Conventional vibro hammers have a constant eccentric moment. When passing through the critical frequency area during start-up and stop, the constant amplitude causes disturbing negative vibrations in the boom of the crane and in the soil; not just at the spot, but with a considerable perimeter distance.
However, when making use of a resonance free vibratory hammer with an adjustable frequency of zero to a maximum of 2,350 revolutions per minute, critical vibrations in start-up and stop are eliminated. After passing the critical frequency area, the eccentric weights are automatically adjusted and synchronised to the current eccentric moment.
It is not necessary to readjust the vibro hammer when stopped and re-started. The hammer will automatically select the last setting. Resonance free vibro hammers can even work next to dilapidated structures without causing any damage. The advantage of resonance free vibratory hammers is that these do not pass bad or harmful vibrations to the surroundings and thus can work in city centers and congested areas.
(Communication by the management of the company)