Bridge Inspection – Ready for the future?

Johannes: Today, we’re discussing bridge inspection in Switzerland. Joining us is Mr. Reto Herrsche from the engineering firm F. Preisig AG. Reto is the project manager for structural maintenance and rehabilitation at the St. Gallen site, where he also inspects infrastructure buildings. Welcome, Reto!

Reto: Hi Johannes, thanks for the invitation. I hope to provide some insights into this field today.

Johannes: Thanks for taking the time. To start off, what do you enjoy about the field of structural preservation and rehabilitation?

Reto: That’s a good question. What do I like about it? I think a particular challenge is that each object must be assessed individually. In structural preservation, we don’t just build somewhere on a green field and put up a new building. The conditions are largely predetermined, whether by the exposure of the structure, its prominence, or even adjacent buildings and the layout of traffic connections above or below, which more or less dictate the conditions. The goal is to find the best possible solutions for an object so that it can also achieve the necessary remaining life expectancy.

Johannes: One might say that these projects are also somewhat shorter because they do not start from scratch but from existing structures, and therefore involve several projects.

Reto: No, I wouldn’t say that, because the process is actually quite long. It usually begins with a visual condition assessment, where the condition is roughly recorded, damages are highlighted, and the causes of the damages are investigated. And then…

If necessary, through material investigations, we try to make a more precise statement, if not everything is evident at first glance, especially when it comes to the extent of the damage. Because many see, with chloride damage you do not immediately see…

what all is contaminated, so further clarifications are needed. Only after all clarifications have been made, can one then consider what the goals for the structure are, whether to preserve the building or whether a new construction might be better. And so, one tries to really find the best possible solution or the best possible measures for each individual object.

Johannes: Does that mean that in structural preservation, more in-depth investigations are always necessary after the visual inspection? How often does this happen?

Or is a visual inspection sufficient?

Reto: It really depends on the damage. Sometimes, you can see what the causes are.

Reto: For example, if the sealing is faulty, then you know, it’s such a silly, bad example.

Johannes: Maybe I’ll ask again, how often does it happen that after a visual inspection, a more in-depth, possibly destructive examination of the component has to be done?

Reto: So the material investigations are done so that one can make a better or more precise estimate of the extent of the damage…

that one knows, in these concrete components, the likelihood of damage is higher than in another. In the instance of setting, one can do a comprehensive setting, which means, you do everything, which also results in higher costs or you really try to filter out where measures are really necessary and for that, laboratory technical investigations are also important.

Johannes: So it actually occurs quite standardly, but only during the project.

Reto: Exactly, yes.

Johannes: Maybe we can expand a bit and generally discuss how these inspections are handled in Switzerland’s infrastructure. Both nationally by the Federal Roads Office, Astra, and at the cantonal level.

Reto: Essentially, it is also legally stipulated that an owner is responsible for his work. That means, any necessary inspections and maintenance work are the responsibility of the respective owners. It does not mean that the owner must do it himself.

Or it is like this, if damage or a defect occurs, then the owner is liable for it. And the public hand, Astra, SPB, or also the cantons, where there is a regular inspection cycle of all structures. Normally, it’s every five years, while the same structures are inspected again.

Depending on the need, the interval can also be shortened. If damages occur that require intensive monitoring, then one can also say, okay, we’ll look at it every year or every two years. It then also depends on the discretion of the respective owner. Whether the inspections are carried out by the owner

or given to external parties. That depends on the owner. In some cantons in Switzerland, they do their inspections themselves. These are mainly also smaller cantons that still have sufficient free capacities to

carry out these time-intensive tasks. At Astra, on the other hand, the inspections are mainly conducted by external people. I think that’s mainly because Astra has an extremely large number of structures. So nationwide, I don’t know the exact number, but…

Reto: is probably somewhere between 15,000 and 20,000 objects and the individual branches probably really lack the capacity to inspect themselves.

Johannes: Structures are bridges, retaining walls, support

walls, tunnels, etc.

