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Active heave compensation (AHC) is a technique used on lifting equipment to reduce the influence of waves upon offshore operations. AHC differs from Passive Heave Compensation by having a control system that actively tries to compensate for any movement at a specific point, using power to gain accuracy.
The sheaves make up the pulley system that holds the wire ropes, and the wire ropes extend to latch onto objects. [1] Of the most commonly used cranes in modern-day construction, the crawler crane is the largest and can lift loads in excess of 2,500 tons. This crane is mounted on an undercarriage with tracks, which ensures mobility and stability.
Strong tones can occur in both rectangular and circular jets when the pressure ratio is greater than the critical and the flow becomes supersonic on exit, resulting in a sequence of repetitive shock cells. These cells can be seen in the exhaust of rockets or jets operating with an afterburner. As with subsonic jets, these flows can be unstable.
An example is counterweights. Often a crane will be followed by another truck hauling the counterweights that are removed for travel. In addition some cranes are able to remove the entire upper. However, this is usually only an issue in a large crane and mostly done with a conventional crane such as a Link-Belt HC-238.
The terms "ultrawave" and "hyperwave" have been used by several authors, often interchangeably, to denote faster-than-light communications. Examples include: E. E. Smith used the term "ultrawave" in his Lensman series, for waves which propagated through a sub-ether and could be used for weapons, communications, and other applications.
Basically, if ten waves travel along the surface of the earth at the same speed, there is no dispersion. If several of the waves start to travel faster than the others, dispersion is occurring. Surface waves of varying wavelengths penetrate to different depths (Figure 2) and travel at the velocity of the mediums they are travelling through ...
The waves are stable, and can travel over very large distances (normal waves would tend to either flatten out, or steepen and topple over) The speed depends on the size of the wave, and its width on the depth of water. Unlike normal waves they will never merge – so a small wave is overtaken by a large one, rather than the two combining.
A salient property of water waves is dispersiveness; i.e., the greater the wavelength, the faster it moves. Waves generated by a ship are affected by her geometry and speed, and most of the energy given by the ship for making waves is transferred to water through the bow and stern parts.