10 out of TEN Group: A Quality Q&A Session with Australia’s The Energy Network (TEN Group)

Tell us about how TEN Group collaborates with customers to support their cable installation needs.

Kevin Harrold:
Ideally, customers are calling us right at the beginning, when the concept of the project is happening, before the contracting part of it.

James Brown:
Yeah, it’s really important for us to be involved on the front end of the project, as there’s a real advantage that we can offer in how they do the work. If it’s a whole new project and we get a chance to talk to the electrical engineers when they are designing and developing the conduit routes, then we can plug it into the Polywater Pull-Planner software. This gives us a tremendous opportunity to maximize cable installation distances by running calculations to lower cable tensions and side-wall loadings. There’s also a real product specification piece from the client side that flows through to the contractor — like working through and identifying what the right lubricants are and understanding how we can maximize their chances of success. There’s real value in allowing us to offer a whole solution package.

Kevin:
Yeah, it flows through also from the other products that we offer, equipment-wise, that they may need, to complete a project successfully from end-to-end.

James:
We don’t always get the opportunity to be on the front end of a project, as sometimes we are coming in and working with the contractor on the back end. But we also work very closely with them around the Pull-Planner to understand the pulling forces, pulling tensions and sidewall loading. That’s an important thing. I think we’re adding science to what can traditionally be quite unscientific from a cable hauling perspective.

What are the common challenges that you are seeing these days in terms of supporting your customer’s cable installation needs?

James:
One of the challenges we see is with workforces. It’s hard getting labor these days. So, there’s a lot of what we would call, “relatively green people” coming into the industry. We see an opportunity to work as an educator to those who perhaps haven’t seen the range and diversity of cable installations that we have. It’s sharing all this knowledge and understanding around a cable haul — things like coefficient of friction, side wall loadings and tensions, the impacts of reversing pull, the impacts of adding a pusher on the front of a pull, understanding the lubrication points, and the ability to lubricate ahead of the cable. These are all things not traditionally taught in the training programs they would work through.

Kevin:
I would also add that there’s a lot of new engineers starting out that also don’t have the depth of experience when it comes to cable hauling. There’s an opportunity in sharing with them the education piece as well.

Charlie Cole:
I agree. We bring tremendous value in our ability to bridge the knowledge gap from traditional training programs and the specialized knowledge that goes with experienced cable installation—for engineers, contractors, and installers, alike.

Another education opportunity is around medium and high voltage underground installations. From a global perspective, there’s a rise in these types of installations. This has brought installers who have experience with low-voltage type installations into these bigger medium and high voltage application projects, which is a completely different ball of wax. The cables and the distances to install them are a lot bigger and heavier. And therefore, it’s important that we work with them to understand the differences and what that means in terms of the equipment that they may require or might have to acquire to do the job.

Kevin:
When we talk about the newer types of cable sizes for medium and high voltage; naturally, the cable jacket can change too. That’s an important factor in terms of understanding the coefficient of friction. There may be new compositions that need to be considered.

Charlie:
And other factors that must also be considered. But cable manufacturers do change their cable chemistry, especially when they’re getting into high voltage DC and some of these specialized installations like offshore wind and solar. That’s why we advise and consult about coefficient of friction. This is the business we are in.

James:
Yeah, there’s certainly newer and bigger cables being pulled. Along with that, there’s an outdated mindset as to how to go about doing that work. They’re not used to having highly specified and tested lubricants and understanding what the impact of that can be on the job.

So, from a design perspective, they’re planning to pull 250 meters (about 820.21 ft) of cable, and then stop, put in a joint bay, and set up again for another 250-meter pull.

One of the things we really like, and push for, during the design phase is to maximize the length of the pull. We’re asking those questions like, “what is the actual total length of the pull” and “the total number of joint bays” in scoping a project. We can help make a 1,000-meter pull happen and eliminate the need for additional splicing and joint bays. If we knock one or two joint bays out of a project, that’s a pretty significant cost savings. Plus, from a reliability perspective, it’s eliminating a potential point of failure.

Are you seeing a lot of customers moving from aerial to underground cable installation?

