Long reach excavator

The phrase "long reach excavator” was most likely first coined by Richard Melhuish (then Chairman of MHJ Ltd) who during the 1970’s operated the UK’s first hire fleet of these new and innovative long reach hydraulic excavators. Richard Melhuish’s first long reach excavator was the Hymac 580 BT All Hydraulic 360 “Waterway” machine – so called because it was designed with a long arm to allow it to work on Waterways. These early machines produced by Hymac and changed attitudes towards hydraulic excavators for the first time and positioned them as a serious alternative to the more traditional drag lines designs. Around the same time Priestman (and later Ruston Bucyrus) VC (Variable Counterweight) excavators started to become more popular. However, the work VC machines could achieve was slightly constrained by design limitations and so the popularity of fully hydraulic "long reach" machines steadily increased, especially with the arrival of more reliable machines from Japan built by manufacturers such as Hitachi and Komatsu. These Japanese designed machines used higher quality hydraulic fittings and connectors and hardly ever leaked hydraulic fluid. This was especially important when working on and around water due to the environmental impact.

Long reach excavators are often confused with high reach demolition machines – but the two products are very different. Long reach machines are not suitable for the high side twisting forces that can be exerted by demolition attachments and many demolition machines are unstable at large radius – so they are often assisted with electronic cut off devices that restrict the operating radius of the machine. Long reach machines excel at dredging operations where large quantities of material needs to be removed from underwater while the physical plant stays above water.

A long reach excavator being used to demolish an office building in Rosslyn, Virginia

The high reach excavator is a development of the excavator with an especially long boom arm, that is primarily used for demolition. Instead of excavating ditches, the high reach excavator is designed to reach the upper stories of buildings that are being demolished and pull down the structure in a controlled fashion. It has largely replaced the wrecking ball as the primary tool for demolition.

UHD demolishing a high-rise building

Ultra high reach demolition excavators (UHD) refers to demolition excavators with several tens of meters of reach.[1][2] Reaches of up to 48 metres (157 ft) are in operation as of 2016.

Trivia

The long reach excavator imported to New Zealand for demolitions of tall buildings following the 2010 and 2011 earthquakes has been nicknamed Twinkle Toes. It is the largest excavator in the Southern Hemisphere.[3][4]

References

  1. ↑ http://www.worldhighways.com/categories/road-highway-structures/features/long-reach-equipment-simplifies-demolition/
  2. ↑ http://www.agg-net.com/news/caterpillar-introduce-the-new-340f-demolition-excavator
  3. ↑ Wright, Michael (16 November 2011). "Twinkle Toes tackles largest project to date". The Press. Retrieved 13 September 2012.
  4. ↑ Wright, Michael (17 November 2011). "Firms target high-rise buildings". The Press. Retrieved 13 September 2012.
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