Reading Utility Plans: Loop In Loop Out, Teed Off, and Tracing HV

0:03Hello everyone. Thank you for joining me. This next video I've got for you is again in relation to utility plans. Um, I'm going to run through a couple of things really focused on how to get the best out of them and what kind of things you might want to look for, um, on utility plans, um, things to spot. Uh, before we start, I'm Pete Ashcroft. I work for Sygma Solutions, and we're a specialist training company in utility location, um, and avoidance.

0:35I should also add that I'm no YouTube video editor, so don't expect anything too slick today. It's all about the content. It's not scripted. It's just me having a chat with you about some things that you might find useful. Uh, for some of you, you you may know all this already. Uh, others may learn something new. Um, I'm hoping it's something that if you have got teams on the ground doing excavations, you might want to share with them for a toolbox talk or something like that just to look at some things to spot, um, on utility plans.

1:03Um, so let's make a start then. I'm just wanted to run through what I'm what we're going to look at. Um, we're going to look at first of all, street lighting on a plan. We're going to specifically talk about using your eyes in conjunction with your plan, um, observation and and looking around. We're then going to talk a bit about the pre-planning, and what I mean by this is the person who's actually producing the plans, do they know what is relevant information? Um, and for example, what size area do you need?

1:31Um, sometimes we see it where plans might be zoomed in a little bit too much, um, in the belief that we're helping people, but as you'll see coming up, that might actually hinder somebody. Um, is voltage relevant on a plan, which links back to some of the things I talked about on compiled stats drawings? Another one that comes up, we're working in gardens, we don't need plans, so we'll have a look at that, see if it's true.

1:52And then the last bit, um, I think is important, we're going to look at how we can use plans to assist in planning a detection survey. So how can we use them in conjunction? And then also the assistance of plans locating HV. So that's what we're going to have a look at today. And I want to be clear, I'm not I'm not doing this session to try and tell people to rely on utility plans. We all know how inaccurate they can be, and we all know not to rely on them.

2:18But we have this tool available to us, so let's look at what information we can get from them, um, assumptions that can be made, and as I said, how we can use it to plan the the survey. So, the first thing to talk about is is street lighting. Now, street lighting generally works in the UK in two different configurations. Um, we have a loop-in loop-out system or a tee'd off system.

2:42So, the tee'd off system is where the column is fed off the LV main, um, and it and there's a tee-off branch to it feeding the cable just as it would it would feed a house. Um, and the loop-in loop-out system is where it's a separate dedicated cable. So, this could typically be like a council-owned lighting system where the cable is completely separate to the LV, uh, and it runs separate. And and the difference in terms of plans is that the utility owners, power companies, for example, will only show cables that they own.

3:12So, if the street lighting's fed off their mains and things, you might see lighting on there. If it's a council-owned street lighting system, it might not be on there. Everywhere in the UK that I've worked is different. Different regions, different power companies, even different streets, you could have either or or a combination of these systems. And sometimes you might not know until you get to site which of these two systems that that that you're dealing with.

3:35So, if we go on to the first example of a plan, this is um, an example of a Scottish Power plan. So, for anybody that that doesn't know, on a Scottish Power plan, they show low voltage cables in in brown. So, there's an LV network here with some HV over on the on the right-hand side. It surprises me, um, in Scotland, how many people don't know what these um, white squares are on a on a plan. People often say the lids and things like that, and because it's a square, I think that's the assumption it makes.

4:07But these are actually a supply of electricity into something. So, typically what they could be are lighting columns, they could be feeder pillars. Um, I've even had these, um, showing, um, a BT cabinet where a power supply is going in. So, that's what these white squares mean. It's a supply of electricity into something. So, on this street here, we've got three of them that you can see here. Okay? And if we look at the view of the street, you can see this column here and this column here.

4:35And just to go back, that's this one I was showing you, and then that one in the grass verge. So, these are lighting columns, and these are fed off the main LV. Okay? So, in this example, the street lighting is shown on the utility plan. You might not get every column on there. Okay? So, sometimes you get the oddball one, but it's on. In terms of locating, what this also means, I've worked in this street quite a lot, and what you can actually do in this street, by applying your Genny signal here and here, you can actually locate all that network.

