DISCUS THROW

Discus throw is a throwing event where athletes throw a 2kg platelike implement from a 2.5m circle. The discus is launched after the thrower, starting at the back of the circle, has completed one-and-a-half turns. The facility for discus throw includes a throwing circle, protective cage and landing sector.

The throwing circle is made of bank iron, steel or other suitable material, the top of which is flush with the ground outside. The inside diameter of the circle measures 2.5m (±5mm) and the rim at least 6mm in thickness, 70mm to 80mm deep and painted white.

The interior of the circle is constructed of concrete, asphalt or some other firm but not slippery material. The surface must be level and 1.4cm–2.6cm lower than the upper edge of the rim of the circle.

All discus and hammer throws are made from an enclosure or cage to ensure safety of spectators, officials and athletes. The cage shown in the following diagram is intended for use when the event is held in the arena with other events taking place at the same time or spectators are present. Where this does not apply, and especially in training areas, a much simpler construction may be satisfactory.

The cage is designed, manufactured and maintained to be capable of stopping a 2kg discus moving at a speed of up to 25m per second. There must be no danger of the discus ricocheting or rebounding back towards the athlete or over the top of the cage. If these requirements are satisfied, any form of cage design and construction can be used.

The cage is U-shaped. The width of the mouth is 6m, positioned 7m in front of the centre of the throwing circle. The end points of the 6m wide mouth are the inner edge of the cage netting. The height of the netting panels or draped netting at their lowest point is 4m. Provision must be made in the design of the cage to prevent a discus forcing its way through any joints in the cage or the netting or underneath the netting panels.

The netting is made from suitable natural or synthetic fibre cord or from a mild or high tensile steel wire. The maximum mesh size is 44mm for cord netting and 50mm for steel wire.

The maximum danger sector for discus throws from this cage is approximately 69°, when used by both right and left handed throwers in the same competition. The position and alignment of the cage in the arena is critical for its safe use.

The surface of the landing sector must allow for the discus making a mark upon landing. It is made of natural grass or other suitable material. The landing sector is laid from the middle of the circle with an angle of 34.92° and marked by 50mm wide white lines, the inside edges of which form the boundary of the sector. The length of the sector is 80m. The angle of 34.92° is attained if the two sector lines at a distance of 80m are spaced 48m apart.

The maximum allowance for the overall downward inclination of the landing sector, in the throwing direction, shall not exceed 0.1 per cent.