The process of line boring takes a considerable amount of time, which will depend on the size of the job and the wear on the bore: but what is true across all line boring work is that it is a meticulous process that requires sustained concentration, exact measurement, and plenty of time to get things right.

But that’s no problem for Queensland-based TE Line Boring, which employs an efficient system of simultaneous welding and machining to effectively work on multiple bores at the same time.

And according to TE Line Boring founder and chief operator Tyne Carlin, this is a core feature of his business.

“Say I’m working on a dump truck tray, for example, and the bores are 3m across, I can be machining on one side, welding on the other, and setting up on the chassis. It just saves time for the company, and I’m not just standing around waiting for something. I’ve always got a job to do,” he said.

The line boring process involves the use of specialised rotary welders and line boring machines, which restore worn or oval pin bores to a perfectly circular shape before this oversized hole is then reclaimed with weld before being machined to OEM specifications.

The system of simultaneous line boring combines the welding and machining functions of the refurbishment into a unified and concurrent process, saving operators and their clients valuable time and money.


Imagine you’ve got a loader bucket with 150mm bores that need to be machined back to active service.

There are four on the bottom, which pivot and hold it on the machine, and four on the top, which make it pivot forwards and backwards.

To work on them simultaneously, the bottom set are bored out, and then the bar is taken out and put through the top and left there. Multiple robotic welding machines are set to the bottom bores, and as that process continues, the top bores are worked on with the boring head.

In this way, welders are running on the bottom while the boring process continues for the top set.

“If I was doing a bucket, there’s two sets of pins on there,” Tyne said.

“I’d be machining the bottom ones and welding the top ones. And then I swap them over, the bottom ones would be welding while I’m machining the top. In this way, I’m always doing something.”

Tyne said his team didn’t “just stand and watch the weld, before they begin the boring process”.

“We don’t just sit there to run up the hourly rate, to drag the job out,” he said.

And it’s a job that can be easily dragged out. The welding process alone can often take up to three hours to complete.

The TE Line Boring method incorporates a standalone welding rotating machine, enabling operators to bore on one end and weld on the other.

“It’s like you can do two jobs at once,” Tyne said.

A robotic welder in operation.

For Tyne, this means increased productivity on his part. For a company that hires TE Line Boring, it means one of the quickest and most efficient line boring services on the market.

In a competitive line boring marketplace, efficiency is the key to success.

“We want to be competitive and get the job done as quickly as possible,” Tyne said. “Just standing around and watching, that’s not who we are.”

This system of simultaneous boring and welding comes about through TE Line Boring’s careful selection of equipment.

Rather than using a standard Climax model, Tyne employs a bespoke system designed and built by Triangle Engineering Consultants, a Perth-based designer and manufacturer of line boring equipment.

The set-up is a combination of Hoffman line boring devices and equipment from Triangle, all of which are geared around a two-inch boring bar.

The reduced weight of the bar makes it easier for the operator to set up and use on big machines.

The lighter weight also reduces the risk of back injuries.

For Tyne, the chief benefit is that the Triangle system is designed by a line boring veteran, one who knows what line borers need in the field, and then organises the system accordingly.

TE Line Boring is a mobile on-site operation.

The need for a light-weight, versatile and portable line boring system is thus of paramount importance.

An additional advantage is that the device doesn’t need to be taken apart very often.

The reduced need to disassemble the equipment means less set-up time, and more time focused on the job at hand.

“The Triangle system is the most compact, powerful and user-friendly out there,” Tyne said.

“It’s much quicker to set up, for a start,” he said.

“And we can get into some pretty tight spaces.”

Though located in Chinchilla, TE Line Boring has been deployed to a range of mine sites spread across Queensland and NSW.

“We’ve been up as far as Moranbah in Queensland, and down to Narrabri and the Hunter Valley in NSW and everywhere in between,” Tyne said.

“We also do a lot of work in Brisbane and in the local coal mines in Chinchilla.

“We’ve just focused on trying to make the whole process as quick and affordable as possible.

“Our core focus is getting the machine back on line as quickly and safely as possible.”

But while saving companies on time is just one of TE Line Boring’s edges, versatility is another.