Reto: Yes, so there are bridges, as you said, tunnels, overpasses, underpasses, support walls, noise barriers, culverts, utility ducts, and all roads.

Johannes: And at SBB it’s similar, more external. Do you know what?

Reto: I assume it is handled the same way at SBB as at Astra. How many structures there are, I do not know. I cannot give an approximate number. But it will probably…

also be in that size range.

Johannes: Okay, interesting. I remember, Austria, they inspect every six years and then in Switzerland it’s every five years. We just briefly discussed last time, you are currently inspecting the N7 in the Canton of Thurgau, which is the highway between Winterthur and Constance. I would like to go into more depth here, what exactly was the assignment? In this case from

Reto: Okay.

Reto: Last year, we were allowed to carry out the five-year main inspections on the N7. During that, we were allowed to look at all the structures.

Johannes: What exactly do they want from you?

Reto: There is a distinction, inspection of the route and inspection of the structures. We were allowed to do and look at the structures. That was about 200 objects. So across the board tunnels and bridges, as we said before. The order itself included only the pure visual condition So the recording of the damage.

So no laboratory technical investigations. We documented the damage using simple hand tools like a hammer or crack width meter, took a photo, and then handled it in a report.

Johannes: Because you said earlier, there is a distinction between structures and Tracé. The Tracé is the pavement or the road. Is that also inspected every five years?

Reto: Exactly, since I have never been allowed to inspect the Tracé, I do not know how they have the inspections here. But I think it is also within the same framework.

Johannes: And so that one can imagine the process a bit from your side, how many objects, I know by chance, do you inspect on average per day? If there are 200 in total? That is probably difficult to say.

Reto: It depends on the size of the structure. There are objects that barely take two days and some objects can be looked at in half an hour. Generally, an inspection day for us looks like this, that we start in the morning at 6 am and are back in the office in the evening at 6 or 7 pm….

that makes 11-12 hour days.

Johannes: That probably sounds a bit stressful, it sounds like getting all the objects into a certain time period, or is that no problem?

Reto: Yes, it definitely requires a certain organization and above all, it also requires the necessary capacity. We have the requirement that we must be out there with two people for safety reasons. So that means there are at least two people that you have to plan for.

The other thing is then, of course, you don’t want to be out on inspection for weeks at a time, but you also have other work to do in the office. And on the one hand, the inspections take place outside, but the post-processing of the inspection, that takes place in the office. When you are outside, then everything else also piles up a bit.

That means, of course, you also try to accommodate as many other engineers as possible in this order, so that the number of objects per inspector becomes a bit more bearable. And the two…

Johannes: Was there another company involved in this case, or were you the only ones for this section at Your7?

Reto: So ultimately, this year’s or last year’s main inspections were not just about the N7, but there were also other highway sections that we were allowed to look at. So in total, there were already 600 objects and we conducted these in one

Johannes: Okay. And all from the Winterthur branch of Astra, the MR5 branches, these 600 objects were all at the Winterthur branch.

Reto: Exactly, yes. The Astra branch Winterthur, the whole branch area is divided into five sections, so that it works out with the 5-year cycle and each year a different area is looked at. That changes each year.

Johannes: Okay. And one of the five areas is just this section, these national roads, which you are currently inspecting in the community, where there are 600 objects involved. Did I understand that correctly? Okay. Are road closures sometimes necessary during inspections?

Reto: Exactly, yes.

Reto: Yes, sometimes that’s necessary. In general, we have the requirement that we must not disturb the operation of the national roads. But another condition is also that we must inspect all

components, at least all visible components,

at arm’s length. That means we also have to get quite close to these structures. That’s a bit of a conflict of interest. On the one hand, we have to get close to the structures, but on the other hand, we must not unnecessarily disturb the operation. That’s also then the challenge, to see where we need to disturb the operation.

That means, where do we need to go on the roadway? Because we can’t just put a ladder on the roadway and then take a look, right? That’s just not possible for safety reasons, with today’s traffic volume. And then it also requires coordination with the regional units. Because the closures, they are carried out by the regional units, only by the regional units. We are not allowed to do that ourselves.