5:09So, I call that easy street. Nice and easy, just by using the columns, we can locate all that network. Okay? So, that's one example of a tee'd system and where the lighting, excuse me, is shown on the plan. This next example is Scottish Power again. Um, it's in a slightly different area, but it's Scottish Power. Excuse me. And when we look at this plan, straight away, we can see a few little differences. And the first one that I spot on this is how many white squares have we got? And this is even before we get to the site.

5:43We've only got the one down here. And then you think to yourself, well, how likely is it that there is only one lamp column in that street? And straight away, we're thinking that's that's very unlikely. Okay? But we've only got this this white square on here. Let's now have a look at that street. And this is where we're going to talk about the importance of observation as well and thinking about how a network works. This is that street. Now, what that white square on the plan is, it's that feeder pillar here. That's what it's referring to.

6:12But have you noticed that we've also got a column here? Now, just to go back to the plan and show you where that relates to, that's actually here. So, we've got a column there that we can see in the street, but there is no power cable there. So, you then start thinking, well, where does it get its power supply from? Let's look at this one down here. This one here, again, is not on that plan. This and this is here.

6:39So, what actually happens in this street is there is a lighting cable that runs down here, crosses here, and goes there. And there's also a row of columns down here, and there's another cable that comes down here to feed the lighting. So, if we solely relied on the plan, we could very easily believe there is no power cables here or any power cables that that are here. But using our eyes in conjunction with the plan, straight away, you start thinking, hang on a minute, where does it get its power from? Where are these columns fed from?

7:14And the other thing about this street that's different is we can hook up to all the columns in here, and we generally only get the lighting network. You do get some signal going back to the pillar and down the LV, but this street, to find everything and the house connections, takes more

7:44to these buildings. What we have to do is hook up and and trace back in a lot of cases to find them. So, that's just two little examples to show you where we sometimes get street lighting on a plan and sometimes we don't get street lighting on a plan. And again, just to reinforce that point, that's why our observation skills are really important when we're on site, looking if things fit together or not.

8:06Another Scottish Power drawing. Um this one um is showing this is a 33 kV cable up here, and we got high voltage here, the 11 kV, and then um we've got LV across here. Um so, one thing to spot on here is if we saw any columns here, we should know that we can't feed columns off high voltage. So again, the same thing applies. They're not going to be fed off this cable. Where do they get the power from?

8:30And let's have a look at that street. Can you spot this little hidden column here? And if again if I show you where that relates to on the plan, that's actually here. And what you'll notice here is there's a little stump of a cable here, and that goes into a feeder pillar. And and and that's the end of Scottish Power's responsibility then, if you like. They've put a supply of electricity into here to that pillar, and then from there, the council have got a lighting cable and it kind of comes up, does this, and actually feeds across to a column here somewhere, I believe, as well. Now, I can't remember It's been a while since I've been here, but that's how it works, you see. But again, that is not on that on that utility plan.

9:14So, just just moving on to the next section. Before I do, one one thing I thought I'd just throw in here, um this is obviously specific to anybody working in in a Scottish Power area now, is that on Scottish Power, you'll often see lines with these blue arrows on. I don't know if you can see it's got blue arrow here and here. And it's a again, it's amazing how many people don't understand that these mean assumed routes.

9:38And it literally is assumed. It's a complete guess. What they wanted to do was show that every house had a power cable. So, if you didn't already have one showing, they just drew lines on the drawing, which is why you tend to find them all very straight. If you look at this example here, there is no blue arrows here. So, that's again, we're not saying it's accurate, but that's Scottish Power kind of saying that that's what they believe happens here. With the blue arrows, they're saying they don't really know how that gets there, but please remember that every house has a power cable. And the truth is what this one does do, this one, sorry, is it does come across as a single cable and then split. And the other interesting one is this one at the bottom here.

10:16What you'll see here is there is one cable here without blue arrows on, and these cables here do have them on. And the truth is that these three don't exist. The whole of that block is fed by that one. So, it's just something to look out for if any of you are using Scottish Power drawings. Look out for these blue arrows and understand what they mean. They mean an assumed route.

10:39What size area is relevant? So, this was I touched on this during the intro. So, what I'm trying to get at here is that what I often see on site, and it's done to try to help people, is we give them a really zoomed-in plan. And I'm a great believer in having maybe a zoomed-in one for the area you've got to excavate, but then a a bigger one, and in an ideal world, a live one that you can move around. So, let me just show you a little extreme example. This is an extract from a Western Power drawing, zoomed in. And if you think about it, let's just say the the excavation here is to replace some curbs here.

