN | 31.4 kN point | 47.1 kNm | 4.4 |
| 5 t crane hanger, 68.6 kN | 68.6 kN point | 102.9 kNm | 9.5 |
A 5 tonne suspension crane puts almost ten times the bending moment into that beam that the imposed load does. Snow cover helps, and real hangers usually land at third points rather than mid-span, which cuts the moment by a third. It still does not close a 9.5 times gap.
This is why the engineering answer to "can I hang it from the existing roof?" is usually no, and why the carbon answer is not about the crane.
Four items. Track beams, hanger assemblies, sway bracing, and roof strengthening. Table 5 is a 2 tonne crane at 16.5 metre span with 60 metres of runway.
| Item | Basis | Mass | CO2e at 2.34 |
|---|---|---|---|
| Track beams | 2 x 60 m IPE 220 at 26.2 kg/m | 3,144 kg | 7.36 t |
| Hangers and brackets | 22 points at 6 m spacing, 14 kg each | 308 kg | 0.72 t |
| Sway bracing | Four corners, both directions, at splices | 550 kg | 1.29 t |
| Roof strengthening | Plates or secondary beams at hanger points | 1,050 kg | 2.46 t |
| Total support steel | Against a 2,783 kg crane | 5,052 kg | 11.82 t |
The bracing is not optional and it is not decoration. ASME B30.11 requires it in both directions at all four corners of the layout, plus intermediate bracing at the hangers nearest each track splice. It stops the track from walking sideways under every acceleration and every brake.
Roof strengthening is the item that gets argued about. It is also the item that most often turns a 9,000 dollar crane into a 20,000 dollar project once a structural engineer has looked at the beam.
Roughly linearly, with a step at each track section change. Table 6 keeps the 16.5 metre span and 60 metre runway and only moves the capacity. Carbon columns use blast furnace steel at 2.34.
| Capacity | Crane mass | Track section | Support steel | Support / crane | Crane CO2e | Support CO2e | System CO2e |
|---|---|---|---|---|---|---|---|
| 0.5 t | 1,960 kg | IPE 160 | 3,038 kg | 1.55x | 4.0 t | 7.1 t | 11.1 t |
| 1 t | 2,309 kg | IPE 180 | 3,670 kg | 1.59x | 4.8 t | 8.6 t | 13.4 t |
| 2 t | 2,783 kg | IPE 220 | 5,052 kg | 1.82x | 5.7 t | 11.8 t | 17.5 t |
| 3 t | 3,019 kg | IPE 240 | 5,934 kg | 1.97x | 6.2 t | 13.9 t | 20.1 t |
| 5 t | 3,675 kg | IPE 270 | 7,034 kg | 1.91x | 7.6 t | 16.5 t | 24.1 t |
Support steel runs 1.55 to 2.0 times the crane mass. On carbon it is worse than that, because the track beams and plates are hot rolled sections while the crane's 12 percent of non-steel mass dilutes its own average.
So a 2 tonne suspension crane is a 17.5 tonne CO2e system, of which 5.7 tonnes is the machine. If a supplier quotes you a carbon figure of 5.7 tonnes for that crane, they have answered a question nobody asked.
A little. Hanger spacing is the lever, and it works against itself. Move the hangers closer together and the track beam can be lighter, but you buy more rods, more brackets, and more strengthening points on the roof.
| Hanger spacing | Track beam | Track mass | Hangers | Strengthening | Total support |
|---|---|---|---|---|---|
| 6 m | IPE 220 | 3,144 kg | 308 kg | 1,050 kg | 5,052 kg |
| 4 m | IPE 200 | 2,688 kg | 462 kg | 1,200 kg | 4,900 kg |
| 3 m | IPE 180 | 2,256 kg | 616 kg | 1,350 kg | 4,772 kg |
Halving the spacing saves 280 kg, about 5.5 percent. Worth having, not worth changing a building programme for. Bracing cannot be trimmed at all, which is the honest answer when a buyer asks us to value-engineer it out.