James:
There are some stats a few years ago, something like 40-50% of new construction was going underground. That’s traditionally a lot more than we would have seen. There are big underground projects underway. A lot of it’s come from environmental and weather impacts right across the northern region of Australia. We have issues with cyclones much like you would have hurricanes in the US. Obviously, exposed aerial networks are at risk in those sorts of weather events. I’d say over the last 15 to 20 years we’ve seen a shift to underground. Certainly, in urban areas with all new residential development we’re seeing it undergrounded. Typically, that’s managed by the developer so going underground is partly for aesthetics, but primarily for reliability.

Charlie:
Are the cables being installed in an open trench or in duct?

Kevin:
Yeah, in duct. We’ll have all the ducts installed as part of the roadways going through. They’ll build the whole network out.

A big driver of the network expansion has been residential development. A lot of that is done underground, almost by default these days. There’s no hard and fast rule for going underground. But they’re still building overhead power lines in industrial areas, as it is still an economical option.

James:
In the next 10 to 15 years, there are plans to build out the network with big interconnectors across Australia.

This is around 10,000 kilometers (6,214 miles) of new transmission line construction. These are the big cables going underground. With the bigger, heavier cables, there’s a greater need to have the lubricant conversation and ensure we’re able to install safely. So, we’re seeing and quoting a lot more underground transmission projects.

Tell us about the type of support TEN Group provides customers who are looking to make the transition from aerial to underground or are in the process of that?

James:
At the start of any project, whether it’s a big transmission project or a distribution project, we need to understand the job requirements. Things like the cable type, cable jacket materials, length of the pulls, the number of ducts, and if there is any challenging terrain or access. Having all that information allows us to have a very well-rounded conversation about how they’ll spool cable off the drum and into a duct. Or how they’re understanding and thinking about those pulling tensions and how they’ll lubricate.

We like to think of ourselves as a partner in that project. We’re there to provide our knowledge and experience to support and advise. We can add a lot of value to the conversation, be it around the hard equipment like the rollers, winches, and the drum stands or around the lubricants. There’s also an engineering side of that in being able to provide the field-based coefficient of friction and relay that back to the reliability engineers on how the cable was installed.

Kevin:
Yeah, well said. We really like to think of it as a partnership. And I would add to that, as equipment improves and changes, we are able to assist and advise our customers about new things that are coming on board and how they can improve their operation. So, we’re really looking out for them.

James:
An example of that is the introduction of more electric winches into the market. We’ve gone from these hydraulic, agricultural-type winches that do not provide great control over the pulling tensions, to working with electric winches where we’re able to finitely control that tension and speed. They provide much better control over the cable pull.

How do you guide customers to select the right winch for the job?

Kevin:
We need to understand a few things first; location of the job, length of the pull, the type, size and weight of the cable, cable jacket material, what they’re pulling through, and what the tensions are. Then we can advise them on winch selection. Typically, there are a whole range of options, so getting a better understanding of what they are trying to do, helps us guide them.

James:
It’s quite common for a customer to look at their drum size and weight. Let’s say it’s four or five tons. Then, they ask us for a six-ton drum stand and for a six-ton winch. We know that very rarely would you ever need a six-ton winch. There’s a lot of cables that you couldn’t possibly put that amount of force onto. So, that then starts us asking a series of questions. The job might be big, but the winch doesn’t need to be.

To guide them to the right winch for the job, we’ll work through the process of understanding the cable run and use the Pull-Planner to do the calculations. Typically, we find they’re working off an old specification for a Coefficient of Friction (COF). It might be calling for a 0.3, 0.4, or 0.5 COF. Now, we know that with our common cable and the duct configuration in Australia, we might be at a 0.09 or 0.1 COF. So, with the Pull-Planner, we can get that estimated pulling force down from what might typically look like 2.5 tons to less than one ton. That moves us from a big winch that might be more to hire or buy to something much smaller.

Outside of COF, the other factor that impacts the selection process is the duty cycle. It’s not just the tonnage for a winch that’s important, we also need to understand how hard this winch needs to work. If the customer is doing a whole series of conduit banks and they’re planning to be pulling cable all day, they’re gonna need a winch that can keep up. That’s where we might specify a little bigger or go to a bull-wheel style winch, versus a capstan. If they’re doing short runs, they’re doing some low voltage work in residential development, a capstan would be a good option.

