Tool · Engineering calculator

Crane Wheel & Rail Sizing Calculator

Check a rail wheel and its running surface to AS 5228.1:2021 (ISO 16881-1 MOD): capability and wear equations, limiting pressure P_L, speed and mechanism-group coefficients, useful rail width and the Australian annex rail check. Indicative only — see the disclaimer.

Engineering disclaimer — read before using this tool

This calculator is not a substitute for professional engineering advice. It is provided by Sorian Holdings Pty Ltd (trading as Sorian Cranes) for general information and preliminary sizing only. It is not engineering advice, not a design verification or certification, and not a design to AS 1418, AS 4100 or any other standard.

Results depend entirely on the values you enter and on the simplified, published methods described on this page, which may not apply to your crane, beam, structure, materials, duty or site. The tool cannot see your installation and does not check fatigue, global beam strength, deflection, lateral-torsional buckling, connections, runway alignment, wear, corrosion or existing damage.

Any crane, monorail, runway or structural design must be prepared or verified by an appropriately qualified professional engineer who has reviewed your actual conditions — and, where state law requires it (for example Queensland's RPEQ scheme and Victoria's Professional Engineers Registration Act), a registered professional engineer — before fabrication, installation, modification, load testing or use.

To the maximum extent permitted by law, Sorian Holdings Pty Ltd and its directors, employees and partners accept no liability for any loss, damage, injury or death arising from use of, or reliance on, this tool or its output. Nothing on this page excludes, restricts or modifies any consumer guarantee or other right under the Australian Consumer Law that cannot lawfully be excluded. By using the calculator you accept these terms and our website terms.

Inputs

Wheel loads (per wheel)

P_max static (kN)Maximum static wheel load, crane loaded at MRC in the most unfavourable position, no dynamic factor. P_min static (kN)Minimum static wheel load for the same wheel (crane unloaded, load at the far end). Dynamic / test factor on P_maxApplied to P_max for Equation (1) only. Use the governing value from the AS 5221.1 load combinations (φ₂ hoisting, or 1.25 for the static test load if it governs). P_mean is calculated without φ, per Clause 4.1.2.

Wheel

Wheel type Tread diameter D (mm)Formulae valid to 1250 mm (Clause 4.1.7). Wheel material, min. UTS f_u Table 1. Tread hardening may be counted only if its depth is at least 0.01 D (Clause 4.1.4). Confirm with the mill certificate. Travel speed v (m/min)Normal (usually maximum) speed of the motion — sets wheel r/min for c₁ (Table 2). Mechanism group (AS 5246.1) Group of the travel mechanism the wheel belongs to — c₂ from Table 3. Not the crane class A1–A8. Contact profile

Rail or wheel has a slightly convex bearing surface — P_L may be increased 10 % (Clause 4.1.3)

Rail / running surface

Rail or running surface Rails in AS 5228.1 Table 102 carry their minimum UTS and p_TS; head widths are pre-filled from the AS 1085.1 and DIN 536-1 profiles. Billets and the 31 / 47 kg rails are checked with Equation 103(2) from the material grade you enter. Rail head width l (mm) Head corner radius r (mm)b = l − 2r, Equation (4). Use the chamfer size for a chamfered billet. Rail / surface min. UTS f_u (MPa)Table 1 sets a minimum rail UTS for each P_L row; P_L is governed by the weaker of wheel and rail (AS 1418.18 Cl 5.12.4). Rail / surface yield F_YT (MPa)Used for unlisted rails, billets and beam flanges: P_TS = 0.0049·D·b·(F_YT/400)², Equation 103(2). Grade 300 billet ≈ 300–320 MPa yield / 440 UTS; K1045 and 4140 from the mill certificate.

Rail duty (Australian annex, Cl 4.1.106)

Class of utilisation U (AS 5246.1 Table 2) Upper bound of the class is used for U_n. Wheels travelling on this rail N_WNumber of wheels that run along the one rail (e.g. 2 for a 4-wheel crane). Rail attachment

Results

—Enter the wheel loads, wheel and rail to run the checks.

Indicative only. Not professional engineering advice and not a design verification — see the disclaimer above. Have an appropriately qualified engineer verify any design before fabrication, installation or use.

Ask an engineer to check it →

Method — what the calculator does

Every number comes from AS 5228.1:2021 Cranes — Design calculation for rail wheels and associated trolley track supporting structure, Part 1: General (ISO 16881-1:2005, MOD), which AS 1418.1:2021 and AS 1418.18:2024 call up for wheel and rail design. Clause references below are to AS 5228.1.

1. Wheel loads

Enter the maximum and minimum static wheel loads for the wheel being checked. The capability check uses P_max multiplied by the governing dynamic or test factor from the AS 5221.1 load combinations (Clause 4.1.1). The mean load for the wear check is taken without dynamic coefficients (Clause 4.1.2):

P_mean = (P_min + 2·P_max) / 3 Eq (3)

2. Useful width and the two wheel checks

b = l − 2r      rail with rounded corners of radius r          Eq (4)
b = w − r       flat, tapered or convex wheel on a beam flange  Eq (5)

P_max / (b·D) ≤ 1.9 · P_L                 capability             Eq (1)
P_mean / (b·D) ≤ P_L · c1 · c2            normal duty / wear      Eq (2)

P_L is the limiting pressure from Table 1, read against the wheel material's minimum ultimate tensile strength; each row also carries a minimum rail strength, and the calculator drops to the highest row both materials satisfy (AS 1418.18:2024 Clause 5.12.4: P_L is determined by the ultimate strength of both). A 10 % increase is allowed for a slightly convex rail or wheel (Clause 4.1.3). Formulae apply to wheels up to 1.25 m diameter (Clause 4.1.7).