An acoustic alignment set-up with centralised wire.

The company specialises in line boring diameters ranging from 35mm to 1m.

As such, the company isn’t limited in terms of the machinery it can work on.

“We can work on all kinds of bore sizes,” Tyne said.

“It’s not a problem for us. What we do is, we have extensions that we mount onto the boring bar, and it just pushes out the cutting tip a little further.

“So if we need to bore bigger diameters, that’s not a problem for us. The system is versatile and compact.”

And though line boring is its prime business, the company can take on a range of affiliated jobs such as face welding and face machining.

In addition to versatility and efficiency, another interesting feature of the TE Line Boring service is its commitment to acoustic alignment.

Before boring can begin, the bearings for the bar must be set up and lined up perfectly, and acoustic alignment guarantees precisely lined up bearings.

“There’s a few people who use this process, like us, but there are a lot of people who don’t,” Tyne said.

“And the thing is, you never ever get it straight enough if you only use the bar.

“If you imagine a two-inch bar, two meters long, if you try to hold it at each end, it’s going to have sag in the middle.

“But if you use acoustic alignment, and set up your bearings that way, you can get it perfect, out to 6m without a problem, and the bar just slides through beautifully.

“So with a dump truck tray, for example, when I do one of them, they’re 3m to 4m across.

“And I only usually use a 1.8m long bar, and I move it from one side to the other. But because of the acoustic alignment process I stick too, I know that my bores are straight.”

Using a Triangle alignment gauge, the support bearings are perfectly aligned inline to the bores to be machined.

A wire tensioner is attached to the outer support bearings, and alignment cups to the support bearings in between.

A piano wire is threaded through the centre of the alignment cups and tensioned out to 40kg.

The audio from the wire tells whether the wire is centralised, and if the bearings need to be adjusted accordingly.

The process of machining is equally meticulous. With each cut, Tyne uses an internal micrometer for measurement, and then adjusts the cutting tool with a dial indicator. Measuring off the bar is also an option.

“I know my bar diameter is 50.80mm, so I can just measure either side of the bar, and you can do it pretty quickly that way,” Tyne said.

Speed, however, doesn’t come at the cost of accuracy or the precision of the cut.

“It’s just as accurate that way,” Tyne said. “I guess that just comes from experience.”

The insertion of bushes and pins is a common step in the post-boring process, and TE Line Boring can easily accommodate this part of the job.

“We shrink fit the bushes back into place using the liquid nitrogen process,” Tyne said.

“We heat the bores up to 120o, then freeze the bush into liquid nitrogen and sit it in that until it stops boiling, and then put it in.

“Once it’s in you’ve got to commit, because once it touches the hot bore, it starts expanding and it can lock in there.

“If it’s not fitting, you’ve got to back out, or go for it, usually you’ve got a copper hammer on hand to tap it in or out.”

Generally speaking, Tyne said the difference between the finished internal bore size and the external diameter of the bush to be inserted will vary from job to job.

“It depends on what the company wants. Each job is specific,” Tyne said.

Furthermore, TE Line Boring has the experience and skill-set necessary to take on a range of other mining affiliated jobs, such as steel fabrication and maintenance work on pumps, crushers and wash plants.

TE Line Boring has acquired all the certifications and tickets necessary to work on a wide range of mine sites to the highest levels of safety and professionalism, including the standard 11 Coal Mining Induction certificate, S1 S2 S3 and G7, RII permit holder and issuer, RII EWP, RII operate and maintain 4×4 vehicles, RII working at heights and confined spaces, current first aid CPR and  also a list of various site inductions.

Though it’s a mobile operation that specialises in on-site work, TE Line Boring is building up a specialised workshop based in Chinchilla.

One advantage of TE Line Boring is that it is an owner-operated business.

When a company hires TE Line Boring, it is hiring a line boring specialist with 15 years experience in the business, without any intermediate bureaucracy getting in the way of a clean and efficient service.

Experience and range of service matched with mobility and efficiency makes TE Line Boring a top-tier option for mining operators throughout Queensland and NSW.

TE Line Boring
Ph: + 61 407 352 281