international
construction
may 2014
DEMOLTION&RECYCLING
50
Cutting-edge techniques
River restoration
Dams demolished usingmodified breakers
A
s part of the project to restore the once-pollutedCuyahogaRiver inOhio, US, to its
pre-industrial state, River ReachConstructionwas awarded the contract to remove
the SheratonMill Dam and the LeFever Dam that once provided hydroelectric
power. Among the keymachines usedwere Atlas Copco hydraulic breakers equippedwith
underwater kits.
Atlas Copco distributor Columbus Equipment Company suppliedRiver Reachwith a
heavy duty HB 3100 breaker and amuchmore compact SB 552, alongwith an XAS 185
Atlas Copco compressor, whichwas used to pump air into the breakers and prevent water
entering the percussionmechanisms.
The 12mwide, 3m highSheratonMill damwas demolished from an upstream position,
using the SB 552mounted on amini excavator, whichwas positioned on a bargewith the
compressor. The techniquewas then to open up ‘windows’ in the structure to let thewater
through and lower the reservoir behind the dam.
Then a 36 tonne excavator equippedwith theHB 3100moved in from downstream and
it took just a day to remove the rest of the structure. “It was almost too easywith that big
breaker,” said operator ShannonSwaino.
The LeFever Damwas larger at –27.4mwide and nearly 4m high, but the process
proved easier as River Reachwas able to construct downstream access, so no upstream
bargewas needed, and the jobwas completed quickly.
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The last two years have seen this need for flexibility addressed
even furtherby thedevelopmentofnewconcepts.Thishasreached
the point where a single carrier can be supplied with a range of
front ends allowing it to be used across different applications in
addition todemolition and standarddigwork.
One company at the forefront of this is Kocurek Excavators,
based in Ipswich, UK. In 2013, working together with UK
demolition contractor Armac, which was the driver behind the
project, it developed what is now known as the ABC concept.
This consists of a single carrier than can be equipped with three
different front ends thatprovidevariableworkingheights and tool
sizes in addition to a standarddigboom.This allows themachine
to be tailored to the application, but more importantly, only the
single carrier is required for fourpotential applications if all boom
configurations are available.
And the flexibility concept is being taken amassive step further
by Kocurekworking in partnershipwithGermanHitachi dealer
Kiesel.The result is a single carrier, in the first instance aHitachi
ZX470LC, which is able to carry an evenwider range of booms
for a varietyof different applications forGerman customerAWR.
It is thefirst inwhatwill beknown as theKMC470-BTV range.
KMC is theacronym forKieselMultiCarrier,with theB standing
for the OilQuick boom connect system, T for the Tritech three
cylinderquattrovalve lift systemandV for variableundercarriage.
The idea is that every470producedwill have the same stubboom
with the OilQuick and three lift cylinders. The three cylinders
provide the necessary power when in demolitionmode with the
valve providingmore normal flows for when themachine is in a
standard excavation configuration.
Range of booms
Kiesel and Kocurek are developing a range of booms for the
carrier, offeringvertical reaches from18m to34m fordemolition
work, as well as materials handling equipment and the standard
excavator boom.
The concept is also being applied toHitachi’s ZX350machine
to turn it into theKMC350-BTV.The various boomoptionswill
allow this to work as a standard excavator, materials handler or
demolition excavatorwith a range of reaches up to24m.
The fact that companies like Kiesel and Kocurek are at the
cuttingedgeofhigh-reachdemolitionexcavatordesignunderlines
the fact that this is an area where European companies tend to
lead theway.However, that is not to say that high reachmachines
are only used inEurope. Far from it.
Visitors to this year’s ConExpo-Con/Agg exhibition in Las
Vegas, US can’t have failed to notice the high-reachmachine on
Kobelco’s stand.The 112 tonne SK1000DLCoffers amaximum
reachof 38m.
The Japanese manufacturer said that it would be bringing 19
variants of its demolition machines into the US, along with 12
scrap handlers, over the next fewmonths. Interestingly, Kobelco
Hitachi’s 25m ZX470LCH is one of only three high reach excavators currently
available that complieswith the latest engine emission regulations.
Volvo launched Stage IIIB versions of its 27.4m EC480DHR
and 21m EC380DHR at the Bauma exhibition in April 2013.
Here the first EC470DHR is at work in Helsinki, Finland.