11:13So, it's a small small excavation that's going on to replace the curbs. And if you look at just that section really zoomed in, we can see that there's no power cables here. But it's obvious, isn't it, that these are going to have power? Where do they get it from? If we just zoom out a little bit and make that area bigger, what we can see So, this is that same area now, but now what we see is the LV mains here. Well, what does that tell us?

11:40Well, it tells us that these are fed across here. So, if you was replacing any curbs or doing any work here, even in the road, you'd have to consider the potential of these coming across through the area you're working. But by giving people that bit more information, and a bit of education as well, this is this is why it's important that people understand this, that yes, there's no cable here, yes, there's no services, but if we have a house, it has to have a power cable. And if that's the LV main, there's a strong likelihood it's going to come from there. Not guaranteed, but there's a strong likelihood, and we start considering that option.

12:16And on that subject, when we look at cable strike investigations sometimes, there was there was one that I saw recently, and the the team hit a cable to a house, and it was just like this. It wasn't shown on the plan. And the outcome of the investigation was the cause of that cable strike was because it wasn't on the plan. Is that really the cause, though? We should know, shouldn't we, that buildings have a power supply? And if that's the LV main and that's the building, it's got to get there somehow. So, another little example for you.

12:51Also, on on this one, it's it's similar. So, the the first thing I want to show you, by the way, I don't think I mentioned on the last slide, but Western Power, just just for anyone that doesn't know, they show LV in blue. So, the blue is LV, and the red's um the HV, the 11 the 11 11 kV. This next section is also about how understanding power networks is also important. We've got these two houses here. Now, we know that we cannot feed these houses off a HV cable. Okay? It has to come from an LV cable. So, these are not going to be fed from here. The likelihood is, and and I've actually worked in this street, so I know what happens, is that these are fed across the road from the LV.

13:36Okay. Now, going back to the video I made about overlay plans, another thing to consider here is if we overlaid these electric into a compiled stats drawing, the way that most of them are done is that they would show both of these in red as electric cables because there aren't enough colors to go around to show all these different voltages. So, they would potentially just be shown as two red lines. So, if I looked at that line, and the only information I had was there's an electric cable here and electric cable there, I didn't know the voltage of each, I would then probably assume that they're fed from here because I don't know that's HV, you see. So, this again relates back to what I was saying that people often say, "Well, does the voltage matter? It's an electric cable." From a hitting it point of view, no, it doesn't. They're both electric cables. But from an understanding point of view, I would argue, yes, knowing the voltage does matter because we know we can't feed buildings off HV cables. They've got to come off LV. Um so, I hope that made sense for you um on on that one. Um moving moving

14:20From a hitting point of view, no it doesn't, the electric cables. But from an understanding point of view, I would argue yes, knowing the voltage does matter because we know we can't feed buildings off HV cables. We've got to come off LV. Um, so, I hope that makes sense for you, um, on on that one.

14:38Moving moving on to to one more. Um, this is about where does it get its power from? We've we've touched on some examples here. Let's have a look at this little map here. Again, Western Power. So, again, we got buildings over here. We got the power cables shown over here. But let's also look in that street now.

14:58On the left-hand side of that footpath, we've also got column. It's got to get its power from somewhere. Go back at the plan. How does it get its power? Okay. So, it's just things that we need to consider. It's more than likely road crossing. The other thing as well is that if you look here, you'll see 5C, okay, which means five-core.

15:16Our LV cable is a five-core cable. And typically, when you have a fifth core in a cable, the street lighting is fed off it. Okay. So, again, sometimes this information isn't always carried over when we overlay. Is it that important? I don't know. They're just observations, these, everyone. So, just things that I look at. So, we've got 5C here, LV here, pole over here.

15:37Again, we're not going to assume anything, and I'm not encouraging people to assume. You know, we're going to trace it out and spot it. I'm just trying to give you information you can look for and gain from the use of some of these plans. Working in gardens, we don't need plans. A lot of the training we do

15:56um is quite often for people like local councils who work on the housing department. So, they're typically doing fence posts in gardens, soakaways, um and fencing contractors, anybody like that. And they're working in gardens, and the assumption always is, um and I come across this quite a lot, they haven't got any plans. They say, "Why don't you get given plans?"

16:16"Well, we're working in gardens, they don't show services, so there's no point." And I don't agree, as you've probably guessed. So, I'm going to show you a couple of little examples here. I could show many, but first of all, let's look at this Western Power one again. Working in the garden, don't need cable don't need plans.

