Genius Childcare at Westfield Chermside

I was asked by Wayne Cadwallader at SSS Manufacturing in Yatala to provide him with a scan survey for use in Tekla Structures of the roof of a new tenancy at Westfield Chermside.. Workshop drawings were required for some new Sunshade steelwork and these would be provided by a 3rd party draftsman who would be using our laser scan data.

This was to be a bit of an experiment as SSS Manufacturing and Mulherin Rigging wanted to test BIMTeks workflow to see if it what we offer actually works.

What does BIMTek offer to construction clients?

"An end to end service starting with a scan survey to establish the as built conditions before the design or workshop drawing phase. We then overlay proposed design on our accurate survey to spot any obvious problems. The design or workshop drawings are then produced either by BIMTek or your own drafting team. Then after clash checking your proposed structure within the laser scan environment we revisit site and layout every hole you have to drill and every weld on bracket you have to install, all new penetrations and any other general setting out that is required. Using this system problems can be spotted before you start drawings,  fabricate and later, before your install team gets to site. This saves you money."

The site situation was going to be very fast moving and sure enough after the initial laser scan a redesign was decided upon by the client to suit some further requirements that had come up.

Initial site scan.

The design changes took a couple of months so we had to return to site to re-survey as new walls were built and play areas were starting to be installed. This proved to be a very good move as the new structures that had been installed had an impact on the steelwork which required some quite major changes to the steel model. The new scan was turned into a Tekla friendly format and delivered to the draftys. The revised steel model was then merged with the second scan for a clash check.

Second visit scan

Second visit scan with model

Second visit scan with model

Second visit scan with model

Further alterations had to be made as we had columns clashing with a couple of the dwarf walls. All of this was done prior to fabrication.

Then BIMTek returned to site to lay out all of the Chemical anchor bolts for the columns and 2 penetrations in the wall. This was to prove challenging as the build had carried on regardless. We now had sand pits and mulch areas where there were none before and of course most of our columns were in these areas so I had to get a shovel and start digging holes whilst Paul started laying out the column drillings.

The layout was not without its challenges. Whilst we were marking out the landscape guys were moving big bags of sand. Whilst our backs were turned the total station was either knocked or had moved due to the weight of sand being dumped close by. This caused a rotational error in our layout. Luckily, due to the frequent checks we do, Paul spotted the problem and we corrected the error and carried on. The Total station is very sensitive and a knock is enough to cause you a headache if you are not careful.

Below are some pictures of the installed structure.

Now that the installation is complete I took the opportunity to chat to Wayne Cadwallader of SSS Manufacturing. I asked him for his thoughts on the BIMTek process and he states that

"Using Laser scan data from site to communicate with 3rd party draftsmen is invaluable. The scan communicates complex site details visually and makes it easy for the draftsman, no matter where they are located, to understand the design problems and requirements and react to them rather than write lots of RFI's."

I also got to ask Terry Nolan of Mulherin Rigging his opinion on the layout that we did and he said.

"Using your layout services on difficult cluttered areas makes life very easy for us"

So all in all this was a very successful project. Using BIMTek for the survey, analysis of documentation and layout of a project will save you time and money, reduce errors to virtually zero and give you the additional time on a project to perform other important tasks.

Challenging Times on the water.

Gold Coast Water Tanks

I was contracted by a local fabricator to survey 2 of 3 huge water tanks on the Gold Coast. The initial brief was to laser scan survey the 2 tanks so workshop drawings could be produced. I turned up on site and started what was the most challenging project so far.

Tank Panorama

The largest tank was huge. It was 61m in Diameter, 11m High and full of water. Once I had got all my gear to the top of the staircase I was faced with the first problem. How do I set the RTS up? There was only a grating landing at the top of the staircase and that really was it. I managed to get the tripod erected with its feet on the stair steelwork and it proved just stable enough to set up a control network provided I didn’t move to much. Once we had paddled our way around the tank installing control point stickers and paper targets we were ready.

