Two mobile yard ramps, both stamped 10 t. One of them is overloaded every shift by a forklift-and-pallet combination that never weighs more than 8 t on the scale. The difference is not the steel or the welds — it is the rating method behind the number, and it is the most expensive misunderstanding we see in RFQs from North America, Europe and Australia.
A Capacity Number Is a Rating Method, Not a Load Limit
Every ramp rating answers four questions that are never printed on the plate: which load, in which position, travelling how fast, and how many times per shift. A 10 t figure can mean 10 t sitting still and evenly spread, 10 t rolling across the middle two hundred times a day, or 10 t with the design factor already consumed inside the number.
Three rating systems generate the numbers you meet in tenders. North America rates built-in leveling devices with a comparative industry rating tied to the ANSI MH30.1 and MH30.2 test standards. Europe defines loads rather than publishing a nameplate ladder, under EN 1398. Mobile yard ramp specifications, including ours, quote a working load with the design factor already inside it. Converting between those three systems is not optional arithmetic — it is the difference between a ramp that lasts fifteen years and one that goes out of alignment in the second year.
Static Capacity: The Stored, Evenly Distributed Load
Static capacity is the weight the deck supports when the load is stationary and distributed across the platform. It is the easiest condition the structure ever sees: no impact, no wheel-load concentration, no travelling bending moment. It is also the condition least like real work.
Read a rating plate carefully and you will find the static figure described in exactly those terms — stored, stationary, uniformly distributed. Nothing about it accounts for what happens when a loaded forklift drops onto the deck edge at walking pace, which is the moment that actually decides whether your ramp survives.
| Rating type | What it describes | Load condition | Where you meet it |
|---|---|---|---|
| Static capacity | Weight held by the deck | Stationary, evenly distributed | Catalogues, most nameplates |
| Dynamic capacity | Weight moving across the deck | Loaded forklift in transit | EN 1398 submittals, tenders |
| CIR | Comparative industry rating | Stored, evenly distributed | North American built-in levelers |
| Working load | Rated load with design factor included | Normal operating use | Mobile yard ramp datasheets |
Dynamic Capacity: What a Loaded Forklift Actually Puts Into the Deck
Dynamic capacity is the number that decides whether you are overloading. It is the heaviest combination of truck and load that can cross the deck in normal operation, and it is always lower than the static figure for the same structure — because acceleration, braking and the drop at the lip generate forces well above the parked weight.
The working method used across the industry is simple: take the forklift’s gross vehicle weight — truck, attachment, operator and load — and multiply it. A factor of 2.5 covers standard single-shift duty. High-cycle or heavy-duty operations run 3 to 4. Run that arithmetic and the reason two 10 t ramps behave differently becomes obvious.
| Forklift + load (GVW) | Standard duty × 2.5 | High-cycle × 3 | Realistic application |
|---|---|---|---|
| 4,000 kg / 8,800 lb | 10,000 kg / 22,000 lb | 12,000 kg / 26,500 lb | Light warehouse, pallet trucks, single shift |
| 5,000 kg / 11,000 lb | 12,500 kg / 27,600 lb | 15,000 kg / 33,000 lb | Standard counterbalance, general distribution |
| 6,500 kg / 14,300 lb | 16,250 kg / 35,800 lb | 19,500 kg / 43,000 lb | Dense loads, two to three shifts |
| 8,000 kg / 17,600 lb | 20,000 kg / 44,000 lb | 24,000 kg / 53,000 lb | Heavy industry, steel, paper, coils |
This is where most off-by-one-capacity mistakes start. A 5,000 kg truck carrying 1,500 kg is a 6,500 kg crossing, not a 5,000 kg one. Put that combination on a ramp sized to the truck’s own weight and you are outside the rating on every single trip — and the failure mode is not a snapped beam. It is a deck that slowly loses its camber, a lip that stops landing square, and a repair bill in year three.
CIR: A Comparative Yardstick, Not a Test Result
CIR stands for Comparative Industry Rating. North American manufacturers of built-in dock levelers use it as a shared sizing ladder, defined against the ANSI MH30.1 performance and testing standard. The important word is comparative: CIR lets one 35,000 lb unit be compared with another 35,000 lb unit. It does not describe the strength of the steel in front of you.
Two levelers with identical CIR can differ substantially in structure, and the difference is entirely visible in the submittal — deck plate gauge, cross-member section, lip plate thickness, hinge tube wall. That is why an experienced buyer reads the CIR as a shopping bracket and then reads the construction notes underneath it.
| CIR | Metric equivalent | Typical duty | Structure normally behind it |
|---|---|---|---|
| 25,000 lb | ≈ 11,300 kg | Light, pallet trucks | Roll-formed C channels, 1/2 in lip |
| 30,000 lb | ≈ 13,600 kg | Standard single shift | Roll-formed C channels, 5/8 in lip |
| 35,000 lb | ≈ 15,900 kg | General distribution | Structural C channels, 5/8 in lip |
| 40,000 lb | ≈ 18,100 kg | Busy cross-dock | Structural C channels, 5/8 in lip |
| 45,000–50,000 lb | ≈ 20,400–22,700 kg | Heavy industry | Structural channels, 3/4 in lip |
| 75,000–100,000 lb | ≈ 34,000–45,400 kg | Mill and port duty | I-beam frame, 3/8 in deck, 1 in T1 lip |
One more rule from the same standard family is worth memorising: ANSI MH30.1 requires the lip to overlap the trailer bed by at least 4 in (100 mm) for a safe purchase. A ramp can be perfectly rated and still be unsafe because the lip is only half on the trailer. Capacity and lip bearing are separate checks.
