How did HICAD first get involved in laser scanning?
Medley: Hi-Cad Technical Services started its work in the North Sea in 1988. That was when BP, ExxonMobil and other owner/operators were first looking for ways to keep the hot work from being done on offshore platforms. They told the engineering contractors and fabricators in effect that they wouldn’t tolerate any more rework offshore. That’s when a lot of these companies first started developing techniques and tools aimed at having as few field welds done offshore as possible. That was the background for Hi-Cad’s development of an electronic survey measurement technique that led to D.I.M.E.S., our Data Integrated Management Engineering System software.
The HICAD America business was established in 2000. We first met up with some of the laser scanner manufacturers in early 2001. As a dimensional control company, we judged the technology at that time was not as accurate as we wanted. In fact we saw it as a competing technology. Also, we came across a lot of projects where the client should never have been talking to a laser scanning company, because it was either overkill for the job or wasn’t going to fit with the client’s software and procedures. Only in the last year have we started to push laser scanning services. We’ve always been willing and able to use new or alternative technologies – we’ve developed new technologies
ourselves over the years – but from the standpoint of dimensional control management, we always try to look at what’s the best solution for the client.
Swymn: I joined HICAD a few months ago from a major engineering contractor. As a senior piping designer I evaluated laser scanning as an option for the contractor’s use, then we worked with one of the scanning service providers to help guide development of their proprietary software. I got to know laser scanning on a pretty deep technical level. I’ve worked with the scanner in the field, and the data in the office. I worked on just about every laser scanning project that one of the contractor’s offices did in the past three years, and then got involved with another one of their offices as well. I’ve probably had some part in about 20 laser scanning projects in all.
What industries do you specialize in?
Medley: The petrochemicals industry has always been a big market for us. But any industrial facility that has to be dimensionally controlled for one reason or another is something we might work on. We surveyed the Reliant Stadium roof in Houston using total stations and D.I.M.E.S., as just one example out of many. Hi-CAD is an as-built company, not a laser scanning company.
Is it a challenge to maintain competencies in both laser scanning and other dimensional control technologies?
Medley: No. As long as we define the work processes, and the client’s employees fully understand our work processes and fundamental approach, I don’t think there are any difficulties. We’ve used one, two or even three technologies – laser scanning, photogrammetry, total stations — on a single project. When we undertake a job, we sit down with the client – specifically the people who’ll be working with our deliverables – to understand exactly what they need. Our first task is to find out their expectations, and make sure everybody involved in the project agrees on the objectives. It helps to develop the fundamentals in your own company so that every project is approached in the same way.
What were the biggest challenges you faced in moving into laser scanning?
Swymn: The biggest challenge was making sure that users had tools they could use. The people in the office that actually have to use the data – those are the people who make or break the project’s success. If they can’t use the data, there’s no point in having captured it. Designers in various disciplines – mechanical, piping, structural – those people are the primary end users of the data. They need a way to accurately measure point clouds. And they need to be able to compare the point
cloud against their CAD models to support the design work and do clash detection. Another issue that has come up on almost every project is ensuring, up front, the coordinate system. In every plant there’s a coordinate system for the overall plant. Then inside the plant, each unit may be documented with a different coordinate system, and these may not match up. Establishing a coordinate system that everybody agrees on, and agrees to use, can be a challenge. That’s not just with laser scanning – it goes throughout engineering. For the laser scanning job you have to know what the coordinate system is, and where it starts from. I can’t stress enough how important it is to be sure that information is agreed on.
What hardware and software do you work with?
Swymn: My experience personally has been with Z+F, Cyra [Leica HDS] and Quantapoint. At the moment HICAD is using the Leica HDS4500 scanner OEMed from Z+F. Hi-Cad Ltd. also owns a Leica HDS2500 scanner. On the software side, Z+F has a suite of software that we use, and we also use LASERGen from BitWyse. I don’t recommend building a model from the point clouds. I know there’s a place for that, but in typical design work I don’t recommend it at all – there’s too much room
for human error. The ideal situation is to use the point cloud as it is. In the beginning you had to model, because the hardware and software couldn’t support the whole point cloud at once. But now that the technology’s catching up, we don’t have to go that way.
Has laser scanning crossed from a market for the technologically curious, to one where customers are driven by the business benefits?
Swymn: It was only a matter of time before laser scanning or some other technology was developed to capture existing conditions. There’s been a need since day one – engineering firms have spent a fortune on the problem. They dabbled with photogrammetry 15 years ago, but it just wasn’t feasible. It was just time for laser scanning to emerge.
What’s still needed in the technology?
Swymn: Scanners are getting a lot better, but they’re still heavy and somewhat slow. They need to be faster, more durable and more agile – we have to take them into some pretty harsh environments. From a software standpoint, integration between the various tools is needed. As it is, you have to buy several different modules of software from possibly several different vendors to compile the best set of tools needed to effectively work with scan data.
What job are you most proud of – the project where your work had the biggest impact?
Swymn: I was involved in a job that my former employer did for a major oil company. Because of the laser data we captured and the way we captured it, the mechanical designer in the office was able to find a better routing for a very big pipe that saved the client $700,000. The laser data gave him a view into how to route the line that you couldn’t get from any other vantage point. From the ground you looked up, and it wasn’t evident there was any better way to route the duct. Only by flying the
viewpoint over the point cloud could you see this routing, which was a much better one in terms of distance and material than any other. I helped capture all the data on that job – I was in the field managing where the scanner was to be positioned. I had understood the scope of the job, and went out to the field to make sure we captured everything that was needed.
What about a job that went wrong – what did you learn from it?
Swymn: We haven’t had any jobs that went bad. But the lessons learned in the early projects were to have somebody very familiar with the process involved in the laser scanning in the beginning, to ensure we got everything scanned that we needed, and didn’t waste time scanning things that weren’t needed. It’s very important to have somebody from the project involved who understands the scope of work, knows what tie-ins are needed and so forth. They need to guide the field crew.
There have been many lessons learned. An example of a small but important one is to make sure that in at least one scan you can see the monument with the coordinates on it. That way, if something is off in the point cloud, you can go in and verify it’s where it’s supposed to be. In one case I know of, the surveyor wrote down a ‘4’ as an elevation value, and then read it as a ‘9’ when he was registering the point cloud. To trace the error, we found the monument, clicked on it, and saw that the east/west
coordinate was correct but the elevation was wrong. So we used the survey control to correct the elevation reading, which corrected the placement of that scan in the registered cloud set.
What’s your greatest frustration today?
Medley: Getting the client to understand and follow through on the dimensional control procedure we develop for them. When we develop a dimensional-control policy and procedure for the client to follow, often the company doesn’t give its own people the opportunity to understand it, because they want to get to production – they want to get something out of the asset immediately. But they need to sit down with the dimensional control company and understand how long it will take for our work to start producing advancements in what they’re trying to achieve.
Another frustration is that lots of times the client insists on the wrong tool. When I went to look at a project two days ago, the client said, ‘We’ve got a photogrammetry job for you.’ I said, ‘No, it’s a laser scanning job.’ Then yesterday I went to a fab shop, and the client said, ‘I’ve got a laser scanning job.’ I said, ‘No it’s a total station job.’ When the client comes in at the beginning and says, ‘This is a laser job,’ often it’s because – especially on offshore projects – they’ve been talking to service providers
who want a trophy job that will let them say, ‘We can do laser scanning.’ But on an offshore platform, or anywhere there’s heavy vibration, the dimensional capture process has to be tightly controlled. If you don’t know how to control it, it’s going to be a disaster. That’s why we don’t market ourselves as a laser scanning company, but rather a dimensional control company.