Custom linear actuator is based on 2350mm stroke screw jack

Power Jacks products are helping to control the flow of a river - and support a major hydro-electric scheme - in one of the most scenic areas of Scotland. The company has supplied a 100kN S-Series rotating screw jack in a ram style linear actuator design, together with motor and reduction gearbox, for a weir system on the River Morar, near Mallaig on Scotland's west coast.

The river Morar, which is only a few hundred metres in length, forms the link between the extensive waters of nearby Loch Morar - which reaches depths of over 300m - and the sea.

Constructed a short distance from a hydro-electric dam and fish ladder at the west end of Loch Morar, the weir is a pivotal element of the wider water flow systems at the locality.

Power Jacks' screw jack is connected to the weir dam gate, raising or lowering the gate depending on the river level. It has worked successfully since its installation in 2001, being subjected to only one upgrade in which the electric motor was replaced with an alternative unit with integral handwheel. Complementing the type SR100 rotating screw jack, the technical features of the installation include:

• A screw jack that operates over a stroke of 2350mm
• Integral trunnions located midway on the ram's outer tube
• At the end of the ram a clevis end with spherical bearing connects the unit to the weir gate
• Originally the screw jack was driven by a 2.2kW geared motor with position feedback coming from end-of-stroke limit switches and an absolute encoder that links back to the control system

Follow the link for more information about Power Jacks S-Series rotating screw jacks.