A ski gate has to come apart when it is hit, and stay together when it is hit

Most sports treat their furniture as something to be avoided. A goalpost is a boundary, a net is an obstacle, a hurdle is there to be cleared. Alpine skiing is unusual in that its furniture is designed on the assumption that a competitor will hit it, repeatedly, at speed — and the rules governing gates are almost entirely about the collision.

The pole that bends

Flex poles are fitted with a bending device and must conform to the FIS specifications. They must be used for all alpine competitions published in the FIS Calendar except downhill, and in downhill the Jury may request them.

Reference That flex poles are fitted with a bending device, must conform to FIS specifications, and must be used in all alpine competitions in the FIS Calendar except downhill, where the Jury may request them, from Articles 680.2 and 680.2.1.

The requirement is targeted, not general. In slalom, the turning pole must be a flex pole; rigid poles may be used for the outside gate or pole, and in exceptional cases such as high wind, as the outside pole of the turning gate.

Reference That the slalom turning pole must be a flex pole, that rigid poles may be used for the outside gate or pole, and that in exceptional cases such as high wind a rigid pole may be used as the outside pole of the turning gate, from Articles 680.2.1.1 and 680.2.

That division follows the geometry of the sport exactly. A slalom racer’s line takes them through the turning pole — knocking it down with a forearm or a shin is the correct technique, not a mistake — and past the outside pole without touching it. So the pole that gets hit bends, and the one that does not need not.

The exception for high wind is the tell that this is engineering rather than principle. A pole light enough to fold under a shin is light enough to be moved by weather, and the Jury is given the discretion to trade one problem for the other.

The panel that must do two opposite things

Giant slalom and super-G add panels, and the requirements on them are the most interesting sentences in the article.

Gate panels should release from the pole when a competitor gets caught by it, and the panel must meet the test requirements for that as defined in the specifications for Gate Panel Homologation.

Reference That gate panels should release from the pole when a competitor gets caught by it, and must meet the test requirements defined in the specifications for Gate Panel Homologation, from Article 690.1.

And immediately afterwards:

During normal collisions, the gate panel should not release from the pole — and the panel must meet the test requirements for that, too.

Reference That during normal collisions the gate panel should not release from the pole, and must meet the test requirements defined for that in the Gate Panel Homologation specifications, from Article 690.2.

Read side by side these look contradictory. They are not; they are a specification with two thresholds, and the distinction between them is the difference between a skier hitting a panel and a skier being caught by one.

A racer brushing a panel at speed transfers a large force for a very short time. A racer whose arm, ski or clothing snags on a panel loads it in a sustained way, and if the panel holds, the skier is now attached to a fixed object on a mountainside. The first case must not tear the course apart; the second must let go immediately.

Designing a fastening that distinguishes between those two loadings is a real materials problem, which is why FIS does not describe the fastening at all. It states the two behaviours, points at a homologation test for each, and publishes a list of panels that have passed.

Reference That gate panels conforming to the FIS Specifications must be used for all giant slalom, super-G and downhill competitions in the FIS Calendar, and that a list of homologated panels is published on the FIS website, from Article 690.

This is the same pattern the UCI uses for wheels — the governing body defines the required behaviour and delegates the test — and the opposite of the approach it uses for a bicycle frame, where the rule draws boxes and measures the shape.

The panel that must let wind through

One more requirement sits beside the release behaviour, and it is easy to miss: the panel must be made of wind-permeable material.

Reference That the panel must be made of wind-permeable material, from Article 690.3.

A panel roughly 0.75 m wide and 0.50 m high, mounted about a metre above the snow, is a small sail. On an exposed slope, a solid one would either bend its poles out of position or take them out of the ground — and a gate that has moved has changed the course between the first competitor and the fortieth.

Which explains the clause that follows it, and which reads like a note from a commercial department that has been overruled: advertising on panels should not reduce wind permeability or the release mechanism of the panels.

Reference That advertising on panels should not reduce wind permeability or the release mechanism of the panels, from Article 690.4.

The panels carry sponsorship. The sponsorship may not be printed in a way that fills the mesh or interferes with the fastening. Two of the three requirements on a gate panel are, in practice, requirements on what may be printed on it.

Colour, and the one place softness is allowed

The rest of the specification is about being seen. Consecutive slalom gates must alternate in blue and red, gates in giant slalom and super-G must be alternately red and blue, and orange may be used instead of red at all FIS levels — with poles and panels the same colour.

Reference That consecutive gates alternate in blue and red, that orange may be used instead of red at all FIS levels, and that poles and panels should be the same colour, from Articles 801.2.2, 901.2.2 and 695.

Super-G adds a discretionary override: where a panel colour cannot be seen properly against the backdrop — safety netting, for example — the Jury can choose an alternative colour for that specific gate to improve visibility.

Reference That in special circumstances where a panel colour cannot be seen properly against the backdrop the Jury may decide an alternative colour for that specific gate, from Article 1001.3.2.

Per gate, by the Jury, on the day. A rule about colour that acknowledges the colour behind it.

And finally, the smallest clause in the section, which points back at everything above. All competitors and forerunners must wear a crash helmet meeting the FIS Equipment Specifications — and soft ear protection is only permitted for helmets used in slalom.

Reference That all competitors and forerunners must wear a crash helmet meeting the FIS Equipment Specifications, and that soft ear protection is only permitted for helmets used in slalom, from Article 707.

Slalom is the discipline where the racer’s head passes closest to the poles, and it is the only one where the helmet is allowed to be softer at the ear. The whole of Article 680 and 690 is about what a gate does to a skier; that one sentence is the same question asked from the other side.