The Torshamn and Botto Fairways into Goteborg have always had buoys to mark their edges. The new fixed markings will increase safety and accuracy for shipping.

The fairway markings are steel piles varying from 0.8m to 1.5m in diameter. The narrow section passes through and above the water surface while at the top is a platform for maintenance, with an attachment for a beacon and and facade illumination on the pillar.

The fairway markings are painted red and green and are placed so that the correct starboard/port colour is shown when moving along the fairway.

All fairway beacons will flash at the same time.

Fairway marking types fitted vary depending on seabed conditions. In mud, the pipes are vibrated down to a depth of 25m and fitted with a collar to stabilise it on the bed. In rock the pipe is drilled through and secured by means of concrete injection. The longest markings are 25m into the mud, about 20m through water and with 6m above water for a total length of just over 50m.

A weaker section has been deliberately incorporated into the steel pipe at seabed level so that it would break at the weakest point if struck by a vessel and could therefore be repaired relatively easily. Fairway beacons are comprised of numerous LCDs, solar powered and backed up by batteries, with very long maintenance intervals.

The jack-up platform Deep Diver is being used to set out the markings, with each one taking approximately one week to place. The 34 fairway markings for Goteborg were manufactured in Denmark and Poland, with the installation contracted to MT Hojgaard a/s.

MJ Information No: 19594