16:34So, this isn't even relevant to services, but in these gardens, we've got HV, and we've got LV. So, yes, if you work in the garden, you do need plans, because you've got this. And the other thing is, even if they don't show services, so if you look at a gas drawing that doesn't show services, these houses here, remember in Birks Road,

16:53yes, it doesn't show services, but it does show us where the main is. If that plan is showing the gas main at the back of the house, and the house is here, the likelihood is it's going to come in this way. But if you didn't have this plan, I would guarantee that if you was working in the back here, you'd probably think, "Oh, well, all the utilities are out the front, and everything's coming in this way."

17:14So, this is another reason why, even if you're working in gardens, and even if plans don't show utilities, they're still useful. They still serve a purpose. Going back to what I said before, we know where the main is, we know where the building is, it's got to get there somehow. It might not show it on a plan, but it will exist.

17:38Moving on to the next section, I wanted to show you now how we can use the plans to help us plan our attack, to help us plan where to apply, um, a transmitter signal. Um, and I don't want to turn this into a CAT and Genny training course, so if there's anything during this next section you don't fully understand, please feel free to contact me, and I can do a a live online session with you and and and fill in any gaps that you that you might have. But let's have a look at a couple of examples.

18:04This first one is a UKPN drawing in the South East, and I- you can see already through this section how different utility uh companies have different colors, different regional electricity companies have colors. But UKPN show, uh, in this area, because they cover quite a large area, UKPN, in this area, the green is LV. So, what what they're showing here is, in this footpath, is we've got two LV mains, two LV main cables.

18:29And what tends to happen when you have a situation like this is that when you use, um, a locator on passive modes, power and radio, you tend to get one signal. You'll just pick up- it'll it'll almost show you like there's one cable there. So, the plans are showing us there's two LVs. How do we find them?

18:46Now, some people at this point shout shout "nulling out". And nulling out's great, but but there's better solutions before we get to that stage, because we have to consider that this is only showing us electric. There is other stuff in there, and nulling out one cable, one LV, might not find the other. So, let's instead zoom out a little bit

19:05and look at a wider area. So, this is the area we talked about here. Now, just by zooming out and making that area bigger, I've got additional information. And what I can see is separation. So, for example, I can hook up to the column here with my Genny and trace the top cable and mark it. And then, I could go over here and hook up to this one,

19:24and I could locate the bottom cable. So, I've found both those cables by understanding where to apply the transmitter. But if we give somebody that zoomed-in drawing on site, does that really help with that? So, think about the size of plans we give, and think about how we can get the best out of them. Other things we can do here, and and again, I've worked in this street, we do it, we can hook up to this building, which gives us the top cable, and this one.

19:45Even though it doesn't show the services, I think you'd agree it's pretty obvious where they probably get the power from. What the other thing we can do is we can scan here on power, and then put the Genny on it here. We can scan here on power and do that. Again, that would be a last resort to me. I would always prefer to connect, if possible. But this again is about using those plans to help us plan our attack with our our transmitter.

20:14Another little example, so back to Scottish Power, we have LV and HV in here. You can imagine the response you get from your locator on power in this area. But what we can do here is we can hook up here and get the majority signal on the top one, and then here and get that one. So, again, we can use our plans to help us work out where we can put our transmitter signal, the best place to apply it.

20:39I also just want to add in here as well, this is why, you might see some of my posts on social media or some of my rants, as people call them, this is why I'm a massive believer in real-world training. Because, yes, it's important that we teach people how to operate controls, sensitivity, locate peak signals, locate distorted signals. What I sometimes feel we're missing from training is teaching people how to actually apply it to a real site,

21:00where to hook up to, which way to do it, what to look for. And that's why, when we deliver practical training, these are the kind of environments we're looking for, where we can, you know, do real surveys, look at real world and and how we get signal onto things, which way will it travel, and and all and all that kind of stuff. Um, so, uh, just one last one again, Scottish, uh, sorry, Western Power. You're probably going to get the idea I'm going with this again. Very similar, two LVs,

21:21passive modes finds one. How do we find them? We can hook up here to trace the top one. We can hook up here to trace that one. We could even again find on power and induce. There's multiple ways of doing it, but this is information from the plan that's helping us locate when there's more than one. And I also should add, you know, this

21:30find them. We can hook up here to trace the top one, we can hook up here to trace that one. We could even, again, find on power and induce. There's multiple ways of doing it, but this is information from the plan that's helping us locate when there's more than one. And I also should add, you know, these aren't perfect solutions, they don't work every time. I'm just trying to give you things you can try and things that you can think about when you're when you're out there trying to locate.