The real saving is in track length. Every metre of runway you do not build saves 52 kg of IPE 220 plus its share of hangers, bracing and strengthening, call it 85 kg per metre. Cut the runway from 60 to 40 metres and you save 1.7 tonnes of steel. That beats any section optimisation.
Sometimes, and this is where suspension cranes win on carbon when they win at all. An underslung crane hangs below its track, so the hook can reach the same working height with lower eaves than a top-running crane would need. Our planning figure for the difference is 1.2 to 1.8 metres of eaves, and it is the whole reason people choose this machine.
The building responds to that. Steel Construction Institute cost planning data for portal frames puts frame steel at about 35 kg per square metre for low eaves of 6 to 8 metres, and 45 kg per square metre for high eaves of 10 to 13 metres. Ten kilos over roughly three and a half metres of height, so about 2.9 kg per square metre for every metre of eaves.
| Item | Per 1,000 m2 building | CO2e at 2.34 |
|---|---|---|
| 1 m of eaves height | 2.9 t frame steel | 6.8 t credit |
| 1.5 m headroom gain | 4.35 t frame steel | 10.2 t credit |
| Support steel, one 2 t crane | 5.05 t added steel | 11.8 t debit |
| Net, one crane in the bay | -0.7 t steel | 1.6 t net debit |
| Net, three cranes in the bay | +10.8 t steel | 25.2 t net debit |
So the headroom credit roughly cancels the roof steel for one crane. It stops cancelling at about one and a half cranes per bay, and by three cranes the building is carrying 25 tonnes of extra CO2e that a top-running layout would not have needed.
Which means the honest carbon case for an underslung crane is geometric, not atmospheric. You choose it because there is no column line to hang a runway on, or because the eaves are already fixed and the hook has to reach lower. If you are designing a new building with a free choice, the top-running layout usually wins on steel once you need more than one crane per bay.
That is an uncomfortable thing for a crane supplier to write. It is also the conclusion our own numbers produce, and buyers check.
No. The runway and the roof steel around it very often are. This is the part of the carbon conversation that has money attached, and it turns on customs codes rather than tonnage.
CBAM, under Regulation (EU) 2023/956, covers Annex I goods: all of Chapter 72, selected Chapter 73 codes including 7301, 7302, 7308 and 7318, plus aluminium, cement, fertilisers, electricity and hydrogen. Cranes sit in Chapter 84 under heading 8426. Heading 8426 is not in Annex I.
| What you buy | Typical code | In CBAM Annex I | Who reports |
|---|---|---|---|
| Suspension crane, complete | 8426 | No | Nobody |
| Track beams bought separately | 7308 | Yes | Importer of record |
| Crane rail, QU sections | 7302 or 7308 | Yes | Importer of record |
| Hanger rods, clamps, bolts | 7318 | Yes | Importer of record |
| Fabricated steel for roof strengthening | 7308 | Yes | Importer of record |
The same tonne of steel is therefore either CBAM-free or CBAM-liable depending on who buys it and how it is declared. Ship a crane with its runway beams in the same packing list and the whole consignment usually travels as an 8426 machine. Buy the runway from a steel fabricator in a separate order and it arrives as 7308 goods with embedded emissions attached.
Do not read that as advice to reclassify. General Interpretative Rule 2(a) and the CJEU judgement in Case C-107/22 (27 April 2023) both say that parts presented together and assembled with bolts, rivets or welding are classified as the complete machine. Splitting a crane to dodge CBAM changes the freight bill and nothing else.
The importer, if they cross the threshold. An importer has to become an authorised CBAM declarant once imports of Annex I goods exceed 50 tonnes per calendar year across all CN codes combined, from 1 January 2026. The first declaration and surrender covers the 2026 import year and falls due on 30 September 2027.
