Ben Baden Services recently designed, engineered and manufactured the Baden Crane Borer for TransGrid to assist in the placement process of concrete power poles.
Ben Baden Services has a history in designing and fabricating one off or small volume type projects for various companies.
These projects first started with QANTAS and its requirements for specific ground support equipment, says Ben Baden.
“We’ve engineered and prefabricated various types of equipment for QANTAS in the past. When they initially purchased their Airbus A380, they required a specific type of scissor lift to change out the Auxiliary Power Units. It needed to be a scissor lift mounted on a road going truck capable of lifting one tonne to 12 metre, with a platform could traverse three meters forwards. Not surprisingly, one didn’t exist on the market, so we designed one for them and ended up building four. So yes, there’s a history of low volume project work,” he said.
Ben Baden Services was approached by TransGrid, the main electricity transmission providers for Sydney. TransGrid had an issue, particularly with the increased use of concrete telegraph poles which are naturally much heavier than timber poles.
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“There wasn’t much readily available on the market that could handle the increased weight of the concrete poles, so we sat down with them and we worked out the maximum weight they wanted to lift, at a certain radius, and work backwards from there. Obviously, TransGrid don’t do general hire, so they weren’t coming to me asking for various sizes of crane, they wanted a machine that could lift eight tonne at eight metres but also have an auger or boring attachment to it. That’s how we started the process of designing and building a 20 tonne crane borer for TransGrid,” said Baden.
The lifting capacities of the other products on the market were not adequate for the applications and for TransGrid’s needs, says Baden.
“There is a product out of the US which, off the brochure would meet their requirements, but there are no agents for the product in Australia and there was a degree of risk for TransGrid to go down that path. One of the risks was a blow out in costs due to the fluctuating exchange rate. When a company like TransGrid goes to tender, they want to issue a purchase order on a fixed cost. They don’t want it to be subject to an exchange rate that’s quite volatile,” he said.
“Also, one of these products hadn’t been brought to Australia before, so there were concerns around road regulations, particularly in New South Wales. There was an uncertainty around what level of permit they would be able to run on. TransGrid is obviously operating in remote areas where there are lots of bridges which haven’t had their engineering checked recently, so they are on a low roadability tolerance. All in all, the US product would have come with a degree of risk involved,” said Baden.
Baden says the whole process, from design through to the manufacture of the finished product, took between 18 months to two years.
“That was from the very start of the process, sitting down with TransGrid and really understanding what they wanted to actually have a built product. Certainly, the design challenges were the physical size of the crane. What you can actually mount on a road going truck whilst keeping the weight down and also being able to achieve the lifting capacities that TransGrid wanted with the concrete telegraph poles. That’s obviously the fundamental requirement of the machine.
“Also, a company like TransGrid has other needs and requirements for their operators. They wanted a fully enclosed cabin that can be heated in the winter and air conditioned in the summer and good access and egress built into the machines. They obviously have working with height compliance and general Work Health and Safety requirements, which is completely understandable for a company of TransGrid’s nature. Trying to incorporate all of that into the design was a challenging process,” said Baden.
Being a first of its kind, Baden needed to ensure it met the Australian Design regulations and that it Australia Design approved.
“Of course, we made sure it met all design requirements as well as WorkCover Plant Registration and all of the things that everyone has to do. Anyone with any plant and machinery needs to go through these regulatory processes. Meeting all the appropriate standards is a challenge in itself.
“Eight tonnes at eight metres was the requirement, but we didn’t want the machine to be 100 per cent on its limit, so we built buffers into the design just in case. TransGrid work on telegraph transmission lines and they are generally located in quite rugged areas. The crane has to mounted on an 8×8 truck in this case it’s a MAN truck. It’s an 8×8 drive because the surface roads they drive on are rugged, it’s not like driving on bitumen,” said Baden.
In the design and manufacture processes, particular attention was paid to the slew, says Baden.
“A crane will generally operate very smoothly when you may have a dynamic load, or you have the load suspended from the hook. With a crane borer, you have an auger attachment fixed on to the boom and while they are drilling the hole, the crane is undergoing a lot of shock and stress. It’s not uncommon for them to spend an entire day drilling one hole through rock and shale.
“While they are doing that, the crane is under stress, it’s bouncing, shifting and shaking quite severely. Obviously, that has to be incorporated into the design, you have to use a heavier and more robust design than if you were designing a lifting crane. This robustness has to run through the boom, to the slewing ring and the slewing drive gear. All of that equipment has to be robust and ‘beefed up’ quite a lot to ensure it doesn’t wear before it’s time,” said Baden.
Baden explains the borer’s functionality in more detail.
“At the end of the boom you have hydraulically operated pole grabs. Ideally, they like to grab the pole from the top so when they stand it up it up it hangs perfectly straight and it can then be dropped perfectly level into the hole. With our 27 metre boom, with a maximum tip height of round 30 metres you can do that with quite a high telegraph pole. You can grab a 25m telegraph pole from the end and stand it.
“However, there are situations when they can’t extend the whole boom. This can be due to height of the pole, the weight of the pole or due to height restrictions because they are working underneath transmission lines. Then you have pole grabs at the end of the boom that can grip onto the pole to assist in standing it vertically, when it’s being installed,” said Baden.
“Typically, when the crane borer is on site, the poles will be unloaded horizontally from the truck and set down next to the crane. Then they drill the hole. The reason for the eight tonnes at eight meters is because that’s the minimum distance the crane borer can drill the hole. The auger attachment can’t be closer to the crane than when the boom is fully retracted. This governs the minimum distance that the hole will be from the crane. It avoids having to the pack up the crane up and reset it again. That’s why we worked out the minimum hole distance from the crane, the crane doesn’t move, that has to be where the crane can plant the pole,” said Baden.