Scanning the smaller tank

Next came the scanning which was hard work and nervous work. Trying to stand up in a small boat to position the scanner on top of the steelwork was awful. I was so scared that I would drop a $65K machine in the water and that would be it. Coupled to this the steelwork was covered in duck poo and other delightful things which I was trying to avoid getting all over the scanner. A few hours later we had scanned the tank and as always, the scanner performed and was light and small enough to be able to use it in this kind of situation.

Scanning for a countour map

The other smaller tank went better as I had a bit of a system going. You could also walk around a small ledge on the inside so a boat wasn’t required. I was then asked if I could so a quick set up scan on the third tank which had already been surveyed. The client wanted the drilling on the tanks to be set out. They also required a contour map around the base of the tank which I also agreed to do.


The surveys were completed and fabrication was underway. Now it was time for the layout stage of the project.

RTS mounted on the tank wall.

I firstly had to visit one of the smaller tanks to do the layout and the fun began. I realized very quickly that this was going to be as difficult as the surveys. Firstly, we had to find a way of fixing the RTS to the tank. The initial idea was to mount the RTS on a steel post that would be clamped to the steel or concrete beams towards the center of the tank. Setting up was hard as the boat moved a lot and looking through the RTS to set up on my controls was tricky. However, I soon realized that the steel post was not a good idea as it moves when the sun gets on it. It moves a lot more than you would think. To exacerbate this the tank was moving more that I had ever imagined as well. In the end, we gave up and bolted the mounting post for the RTS to the wall of the tank. This made things much better as the wall moved less but the sun was still a problem. The only way around the sun was to keep checking the level of the RTS and to keep re-setting it up when it had moved. Once set up was done we moved onto the big tank.

The big tank was hard work but the structure of it was different so we could set up in the centre and clamp the mounting post to the steelwork in the centre. We had the same movement issues with the sun but the tank being bigger did not seem to move so much or so I thought until I heard a massive crash which was the tank wall moving slightly and making a beam move and make the bang. It took nearly 2 whole days to mark this tank out. My main problem with the mark out was trying to hold the prism and tablet whilst standing in the boat. It’s hard to keep everything still enough to get a good position mark. The Trimble tablet is very heavy and bulky. It’s hard to use on the ground let alone out of a boat. Trimble… Why can’t we use an ipad? It would be so much lighter and cheaper. However, with all the technical issues we had the steelwork for both these tanks is installed and complete.

Marking the walls

Marking the walls

RTS Mounted on the tank steelwork

The last tank went the best as I could mount the RTS on its tripod. This was where I realized just how much these tanks were moving as they warmed up. I think it must have been about 10mm movement in a couple of hours which was made slightly worse by the small movement of the water in the tank caused by the wind.

All in all, this was an important learning experience. I found out that environmental factors and boats can really throw a spanner in the works at both the survey stage and layout stage of a project. I also learned that it doesn’t matter how good your control network is if the structure moves. However, it is still possible to complete the job successfully so long as you have these factors allowed for.

Most importantly check yourself. Don’t just rely on the technology to tell you things are correct as sometimes even if all your expensive software and gear give you the answers you want it might still be wrong. When I set up I now always perform check measurements between known points just to make sure my set up is good before getting on with the layout job.


BIMTek's scan services

Over the last 6 months I have been slowly building up BIMTek's portfolio of clients that require scanning and BIM Layout services. As you may know BIMTek started using scanning for in-house drafting projects but the company has morphed over the last couple of years to offering scanning services to a range of clients in construction and factory design fields.

The last 6 months have been intense with high workloads and below is a rundown of some of the scan surveys BIMTek has carried out for new clients.

Mt Austen High School, Wagga Wagga. NSW.

Rambler Welding in Wagga Wagga contracted BIMTek to scan some school buildings at Mt Austin High School so they could design and fabricate a new elevated walkway system to join the upper floors of the school buildings. The survey was required as the buildings may not have been in line and there were a lot of features like down pipes and other services potentially in the way. I flew down with my scanner and other gear and spent a day on site in the sunshine collecting this survey.

I extracted the relevant scan data for insertion into Tekla Structures and delivered it along with Recap and Realworks data to Rambler welding for use. The project has gone fantastically and looks great. I am awaiting site photos to see the finished walkways.

