City of Helsinki

10/16/2019 | Press release | Distributed by Public on 10/15/2019 23:09

Arches and changing formations on the seabed – the underwater world of the quays is revealed

16.10.2019 07:12

'Of the City center harbours in Helsinki, approximately 5.6 kilometres of quay structures belong to the Port of Helsinki. The oldest quays date from pre-war times and the most recent quay in Hernesaari was taken into use in the spring of 2019,' says Planning Engineer Tero Sievänen from Port Technical Services.

The quays are constantly being worn down by the sea and the weather conditions. Maintaining quays in the Port of Helsinki requires skill and a good concept of the condition of the underwater structures.

Underwater steel sheet walls and reinforced concrete poles as well as the erosion protection structures at the front of the quays bear the brunt of the rough sea and northern weather conditions. The erosion protection structures are designed to shield the port basin and quays from the erosion caused by slipstreams generated by vessels.

The underwater condition of quays can be examined using several methods, from traditional condition surveys performed by divers to digital multi-beam probes and modelling.

Condition surveys performed by divers are slow and relatively expensive, but result in detailed and comprehensive reports. Diving will not work very well, however, if the water is murky and the diver cannot see farther than their own hand.

Digital surveys, on the other hand, can be used to gain a more comprehensive perspective more quickly.

All of the quays in the Port of Helsinki have been surveyed by diving at least once. Check-ups using multi-beam echo sounding are performed every few years by port area.

Read more:

Port of Helsinki