Then we really have to coordinate with them. The regional unit also has its daily tasks that it must perform. That means, when we need something from them, that also requires a certain lead time. We can’t just call and say, hey, tomorrow afternoon we would like to close the lane like this. Then it means yes….

no people come back in four weeks. Depending on the extent of the closures, there are also various closures, it may only need a shoulder closure or a lane may need to be closed or depending on the situation, a complete closure of the roadway may be necessary, then all of that must also be approved by Astra. That means we have to submit an application, the application is reviewed and depending on….

Reto:
approved or not approved. Sometimes it also means, yes, you have to find another solution for how you can conduct your inspections here.

Johannes: Maybe here a short section for the listeners. In the next episode, we’ll talk to such a regional unit, the regional deployment 6, which includes this rehabilitation. You are welcome to listen in, we will talk about their tasks, including road closures, but also green maintenance, winter service, and so on. It’s a very exciting episode, you are welcome to tune in again. Back to you Reto.

Such road closures are necessary, I can imagine, during a tunnel inspection or at a bridge. There is, I don’t know what they call the vehicles, it’s a kind of lifting platform that then goes under the bridge. These are then cases where you really have to close a road. So at the bridge, it’s often an overpass, a lane I assume. Are these two examples where you then close the road?

Reto: A tunnel always needs a closure because we also have to look at the vault with a lifting platform. That means we have to drive a device in there and then really get close to the vault. Under active operation, that’s not possible. But in this case, tunnels are a bit special.

Annually, cleanings are carried out by the regional unit. So all tunnels are cleaned at least once or twice a year. And then the tunnels are completely closed. And we can then hook into these closures. Exactly, these are mainly at night. It also means for us that we have to be a bit flexible.

Johannes: during the night closures.

Reto: It’s not always easy, but it’s also part of the job.

Johannes: But such a cleaning machine, it drives through quite quickly. Do you have enough time then to inspect everything or does it then go over several cleaning cycles?

Reto: Mostly we have to wait until the cleaning vehicle is through. We can then either run through quickly in front of the vehicle or otherwise we have to queue up behind it. It is also so that when the cleaning is done, then you also see more.

Johannes: Yes. Okay.

Reto: because then the surfaces are also clean.

Johannes: Mhm. Okay.

Reto: has its advantages.

Johannes: Does that clarify with the regional units, if such road closures are necessary, does it run more on an hourly basis, do you have to specify that exactly? Or do you say, day by day, so during the cleaning at night, a night closure is needed for the inspection of the entire tunnel? Or do you say, we need five hours? How exactly is that then with the road closures?

Reto: Basically, we have to estimate how much time we roughly need per object. For tunnels, it’s sometimes a bit more difficult because that depends again on the length. And number of ancillary structures, depending on the ancillary structures can also be inspected outside the regular closures because the accesses are possible from the outside.

the structures on the route, there we have to estimate how much effort we have per object. And then it’s easiest for the regional unit if we book them half-day or day-wise. They need to know how many people they need to provide, what kind of closures are necessary.

And if they know exactly how much time we need, how many capacities they need

to provide for us, then it’s also easier for them.

Johannes: It sounds like there’s quite a bit of communication necessary. On the one hand for the closures, then also for access, probably then also for the preparation because they are often on the road, if they still see something. That’s also part of it, that you coordinate with them. Okay, I understand. Can you maybe give us an overview, maybe once for a bridge? What are the components that are inspected? And maybe then give….

Reto: Yes, exactly.

Johannes: a few examples of what typical damages are at bridges.

Reto: Basically, we have to inspect all visible components. Everything that is accessible at arm’s length. That’s not always easy because sometimes there are central supports with bearings. You can’t just quickly look up there.