There is quite a process involved in winch selection. Understanding the type of job, pulling environment, the cable materials, and conditions, it all really helps you provide the best solution. Undoubtedly, everyone’s goal is to have a successful cable installation. Beyond equipment selection, are there other measures that can be taken to optimize the pull?

James:
We all want a successful cable installation. In order to optimize, we have to understand the project, what those pulling forces are, and the COF. There are several different things that we want to look at and have a conversation about to set up the contractor for success.

First, there’s proving the conduit prior to the cable pull. Often these conduits are installed many weeks or even months ahead of the cable pull. There will likely be water ingress, sand, dirt, rocks, and debris that end up in there. So, this is an exercise of really cleaning out the conduit. This is accomplished with either with a proving mandrel or a squeegee. This also reveals any potential problem areas. It’s a test run before pulling the cable through.

If we know where the tricky parts of the pull are, we can ensure that we get consistency in operating the winch. The last thing we want is to stop the pull. Then, we would have to deal with a static load which can be problematic. There’s a certain amount of inertia when we’re pulling the cable, which is good for the cable and for the winch. As soon as we stop, we’ve got a significant load that we’ve got to overcome. We would have to apply more force on the cable to get it moving again. That’s the last thing we want to do.

Lastly, for the longer pulls or where there’s a lot of bends, we want to lubricate ahead of the cable. It’s one thing to lubricate the cable as it is going into the conduit, and obviously that does a good job. Your lubricants have high cling-ability that’ll pull through deep into the duct, but anything we can put in front of the cable to adequately pre-lubricate those bends can help us avoid having to address re-lubrication points, where we apply more lubricant throughout the pull. This can be done using your front-end packs of lubricant or using a lubricant squeegee and pulling through a good amount of lubricant. Pre-lubrication sets that pull up for success.

Tell us a bit more about why it is important to never stop the cable pull.

James:
It’s undue stress to the cable, conduit system, and equipment, that ultimately, we want to avoid. If we keep the cable moving, that’s the best way to be. There are certain winches where the static load can be even more problematic, and you get an amplification of that effect. For example, let’s say you’re doing only one, relatively short pull using a capstan winch. There’s typically a double braided rope there that has up to 20% elongation. When you stop the pull and try to start again, you’re overcoming the weight of that cable to get it moving again. That’s the static load and you need a big surge of pulling tension to get it moving. You’ve also got a load that’s building in elongation up to 20%. You end up getting a slingshot effect. So, you’re putting a stress on the cable that’s difficult to measure.

How can close collaboration between engineering and installation teams avoid challenges once at the site?

Charlie:
Most of the time, the people that install the duct are different than the people that haul the cable. For the people that are installing the cable, the duct can bring a lot of surprises. It’s so important that we understand how the ducts were installed so we know how that might affect the cable pull.

There was a situation, in Australia, where they installed the duct into an open trench and then filled it up with tons of sand and rock. The weight of all that backfill ovalized the duct and affected the pulling forces that were encountered during the cable installation. That’s an issue you don’t want to encounter on the day of the pull. There are a lot of people involved in this whole process from design to duct installation to cable installation to sealing the ducts. Communication is critical.

James:
Communication is a big piece between the engineers and the installation crews. The project manager is involved throughout the whole process. They’ll be working with the engineers and flowing information through to the civil contractors. Often, we can be the conduit—pun intended—between them because we work across that whole process, and we get a chance to have some dialogue. The engineers, at a theoretical and a design level, aren’t fully aware of some of the site-based challenges that can happen. And likewise, field installation crews don’t necessarily have the appreciation of why something must be done from an engineering perspective. There is a job there to communicate with both sides. Everyone can benefit from learning about each other’s jobs and the entirety of the cable installation process.

Kevin:
I think that the engineers have a good technical understanding, especially if they’ve used the Pull-Planner, of what’s going to happen and how the cable is going to be pulled. But depending on how the conduits were installed, they don’t always route the way they show on the map. It might say there’s a 45-degree bend, but it might actually be greater, or the radius isn’t quite adequate.