Certificate prices for 2026, from the Commission's published quarterly averages, were 75.36 euro in Q1, 75.28 in Q2 and 82.32 in Q3. From 2027 they move to a weekly publication.
| 2026 quarter | Certificate price | Published |
|---|---|---|
| Q1 | EUR 75.36 | 7 April 2026 |
| Q2 | EUR 75.28 | 6 July 2026 |
| Q3 | EUR 82.32 | 5 October 2026 |
| Q4 | Due 4 January 2027 | Quarterly, then weekly |
Run the numbers on a 7 tonne runway package at blast furnace intensity and you get 16.4 tonnes of embedded CO2. The charge is not levied on all of it, because free allocation is phased down against a benchmark, so the number that matters is the gap between your mill's intensity and the benchmark. As an illustration, a half-tonne-per-tonne excess on 7 tonnes at 82.32 euro lands around 290 euro. A full tonne excess lands near 580 euro. Neither is a project killer. Both are arguments a buyer will use in a price negotiation, which is the real reason to have the data ready.
For heavy cranes electricity dominates. For a suspension crane it does not, and that reverses the priority.
Take the 2 tonne machine with its 4.2 kW installed power, a 35 percent demand factor over 2,000 hours a year, which is an A4-A5 duty pattern. That is 1.47 kW average and 2,940 kWh a year, or 58,800 kWh over twenty years.
| Component | EU grid 206 g/kWh | China grid 537 g/kWh |
|---|---|---|
| Crane embodied A1-A3 | 5.7 t | 5.7 t |
| Support steel A1-A3 | 11.8 t | 11.8 t |
| 20 years of electricity | 12.1 t | 31.6 t |
| Total | 29.6 t | 49.1 t |
| Operating share | 41 percent | 64 percent |
On a clean European grid, steel is the majority of a suspension crane's lifetime footprint. That is the opposite of what we wrote about heavy double girders, where twenty years of electricity runs four to five times the embodied carbon.
Which means the retrofit market has it backwards. Buyers ask us about VFDs and energy monitoring on machines that draw 4 kW. The steel decision was made years earlier, at the mill, and it is worth more.
The mill route is the only lever that moves the embodied number by a factor rather than a percentage point. Blast furnace at 2.34, global average 1.92, scrap-based electric arc at 0.69. Switching a tonne of plate from blast furnace to scrap-EAF saves about 1.65 tonnes of CO2.
| Steel premium | Abatement cost | For 5.05 t of support steel |
|---|---|---|
| USD 60 per tonne | USD 36 per t CO2e | 8.3 t saved for USD 303 |
| USD 100 per tonne | USD 61 per t CO2e | 8.3 t saved for USD 505 |
| USD 150 per tonne | USD 91 per t CO2e | 8.3 t saved for USD 758 |
Compare that with EU allowances trading around 80 euro and the CBAM Q3 certificate at 82.32, and low-carbon steel stops being a virtue signal. It is cheaper than the alternative compliance route, at the top of the premium range.
The catch is availability. Mill certificates with a declared EAF route and a verified intensity are still rare from Chinese suppliers outside the major integrated mills. Ask for the mill certificate with the heat number and the route, not a letter saying "environmental steel".
No, and be careful with anyone who says yes.
EN 15804+A2 puts recovery benefits in Module D, outside the system boundary. The 5.05 tonnes of support steel will mostly be recovered at end of life, and at 85 to 98 percent recovery with a 1.65 tonne credit per tonne of scrap substituted, that is 7 to 8 tonnes of credit on paper.
It sits outside the boundary on purpose. Using it to net off A1-A3 lets anybody claim a neutral crane by promising to recycle it in thirty years. When you see a supplier present a carbon figure with a minus sign in front of it, ask which module the minus belongs to.
