Surveying Techniques, Laser Scanning

When I joined Martin & Ottaway, Harry Ottaway told me that Francis Martin used a horse and carriage to be dropped off at the various surveys.

Roy Kanapaux, a surveyor that still worked with Martin & Ottaway in the early eighties (at age 80!) and whom I met when I visited my father at the office, never had a driver’s license and used cabs to get him to jobs. In the last few years that became difficult because there were certain areas of the New York waterfront where cabbies would drop you off, but not pick you up when you called from a pay phone.

I myself started with Martin & Ottaway when we just acquired personal 35mm compact cameras. Before that we shot in 110 format (ugh) or, much nicer, by means of a shipyard professional photographer. Today, digital photography is really just too cool, and since a picture tells a thousand words, emailing a picture is often much easier in trying to describe a complex problem than words alone.

It can be argued that surveyors will adopt any technology that makes their life easier, and I suppose there is nothing wrong with that. We still occasionally use our ultrasonic hatchcover tester, not too long ago some surveyors tried rappelling gear for tank inspections and now we are messing with drones. All fun stuff, but, of all the new stuff, I like laser scanning best, because it accomplishes a task that I could not effectively perform before.

It allows one to quickly and quite accurately record complex shapes that need to be analyzed. In my younger days that often involved getting manual offsets from existing hulls, a really annoying problem, but today a laser scan can do the job quite quickly and not too long ago we scanned the hull of a flatsboat that had a tendency to go end for end with deadly consequences.

Laser Scanning gear is too expensive and the learning curve too steep to be cost effective for the occasional use that the typical surveyor has for it. But when it is needed, boy does it save a ton of work.

When we need laser scanning, we ask our friends at Horizon Naval Architects who have the equipment and the knowledge and experience to deliver what is needed as quickly as possible.

The actual scanning is only one part of the process, the more important issue is to turn the scan into something that is technically useful, and that is generally a 3D model that may simplify the scan, but not change the measurements.

On an operational level a laser scan can be a very fast method of determining the available space and connection locations for a new piece of equipment like a Ballast Water Treatment system, but the scan itself only becomes valuable when a naval architect or marine engineer reduces the scan to its useful components.

We found that Horizon can do both the scan and the data reduction quickly and at a reasonable cost, and they jump to it with minimal specification and explanation requirements. We like quick. When accidents like collisions and spin outs occur, it is often best to get things recorded as quickly as possible and laser scanning can be a real help in that.

It has not happened yet, but I am also looking forward to using a laser scan to create 3D printed models of the incident for further forensic analysis. 3D scale models of the damages to the two vessels in the collision, now that is a way to visualize things.