Amphibious attachments

Sandhurst’s amphibious attachments demolish a half weir at Wandsworth on the River Wandle making way for fish, invertebrates and wildlife.

Sandhurst were called in by Land and Water to supply specialist attachments for the demolition of a half weir at Wandsworth and delivered a hydraulic breaker, rotating steel shear, pile driver and ripper tooth to help complete the job. The half weir was at the confluence of the River Wandle and the River Thames.

The project will improve water flow to help restore a wildlife habitat measuring roughly a hectare in size that has the potential to become a spawning area and nursery for young fish.

Land & Water were appointed by Wandsworth Council to remove the half-tide weir on the River Wandle, with a contract duration of 6 months and value of £1.7m.

The Wandle Weir project called for a range of Land & Water's specialist equipment including a mini amphibious machine to collect sediment samples and a spud pontoon with marine crane and JS 145 long reach excavator, to complete the dredging.

For the demolition phase, a Hitachi Zaxis 350 long reach excavator working from a pontoon, mainly positioned above the half weir, facilitated use of the various Sandhurst attachments used during material removal .

One of Sandhurst’s powerful mid-range Atlas Copco breakers was supplied with an underwater kit to allow breaking below water level. After breaking the reinforced concrete, a 1 tonne shear was used later in the process for cutting rebar. Removal of embedded sheet piles was achieved using a combination of vibratory pile driver, underwater breaking and the ripper attachment.

Barges moved the silt and demolition material to the unloading area where they were discharged with a 22 tonne long reach excavator and clamshell grab. An estimated 7000m3 of silt and waste material will be removed over the project duration.

Removal of the weir and silt deposits will take out the barrier between the river Wandle and the tidal Thames assisting improved natural tidal action at the river mouth restoring valuable habitat for fish, invertebrates and wading birds. The improved water flow will restore a wildlife habitat measuring roughly a hectare in size that has the potential to become a spawning area and nursery for young fish.

Contacts at Sandhurst:

Simon Lewin (Rental Operations Manager).  Email: slewin@sandhurst.co.uk
Keith Evans (UK Attachments Sales Manager). Email: kevans@sandhurst.co.uk