Cable Span Reference

Span, sag, and cable length by tension assumption

Every span below uses the same illustrative cable weight (1 kg/m) at three tension assumptions. Sag and cable length are read straight off calcCableSag() and calcRopeLength() — nothing here is a hand-typed number.

Span	Light tension		Medium tension		Taut tension
	Sag	Cable length	Sag	Cable length	Sag	Cable length
50 m	1.53 m	50.1246 m	0.61 m	50.0198 m	0.31 m	50.0051 m
100 m	6.13 m	100.993 m	2.45 m	100.1598 m	1.23 m	100.0403 m
150 m	13.78 m	153.3074 m	5.51 m	150.538 m	2.76 m	150.1353 m
200 m	24.5 m	207.7151 m	9.8 m	201.2732 m	4.9 m	200.3197 m
300 m	55.13 m	324.8265 m	22.05 m	304.2658 m	11.03 m	301.0779 m
450 m	124.03 m ⚠	524.5404 m	49.61 m	464.1592 m	24.81 m	453.621 m

⚠ marks a cell where sag has grown large enough, relative to the span, that the shallow-sag (parabolic) approximation is no longer considered reliable — see the FAQ below.

Ascent time by span and line speed

Using each span as the ride distance, calcAscentTime() gives the travel time at a few typical line speeds. No station dwell time is added here — see the Ascent Time Calculator to add your own.

Span	4 m/s	5 m/s	6 m/s
50 m	12.5s	10s	8.33s
100 m	25s	20s	16.67s
150 m	37.5s	30s	25s
200 m	50s	40s	33.33s
300 m	75s	60s	50s
450 m	112.5s	90s	75s

Hourly capacity by carrier size

Held at one fixed, illustrative spacing (80 m) and line speed (5 m/s) so only carrier size varies, sourced from calcCapacityThroughput(). This is independent of span — see why in the FAQ below.

Riders per car	Headway	Cars per hour	Riders per hour
4	16s	225	900
8	16s	225	1,800
15	16s	225	3,375
30	16s	225	6,750

What this reference is showing

Read any single span across its three tension columns and the core trade-off in ropeway cable engineering becomes visible without any calculation of your own: pulling the same cable tighter always reduces sag, and it does so sharply, not gradually. At a 200 m span, moving from light to taut tension cuts the sag by exactly the same 5× factor the tension itself increases by — and the cable-length column shows the direct consequence: a slacker cable needs noticeably more physical rope to cross the same horizontal distance.

The warning triangle on the 450 m row is the other half of the lesson. The shallow-sag approximation this whole site’s calculators use is a stand-in for the true catenary curve, valid only while sag stays small relative to span. Push a long span to a light tension and the model itself tells you it’s left its comfort zone — which is exactly the kind of boundary a real design process would need to check with the full catenary equation, not this approximation.

The ascent-time and capacity tables are deliberately independent of each other. A longer span simply takes longer to ride at a given speed — it does not, on its own, move more or fewer people per hour. Hourly capacity instead comes entirely from how tightly cars are spaced and how big they are, which is why the capacity table holds span out of the picture and varies carrier size on its own.

Every figure on this page is illustrative physics computed from a simplified, educational model — not a specification for any real cable car, gondola, or funicular, and not a substitute for certified ropeway engineering.

Use it with

Cable Span Sag Calculator— run your own span, weight, and tension instead of picking from the presets above.
Sag and Tension: The Trade-off Every Ropeway Cable Makes — the guide behind the sag table, with the reasoning spelled out.
The Catenary and the Parabola: Two Different Curves, One Sagging Cable — why this page uses a parabola at all, and where that approximation stops working.

Frequently Asked Questions

Is this table a design reference for building a ropeway?

No. Every number on this page comes from the same illustrative, shallow-sag physics model behind the Cable Span Sag Calculator, Rope Length Calculator, Ascent Time Calculator, and Cable Car Capacity Calculator — it exists to make the relationships between span, tension, sag, speed, and capacity visible, not to spec a real installation. Real ropeway cable, tower, and drive design is a certified engineering discipline governed by codes such as EN 12929 or equivalent national standards, carried out by a qualified engineer with margins this page does not model.

Why does the same span show three different sag values?

Each span is run through the sag formula three times, once per illustrative tension assumption (light, medium, taut), holding the cable's weight per meter fixed. The three sag figures for one span show the same inverse relationship the Cable Span Sag Calculator demonstrates for any single input: more tension always produces less sag for an unchanged span and cable weight.

What does it mean when a cell is marked as outside the model's valid range?

The shallow-sag (parabolic) approximation used here is only accurate while sag stays small relative to the span — as a rule of thumb, while sag is no more than about 20% of the span. The 450 m row at light tension crosses that threshold, which the table flags rather than silently reporting a number the model can no longer be trusted for. Past that point a full catenary solution is the correct model, not this approximation.

Why does the capacity table not change with span?

Hourly capacity in this model is a function of carrier size, car spacing, and line speed — not the total span length. A short span and a long span running the same spacing and speed move the same number of riders per hour; what changes with span is how long the ride itself takes, which is what the ascent-time table shows instead.