50 Graham Rd, Carseldine. Qld.

Anthony Smith of Struc-tech Steel Detailing asked me to deliver a scan survey of the existing steel work at the Aspley Hornets Clubhouse.

The existing frame was to be extended as part of an extension to the building. The scan was required to pickup the existing column and rafters along with the purlins. The existing purlins would need to be joined to new purlins with an overlap type connection so accuracy was important.

Upon delivery Anthony immediately identified issues between the as built situation shown in the scan and the indicated levels on the design drawings. Using this data he was able to inform the main contractor of the problem and alter the steel model to suit. This saved thousands of dollars in re-work had the issue not been spotted.

Historic Aircraft Hanger preservation.

Idec, a steel fabricator in Hemmant, QLD, contracted BIMTek to undertake a scan of an historic Aircraft hanger.

The "Bellman" hanger is a historic and important design as it is modular and can easily be dismantled and moved in small standard sections on trucks. The Brief was to capture the structure of the hanger with special attention paid to the doors and tracks. The hanger would then be dismantled and erected in a different location. The scan was partly for preservation and partly so new sections could be fabricated should the need arise.

Unfortunately no images are available for this one, however here is a link to the UK governments entire PDF design manual for this type of kit building.

WW2 Bellman Hanger at RAF Stoke Orchard. UK.

Genesis Childcare

I was contacted by Wayne Cadwallader at SSS Manufacturing to provide him with a scan survey of the roof of a new building at the new Chermside Westfield extension here in Brisbane. BIMTek had already provided the workshop drawings for this building about a year ago to a different fabricator so we were very familiar with the building.

The scan was required as new steel pergola's, seating areas and sunshades were to be detailed and fabricated for the Childcare center who was the new tenant of this area. This project is unfortunately still in the design phase but hopefully will be installed and completed soon.

There are some in-depth blog posts to come.

6 Months and lots of challenges

Its been a while since I last got a moment to update the BIMTek website and write a blog post.

BIMTek has been lucky enough to win so much work we just haven't stopped but here is a rundown on whats been happening since the last post.

1, The last post.... I received quite a bit of criticism about my last post. I must admit I was feeling a bit thin skinned at the time and have been reluctant to post more blog entries. I really upset a few surveyors as I said in my last post that laser scanning can be cheap, we discussed pricing and disagreed on my pricing model. Lets just finish by saying that the internet is not for the thin skinned.

 Roma Street canopy - The subject of my last post.

Roma Street canopy - The subject of my last post.

2, BIMTek was contracted by Steel Fabrications Australia to detail the 2 link bridges at the Brisbane Airport International Terminal upgrade. These were two 100+ tonne truss bridges that span from the new terminal extension to a node building that houses the air bridges. This was a huge challenge as the deadlines were short, information scant and pressure immense. However, the node buildings are now erected and the 1st link bridge is starting to be delivered to site for erection. Each link is made up of 8 pieces and will be bolted / site welded on the ground and lifted into position. 

 Link 74 Brisbane International Airport

Link 74 Brisbane International Airport

3, BIMTek bought a Faro X130 Laser scanner. Yes I finally "Bit the Bullet" and purchased my own scanner. I am so glad I was brave enough to invest as the scanner has been very busy since. Its so handy, especially on smaller jobs, to just be able to get the scanner out and measure. The $700 per day hire fee made it impossible to provide surveys for small projects.

I have also been able to re-visit sites and re-scan areas easily where the pace of change on site is so fast a QA scan necessary to ensure things are going to fit.

Its a great addition to the company and enables me to go forward and try to get more scanning work.



4, Since January we have been involved in several scan and BIM projects. I have been down to Wagga Wagga to scan school buildings for Rambler Welding and learned that taking scanning and survey gear on a plane is horrible especially when you see the baggage handlers unloading the aircraft. I scanned the Carrara indoor sports stadium for Hyforce engineering which was a small job that turned into a huge project. Also there have been several scan surveys in Brisbane for a range of clients.

I will be writing about these in the next few weeks in more detail.