Ten lines. Ask for them in writing, and treat a refusal as an answer.
| # | Ask for | Why it matters |
|---|---|---|
| 1 | Crane deadweight and wheel load drawing by span | Every other number depends on it |
| 2 | Suspension point design load, with the dynamic factor stated | Not the same as rated capacity |
| 3 | Hanger spacing assumed and track section proposed | Sets both mass and roof strengthening |
| 4 | Scope split for rods, brackets, bracing, strengthening | The classic gap between two quotes |
| 5 | Who signs the roof capacity check | Your engineer, not the crane seller |
| 6 | Track tolerance standard and acceptance method | ISO 12488-1 is the usual reference |
| 7 | Steel route and mill certificate with heat number | Moves the number by a factor of 3.4 |
| 8 | Whether track ships with the crane or separately | 8426 or 7308, which decides CBAM |
| 9 | Bracing layout in both directions, corners and splices | Required by ASME B30.11 |
| 10 | Load test report, 125 percent static and 110 percent dynamic | The file that ends arguments |
Our own suspension crane range is quoted with items 1 to 3 as standard, because a suspension point load that arrives after the roof drawings is a redesign, not a price. If the bay has columns free, a top-running single girder will usually carry the same load with less total steel.
Write the four numbers down before you compare prices. Crane steel, support steel, mill route, and building height. Then decide. The crane is the smallest of the four, and it is the one everybody negotiates over.
Sometimes, but less often than buyers hope. The deciding number is the suspension point load, not the rated capacity. A 2 tonne crane typically puts about 3.2 tonnes into a single hanger point once wheel load and dynamic factor are included, and a general warehouse roof was designed around 0.4 kN per square metre of imposed load. Have your structural engineer check the beam, the local flange condition where the clamp sits, and the connections.
Roughly 5 tonnes for a 60 metre runway at 16.5 metre span, against a crane that weighs 2.8 tonnes. That breaks down as 3.1 tonnes of track beam, 0.3 tonnes of hangers and brackets, 0.55 tonnes of sway bracing and about 1 tonne of roof strengthening. The bracing is mandatory under ASME B30.11 in both directions at all four corners and at splices.
Only if it replaces building height. An underslung crane needs about 1.2 to 1.8 metres less eaves, which is worth roughly 6.8 tonnes of CO2e per metre per 1,000 square metres of building. That credit roughly cancels the roof steel for one crane per bay. With three cranes in the same bay you are 25 tonnes of CO2e worse off than a top-running layout.
No. Cranes are classified in heading 8426, which is not in Annex I of Regulation (EU) 2023/956. Track beams (7308), crane rail (7302 or 7308), hanger rods and bolts (7318) are in scope when imported as separate goods. If the crane and its runway ship together as one machine, the consignment usually travels under 8426. Splitting the order to avoid CBAM does not survive Rule 2(a) or Case C-107/22.
About 5.7 tonnes of CO2e at blast furnace intensity, 4.7 at the global average, and 1.7 with scrap-based electric arc steel, using worldsteel 2024 intensity data. Add roughly 5 to 8 percent for fabrication electricity. The support steel around it adds another 11.8 tonnes, so the system figure is nearer 17.5 tonnes. See our underslung crane specifications for the mass figures this is based on.
No. Catalogue deadweight covers the bridge, end trucks, hoist and electrical set. Track beams, hanger rods, brackets, bracing and any roof strengthening are separate scope, usually quoted by a steel fabricator or by the building contractor. That is why two quotes for the same crane can differ by a factor of two once the support steel is priced.
Related articles:
Crane Carbon Footprint: What a Single Girder Crane Emits Before It Lifts Anything
Crane Embodied Carbon: What a 20 Tonne Double Girder Actually Carries
Suspension Crane Energy Consumption: What the Machine Really Draws, 0.5 to 5 Ton
Suspension Crane Installation and Commissioning: Hanger Loads, Bracing and Load Tests
Suspension Crane Cost: Equipment, Installation and Ten Year TCO, 0.5 to 5 Ton
Suspension Cranes: 0.25 to 5 Tonne, 3 to 16 m Span, Roof Suspended Track