Power Jacks Going With The Flow

We have provided 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, only a few hundred metres in length, forms the link between the extensive waters of nearby Loch Morar – which reaches depths of over 300 metres and is reputed to be home to ‘Morag’, cousin of the Loch Ness Monster – and the sea.

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

Our screw jack essentially performs the function of connecting with the weir dam gate, raising or lowering the gate depending on the river level. The unit has worked successfully since its installation in 2001. Since then it has had one upgrade where the electric motor was replaced with an alternative unit with integral hand wheel.

Complementing the type SR100 rotating screw jack, the technical features of the installation include: Screw jack operates over a stroke of 2350mm, pivoting on its 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 a absolute encoder that links back to the control system.