Its been a while

I have been neglecting this blog because I have been swamped with work. I figured it was about time I got back on to it and let you know what I had been up to.

Since the Alexandra Hills Hotel project, which incidentally is currently being erected, I have been busy with several scanning and detailing projects. I have continued to learn a lot and develop my workflows and I have also learned that its not always nice giving people bad news. To follow is a rundown of the most interesting work I have been doing since then.

To start with I was contracted to scan a station footbridge in Sydney for a detailer who was adding a steel roof. This was a problem for me as I couldn't get there fast enough for the project timeline. Instead I used a colleague in Adelaide who flew out there for me with his scanner and did the survey on my behalf.

This worked out well and we delivered all of the laser scan survey extracts for Tekla Structures to the detailer in about 2.5 days! The scan quality is excellent and was done with a Faro Focus 3D Scanner.

The next project that has kept me busy was a impressive and complicated canopy at No 1 William Street in Brisbane. The steel fabricator required my services to survey the canopy in his fabrication yard to establish its true geometry as they were having problems fitting the rafters to the tube frame. The Rafters and Tubes had been made in different workshops.

William St Canopy in Yard

The first scan was delivered and adjustments made. I was then asked to go back and re-scan as a further inspection was required. Again the massive canopy was in the fabricators yard. It was only about 4m up to its highest point so was easy to scan and get good results. When the scans were inserted into Tekla Structures the detailers could see instant improvements in the Rafter and Tube Geometry and fix what was not so good.

The tube section of the canopy was erected back in May and I was again asked to scan it in its erected position. This way the fabricator could re-check how the massive rafters would fit prior to their installation. The scan was performed on a very busy site and was problematic. I couldn't enter one area due to overhead works and had to turn the scan resolution and quality up to try to get a decent image of about a quarter of the canopy. Along with the scan I shot every end plate in 6 locations with the Total Station just to ensure we had the data we needed. The result was an excellent scan survey. In fact even at over 10m away the scan shows the outlines of bolt holes. I was not expecting that! Results were delivered for Tekla Structures in 24hrs and I learned that its hard to deliver bad news. The canopy was significantly different over the length of the rafters. It had grown.

This is the point of these surveys. Sometimes you have to deliver bad news. Its not nice but it saves money in the end as site work to alter anything that has been prefabricated incorrectly is very expensive. Using the scan data the fabricator was able to rectify the problems and save costly site delays.

The Busy Site area at William Street

The erected canopy

The other project that has taken a lot of my time was layout work at a site at 310 Ann street in Brisbane. Mulherin Rigging asked me to set out holes for site drilling. This all sounds fairly simple but it was a 15 floor building with hundreds of holes on each floor to be marked. The holes were in the walls and roof slabs and were problematic and time consuming to mark out manually. Below is an installed version of beam i was marking out drillings for. To compound the difficulty factor an error had been made in reading the original site survey and nobody had thought to compare 1 floor to the next. Each floor had a central column which was assumed to be in the same position on every floor. It wasn't. I had to take the BIM model from the drafting company and move the drilling locations around so they suited the central column on each floor. It took a lot of office based work but I made the changes and the steel work was installed without incident.

Installed steelwork

Marked positions and laser on new position

Trimble RTS 773 hard at work

The Trimble RTS773 performed perfectly and I was able to mark out 3 1/2 bays per day at more than 80 holes per bay. (Manually they could do 2 at best). More importantly the RTS increases the accuracy of the mark out as all holes are relative to each other as you only tend to set the RTS up in 2 or 3 locations and use the same reference points. This way human error can be reduced significantly.

310 Ann St Steelwork installed

All in all its been a very busy few months and I hope in continues.

Scanning for HVAC companies and shiny things.

I was recently contracted by a new client who wanted to try a laser scan survey on a shop tenancy at Pacific Fair on the Gold Coast. The premises needs an air conditioning and extraction system fitted but it all has to fit around existing ducting.

I headed down at 5am one morning to do the survey.

As everything was so tightly packed in already I had to perform about 15 scans as I wanted to make sure the scanner could see between duct runs and alike. The job was completed in about 4 hrs. No problem I thought.

