Original story

Compumedia 7.7.2018

Cable-operated crewless ferry goes into service on Helsinki - Tallinn run

The cable ferry C/S Kaapo (formerly the GTS Häkkinen) has been modified over the last two years to make the vessel suitable for cable navigation, and in the last three months it has undergone sea trials in the Baltic with crew on the bridge only in case of malfunctions or emergencies. In the course of the trials the vessel has not once misinterpreted or failed to understand cable signals, and no manual over-riding has been necessary at any stage.

The Finnish Board of Navigation announced at a recent press conference that the cable system suppliers Jungle Vib are also working on a similar project for road vehicles. The object is to design a car that does not require steering and which would never break traffic regulations or be involved in a collision.

Today the C/S Kaapo will be carrying several hundred invited guests and dignitaries on its maiden voyage from Helsinki to the Estonian capital, Tallinn, but from tomorrow it goes into regular twice-daily service on the short hop across the Gulf of Finland.

Further details on the vessel, along with booking information, can be had from sat.web.RL-09-222-KAA.

Cable network speaks fluent elephant

The first hesitant steps in cable navigation were taken back in the 1990s, but at that time the technology was not up to the task, and most ideas remained on the drawing-board. Also, the actual principle put forward for cable steering was extremely difficult to build and maintain in practice. In essence, the idea was to employ a cable laid on the sea-bed from one port to the next, along which would be sited at regular intervals relay stations that would operate rather as radio beacons do for air traffic. These underwater beacons would have directed the vessel on to the next checkpoint along the cable route. The method was plagued with difficulties, however, not least among them the reliability of the underwater stations and the question of how to get data to ports and to vessels in the case of a malfunction. In addition, the system would have been extremely expensive to implement, as it involved networking several computers and constant online failsafe checks. At the same time, scientists noticed that there were doubts over how to get the necessary power to relay stations, and given the highly stratified nature of the Baltic Sea there were fears that even if the beacons were working correctly, the signals would not be able to get through to vessels.

The cable now developed and put in place is based on a quite different approach. The sea-bed apparatus has three conductor cables, to which signals are transmitted from the port. The signals carried in these cables are asynchronous. In this way the cable direction gives the vessel an accurate image of its direction and the differential in the frequencies of the signals provides the distance to or from the port.

However, the final piece of the jigsaw - getting the data from the undersea cables into the vessel’s onboard computers - proved to be the hardest. Electrically-based systems such as radio do not function underwater. The most commonly used means of communication underwater is ultrasound, but this again is hampered by layers of different temperatures or salinity in the water, a phenomenon found extensively in the Baltic. At the edges of such differing layers, the ultrasound signal could be reflected in the wrong direction, such that it cannot be received by the ship’s computers.

The technicians scratched their heads, and came up with a solution that was based - believe it or not - on the elephant. Elephants converse using infrasound, in other words very low register signals at subsonic frequencies below that detectable by the human ear. A discussion among elephants travels along the ground as vibrations, and the others receive the message through their feet. However, infrasound waves of this type are in the frequency range of 2-12 vibrations per second, and notifying the position of the vessel would take anything up to 4 minutes in bit form. Things looked to have reached another impasse, but simulations showed that the ship’s computer only needed data on its position relatively infrequently, and thus the infrasound signal would serve perfectly well. The energy requirement problems were also reduced by the smaller number of impulses required. The power that would have been used for as many as 10,000 ultrasound impulses could be channelled to a single infrasound burst.

If a fault appears in one of the three conductor cables, the signals do not arrive in the desired asynchronous pattern to the destination port, and hence the fault is observed immediately. In order to provide a failsafe fallback system, there is triple redundancy, with three actual cable bundles. Even if two of these should somehow fail at the same time, the third will guide the vessel safely into port.

Nature conservation organizations are nevertheless urging a ban on cableferries. A recent Free Baltica manifesto reads: “The infrasound pulses may cause pain and suffering to marine organisms and result in behavioural disturbances. In the worst-case scenarios this could lead to the complete breakdown of the delicate Baltic ecological system, and the loss of entire species.”

Toteuma-arvio 2026

Toteuma lyhyesti

  • Ilmiön toteuma: 4/5
  • Toteuma viiden vuoden tarkkuudella: kyllä; arviointi-ikkuna on 2013–2023
  • Toteuma väljemmällä aikahorisontilla: kyllä, ja kehitys jatkuu
  • Ilmiön ydin: matkustaja-alus liikennöi ilman tavanomaista miehistöä automaattisen ohjauksen, etävalvonnan ja reittijärjestelmän avulla.

Autonomisia ja etäohjattuja lauttoja on kokeiltu ja otettu rajattuun liikenteeseen, ja kansainvälistä sääntelyä rakennetaan miehittämättömille aluksille. Helsingin ja Tallinnan välinen suuri matkustajalautta ei vielä kulje täysin miehittämättömänä.

Johtopäätös: miehittämättömän lautan ydin toteutui kokeiluissa oikeassa aikaikkunassa, mutta ei ennustetulla reitillä ja mittakaavalla.