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Sustainable construction equipment: A greed for green

Skanska is determined to lead the world on sustainability issues, but how realistic is this in the equipment-heavy world of its piling business? Margo Cole reports.

All of Skanska’s rigs are being converted to use biodegradeable hydraulic oil

All of Skanska’s rigs are being converted to use biodegradeable hydraulic oil

According to Skanska senior sustainability manager Nigel Sagar, the company’s aspiration is “to be seen as the leading sustainable contractor and developer”, and it has made public commitments to move towards what it calls a “deep green” or zero carbon world.

“The Skanska colour palette is split into three areas: vanilla is compliance with local codes and standards; we want to move everything to deep green; and everything in between is green,” explains Sagar.

“There are four priority areas - energy, carbon, materials and water,” he adds. “To get from vanilla to deep green, there are stepping stones in the green section for all of these areas. We can map our projects and see where we are in the colour palette.”

Cementation Skanska has taken the colour palette and applied it to their scope of work to make it more relevant to them. That includes the plant - the rigs - and how they operate

Every aspect of the company’s construction and development operation is committed to the deep green aspiration, not least its piling business Cementation Skanska. A project currently under way to build new offices and upgrade the workshops at Cementation’s Bentley Works near Doncaster is Skanska’s first deep green site in the UK, and only the third anywhere in the world.

The Bentley Works site - which has been in operation for over 100 years - is where Cementation services its piling rigs and fabricates structural steelwork. The project to upgrade the site includes energy generation and energy efficiency measures that will make it carbon neutral, including photovoltaic panels on the workshop roof that will supply the site’s electricity, as well as rainwater harvesting for all the non-potable water.

More relevant machinery

But the site redevelopment is only one part of the piling firm’s sustainability efforts; the real focus is on the everyday activities of installing piles and the equipment needed to do that. As Sagar says: “Cementation Skanska has taken the colour palette and applied it to their scope of work to make it more relevant to them. That includes the plant - the rigs - and how they operate.”

Fuel use directly links into the carbon footprint. For Cementation Skanska that footprint is all about concrete, steel and fuel

Bentley Works manager Steve Joynson says piling rig manufacturers - in common with general construction equipment firms - have been driven to improve their machines by legal compliance in recent years, specifically new European standards on engine emissions.

“That has been a big driver for the last 10 years, and we have been prominent in putting together the way the standards should look in terms of foundation equipment,” says Joynson.

“Since 2006 manufacturers have been working from [emission standard] Tier 2 to Tier 3 towards Tier 4. They have had difficulties in the design of machines because they have larger cooling systems, larger exhaust systems etcetera, so the superstructure of the machine has to be changed. We work in partnership with the main suppliers from Italy, ­Germany and Austria to develop the machines and assist them where we can in coming up with better solutions.”

But while engine emission reduction is important, Joynson says they key driver for the unit cost of operation is fuel reduction. “We purchase machines that are as efficient as possible in terms of fuel use, and we are looking at how we operate each piece of equipment to maximise the fuel,” he adds.

And, as Sagar says: “Fuel use directly links into the carbon footprint. For Cementation Skanska that footprint is all about concrete, steel and fuel, so if they can reduce fuel, it meets one of those [issues].”

Fuel monitoring

The company monitors the fuel used by its 42 piling rigs, and is building up a picture of the amount of fuel each machine uses in each discipline it is involved in - depending on the type of work and size of engine. This picture helps to set parameters for the rig operators to ensure they are using the machines in the most efficient way.

Learning how certain components may fail, it can steer you into better education for your operators

As Joynson says: “In the past some of the operators would have [operated the machine] at full throttle all day. But that is not the optimum.”

According to Joynson the rig operators are just as engaged with Skanska’s green philosophy as the managers, and are encouraged to share ideas.

“A lot of great ideas in terms of plant modifications and technology come from the guys on the shop floor,” he says, adding that around 60% of all the improvements that have been made to the equipment - many of which have since been taken up by the manufacturers - have come from the people who operate the machines.

Skanska has an internal structure for people to communicate ideas, including an “ideas app” for the smart phone. Any suggestions relating to piling equipment - including sustainability ideas - go to a five-person team within Cementation Skanska that includes the managing director and civil and mechanical engineers.

If the idea is thought to be worth taking forward, it goes through a series of gates, with the person who came up with the idea kept informed at all stages about what has happened to it.

“It’s all about the engagement,” says Joynson, who believes there is a “buzz” to being known for being green.

Waste oil re-use

Among the green initiatives that Cementation has adopted in recent years is the re-use of waste oil from the plant fleet to heat the buildings at the Bentley Works.

This will continue in the redeveloped site, but Joynson is also keen to ensure the company is minimising the amount of waste oil that comes from the machines.

It is a key driver for me and for Cementation Skanska that all of our unit plant fleet have multiple capability

One way it has achieved this is by regularly sending oil from the machines to be tested and analysed. This not only provides useful information about the oil itself - such as how soon it will need replacing - but also flags up any wear and tear in the machines’ components. This, coupled with remote monitoring of the rigs, is enabling the company to be more proactive about its servicing and maintenance, in some cases extending the life of individual components, or operating the machines for longer between services.

As Joynson explains, having more knowledge about the rigs and the condition of the components within them means replacement components can be ordered and fitted at a time that does not disrupt activities on site.

“By building up that history and learning how certain components may fail, it can steer you into better education for your operators and give you a better idea of when certain components need to be changed and how long certain components will last,” he adds.

Flexibility is key

Cementation Skanska took a decision a few years ago to optimise its fleet by only buying rigs that could be used for more than one type of piling.

It has been at considerable cost to the business, but it was the right thing to do

“It is a key driver for me and for Cementation Skanska that all of our unit plant fleet have multiple capability,” says Joynson. “It gives greater flexibility in terms of what they can do, and also allows you to maintain fleet value in terms of numbers and increased utilisation.

“We don’t purchase a machine that has less than two piling disciplines - and typically we look for four or five,” he adds. “There is an additional cost, but over the whole lifecycle it is worth it.”

Every new machine must also work using biodegradable hydraulic fluid, as well as meeting the latest engine emissions standard and, where possible, being equipped with start/stop technology and remote monitoring.

“In 2012 we started converting all the existing machines in the unit plant fleet from mineral hydraulic oil to biodegradable, and we’re 80% through the fleet now,” says Joynson. “It has been at considerable cost to the business, but it was the right thing to do.”

In addition to the 42 piling rigs, Cementation Skanska also owns 10 cranes, which it is in the process of replacing to meet the latest engine emission ­standards.

“The crane fleet was ageing and needed to be brought up to the standards we expect,” says Joynson, adding: “It’s how we want to see ourselves in the market - as having the greenest plant fleet there is.”

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