Once I got back to the office and registered the scans I noticed that the scans were very noisy indeed. I was using a Faro Focus X130 which was very new so I was slightly concerned that the equipment may have been damaged or faulty in some way. It was then the penny dropped and I realized that the shiny ducting might be the problem. I had about 16 million points in the model that were just noise or rubbish to clean out. Once I had spent a few hours cleaning out the rubbish I was able to produce the extracts the clients Revit draftsman required.

So watch out. Highly reflective surfaces can be tricky. Its not that the scanner doesn't capture the data its that it captures a load of spurious data in with it that could throw a client that isn't aware of it. Scanning might be sold as the be all and end all of surveying solutions but if you don't watch what you are sending to clients it could be disastrous for you.

After the clean up I have a happy drafty and client.

As far as HVAC and MEP scanning in concerned I am of the opinion that on existing spaces, especially where there are a lot of existing ducts, pipes, structure and penetrations to design around a laser scan survey is invaluable. Your designers and draftsmen can then work in the actual environment you are installing in to. This will reduce clashes, poor fitting and reduce site work. My client is also convinced as he has contracted me to scan Dalby court house for a refit of its air conditioning system, and roof access systems.

Interestingly the laser scan has been useful for getting the shop designers to have another look at their plans. The scan showed that the proposed system simply wouldn't fit within the envelope allowed by the architect. This is the risk of only designing in 2D with only "As-Built" drawings to work with :-)

Singapore Airlines Silverkris Lounge. Brisbane International Airport.

Just before Christmas I was asked to perform a laser scan survey for a Steel fabricator who was contracted to fabricate and install architectural structural steelwork to the new Singapore Airlines Silverkris Lounge at Brisbane Airport. The survey was required to ensure that we did not clash with the existing airport steelwork and that we could fit between the existing walls with the minimum of clearances. In addition to that we had to fit new base plates around existing base plates again with very low clearances.

Lounge space Looking South

Lounge space Looking North

Lounge space Looking North

The lounge area consists of 2 parts. The South end is open with new architectural steel trusses above running across and along the space. The rear North part of the lounge had new stud walls that will contain supporting steelwork for a small plant mezzanine above. Columns for the trusses are required to be hard up against the walls and the scan was invaluable for proving that the walls were fairly plumb and that the steelwork would fit.

New Steel Trusses looking South

New Steel Trusses looking North

I use Trimble Realworksa lot for visual clash checks. So long as your laser scan in Realworks and your Tekla model (or other model) use the same co-ordinates you can merge your new model with the laser scan with ease. This can be used as a very good visual clash and fit check. Below shows the front view of one of the main trusses on this project. In Realworks if you zoom into the columns you can see that the wall does not clash with the column top. The snapshots below that show the zoomed in image in detail.

Front view of Truss using the limit box extraction tool

Top of column and wall line

 Column base plate, Wall and floor level. The stud wall has to be cut to allow the base plate to penetrate the wall.

Column base plate, Wall and floor level. The stud wall has to be cut to allow the base plate to penetrate the wall.

The builder requested that we return and make a further survey to ensure that the new stud walls would match the steel plan. It was a good call as some of the walls had been moved to suit site conditions. The steel work model was then easily altered on site to suit. The wall changes did show up a clash between the existing steelwork and the new so again we were able to let the design team know prior to fabrication.

Mezzanine steel work

Mezzanine steel work looking south

Although this was a simple area to survey it just shows how useful the scan survey can be when it comes to things you didn't even know you might need. For me the main thing it gives is certainty and I like being 100% certain things will fit before its made.

Chermside Food Store.

Firstly Happy New Year. I hope 2016 will be better and more Laser Scanning, BIM Surveys and layouts will be required by Australia's Construction industry and the world over.

Its been 6 months since I complete this food store project but I have finally managed to get a couple of pictures to show the finished store.

I was asked to survey existing columns and the interior of the roof of this food store so we could then add on steel work to extend the store about 8m to the side. The problem, as with all these stores, was that they couldn't close, keep the public away or open up too many holes due to weather issues so a good BIM survey was the solution.