Reto: It’s a bit object-specific, it also goes a bit into the preparation, that you make a picture of the object before you even go out, just take a look. That all happens in the office, that you first look at the old inspection report or study cadastral plans and then see, what aids.

do I need at all or additional aids. What is also the accessibility to the individual structures? Can I drive from the outside? Do I have to go over the roadway? Because if over the roadway, then it needs additional closures or we are not allowed to just park the car on the emergency lanes. That’s not allowed. Those are the basic things that you have to, yes, think about before you even go out.

think about. And when you go out, then the goal is to look at everything, so everything that’s possible.

What is not possible, such as foundations, they are mostly buried, there is not the goal that we dig them up and look at them, but rather then it’s more about looking for any external signs, like slippages or other signs of settlements.

stands the abutment upright, is the bearing position as one would expect for a healthy structure or are there conclusions to be drawn from differential settlements or a hazard that cannot be read directly from the component now.

Reto: visible components. There you can of course look at all the damages that exist and then also interpret the damages. So also explore the cause of the damages, not just take photos and say yes there is now a crack, there is now a chipping, but also really think about it. Why are there now these cracks? Why is there this chipping? Are there possibly

Yes, are there other components that we need to look at, for example color transitions that seem tight at first glance, but because there is water somewhere in the abutment, one can then still assume that it is not tight, or does the water come from somewhere a possible and tight drain

ah…. the causes

This is an important step for the interpretation of the damages.

Johannes: It probably depends on when you exactly go into the district, whether it has just rained or not. If it is dry, then you probably also do not see leaky spots. Or that’s probably a factor that plays into it.

Reto: Exactly, it’s of course so, if you are outside in the rain, then you see leaks. But it is not so pleasant when you have to inspect outside in bad weather or snowfall. Of course, you like to go out when the sun is shining, but likewise, I say now indirectly

Reto: actually also when the weather is accordingly also.

Johannes: You can’t plan it, can you? As you said before, you have to notify the regional units weeks in advance when you are going to look at it. Then you can’t postpone and specifically choose a rainy day. Namely then.

Reto: Exactly, yes. So it’s still difficult then just to say, hey we’ll come a week later or something. Simple it is not.

Johannes: That means, you said, you inspect all Visible. Maybe you can give us a few examples of what you inspect, then exactly like the roadway transition for example, bearings and then also describe classic damages, cracks and so on.

Reto: Exactly, yes. So damage to the pavement, to the concrete components. Yes, that’s it….

Johannes: So more concrete components, because pavement does less, or?

Reto: No, it’s still distinguished. The pavement and the sealing, which lie on the structure, belong to the structure. That means, overpasses, underpasses, bridges we must…. The pavement goes so from abutment to abutment.

Reto: And outside the color transition is then the responsibility back at the Trassee. But that of course does not mean that if we now see damage in the foreland, that we are allowed to simply ignore it. Because depending on the damage, they then also have an influence on the structure. Be it from settlements or

leakiness.

Johannes: Yes and so classic damages that often occur.

Can you say a few or is that difficult?

Reto: Yes, simplified.

Johannes: So for example, cracks are very common or problems at the bearing, corrosion, AAR, chippings and tight spots.

Reto: I’ll say it simplified, if water is present, then you have to look more closely, because the water comes from somewhere. And it’s also so that water is the biggest enemy of a structure.

Reto: If there is water somewhere, one must explore safe reasons where the water comes from. Be it a leaky color transition or a leaky drainage. In winter, when then worked with de-icing salt, the de-icing salt dissolves in the water. Then it seeps out of its line somewhere, lies somewhere in a box girder. Then it diffuses into the concrete and depending on, are in 15 years, depending on, suddenly there’s corrosion on tension cables or on reinforcement irons. Then it also becomes….

Johannes: That means, leaky spots means chlorides and chlorides then mean corrosion. And corrosion means, 10, 15 years there are big problems. Can one say, so just as we discussed earlier, with the leaky spots and the rain, that you are not always there when it is wet, does the regional unit help you, that they report it, if they notice it during the year.

Reto: Critical, right?

