Elevator rope calculation example
Two complete sample calculations generated by RopeFactor: a metric example using ISO 8100-2 and an imperial example using ASME A17.1. The full PDF reports are available for download. Each report gives the inputs, formulas, substituted values, results and applicable references for every check.
Metric example: ISO 8100-2
Mid-rise passenger elevator with a 1,450 kg car, 1,600 kg rated load and 2,250 kg counterweight. Five 13 mm ropes on a 560 mm drive sheave, 1:1 roping, 45 m travel and a rated speed of 1.6 m/s. Traction is based on a 90° undercut U-groove with a 35° groove angle. The example assumes office service at 200 trips per day.
| Check | Result | Basis |
|---|---|---|
| Factor of safety | 16.96 vs 13.88 required | ISO 8100-2 §4.12.3 Formula (36) |
| Sheave ratio Dt/dr | 43.08 vs 40 required | ISO 8100-1 §4.5.2.1 Table 11 |
| Per-rope tension Tmax | 6.31 kN | car side, full load |
| Rope loading | 2.81 % / 5.90 % of MBF | empty / full |
| Hoist rope order | 65 m per rope | overhead 1:1, planning estimate |
Imperial example: ASME A17.1
Passenger elevator with an 8,000 lb car, 4,000 lb rated load and 10,000 lb counterweight. Six ½ in ropes on a 24 in drive sheave, 1:1 roping, 200 ft travel and a rated speed of 350 fpm. The example uses 180° rope wrap and assumes office service.
| Check | Result | Basis |
|---|---|---|
| Factor of safety | 12.71 vs 9.50 required | A17.1 §2.20.3, exact Table 2.20.3 speed row |
| Sheave ratio Dt/d | 48.0 vs 40 required | A17.1 §2.24.2.2 |
| Max static load W | 12.56 kips | includes suspension-rope self weight |
| Rope loading | 5.19 % / 7.87 % of MBF | empty / full |
| Hoist rope order | 250 ft per rope | overhead 1:1, planning estimate |
Download the ASME report (PDF)
What is included in the report
- Rope selection and factor of safety — rope properties, installation data, required and actual factor of safety, and rope loading, with the applicable standards referenced.
- Traction — groove friction calculation, and available traction compared with the requirement for normal loading, emergency braking and stalled conditions.
- Rope life — estimated bending fatigue from the traction sheave, simple bends and reverse bends, including Palmgren-Miner cumulative damage and 10th-percentile and mean service life.
- Elongation — estimated elastic elongation at rated load and constructional stretch.
- Rope dynamics — lateral and longitudinal rope frequencies over the travel, compared with sheave excitation frequencies.
- Groove pressure — calculated specific groove pressure for the selected groove geometry. No code acceptance limit is applied.
- Rope order estimate — estimated hoist, governor and compensation lengths, with the allowances used and their source, on a separate planning page.
See also
ISO 8100-2 minimum rope safety factor ASME A17.1 minimum rope safety factor by speed Elevator rope order length — the four reeving formulas Elevator overhead: which dimension is used?