Armed with a Trimble TX5 Laser Scanner and the trusty Trimble RTS773 Robotic Total Station I went to site. Due to problems with getting to the existing steel work I had to use both pieces of equipment to gather all of the required information to produce the new steel model. The scanner could not see enough of the existing columns so I shot the center of these with the RTS. The scanner picked up the rest of the details and roof slope. The survey did pick up a grid problem from the start so we straight away could factor this in. (The marked Grid was 50mm longer than the store and consequently the existing columns did not match the grid marked out by the builder)

The next challenge was to scan the inside of the roof space so we could get the plant area steel work that was to be extended and the internal trusses. this is challenging in a working store with the public around but it worked well. I use Trimble Realworks to trim out the details I want from the internal scans and then load them into Tekla Structures as reference models.

The steel detailing model was born from this information and delivered ahead of schedule to the fabricator. Once the steel was fabricated I then returned to site to mark out the weld on cleats and base drillings that were required. I also checked the 2 cast in bolt sets for the relocated sign and found that they were placed about 25mm south of where they should have been. Using this info we were able to alter the new sign bases prior to the steel being painted. This saved a lot of money and heartache.

The steel went together well with no alterations and as you can see from the above photos the overall finish is excellent. This was a relatively simple job I admit but it brought together all of the services that BIMTek offers, it saved the fabricator and undoubtedly the builder money by spotting problems prior to installation and it saved heaps of time.

Information is power. If you know what you are building to you are forearmed and a whole less stressed out.

Its been a big year.

We are now approaching Christmas and I'm left wondering where the time went. Its been a roller coaster year for me and BIMTek in the Laser Scanning and Steel Detailing fields.

It started last Christmas with me handing in my notice at Steel Fabrications Australia. I left to begin a Steel Detailing project at the new Mascot Ice Rink in Sydney. The idea was to procure a Laser Scan survey of the existing building shell to enable us to set out the steel work efficiently and with certainty.

Mascot Ice Rink Shell

Mascot Ice rink with new steelwork

I was next asked to perform a laser scan survey on several parts of a shopping center at Lismore in NSW. We could then go on to produce design drawings and workshop drawings for the steel and aluminum elements required to upgrade the entrances. It was 38 degrees on the day of the survey and I realized that the scanner will only work for short periods due to overheating.

Lismore Shopping Center scan

Lismore scan with steel

Then onto a laser scan survey and steel detailing contract for an Aldi extension in Brisbane. These are a challenge as you need to merge the inside and outside of the store with the added complications of the public being around. You certainly get some interesting characters when you are out scanning. Whilst I was on this project I was getting training on the Trimble RTS 773. This was to enable me to Geo-reference laser scans so I could accurately align them to a grid. I also needed to learn how to return to site, set up and accurately lay out points for new holes and weld on cleats.

Aldi Chermside

Aldi Chermside

During the food store project I was contracted to undertake a small laser scan survey in a very big warehouse. The steel fabricator needed survey information to build a new mezzanine office frame that had to fit between the existing steel work. This was the first project that I did on my own with both the scanner and RTS. It went perfectly.

BAC Warehouse Mezzanine

This project grew exponentially. There was a new requirement to scan the entire building. The data was needed to dimension new steel for strengthening works to the roof. It took about 25hrs and 106 scans to cover the building and then another 5 or 6 hours to process and register the data. As the job was so big I used 2 Faro laser scanners and the help of my son. Once the drafting was done by a team in China I returned to set out the steel work which took about 3 full days.

BAC Warehouse full scan

BAC Warehouse internal

The next contract was at the University of Queensland at St Lucia in Brisbane. This was a challenge as we found that Laser Scanning does not work all that well on black colored items. As you can see in the below pictures the scanner misses a lot.

UQ Bridge with Steel work

Scan problems

After that, and the last scanning project I can show you was Redlands Hospital Fence. This was the final project to reach my training goal. The aim was to take a project from beginning to installation and use the Trimble and Tekla technology from end to end. The steel work installed without a single problem and is now clad with its security screening.