Reto:

So the regional unit, they also do annual checks, which are not as extensive as now a main inspection, but there they look more, are there maybe chippings that endanger the operation.

Johannes: Does the regional unit also report if something is moist or do they not look so closely that they could report something like that?

Reto:

smaller places that could fall on the roadway and then also pose a hazard to the operation. If a drainage line is leaky.

Then they record it. If this drainage line is in a box girder, then they tend not to record it, because they do not always look into the box girders. That will then happen during the main inspection. And then it is already so, if the water then stands in a box girder for five years,

then the damages also develop accordingly.

Johannes: And such small measures, that’s what the prayer units do then, we’ll discuss that in the next episode, but they then do such small structural maintenance or they can quickly reprofile such chippings themselves.

Reto: Yes, exactly, so we have to judge then, if there is damage to the structure, if we recommend a measure, then we have to define to what extent this measure should take place. So there are, as you said, the small structural maintenances, those are smaller Inst

which are carried out by the regional unit themselves. Then there are measures that are carried out by an external contractor, but then also run through the regional unit. So the Inst then also run through the regional unit. For larger stories, a separate project is then made. Depending on the scope.

then a project is generated and then implemented in the usual scope with preliminary project, construction project, execution project, as we know it, in the normal process flow eventually.

Johannes: Okay. Then a question, the damages that you identify during the inspection, where are they recorded? Is there a database?

Reto: We look at everything using an iPad, we record the damage. There is a specially developed app for this and in this app all structures from the Astra structural database are,

We then enter the inspection directly on the structure. All damages, all photos, all measures are recorded directly on the structure. These entries are then automatically taken over and stored when returned to the database.

Johannes: and from there a report can then be created and printed.

Reto: Exactly, so the report, we can also generate it already with the iPad. That is, yes, it is then standardized, the report is then issued in Word and PDF format and these reports, we collect them and then submit them to Astra for filing.

Johannes: Okay. And you said measures, that means, you then write a measures recommendation, so a summary per object. Or how does that work? Okay, and that also goes into this database.

Reto: Exactly, yes, that is a separate field in the app, where we can enter what we recommend with the date, when that or when the measures are recommended or by when these measures should be implemented.

and a rough cost estimate, so that then for further maintenance planning, for budget planning, that ASSA then also has approximately an order of magnitude, with what costs they have to reckon in the next years. That is now in the branch area Winterthur, are there about 3000 objects or? So there come….

over five years then

already some measures together.

Johannes: That is also difficult to keep an overview. It’s probably mainly about the measures until the next inspection in five years.

Reto: Brilliant, yes.:

Exactly, our goal is actually just to judge, does something need to be done in the next five years or is a new assessment with the next main inspection sufficient.

Johannes: Are these rather renovations that you recommend, or rather further inspections? You mentioned earlier, laboratory technical investigations that you recommend.

Reto: Depending on the size or scope of the measure, these laboratory technical investigations are carried out within the project.

Sometimes with smaller stories, if it can be reduced to individual components, then we can recommend such laboratory technical investigations as further investigations.

Whether they are then made within the project or whether these are made separately, that is then decided by Astra itself in the further processing.

Johannes: I just wonder about chlorides, because you don’t see them. Then you have a suspicion that there could be chlorides inside, due to, for example, moist spots, proximity to the highway. But how can you be sure that it is no problem or that it is a problem? I wonder a bit about that.

Reto: If the surface is intact, then we cannot say. Then we can only suspect.

In this case, it always depends a bit on where these components are.

If abutment walls are affected, which are not coated or do not have a surface, then you can either define as a measure, one should apply such a surface, but that then requires, that also prior such laboratory technical investigations are carried out. It does not make sense to apply a coating if the concrete below is already contaminated.

In such a case, it makes sense if we then also say, hey, do a prior such examination.

Reto: or also with other components, where now, where there really is a suspicion that there are also damages present, which are not visible externally. Then you can already suggest that and then ultimately it is up to the master to decide.

Do you possibly wait until the first damages become visible? Or do you do an Inst anyway in the next five years?

