Product profile: Hidromek HMK145LC-3SR H4

By: David Lott, Photography by: David Lott

Auckland-based Aarons Contracting recently took delivery of a new Hidromek HMK145LC-3SR H4 that it has paired with multiple high oil flow attachments

The primary attachment is a Vosch rotating grapple saw

You may recall us visiting Aaron Blackbourn of Aarons Contracting Ltd in 2018 (DOW 302), where we took a look at some of the equipment used in his tree felling and arborist business.

Mulching on-site at Hobsonville

Over the past four years, he has added a number of machines to the fleet and on the day we caught up with him on a Hobsonville site in north-west Auckland, our focus was firmly on the latest addition — a Hidromek HMK145LC-3SR H4 (LC/SR = long carriage short radius).

The company works mainly around the Auckland region and any one day will see Aaron and his crew spread around multiple job sites. "Each day brings up new challenges, but we’ve been at this for a few years now, so I’d like to think we have a good understanding of what we’re doing," says Aaron.

Popular choice

Hidromeks are known for their tough steel panelling

Supplied by New Zealand distributors Magnum Equipment, the 16.8-tonne excavator is the latest model (H4) supplied by Hidromek and is proving to be a popular choice for contractors requiring a workhorse with low centre of gravity, heavy-duty frame, and solid panelling for use on busy job sites.

Aaron says one of the main reasons for selecting his particular model of Hidromek was the solid footprint and the short radius that comes into its own when working in tight areas.

Double-auxiliary piping comes standard

Another primary reason was the high oil flow of the two auxiliary circuits, allowing attachments such as a mulcher and grapple saw to be efficiently operated. "I also think the colour of the machine is different and helps our equipment stand out among the others on worksites," says Aaron.

Working days

Aaron Blackbourn (left) and operator Henry Fouwler

During our site visit, we saw the HMK145LC-3SR H4 at work mulching on the perimeter of a soon-to-be commercial subdivision. The Hidromek/mulcher combo makes quick work of the long-neglected vegetation, some of which consists of decent size wattle and other exotic species.

The HMK145LC-3SR H4 has two upper and seven lower rollers

The short tail of the excavator ensures the counterweight will remain unscathed as operator Henry Fouwler carefully works his way through the overgrown greenery.

The engine bay is dampened to reduce noise levels for the operator

"We’ve had the mulcher for a few years, and it’s been running really well on the new Hidromek," says Aaron. Once Henry finishes his work, the team will begin felling a large stand of pines that once formed a shelter belt to the property.

"We will be felling these trees by hand, as they are too big for the machinery to handle; otherwise, we would be using the grapple saw attachment," says Aaron.

Rotating grapple saw


The Vosch rotating grapple saw is another one of the company’s latest equipment acquisitions and specifically used on the Hidromek. "The grapple saw gives us the ability to safely hold and fell trees without the use of a person on a chainsaw, and without the tree falling uncontrolled," says Aaron.

According to Aaron, the big advantage the Vosch unit has over other vertical tree shears and saws is that the unit can rotate up to 360 degrees, allowing the excavator operator to dismantle lateral limbs at almost any angle in a fully controlled manner.

"The Hidromek was a good carrier because of the two auxiliary circuits from standard, meaning we only needed to fit one more circuit to run the cutting action of the saw," says Aaron.


Providing the trees are of the size that can be handled by Aaron’s equipment, the pairing of the Hidromek and grapple saw must be a godsend for utility companies, especially those working alongside roadways and near powerlines, allowing for a reduction in staff numbers to carry out the work.

"This unit makes powerline and roadside tree clearance more efficient and safer, as only the operator needs to carry out the tree felling. The machine can sit alongside the roadway and reach over fences or hedging, remove the limb, or the whole tree and then swivel it out of the way — easily and unobtrusively," says Aaron. "It’s a no-brainer."

Handling the workload


Aaron says the Magnum Equipment team have been good to work with and are there promptly when required. "The excavator has been performing well and is suited to the work we are throwing at it.

The machine doesn’t have a dedicated operator, so we all have the opportunity to get behind the controls whenever necessary," says Aaron. "The cab is well set out, has a good aircon system, and it’s nice to operate."

Like other contractors, Aaron’s biggest issue is finding skilled staff to keep up with the workload. "Most of our people come off the tools and their prior knowledge of the type of work we do helps a lot. With the automation the Hidromek and our attachments provide, this will help us operate more efficiently."

Hidromek HMK145LC-3SR H4 specifications

Operating weight 16,850kg 
Engine Isuzu AJ 4JJ1X
Power 73kw(98hp)@2000rpm
Maxtorque 385Nm@1600rpm
Emission system Tier 3
Main pump 2 x variable displacement piston pumps
Max pump oil flow 2 x 129L/min
Max oil flow (Aux 1) 240lpm (double pump setting)
Max oil flow (Aux 2) 60lpm
Max travel speed High 5.7km/h Low 3.4km/h
Bucket digging force 96kN
Arm digging force 69kN
Max digging reach (std arm 8210mm
Max dig depth 5660mm
Max dump height 6690mm
Min swing radius 2100mm
Max clearance 430mm

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