Redlands Hospital Garden

Garden with screen support steel work

Redlands Hospital finished Screens

Redlands Hospital finished Screens

Since the Redlands Hospital project I have been asked to deliver laser scan surveys at 2 big food processing factories in Sydney. Unfortunately I am working on getting their permission to share images of these scans on my blog and website. I imagine as laser scan surveys become more popular more surveyors are going to be bound by confidentiality agreements.

Hopefully 2016 will be a good one for everyone and with any luck BIMTEK will still be there offering scanning and detailing services. Have a good Christmas and a better new year.

Surveying, Detailing and laying out.

I discovered laser scanning and surveying using high end Trimble equipment because steel fabricators rarely get the information they specifically require from the project team to successfully build to existing structures.

A Typical Small Commercial Project in Australia.

I was offered a project to produce workshop drawings for an extension to a food store but there was a catch. We had to build to the existing internal steel work but there were no as-built drawings. The architectural drawings for the existing building had no dimensions apart from the grid, in fact most of the detail drawings were missing their dimensions. The builder could not remove the cladding so we could access the steel before erection day as the rain would get in and the store would not close or remove its false ceiling due to loss of trade. There was access to the roof space so we could see the gable end truss but we would still be over 10m away from the parts we had to measure. Plus we needed to connect to every purlin. This was a challenge.

 Food store Plant room - shot from a Trimble TX5 scanner

Food store Plant room - shot from a Trimble TX5 scanner

Laser scanning immediately jumped to mind because there was so much information to capture. I contacted Surepoint a company that I knew did this sort of survey work and got them to agree to train me and start me on the road to enlightenment. Paul Seifert, who is now employed by Building Point in Brisbane trained me. Paul Seifert is a scanning guru. He has supported me all the way with patience, even when my questions were repetitive and somewhat basic.

Moving on.

I soon realised the possibilities. The first project I undertook went without any problems even though I was still learning to use the data in a way that Tekla Structures could cope with. At that time there was no good application to convert a large point cloud to a usable Tekla format. On the back of the first project I got a second and again asked Surepoint (now Building Point) for help and more training. The second job went smoother that the first and this set me on the road.

Since then I have been contracted to survey and detail 5 of these stores now and each one has been a challenge as each one has its own problems to get around. A new problem raised its head. Can we set out the new steel work to the existing with limited access easily and efficiently? I again went back to Paul Seifert at Building point to get training on the Trimble RTS773 Robotic Total Station. I knew this could do the job as I had, a long time ago, seen a demo by David Grant who is now the Regional Manager for Trimble in SE Asia, Australia and New Zealand. At the time I was blown away by the simplicity of its operation and the smart way in which it took and displayed points in the field. Paul Seifert agreed to give me more training and I was amazed at how fast I learned to operate the RTS in the field. We trained on a live project and I have been hiring them ever since for every survey and for most set outs.


Today I have been on site at the trickiest set out I have done so far. This time I had to work from grid lines that another surveyor had put down. These had also been there a while so I imagine they had been knocked about or had settled over time. I shot the Grid lines and a datum and entered the coordinates into Tekla structures using the Trimble Layout Manager. Straight away I noticed that you need to find the best fit for your points as you are never going to be bang on. Once I entered this data back into Trimble Field link I checked the existing cast in base bolts. They were within 6mm so I don't think that's too bad but it does show how accurate the equipment is and how the inaccuracies in the as built situation build up. Scanning in fact makes it even easier to see walls out of plumb and sagging steel work. Knowing these things is arming yourself when problems arise and preferably before.

So with lots of help from Building Points Paul Seifert and Aiden Battenally I have set myself up to solve these problems. Now to sell this service to people that don't even know it exists or believe its even possible.


Laying out points on site has never been easier.

BIMTek offers a site layout service to our clients as part of the one stop shop service we offer.

Its never been so easy for us to layout points for steel erectors or any other installer to take advantage of. So why is nobody really doing this? Why are fabricators still expecting riggers to set out drilling's and weld on plates using string lines and tapes? I don't know the answer to this question but I'm guessing that its got something to do with low expectations of the technology, low expectations of accuracy and expectations of high pricing. It might also be due to the lack of exposure this technology gets in the industry as it is seen and expensive and to some almost like magic.