21:58Moving on to locating high voltage cables. They're they're they're very very difficult to locate a lot of the time, HV. And sometimes that surprises people. People think high voltage, big signal, but when we look at things like power mode, for example, quite often because of the balancing effects on the HV, the the magnetic fields are actually weaker. You can often get stronger power signals off low voltage cables than than high voltage cables.

22:26Okay, excuse me. The other issue that we have is the depth. So, let's just look at a footpath. What you might have is the LV cable kind of here and the HV here. And as we said, this has got a stronger signal on it, so this kind of gets masked by it. And again, before anybody starts shouting nulling out, it's an option we can come to later, but let's look at other things to consider.

22:47So, these are some of the problems with it. And the And one of the biggest issues with HV, for most of us that are out there working, we haven't got access to connect to it. With With LV, lighting networks, LVs to buildings, we can use buildings, pillars, lamp columns, etc., to hook up to. Typically speaking, without access to a HV substation to a HV cable, we can't hook up to it. So, we're struggling with passive modes. We're struggling to hook up and and clamp. The option we're we're then left with is induction, is to induce onto it, putting the Genny on top of it.

23:19But look back at this example here. Let me just erase a little bit and look at the problem. What you might find here is, even when you put the Genny over the HV, because of the distance, you'll end up tracing this. Can you see? So, sometimes it can be difficult. You You can be in a situation where you've got HV and you can't find it. So, let's have a look at an example. So, here again, UKPN.

23:42In this area here, we've got an LV, which is the green, and a HV, which is the red. The LV's easy. We can hook up to a column, we can hook up to a building. We've traced the LV. We can't find the HV, though. We know it exists. The drawings are are telling us it's there, but we can't find it. And so, what we've tried is we tried putting the Genny in a few positions here, and every time we do, we only locate the LV. And as I said, it could be because we have this shallow and and deep situation. So, you know, no matter where the Genny goes, we get this.

24:14Let's zoom out. We can now see, when we zoom out, that we have separation here. Because remember, what is stopping me inducing onto the HV here? It's the presence of the LV. If I can find the HV where it's away from the LV, I can induce onto that here. So, I can probably find it on power here now, because it's away from the LV. And I can put my Genny on it here, and that makes it locatable here.

24:41Now, again, I'm not saying you can always do this. Sometimes you can't, but it's just things to look for that might help you. Going back to what I said, though, if we give someone that plan, zoomed in, would it really help in that situation? I would argue that that one would be of more assistance in locating that.

25:01Western Power, you'll probably get where I'm going again, guys. So, same situation here, LV and HV. Again, it's another footpath I've worked in quite a lot. You can't find the HV here, no matter what you do with the Genny. So, what we do is we apply the Genny signal here, induce onto it here, and that helps us locate it.

25:23Final example of what size area is relevant. Um, this is a complicated one. This is an SSE plan up in Inverness, and this is an area um around a substation. And thinking back from the techniques that I've kind of shown you, it looks very complicated here. But what we do here is, again, we apply signals here. So, we we find on power, we apply Genny signals here and here. We can hook up to things, and we can kind of get signals on these going back. It's not perfect, but we certainly find a lot more. But if we give somebody this size plan, it might look like it's helpful, and zoomed in, but it doesn't really tell me how to get signals onto these. What's the most effective way of doing that? You see.

26:07So, I hope that was was useful. Um, again, just just to repeat, I'm not trying to teach people to rely on utility plans. We know they're inaccurate accurate a lot of the time. Um, what I'm trying to show people is don't just think about a utility plan as in where a cable should be. Think about the other benefits that you have by using them, about where we can apply signals. Remember how important observation is from the things that we've touched on, etc. So, so that's us. We deliver um all everything from a one-day course to a five-day course, EUSR accredited, CITB approved. If you want to engage us in any training, more than happy to work with anyone that's watching this. And also, if you just want to arrange a bit of online stuff with me, um live, then then please get in touch. My email is up there. That's a little bit about us. You can obviously visit the website. Um, I hope the video was useful, and I will see you later.