Wheel f_u (MPa)	P_L (N/mm²)	Min. rail f_u (MPa)
> 500	5.00	350
> 600	5.60	350
> 700	6.50	510
> 800	7.20	510
> 900	7.80	600
> 1000	8.50	700

c₁ (Table 2) depends on wheel speed of rotation, n = 1000·v / (π·D) r/min, from 1.16 at 5 r/min to 0.66 at 200 r/min; the calculator interpolates between the tabulated values and flags speeds outside the table. c₂ (Table 3) depends on the mechanism group of the travel motion: M1–M2 = 1.25, M3–M4 = 1.12, M5 = 1.00, M6 = 0.90, M7–M8 = 0.80.

3. Australian annex — rail load capacity (Clause 4.1.106)

The Australian modification adds a check on the running surface itself. The mean wheel load must not exceed the permissible mean wheel load on the rail:

P_T  = C_R · P_TS                                            Eq 101
C_R  = 20 000 / N_XW^(2/3)
N_XW = 2 · U_n · N_W        (min 8×10⁵, max 38×10⁵)             Eq 102
P_TS = D_W · p_TS           rails listed in Table 102           Eq 103(1)
P_TS = 0.0049 · D_W · b · (F_YT / 400)²   other rails, billets, beam flanges   Eq 103(2)

U_n is the number of load applications over the crane's design life from AS 5246.1:2021 Table 2 (the calculator uses the upper bound of the selected U class), N_W the number of wheels that travel along the rail. For readily removable rails the cycles may be reduced to 40 % for a 10-year life (Clause 4.1.106.3 note). Rails must conform to AS 1085.1, DIN 536-1 or be another suitable rolled section designed for a 25-year life if permanently attached (Clause 4.1.106.1).

Rails used in Australia. Most Australian crane runways run on a welded square billet (50 × 50 up to 100 × 100, Grade 300 or a harder K1045 / 4140 bar), an AS 1085.1 railway rail (31, 41, 47, 50, 53, 60 or 68 kg/m — head widths 63.5 to 74.6 mm) or a DIN 536-1 crane rail (A45 to A150). The list is ordered that way. Table 102 gives p_TS and minimum UTS for the 41, 50, 53, 60 and 68 kg AS rails and the DIN A-rails; billets and the 31 and 47 kg rails are checked with Equation 103(2) from the grade you enter. Head corner radii are taken from the rail drawing — for a crowned railway rail the corner radius, not the crown radius. AS 1418.18 Clause 7 recommends billets at least 50 mm high and wheels slightly less hard than the rail.

4. What it does not do

It does not derive your wheel loads. They come from the crane's load combinations (AS 5221.1 / AS 5221.3) and, for a monorail trolley, from the hoist manufacturer — AS 1418.18 notes a four-wheel trolley can carry most of its load on two wheels.
It does not check the local stresses in the girder web or welds (AS 5228.1 Annexes A and B), rail fastening and welding (Clause 4.1.107), tolerances (AS 5229.1), nor the beam itself (AS 1418.18 / AS 4100).
It does not check the bottom flange of a monorail for local bending under the trolley wheels — use the bottom flange stress calculator for that.

Frequently asked questions

Which standard does this wheel and rail calculator follow?

AS 5228.1:2021 Cranes — Design calculation for rail wheels and associated trolley track supporting structure, Part 1: General, which adopts ISO 16881-1:2005 with Australian modifications. AS 1418.1:2021 requires wheel and rail design to AS 5228.1, and AS 1418.18:2024 Clause 5.12.4 applies the same equations to monorail trolley wheels. The calculator implements Equations (1) to (5), Tables 1 to 3 and the Australian annex Clause 4.1.106 rail-capacity check.

What is PL, the limiting pressure?

PL is the limiting pressure between wheel and rail in N/mm², read from Table 1 of AS 5228.1 against the ultimate tensile strength of the wheel material. Each row also sets a minimum ultimate strength for the rail; where the rail (or beam flange) is weaker, AS 1418.18 Clause 5.12.4 requires PL to be governed by the weaker of the two, which this calculator does automatically.

Should I use the crane class (A1–A8) or the mechanism group (M1–M8)?

The mechanism group. Coefficient c2 in Table 3 of AS 5228.1 depends on the group of the travel mechanism the wheel belongs to (M1 to M8 per AS 5246.1 / ISO 4301-1), because wheel wear follows wheel rotations, not the crane's structural class. Clause 4.1.6 of AS 5228.1 shows how to derive the mechanism class from working cycles, travel distance and speed.

Why are there two checks on the wheel?

Equation (1) verifies the wheel can withstand the maximum load (including dynamic factors or static test loads): Pmax/(b·D) ≤ 1.9·PL. Equation (2) is the wear criterion for normal duty: Pmean/(b·D) ≤ PL·c1·c2, where Pmean = (Pmin + 2·Pmax)/3 is calculated without dynamic coefficients. Both must pass.

Does this replace an engineer's design?

No. It is an indicative check only and is not a substitute for professional engineering advice. Wheel loads must come from the load combinations in AS 5221.1 / AS 5221.3, and the final design must be verified by an appropriately qualified (and, where required, registered) professional engineer.

References: AS 5228.1:2021 Clauses 4.1.1–4.1.7, Tables 1–3, Australian annex Clauses 4.1.106 and Table 102; AS 5246.1:2021 Table 2; AS 1418.1:2021 Clause 7.20; AS 1418.18:2024 Clause 5.12.4; AS 5221.1:2021 Clause 6.1. Standards are copyright Standards Australia — this page paraphrases the method and reproduces only the coefficient values needed to run it.

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