The Trimble Robotic Total Station technology enables critical points to be set out on highly complex structures and makes life easy for the installer. It also saves money as installers can start installing as soon as they get to site rather than struggling to set out starting points on ever more complex structures. The Trimble RTS also logs every point you set out as a measurement so you can tell how much packing to use or see how far out that concrete base really is. These measurements can be re-injected into your 3D model for analysis so last minute tweaks can be made to items still in the workshop. This data can also be used to prove to your client who is wrong when something doesn't fit.

Anyway BIMTek is out there doing it! I can operate the RTS from up on a work platform and mark the points I need to mark a lot faster and more accurately than a rigger can with a tape and string. This means I can be ahead of the riggers and mark out while they are doing what they are supposed to be doing like welding on plates and drilling holes all in preparation for the installation of steel. this ultimately saves the fabricator cash.

 Trimble Robotic Total Station and my mark up of a column 10m in the air.

Trimble Robotic Total Station and my mark up of a column 10m in the air.

Don't forget this isn't just ideal for steelwork but MEP, concrete and blockwork installers would benefit from this too.

Redlands Hospital Security Fence

I have been contracted to provide a survey and detail drawings for steelwork fence framing around the top of a garden wall at Redlands Hospital in Cleveland, Queensland. I went to the site to take a look and decided this was a job for the scanner as it would collect all of the needed information faster and more accurately than just the RTS alone.

The wall around the garden was complex with steel awnings over wall alcoves. All of this needed to be built around and fixed to so scanning was the only way I could see of being able to gather all of that survey information

The scan was cleaned up and the vegetation deleted. This time I down-sampled the entire cloud using Trimble Realworks and broke it into 6 sections. These were then converted and inserted into Tekla Structures.

The model was turned around in a couple of days and re-inserted into the point cloud for a visual check. When I did this I noticed a clash between the arch canopy and the new steel. Previously this had not been considered by the design team as they thought the old and new steel would pass each other. This was proven to not be the case and visually demonstrated using the merged point cloud and steel model. Quickly a solution was put forward and implemented with no stress, fuss or arguments.

Next week i will be returning to site with The RTS to set out all of the drillings and site welded plates.

Its a Monster!

This is the biggest scanning project I have completed so far. Its back at the warehouse at Brisbane Airport which was featured in an earlier post.

 BAC Warehouse. Brisbane Airport.

BAC Warehouse. Brisbane Airport.

I was contracted to scan the entire warehouse to capture detail in the first 20m of the roof as the whole building is in desperate need of roof strengthening. The bracing had to be captured along with all of the existing services and all of the purlins in the first third of  the roof.  I used 2 scanners and drafted my son to help. 15hrs of scanning later and 105 scans my poor HP workstation was put to work. Another day later and we had a registration within 3mm!

I had to down-sample the 2.5 million points to help my workstation. The resulting images are a bit grainy but you will see how large the warehouse is.

The job was not without problems. Firstly you get a lot of data and if you don't watch out in Trimble Realworks you end up with even bigger files and mine crept up to 85GB. Secondly I learned that if your target placement is a bit more regular than you intended Realworks struggles to pick one target from another. So in future be very random about target placement. Thirdly we found that using Realworks' Auto-extract Targets and register function we got 2 targets with the same number. We don't know how but it took about 5 hours head scratching to work it out. Lastly we could see that the scanning of this building shows all of the major problems with a scary reality. For example all building rafters can sag a little. The scan shows that in this buildings case its over 120mm and it stands out like a sore thumb.(See below).

 Rafter Sag

Rafter Sag

The data has now been extracted and inserted into a Tekla Structures model for the new steel to be detailed. It will be a month before I have to go to site to set it out so I will report back once the steel starts going in.

Below are a couple of screen grabs showing the color point cloud in Tekla. This makes it so easy to convey all of the necessary information to the draftsmen that have to fit steel to this frame. it is also invaluable in helping the draftsmen avoid clashes for the beginning. Problems can be identified and solved before the steel is even ordered.