As more and more high speed ferries are operating between
Tallinn and Helsinki questions have arisen concerning the
impact these ships are having on both the environment,
and on the populations recreational activities. To this
end, experiments were conducted at five different
locations, Pihlajasaari and Harmaja in Helsinki, and
Katariina, Viimsi, and Naissaar in Tallinn, to measure
the ship waves generated by the various fast ferries.
Each of the locations differed in local seabed geology
and bathymetry, as well as distance to the shipping lane.
Instruments including a capacitance type wave gage,
pressure sensor, and an acoustic Doppler velocity meter
were mounted on a tripod and deployed in water of
approximately 2 meters of depth in the near shore region.
Data was recorded as the waves from the vessels
approached the measurement location. The data was
analysed in terms of average wave height and period,
maximum wave height and period, and maximum water
velocity. In addition, the maximum run-up or swash
height was calculated using the results of the initial
analysis. Following Kelvin's ship wave theory, there was
a strong correlation between wave period and ship
velocity. In addition, the data demonstrates that wave
height decreases with distance and with ship velocity as
the theory predicts. A rudimentary analysis of wind
waves was also conducted for comparison purposes.
Additional experiments should be conducted using similar
methods to increase the size of the data set so that more
definite conclusions can be drawn.
|Place of Publication||Espoo|
|Publisher||VTT Technical Research Centre of Finland|
|Number of pages||39|
|Publication status||Published - 2003|
|MoE publication type||D4 Published development or research report or study|
|Series||VTT Research Report|
- kelvin waves
- wave height
- wave period