Johannes: Yes, that’s so, I have the feeling, is a bit the curse of the civil engineer, whether it’s now at the inspection or in new construction, it’s always difficult to be completely sure, right? You still have to go to sleep with certain decisions.

Reto: Exactly, that’s how it is. So here a bit of experience also helps, right? If you’ve done a restoration once or implemented it, then you have a better feeling also for the object itself. For a newcomer, it is sometimes really difficult to judge, what the condition really is.

Here we also look, if we want to excite new or young engineers for this field, that we also intensively supervise them and also go out with them, so that we can also pass on our experiences, so that they also know, what I have to look at. Or then in the measures recommendation then also know, what makes sense at all.

because there are 600 objects and if you have to look at all 600 objects again in the office afterwards, you just don’t have the time. So actually the engineer outside has to know what he is doing.

Johannes: That means, Astra in this case then gets all the information from 600 objects with measures and they have to now assess what they will do in the next year in the next years. They have to summarize that then because construction sites on highways may only have a limited length. That means, they have to decide.

Reto: Mhm.

Johannes: Which objects do they pull a bit forward in the maintenance section, which is already made earlier, and in which the first one will be made again in, I don’t know, 15 years or so? I believe there is a number, how long the time must be between construction sites of a certain distance, or?

Reto: Yes, I believe, it is 15 years.

Johannes: Then it is considered by the branches to handle these measures and to set the right measures then ultimately also.

Reto: Exactly, we just give a Inst before. Or we say, within the next three years or five years something must happen. Or we say, something must happen immediately. What then Astra does with this information, we no longer have in hand. Or sometimes, if you’re lucky, then there are in the next five to ten years

Reto: U-Plans, so that’s a larger construction site and then you can integrate this instance session there. If no such U-Plans are carried out on sections, so or it only comes in 20-25 years, then a separate project is tendered, where all these measures are summarized and then implemented in a project. These can then also be implemented outside the U-Plan.

Johannes

: Okay, that was all very interesting. Maybe we can summarize a bit, what are the big challenges for you in the inspection?

Reto: So now in relation to the main inspections at Mastra, certainly the number of objects is a very big challenge, because you have to look at 600 objects and you also need the personnel for it. The personnel must be trained, must know how to handle the iPad, must know how a such inspection is conducted.

must also bring the necessary expertise, so that the damages are correctly interpreted and then also the correct conclusions are drawn from them. Because we must always go out with the thought that no one will look at the object in the next five years. That means, in five years a lot can happen and if you only realize in five years,

something must be done, then it is depending on already too late. That’s with 600 objects….

Reto:
and very time-consuming.

Johannes: Okay. Any other things?

Reto: The other is that the objects or the inspections take place under active operation. The safety aspect is a very important topic. The people outside must also be aware that the inspections take place under traffic. That you then do not just quickly run across the roadway.

or take any unnecessary risks because, ultimately, everyone should come home healthy again, right? In the evening. That’s the goal. Your own health always has priority.

Johannes: In this context, I can only imagine, in such box girders in bridges the air or also a tunnel is there sometimes a topic for health.

Reto: Yes, of course in enclosed spaces that are poorly ventilated, there are problems, or can be problems with gas development and too Kolo and so. Basically, there are also guidelines.

how such inspections in enclosed spaces must be conducted. So with gas detectors and Belü Yes, there are already guidelines.

Reto: We also have to implement these outside.

Johannes: Yes. And then, what we said earlier, sometimes places are not accessible or they simply cannot be investigated. That’s then probably not your problem, but it’s probably rather the branches of ASTORs. I assume that is also a bit of a challenge in inspections. And then also, what we also discussed, the visual inspection regarding chloride entry, where then corrosion occurs, which one does not see, is probably also a bit a….

Uncertainty in it. Can we summarize that?

Reto: Yes, exactly, that even the right conclusions are drawn and also that it is then properly handled in the report.