Charlie:
That’s why it’s important to get to the guy that installs the duct talking to the guy that’s installing the cable.

James:
Yeah, it’s the triad of engineers, civil contractors, and cable installers. They’re all different people and personalities with different interests. Ensuring that communication flows is what drives great outcomes.

Makes sense. It all goes back to communication, right? 100% communication is key.

James:
Yeah, it sounds easy, doesn’t it?

There are a lot more longer-distance cable runs being installed. What benefit is there for pulling the longest continuous length of cable at one time?

Charlie:
Speed. You can complete the installation faster. If you’re pulling 1,000 meters as opposed to four, 250-meter pulls, you’ve got equipment to move from pulling pit to pulling pit. Whereas in a continuous run of 1,000 meters, you pull that quickly and you could do a lot more cables per unit time as a result.

Kevin:
Plus, the cost of those extra joint bays and jointing is phenomenal. You’ve got the extra labor as well. So, as Charlie said, if it’s 250-meter sections, you’re jointing four 250-meter joints. That’s a lot of money! And if you can eliminate that, that’s all money saved.

James:
Along with creating efficiencies by not having to move equipment and the significant time and cost savings, there’s also a safety benefit to be gained with a longer pull. The safest pull is gonna be doing as much as we can in one go. When we’re moving big drums of cable and winches and things, we’re just introducing more risks. We’ve often seen that these shorter cable runs come from a historical spec. It was perhaps the standard. Now, backed by data, we can demonstrate using the Pull-Planner that we can go these longer distance runs, safely, with the correct tensions.

Working with the engineer early in the process to potentially remove joint bays—and it might just be removing every second one on a pull or removing the requirement for a re-lubrication point—can have a huge impact on a project. These are all time and money in a construction project. There’s a big advantage for the client in cost savings and for the contractor in getting the job done as quickly and safely as possible. Pulling the longest continuous run is the way to go.

Do you think it’s common knowledge that you should pull the longest distance that you can? Is there any perception of risk when pulling the longest distance possible?

Kevin:
I think many are unaware or untrained.

Charlie:
You get some crews that install low voltage short runs and have an opportunity to do a longer run. They’re very skeptical that you could pull 1,000 meters without exceeding the tensions or sidewall pressures. It’s an educational process, and TEN Group does that very, very well. I think in terms of putting all the pieces together, communicating, and making it happen.

James:
It’s one of our favorite things, to see how far we can pull the cable. If it is 1,000-meter pull and they’re planning to do it in four, 250-meter runs, it’s our “ta da” moment. We take them through the Pull-Planner and show from a pulling force that we can make happen.

Kevin:
I think there’s a frame of reference and an experience piece here. If they’ve only pulled a certain distance, in a particular way, that’s just what they’re used to. It may not be something that they fully understand and don’t appreciate the science behind what a good quality lubricant can do for the pull in getting that far. It’s our job to ultimately educate them, give them an understanding and demonstrate to them that it can be done.

Tell us what sort of tools TEN Group uses to help educate those who are unaware about being able to pull longer distances.

James:
Our go-to is absolutely using the Polywater Pull-Planner. It should be one of those first considerations as a planning tool for any electrical engineer or project manager starting a project. It provides all the data for what’s happening throughout the pull — where the sidewall loadings might be highest, or where the pulling tensions are higher.

From a design perspective, it allows engineers to look at making potential changes to the plan. It raises questions like, “Is there a different route I can go? Should I be putting a larger bend radius in to give it a little more grace around this corner?”

As a tool for us, it’s certainly the starting point. It’s great to demonstrate the simulated pull. From there, we’re understanding what the cable, the jacket, and all the considerations of how much the drum weighs and how much force it takes to get it moving. It’s a great tool for its output. Some of that engineering work that typically has been done in people’s own spreadsheets, formulas and calculations, is put in a nice graphical user output that’s easy to use and gives the user the results at the end in a report that they can share.

We’ve done a lot of work with customers on the contracting side, when they’re bidding for work. They take the pull plan back to the client with their calculations. They can show what the pull looks like, what can be achieved by using a specific lubricant and demonstrate how low the install tension can be.

