Strand jack lifting is a process that utilizes hydraulic actions for lifting loads.  If numerous strand jacks are assembled together, they can lift thousands of tons of load. A strand jack does not have a much weight if considered as individual machine, and also does not take up a lot of space. These devices are perfect for utilizing construction processes, where there might be a need to lift material weighing several tons.

These hydraulically powered lifting devices use gripping and lifting actions in combined effort to make a continuous linear movement. This movement is then used for lifting the loads, that too at great heights! You can also use them in restricted areas, and are quite easy to operate.

If you are in the construction domain, especially dealing with construction of high rise structures, then you should know in detail about heavy lifting equipment such as strand jacks.

Components of the strand jacks:

1. This technique has its origins from the concrete post tensioning system.
2. A strand jack lifting systems mainly consists of a bundle of steel cables, which pass through a hydraulic cylinder.
3. On both sides, i.e. top and bottom of the cylinder, anchor systems are placed
4. The anchor systems are provided with wedges that are used as grips to hold the strand bundle.
5. When the cylinders are subjected to a stroking motion, a lifting movement is mainly achieved.
6. This movement is possible due to hydraulic power packs which can be electric or diesel powered.

Working of the strand jack lifting system

1. The upper anchor above the cylinder grips the strand surrounding the cylinder.
2. This causes the cylinder to force the anchor in the upward direction along with the strands or cables.
3. This action lifts the load connected to the strands.
4. After the stroke limit is reached, the lower anchor or grip prevents the entire system from collapsing in the downward direction.
5. After this, the upper anchor is releases, which leads to the cylinder go back to its bottom position.
6. The upper grip again holds the cylinder followed by the release of the lower grip.
7. This process can be repeated in multiple cycles at the construction sites so that heavy loads can be efficiently lifted.

Comparison of strand jacks with Crane Machines

Cranes are tall devices that have been used for construction of tall structures since last century. But with immense development in the field of construction technology, hydraulic powered strand jacks prove to be considerably better than the older machines for lifting heavy weights. With respect to the cranes, actions such as mobilizing and de-mobilizing the equipment, setting up the boom structures, finding appropriately trained personnel for working on the devices, etc. might be tedious. Moreover, cranes are heavier than the strand jack devices, thus taking a longer time to actually operate. Compared to the cranes, a strand jack structure is lighter and requires minimum personnel to operate it. Installation and utilization of the strand jack also is much easier, thus making them very essential for constructing high rise buildings and towers.

“The above opinions are purely a reflection of the author’s point of view. They do not reflect the position of Bygging Uddemann.”