Johannes: Maybe one last thing. You get to hear, there are always start-ups trying to offer technical support for such inspections. I know for example one in Switzerland, they do image recognition, support with AI, also partly drones for unreachable places, there are also start-ups for sensors, aimed a bit at experience.

on the one hand and maybe you could give your assessment of these technologies regarding the inspection.

Reto: So this year or last year we were actually confronted with this topic or we were confronted with this topic. We had an inquiry from a Swiss university of applied sciences, which also wants to develop such aids. They then accompanied us at selected inspections on site.

At one object at a larger bridge, we made drone recordings. It is important that the resolution of the camera is accordingly good. Because if you then have to evaluate the pictures in the office and you cannot distinguish, is it now just a bad resolution or is actually now a crack there or a damage, then it also becomes difficult.

is the human eye still better. That’s important, or that also the aids are at such a technical level that you can also do something with these pictures. At this bridge, it was definitely an advantage because it was 250 meters long.

So for the inspection of the pavement, part of the roadway would have had to be closed so that a walk on top was possible. With a drone, such a closure is of course not necessary. You fly over the top, have a recording of the pavement, and can then evaluate the damage in the office. In this case, also with high supports, is….

where it becomes very costly with bridges or lifting platforms and also more expensive, there are now for example drones already very cost-effective. Provided they then also deliver the same result. It’s always such a trade-off.

Reto: or which aids one takes and how then also the benefit, so cost benefit. Because ultimately, if you take aids for assistance, then they should also make the engineer’s work easier.

Otherwise, you can also just send out an engineer. It’s definitely an interesting aspect. In the future, more such technical aids will also be used. As I said, the cost must be right.

From my point of view, I don’t know, here I am maybe still a bit too conservative, from my point of view it needs the inspection by an engineer on site. So I think, the work outside

, that cannot be replaced 100 percent. I don’t know, maybe…. Yes….

Johannes
Why do you think?

Reto: I don’t know, maybe I’m a bit too critical of now Kai. But I think at the current time we are not yet so far that we can do the evaluations….

with AI. I think here it still needs also the engineer, who makes an overall consideration of the object, that you can also make an overall picture of the object and there it simply also needs the inspection on site, in my opinion.

Johannes: Also because of the resolution I understood. The resolution of the pictures. Or? Or what are there?

Reto: Exactly, you can of course already send out a drone that makes tens of thousands of pictures for each object and then compile that and you have then a 3D object. What is the benefit with a normal 0815 underpass?

I then ask myself, is it worth the effort and such a data volume to produce?

Reto: if an inspection on site is also equally effective. So what is then more effective, what is then also more economical for the client. And I think with probably 90-95 percent of the objects, it is probably better if the inspection is carried out by an engineer on site.

Johannes: Yes, okay. So I summarize a bit. I understand on the one hand that it is already very high time pressure today, will probably need even more time, these pictures then still to evaluate. At the moment it’s rather double work because the resolution is not there yet. You also need personnel for the drone operation, there are also still personnel necessary. So at the moment there is a bit of a lack of efficiency.

We said, 600 objects, all are probably different. That’s of course a problem. The other are skilled workers, who must already be very much trained today. So the experience, how to proceed in the inspections? They would then have to be trained even more, how they have to deal with the drone information and also if they should fly, also have to deal with it.

Reto: Yes.

Johannes: And then you would have to consider how to deal with these data at all. So on the one hand a huge amount of data, on the other hand what is, if suddenly contradictory information is present. The engineer says so, the image recognition says differently. What do you do then? So here there is simply still a lack of technology and of the introduction of the processes, to really make it easier, that it already takes some work off the farmers during the inspection.

Reto
Mhm.

Reto: Exactly, yes, exactly.

Johannes: Can we say that?

Okay, very interesting. Thank you Reto, I had a lot of fun. I hope the listeners could take away a lot and I wish you much success with the further inspections. Thank you for keeping our roads so safe, being part of it. And yes, see you soon hopefully.

Reto: Yes, thank you.

Johannes: Thank you.