On the client side, we’ve got a reliability engineer on the other side of that conversation. He says, “If you can install it at 800 kg instead of two tons, absolutely!” That’s what we want. If we’re pulling a joint bay out of that run, that’s just another potential point of failure in the system.

Yeah, it really gives them the best chance of success. Ultimately, the Pull-Planner software is the tool that’s a go-to for us, and it has become for our clients as well. It’s used widely around the electrical engineering circles in Australia. It adds so much value for us and for the customers.

That’s great to hear that the Pull-Planner is an excellent tool for the cable pull planning process. Can you share with us how the Pull-Planner can help engineers after the pull is complete?

Kevin:
The client, at the end of the day, wants to know when that project is complete, that we put together this pull plan, and we gave them all the calculations to get the job done. However, we like to get some information from the guys in the field on how it went. We’ll look at the Pull-Planner again and see if that’s exactly how it came out. So with all that information, we can not only evaluate if it’s gone to plan or it hasn’t, but they can then use that data for the next pull.

Charlie:
That’s one of the big benefits of using the Pull-Planner. The software has a feature that allows the user to capture a back-calculation of COF. This is the data from the actual field coefficient of friction. They can then apply it to subsequent cable installations. It just makes for more precise estimation and calculation of what the tensions are going to be in future cable installations that use the same materials and conditions.

James:
We see the data capture as a big driver for our engineers. A lot of these jobs have a specified data recording requirement. It’s not just when the cable’s in the duct that the job’s done. They want to understand what forces were applied on that cable during installation. That’s important for them to log from an asset management perspective. If they ever have a failure on a joint, there’s a significant investigation that goes on, and they want to be able to have access to that information. The nice part about the Pull-Planner is that we’re getting that information upfront, and we’re estimating. Then, when we’re in the field, we’re seeing, whether that is true. Typically, we see that it is! It aligns very well. They get that field-based coefficient of friction and the data of that cable pull. They can then use it for a future job, or they can immediately apply it to the current job, the additional cable pulls they might be doing on that day or the next day.

Kevin:
To get the data from the actual pull, the machines that are pulling can have a recorder that’s documenting the pull. As it’s going around the bends, it’s showing the high tensions—and so that’s the equipment relaying the information back. It might be as simple as a dynamometer to make sure it doesn’t go over tension. But generally, on those bigger jobs it’ll be all data recorded.

The dynamometer, data recording, the Pull-Planner. All of these things provide real field data that they can go back, review, and improve. In a way, the process of cable pulling becomes a process of continuous improvement.

James:
For many years, cables were being pulled in by excavators or by hand, with no control and understanding of the forces put on that cable. From a reliability perspective, those cables probably didn’t fail in year one. But in 10 years’ time, that could be the reason why that cable’s failed. It then becomes a very expensive asset management challenge to deal with. Today, having those data points is game changing. We certainly envisage a future where we’ll have electric winches that are recording by meters at the head of the cable and be able to map against a duct route or a conduit route. You’ll know exactly what the forces were, when, and where because it’s time stamped, and GEO located. We see that’s where the industry is headed, to that data for the engineers going forward.

All right, let’s talk about the future, what current trends are going to affect the future of cable hauling?

James:
Right now, a big thing is system hardening. We see that everyone’s looking to get more out of their networks. It seems that the frequency of extreme weather events is perhaps becoming a little more normal, than extreme or outliers. There’s a real need to prepare the network for some of those worst-case scenarios. We see duct sealants as being an important part of making that happen.

From a cable hauling perspective, we see the impact of electric winches coming in that might give us some greater finite control over variability in pulling tensions, and as I mentioned before, more detailed data capturing capabilities.

One of the big trends we see now are solar and wind farm installations going in. Australia, much like North America, is having a big push to renewables. All those solar farms have some element of cable hauling and installation involved with them. And there’s certainly a system hardening element to those as well, whether it’s sealing a riser coming out of the ground to prevent water ingress or sealing other elements of the system.

Polywater: Well, this has been very informative. Thank you for sharing your thoughts and insights with us. We appreciate your time.

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