Abstract: A test rig for testing blades for a wind turbine includes a fixing structure where a root end of a wind turbine blade can be fixed, a loading mass structure extending from the fixing structure, and an actuation structure which can apply a sinusoidal force to the loading mass structure so that a counterbalanced resonance is established between the loading mass structure and a blade which is fixed in the fixing structure. Due to the counterbalanced resonance, the force from the test rig onto the floor or other building components can be reduced relative to that known from the traditional rigs for blade testing.

Abstract: An extremely low power transducer for use with a meter is able to be powered by miniature solar cells to measure and display a physical quantity such as pressure, force, level or distance. The transducer provides a variable capacitance to an electronic circuit that includes an integrated circuit for conversion to the displayed value.

Abstract: An electronic stress monitoring device (1) is provided that is arranged to detect and record measurements of stress experienced by a structure (2) to which the stress history unit is attached, with the measurement and recordal of stress occurring at substantially the same location. The stress monitoring unit (1) is also arranged to process the detected readings of stress to determine when significant structural events are occurring within the structure (2) to which it is attached. Data indicative of these events are recorded within the stress monitoring device (1). Periodically data recorded within the stress monitoring device (1) is obtained by data reader (4) and then transmitted to a computer (6) for subsequent analysis.

Abstract: A serial element of a load lifting line has a telescoping body held in a short configuration by a linear slip clutch until a selected load on the line is exceeded. The slip clutch then allows the body to extend to a longer configuration in which it is retained as a length unit by abutting surfaces between which an elastomeric shock cushion is positioned. An optional arrangement includes a biasing provision to restore the link to the original condition, for further use, after the load is reduced. By utilizing optional provisions, the link can signal the overload condition by a whistle when the telescoping body extends. Visible signals can, optionally, be provided by members that extend from the body when the body is telescoped to the longer condition.