Those Who Don't Know Their (Structure's) History are Condemned to Repeat It
Over the past month or so I have been helping a new colleague start a secondment role at a large industrial site where I have done a lot of work over the past 10 years. In the short time he has been on site there have been at least 4 incidents where damage has been identified in structures where I (as an outside consultant) know more of the history of the issues than those on site seem to (at least so far as I can tell):
Cracking of a large bin. This structure had a history of cracking in a particular connection going back to (presumably) construction. This recently re-occurred. Unfortunately, this history was only documented for a specific 2 year period (out of its 10 year life).
The only reason the site had the limited history it did was because I had written it in a secondment a few years ago. I was able to speak to a few people who had been involved in repairs and some who had vague memories of the construction of the bin. Without knowing the history of cracking, repairs and modifications it was very difficult to determine exactly what was going on.
Eventually a different engineering consultant installed strain gauges and carried out an FEA analysis. They concluded the cracks would stop growing before they caused serious damage. But if I owned the bin it would still be nice to know the full history of cracking just to be sure…
Cracking of a materials handling machine (call it machine A). My colleague mentioned in passing that he’d looked at some cracking on a particular connection. The site team had decided to weld it up in-situ, and he had reviewed their methodology.
Unknown to him, this connection was identical to a connection on another machine (machine B) that I had investigated about 5 years ago due to fatigue cracks. My recommendation at the time was to install strengthening on B, and to investigate the same connection on A for cracking and possible strengthening. When I found out that cracking had occurred on A I passed the report I’d done 5 years before to him and asked him to investigate more.
My colleague found there was evidence of past crack repairs on A in addition to the repairs just carried out. However, no strengthening had been installed as per my recommendation 5 years ago. Nobody on site seemed to know of either the past cracking & repairs on machine A, of the existence of my report or of the recommendation to install strengthening.
Corrosion damage to a conveyor support. My colleague was interested to see if his current problem was a more widespread issue and found out that repairs had been done to the next support along approximately 2-3 years ago, but could not locate any information on the site’s system about the past repairs. I was able to find some photographs of the repairs in my own records (although they weren’t helpful in this situation unfortunately).
Corrosion damage to cladding. They did not have photographs from the last structural inspection easily accessible - again I managed to find the original copies on our system.
In all these cases the site would have benefited from better tracking of their structure’s history. They would have a better idea which components of their structure were suffering from corrosion and fatigue damage, and when & why, which might allow them to carry out more effective repairs. Also, without this information, in the event of things going wrong (such as machine A suffering a significant failure due to fatigue cracking) there could have been safety hazards to personnel on site and potentially legal or insurance trouble. Finally - it would have saved the site several hours of my time and many more of my colleague’s time, keeping costs down.
At this particular site it’s usually not that they have lost the information entirely, just that much of it is obscurely filed away, and a number of personnel have left (such as the person I delivered my report to). It’s there to be found if people have the time to look, but inevitably when trying to run a large, busy industrial facility no-one has the time.
This is not to suggest that this particular site I drew the examples from is especially bad at structural integrity. In fact, of the sites I work at they are one of the more proactive when it comes to repairs and inspections. These were just a series of recent events that I happened to be aware of due to my involvement. No doubt there dozens of structural repairs over that time-frame without any issues.
So What’s the Solution
I’ve got a few ideas about how this site (and others) could do things better. Some of these are pretty basic, and you should bear in mind that I’m somewhat of an outsider as well - I’m a consulting engineer, I don’t work on these sites everyday so I may miss some of the things that those who work on site full time may know. However, here goes:
A register or other history needs to be kept of any structural integrity issues, especially those that are likely to be repeated events (such as fatigue cracking, or damage due to repeated overloading). This should include photographs and measurements from each event and any other information that could help diagnose the cause.
This is one area where many sites at least in Central Queensland seem to have problems. It is a frequent occurrence that when I or my colleagues identify cracking in a structure there is also evidence of previous repairs, without any apparent knowledge on site of when the previous cracking occurred.
All structural inspection information needs to be stored in a logical and easily accessible location. Ideally this would be tied to the machine or structure first, rather than to the date of inspection or an arbitrary file structure on the server (often on someone’s personal hard drive space unfortunately…).
Any recommendations to carry out repairs or investigations need to be entered into the site’s maintenance planning / work order system immediately.
I have recently been reading Getting Things Done - a personal productivity guide. One of the key steps of the GTD method is directly applicable here: don’t try and remember anything important - write it down! Or in the case of a large industrial site, don’t try and let your people remember anything, get them to put it in SAP (or whatever system you use), even just as a placeholder to make a decision later.
If this had been done, the site I mentioned above would hopefully have had an inspection scheduled for machine A to look for cracking.
After repairs have been completed a record of the repairs needs to be kept. Ideally this would include photographs, notes from supervisors, welding check sheets etc. Where structure has been modified or overplated, site measurements of the final structure should be kept and where possible as-built drawings up-dated. Having a record of what was repaired, when & how allows for better decisions to be made about how critical new damage is and reduces surprises and “uh oh, it won’t fit” moments when carrying out future repairs.
If this history is kept, this should be communicated to anyone working on structural integrity / maintenance. I only just found out (after only 10 years…) that the site I drew my examples from does keep at least some history of repairs in their maintenance system. Checking this before starting repairs may have helped identify potential issues like the machine fatigue cracking problem.
Finally, I have to wonder why Building Information Modelling (BIM) is not used more commonly on these sites. In particular, I can see a huge amount of value in associating the information listed above (history of damage, inspections, reports etc.) directly with a component of a machine on a 3D model. Rather than dig through folders & files to find some photos that may or may not be relevant, they could simply open the 3D model, select a component or group of components and bring up the drawings, past history and inspections and any other relevant data.
It’s true that many of these sites were built before CAD let alone BIM. Converting drawing registers with 10,000+ drawings (100,000+ on some sites), many of which were hand-drawn, into BIM may be cost prohibitive. But for critical structures such as materials handling machines even a coarse 3D model combined with BIM could be beneficial. This could be refined over time as it is used and the machine history develops.
Not So Fast Consultants
Consultants also have a role to play. Often we are pressured to complete structural integrity jobs quickly (or cheaply…), so that repairs can be done and equipment can go back into production. In the rush, information not directly related to the repairs may get left out. This may include things such as site photographs & notes documenting the original issue, investigations into the cause of damage or as-built drawings of the completed repairs.
Maybe we should be willing to push back against our clients a little and suggest that perhaps they really should get an as-built drawing or a proper investigation done this time. If the client doesn’t want / isn’t pushing for this information it is probably unlikely that they’ll pay for it, and doing too much work for free sends consultants out of business - so it’s probably unlikely that there’ll be a radical change in how things work. But maybe we can try a little harder to push our clients to better practices. And where it doesn’t really cost us anything we could just share any information collected with our clients - how hard is it to put our photographs up on dropbox / google drive and email a link?
The End of History
Keeping the history of your structures is an important part of managing their structural integrity. Without it, you may be condemned to repeat it! So if you’re in charge of structural integrity, start a register today with the corrosion you found last week, or put a reminder in SAP to follow up that report you don’t have time to read. If you’re a consultant, think about sending your last inspection photos to your client.
Or don’t - it’ll mean more work for me when things break, so I don’t mind either way 😁