EN 1398 Speaks a Different Vocabulary
European buyers should ignore the CIR ladder entirely, because EN 1398 defines loads rather than naming capacity steps — and it defines three of them, which is where tenders go wrong.
| EN 1398 term | Definition | Worked example |
|---|---|---|
| Rated load | Total weight of goods, transport equipment and driver | 3,600 + 1,500 + 100 = 5,200 kg |
| Axle load | Two rectangular contact areas 1 m apart, footprint ratio W:L = 3:2, area derived from wheel load ÷ 2 N/mm² | Governs deck and lip structure, not the total |
| Dynamic load | Pressure on the platform caused by the moving forklift | Drives the test safety factor |
| Working gradient | Maximum 12.5%, approximately 7° | The slip limit, not a comfortable working grade |
The practical rule is short: the load capacity of the unit must always exceed the rated load. In the worked example above, a 5,200 kg rated load is served by a 6,000 kg (60 kN) unit — that is the standard European pairing for a 2,000–2,200 mm platform width. And on gradient, treat 12.5% as the cliff edge rather than a target. In France and Sweden, separately, dock levelers also fall under national inspection regimes with periodic statutory checks; capacity paperwork that cannot be produced on demand is a compliance problem, not just a maintenance one.
Sizing a Ramp in Five Steps — and Five Ways Buyers Break the Rating
The method that works in every market is the same, and it takes one email:
1. Weigh the heaviest configuration, not the average one. Attachments such as clamps, bale handlers and rotators shift axle load forward and add weight of their own. If the heaviest combination is a truck you only use twice a week, it still crosses the deck, and the deck does not know it is unusual.
2. Apply the multiplier. 2.5 for standard duty, 3 to 4 for high-cycle or heavy material. Write the resulting number down; that is the crossing load you are specifying against.
3. Add a working margin. Twenty to thirty percent above the heaviest realistic combination is normal practice, because cargo variance and operator habits are real variables.
4. Check the ground conditions. Wheel load concentrates over two contact patches. A three-wheel counterbalance truck or a narrow pallet-truck wheel puts far more force per square inch into the deck than a wide four-wheel truck of the same total weight.
5. Check entry and exit geometry. Nothing in a capacity rating compensates for off-centre loading, a steep approach angle or a deck entered at speed.
Then match the number to a real product. Our four hydraulic and mechanical families are built for different working ranges:
| Series | Frame | Lifting system | Working range | Best fit |
|---|---|---|---|---|
| HRHS | Reinforced I-beam plus rectangular tube | Heavy-duty hydraulic | 20–30 t | Ports, heavy logistics, daily industrial use |
| HRES | Reinforced I-beam | Heavy-duty electro-hydraulic | 20–30 t+ | High-throughput distribution, peak efficiency |
| HRYS | Rectangular tube frame | Standard hydraulic | 4–14 t | General warehousing, multi-dock sites |
| HRXS | Hybrid C-beam and I-beam | Mechanical, manual lift | 6–16 t | Cost-focused and remote sites, minimal maintenance |
Dimensions matter as much as the load figure. Our heavy-duty HRHS is 10,300 mm long and 2,200 mm wide (33 ft 9 in × 7 ft 3 in) with a 200 mm (8 in) guard rail; the modular ground-access HRMS widens to 4,400 mm (14 ft 5 in) because it carries two lanes. Same nominal capacity class, completely different traffic geometry.
Frequently Asked Questions
Is a 10 t ramp safe for a 6.5 t forklift and load?
Not automatically, and this is the classic error. 6.5 t is the crossing load, not the rated figure you should buy. Apply a 2.5 multiplier for standard duty and you are specifying against 16.25 t; a ramp stamped 10 t with the design factor consumed is already past its margin.
What does CIR actually stand for?
Comparative Industry Rating. It is a shared sizing ladder used across North American built-in dock levelers, defined against ANSI MH30.1. It allows like-for-like comparison between brands, but it says nothing on its own about deck gauge, cross-member section or lip thickness — read the construction notes as well.
Does a higher capacity rating always mean a safer ramp?
No. A heavier rating on a deck that is narrower than your load, or a lip that only overlaps the trailer bed by 50 mm (2 in), is still a hazard. ANSI MH30.1 asks for at least 100 mm (4 in) of lip bearing in the trailer; capacity and lip overlap are separate safety checks.
How do I compare a European EN 1398 rating with a North American CIR figure?
You do not convert them directly. EN 1398 defines a rated load and an axle load, and requires capacity above rated load; CIR is a comparative ladder. Convert both back to one common figure instead — your heaviest loaded forklift GVW with the duty multiplier applied — and specify against that.
Send the Load, Not the Capacity
If you tell us ‘an 8-ton ramp’, you will get a number. If you send the forklift model, its operating weight, the heaviest load, the daily crossing count and your trailer bed height range, you will get a rating calculation you can file next to the load test report. Start with our mobile yard ramps, then look at the HRHS heavy-duty hydraulic model for 20–30 t duty and the HRYS standard hydraulic model for 4–14 t duty. If your operation is a fixed dock rather than a yard, the same arithmetic applies to our dock levelers. Every unit ships with CE declaration, load test report and English manual; reach us through the contact page and we will confirm the rated capacity for your specific fleet.
